Abstract
A previous study identified genes and metabolites associated with amino acid metabolism, glycerophospholipid metabolism, and inflammatory response in the liver of broilers with immune stress. The present research was designed to investigate the effect of immune stress on the cecal microbiome in broilers. In addition, the correlation between altered microbiota and liver gene expression, the correlation between altered microbiota and serum metabolites were compared using the Spearman correlation coefficients. Eighty broiler chicks were randomly assigned to 2 groups with 4 replicate pens per group and 10 birds per pen. The model broilers were intraperitoneally injected of 250 µg/kg LPS at 12, 14, 33, and 35 d of age to induce immunological stress. Cecal contents were taken after the experiment and kept at −80°C for 16S rDNA gene sequencing. Then the Pearson's correlation between gut microbiome and liver transcriptome, between gut microbiome and serum metabolites were calculated using R software. The results showed that immune stress significantly changed microbiota composition at different taxonomic levels. KEGG pathways analysis suggested that these gut microbiota were mainly involved in biosynthesis of ansamycins, glycan degradation, D-glutamine and D-glutamate metabolism, valine, leucine, and isoleucine biosynthesis and biosynthesis of vancomycin group antibiotics. Moreover, immune stress increased the activities of metabolism of cofactors and vitamins, as well as decreased the ability of energy metabolism and digestive system. Pearson's correlation analysis identified several bacteria were positively correlated with the gene expression while a few of bacteria were negatively correlated with the gene expression. The results identified potential microbiota involvement in growth depression mediated by immune stress and provided strategies such as supplement of probiotic for alleviating immune stress in broiler chickens.
Key words: Escherichia coli lipopolysaccharide, immune stress, 16S rDNA, broiler chick
INTRODUCTION
Chickens, especially the young, are vulnerable to infection by various pathogenic bacteria, since they are continuously exposed to birds’ excreta, litter, and feed (Nolan et al., 2020). Except for increased mortality, chickens with challenge also showed stress characterized by depression and diarrhea, inducing inhibited growth performance and rising veterinary costs (da Rosa et al., 2019). Subtherapeutic supplements of antibiotics to the diets are traditionally used to prevent pathogenic bacteria infection in broiler chickens. However, the Ministry of Agriculture and Rural Affairs of China has banned all in-feed use of antibiotics since 2020 (Bi et al., 2020). Therefore, researchers and feed manufacturers have to elucidate the specific mechanism of immune stress to develop new strategies to control the disease.
There are various methods to induce immune stress in broiler chickens (Jiang et al., 2019; Li et al., 2020a; Wang et al., 2022). In our previous study, internal injection of lipopolysaccharide (LPS) significantly reduced growth performance and enhanced stress-related hormone and inflammatory factor, conforming the model of immune stress. We further investigated the transcriptome changes in liver and found that differentially expressed genes (DEGs) might account for amino acid metabolism, lipid metabolism, defense function, and inflammatory response (Bi et al., 2022c). There is a close functional and physiological link between the gut and the liver (Konturek et al., 2018). However, there were no reports on the relationship between liver and intestinal microbiome and their effect on the immune stress of broilers.
In this study, a Miseq platform was used to investigate the shaping of cecal microbiota in chronic stress of broilers challenged by LPS (Bi et al., 2020). Then, comprehensive analysis of liver transcriptomics and intestine microbiome was performed. The results may help clarify potential mechanisms and provide further information to search for probiotics to alleviate immune stress in the poultry industry.
MATERIALS AND METHODS
Chickens
A total of 80 Shaver brown broilers (1-day-old) were purchased from Sichuan Lihua Poultry Co., Ltd., Sichuan, China and were kept in separate iron cages. The room temperature was maintained at 33°C for 7 d and then ramp down slowly to 26°C by gradually decreasing 1°C every 2 d. All broilers were given sufficient water and feed daily. The animal experiments were conducted with the permission of the Animal Care and Use Committee of Southwest University. The permit number was IACUC-20200701-01.
Reagents
LPS from E. coli serotype O55: B5 was purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO). All other chemicals were of analytical or higher grade.
Experimental Design
The experiment was determined based on our previous studies (Bi et al., 2022a,b). In brief, 80 broiler chicks were randomly assigned to 2 groups with 4 repeats per group, 10 birds per repeat. The model broilers received an intraperitoneal injection of 250 µg/kg LPS at 12, 14, 33, and 35 d of age to induce immunological stress (Table 1). A comparable dose of sterile saline was administered to the control group via injection. At the end of the experiment, chickens were sacrificed and the cecal content was collected and kept at −80°C for 16S rDNA gene sequencing.
Table 1.
Experimental design.
| Group | n | Drug |
|---|---|---|
| LPS | 40 | 250 µg/kg LPS |
| Control | 40 | 250 µg/kg sterile saline |
Cecal Contents Sampling
The cecal contents were taken using a stainless-steel cylindrical driller with a radius of 2.5 cm and stored at −80°C in a portable refrigerator. After delivery to the laboratory, the cecal samples were stored at −80°C in a refrigerator for further experiments.
DNA Extraction
Cecal DNA was well extracted using PowerSoil DNA Isolation Kit (MoBio Laboratories, Carlsbad, CA). Purity and quality of the genomic DNA were verified on 1% agarose gels and a NanoDrop spectrophotometer (Thermo Scientific, Waltham, MA).
PCR Amplification
The V3-4 hypervariable region of bacterial 16S rRNA gene were amplified as previously reported (Munyaka et al., 2015). Two common primers 806R (5′-GGACTACNNGGGTATCTAAT-3′) and 338F (5′-ACTCCTACGGGAGGCAGCAG-3′) were added with a 8-digit barcode sequence. A Mastercycler Gradient (Eppendorf, Germany) was employed to perform the PCR. The reaction volumes were 25 μL, involving 12.5 μL 2 × Taq PCR MasterMix, 3 μL BSA (2 ng/μL), 1 μL Forward Primer (5 μM), 1 μL Reverse Primer (5 μM), 2 μL template DNA, and 5.5 μL ddH2O. The PCR process was set as follow: 95°C for 5 min, 28 cycles of 95°C for 45 s, 55°C for 50 s and 72°C for 45 s, extension at 72°C for 10 min. The Agencourt AMPure XP Kit for PCR was provided by Beijing Allwegene Company, Beijing, China.
High Throughput Sequencing
A Miseq platform (Allwegene Company, Beijing, China) was used for deep sequencing. Then, Illumina Analysis Pipeline Version 2.6. was applied for image analysis, base calling and error estimation.
Hepatic Transcriptomic Analysis and Serum LC-MS/MS Analysis
The methods for transcriptomic analysis and metabolites analysis were described in our previous studies (Bi et al., 2022b,c).
Data Analyses
The original data were first checked and sequences were taken away from consideration if they were no more than 230 bp, got a low quality score (≤20), contained ambiguous bases or did not exactly match to primer sequences and barcode tags, and separated with the sample-specific barcode sequences. Qualified reads were aggregated into operational taxonomic units (OTUs) at a similarity level of 97% using Uparse algorithm of Vsearch (v2.7.1) software (Edgar, 2013). All sequences were classified into different taxonomic groups against SILVA128 database using the Ribosomal Database Project (RDP) Classifier tool (Cole et al., 2009).
QIIME (v1.8.0) was used to generate rarefaction curves and to calculate the richness and diversity indices on the basis of the OTU information. Heatmaps were generated with the top 20 OTUs using Mothur for the purpose of comparing the membership and structure of communities in different samples (Jami et al., 2013). Based on taxonomic annotation and relative abundance results, bar-plot diagram analysis was performed using R (v3.6.0) software. To examine the similarity between different samples, clustering analyses and PCA were analyzed by R (v3.6.0) based on the OTU information from each sample (Wang et al., 2012). The evolution distances between microbial communities from each sample were calculated using the Bray Curtis algorithms and represented as an unweighted pair group method with arithmetic mean (UPGMA) clustering tree describing the dissimilarity (1—similarity) between multiple samples (Jiang et al., 2013). A Newick-formatted tree file was generated based on this analysis.
The correlation analysis between hepatic genes and microbiota were based on our previously-published transcriptome study (Bi et al., 2022c). The correlation analysis between serum metabolites and microbiota were based on the previously-published metabolome data (Bi et al., 2022b).
RESULTS
Diversity of Microbial Community in Broilers
Partial least squares discrimination analysis (PLS-DA) was used to determine the difference of microbiota diversity among different groups at OTU level. PLS-DA revealed that samples from the LPS separated and clustered distinctly from control groups (Figure 1). The trend of rarefaction curves demonstrated that the curve of each group progressively flattened out with the increasing of sequencing volume, indicating that sequencing data were reasonable (Figure 2A). Rank abundance curves further verified that the sample size in this study was abundant for sequencing and the species in the sample had a wide coverage (Figure 2B). As shown in Figure 2C and D, the Chao 1 index decreased (P = 6.597E−1) while the level of Shannon index rose (P = 1.972E−1) in the LPS group compared with the control group.
Figure 1.
Partial least squares discrimination analysis (PLS-DA) of cecal bacterial community. Individual sample was represented as spot with red (LPS) and blue (control) (*P > 0.05).
Figure 2.
Luteolin modulated the structure and diversity of gut microbiota. (A) Rarefaction curves. (B) Rank abundance curves. (C) Chao1 indexes (P > 0.05, Tukey test). (D) Shannon indexes (P > 0.05, Tukey test).
Composition of Gut Microbiota in Broilers at Taxonomic Levels
As illustrated in Figure 3A, the dominant phyla were Firmicutes, Bacteroidota in all the groups. However, Bacteroidaceae and Ruminococcaceae were found as the dominant microbiota at the family level (Figure 3B). Bacteroides and Faecalibacterium were primary genera in all the groups (Figure 3C).
Figure 3.
Species classification and abundance analysis. (A–C) The corresponding histograms of species profiling were produced for each group at the classification level of phylum (A), family (B), and genus (C).
Wilcoxon test was performed to confirm top 20 significant alterations in cecal microbial composition between the LPS group and control group at the phylum level, the class level, the order level, the family level, and the genus and OTU level, respectively. As exhibited in Figure S1, the relative abundance of Actinobacteriota at the level of phylum was reduced in the LPS group (red) compared with the control group (blue) (P = 3.998E−2). At the class level, more Bacilli (P = 3.791E−2) and Rhodothermia (P = 4.858E−3) were observed in LPS group than in control group (Figure S2). Among orders differentially affected, the most notable changes were Enterobacterales (P = 4.662E−3) and Lactobacillales (P = 2.067E−2), both enhanced relative abundances in the LPS group (Figure S3). A tendency toward an increase in Enterobacteriaceae (P = 6.993E−3), Erysipelatoclostridiaceae (P = 1.041E−2), Leuconostocaceae (P = 1.123E−2), and Lactobacillaceae (P = 4.662E−3) at the family level was also shown in LPS group (Figure S4). At the genus level, LPS treatment was characterized by a markedly increase in Escherichia-Shigella (P = 1.564E−2), Olsenella (P = 4.017E−2), Lactobacillus (P = 4.662E−3), and Flavonifractor (P = 4.988E−2) and lack of Blautia (P = 6.216E−4) (Figure S5).
As shown in Figure 4, the OTU 277 (Bacteroides vulgatus dnLKV7) (P = 1.476E−2), OTU 1492 (Faecalibacterium) (P = 3.850E−3), OTU 1062 (Faecalibacterium bacterium ic1379) (P = 3.253E−3), and OTU 279 (Parabacteroides goldsteinii dnLKV18) (P = 1.518E−2) were less in the LPS group. Meanwhile, OTU 17 (Lactobacillus aviarius) (P = 2.953E−3), OTU 288 (human gut metagenome) (P = 2.953E−3), OTU 35 (E. coli) (P = 1.564E−2) and OTU 307 (B. fragilis str. 3725 D9 ii) (P = 4.042E−2) showed statistically significant increases in LPS group. To a lower extent, OTU 469 (UCG-005) (P = 4.988E−2), OTU 1204 (metagenome) (P = 5.351E−3), OTU 473 (Clostridia vadinBB60 group) (P = 4.887E−2), OTU 486 (Christensenellaceae R-7 group) (P = 1.345E−2) and OTU 888 (uncultured organism) (P = 4.584E−2) had a declined relative proportion in LPS group, while OTU 626 (Oscillospiraceae) (P = 2.067E−2), OTU 232 (Erysipelatoclostridiaceae) (P = 3.910E−2), OTU 482 (Flavonifractor) (P = 4.988E−2), OTU 554 (Butyricicoccus) (P = 4.988E−2), OTU 1180 (metagenome) (P = 3.230E−3) and OTU 514 (Intestinimonas timonensis) (P = 4.042E−2) had a higher relative proportion in control group.
Figure 4.
Bar plot of compositional differences at the OTU level in the gut microbiome of chicks in the LPS group vs. the control group by the Wilcoxon test. Data are expressed as mean ± SD.
Linear Discriminant Analysis Effect Size (LEfSe) and Functional Predictive Analyses of Gut Microbiota
As shown in Figure 5A and B, the most differentially abundant taxa enriched in microbiota between 2 groups was shown on cladogram generated from LEfSe analysis. The results suggested that LPS treatment altered the cecal microbiota composition and population structure. In addition, KEGG analysis was performed to find out the potential function of cecal microbiota. The KEGG pathways between the LPS and control group were shown in Table 2A. The gut microbiota was chiefly associated with biosynthesis of ansamycins (P = 2.813E−2) and other glycan degradation (P = 4.988E−2). In comparison with the control group, the activities of metabolism of cofactors and vitamins (P = 6.993E−3) and cardiovascular disease (P = 3.792E−2) were increased in the LPS group. However, the ability of energy metabolism (P = 2.067E−2) and digestive system (P = 1.476E−2) were decreased in the LPS group.
Figure 5.
Linear discriminant analysis effect size (LEfSe) analysis (A). LEfSe identified the abundance of cecal microbiota. The specific differential cecal microbial taxa that focused on each group were characterized with different colors. Control group (red); LPS group (green). The cladogram showed differential colonic microbial taxa among the control and LPS group (B) (*P < 0.05).
Table 2.
PICRUST 2 compared the KEGG database to get the microbiome abundance of each pathway at KEGG pathway level 2 (A) and level 3 (B) between the LPS group and control group.
| A | |||
|---|---|---|---|
| KEGG term | Mean of LPS | Mean of control | KEGG pathway |
| Carbohydrate metabolism | 14.42286302 | 14.41865598 | Metabolism |
| Amino acid metabolism | 12.18329667 | 12.16065171 | Metabolism |
| Metabolism of cofactors and vitamins | 11.63813352 | 12.31190714 | Metabolism |
| Metabolism of terpenoids and polyketides | 9.662242952 | 9.890765499 | Metabolism |
| Metabolism of other amino acids | 7.003209668 | 6.71137746 | Metabolism |
| Lipid metabolism | 6.702214917 | 6.353163336 | Metabolism |
| Replication and repair | 5.97386487 | 5.658709089 | Genetic information processing |
| Energy metabolism | 5.600360789 | 5.698108063 | Metabolism |
| Glycan biosynthesis and metabolism | 5.290240477 | 6.237291053 | Metabolism |
| Xenobiotics biodegradation and metabolism | 3.321699907 | 3.2359613 | Metabolism |
| Translation | 3.216391297 | 3.042512498 | Genetic information processing |
| Folding, sorting, and degradation | 3.159091206 | 3.047476356 | Genetic information processing |
| Biosynthesis of other secondary metabolites | 2.217043895 | 2.178616457 | Metabolism |
| Nucleotide metabolism | 1.975640765 | 1.886912585 | Metabolism |
| Cell motility | 1.80307641 | 1.5560721 | Cellular processes |
| Membrane transport | 1.671946349 | 1.494762771 | Environmental information processing |
| Cell growth and death | 1.485182464 | 1.468883424 | Cellular processes |
| Transcription | 1.154216436 | 1.107532407 | Genetic information processing |
| Signal transduction | 0.346516839 | 0.322106796 | Environmental information processing |
| Transport and catabolism | 0.278569027 | 0.358083804 | Cellular processes |
| Environmental adaptation | 0.19510448 | 0.187462282 | Organismal systems |
| Cellular community—prokaryotes | 0.17739013 | 0.173235207 | Cellular processes |
| Infectious disease: bacterial | 0.167656241 | 0.149592454 | Human diseases |
| Drug resistance: antimicrobial | 0.129372715 | 0.116400133 | Human diseases |
| Endocrine system | 0.085309414 | 0.0775328 | Organismal systems |
| Immune system | 0.062017203 | 0.053602214 | Organismal systems |
| Digestive system | 0.057502562 | 0.085504624 | Organismal systems |
| Infectious disease: parasitic | 0.013541309 | 0.013602308 | Human diseases |
| Cancer: overview | 0.004687948 | 0.002348253 | Human diseases |
| Cardiovascular disease | 0.001153199 | 0.000405166 | Human diseases |
| Neurodegenerative disease | 0.000435491 | 0.000721022 | Human diseases |
| Immune disease | 0.0000126 | 0.0000342 | Human diseases |
| Excretory system | 0.00000837 | 0.00000370 | Organismal systems |
| Signaling molecules and interaction | 6.84E−06 | 5.80E−06 | Environmental information processing |
| B | |||
|---|---|---|---|
| KEGG term | Mean of LPS | Mean of control | KEGG pathway |
| Biosynthesis of ansamycins | 5.550594795 | 5.152785235 | Metabolism of terpenoids and polyketides |
| Other glycan degradation | 2.787746092 | 2.073974257 | Glycan biosynthesis and metabolism |
| D-Glutamine and D-glutamate metabolism | 1.969064527 | 2.067786545 | Metabolism of other amino acids |
| Valine, leucine and isoleucine biosynthesis | 2.019431155 | 2.052404698 | Amino acid metabolism |
| Biosynthesis of vancomycin group antibiotics | 1.82221872 | 1.945391134 | Metabolism of terpenoids and polyketides |
| Peptidoglycan biosynthesis | 1.736034617 | 1.867314173 | Glycan biosynthesis and metabolism |
| Fatty acid biosynthesis | 1.701672753 | 1.828375617 | Lipid metabolism |
| Alanine, aspartate and glutamate metabolism | 1.846384358 | 1.80689758 | Amino acid metabolism |
| Streptomycin biosynthesis | 1.744185307 | 1.792920144 | Biosynthesis of other secondary metabolites |
| Pentose phosphate pathway | 1.745488813 | 1.750228909 | Carbohydrate metabolism |
| Secondary bile acid biosynthesis | 1.565483277 | 1.75014793 | Lipid metabolism |
| One carbon pool by folate | 1.723298985 | 1.700143815 | Metabolism of cofactors and vitamins |
| Lysine biosynthesis | 1.557774363 | 1.62260193 | Amino acid metabolism |
| Pantothenate and CoA biosynthesis | 1.629928763 | 1.618106864 | Metabolism of cofactors and vitamins |
| Mismatch repair | 1.52076776 | 1.615105289 | Replication and repair |
| D-Alanine metabolism | 1.459712896 | 1.61004722 | Metabolism of other amino acids |
| Aminoacyl-tRNA biosynthesis | 1.477613056 | 1.577352516 | Translation |
| Ribosome | 1.462695439 | 1.534269092 | Translation |
| Thiamine metabolism | 1.544106351 | 1.526013144 | Metabolism of cofactors and vitamins |
| Carbon fixation in photosynthetic organisms | 1.556776125 | 1.513354074 | Energy metabolism |
| C5-Branched dibasic acid metabolism | 1.458827327 | 1.486054352 | Carbohydrate metabolism |
| Homologous recombination | 1.416299455 | 1.46990979 | Replication and repair |
| Cell cycle—Caulobacter | 1.417220607 | 1.444951184 | Cell growth and death |
| Protein export | 1.385297325 | 1.39887449 | Folding, sorting, and degradation |
| Drug metabolism—other enzymes | 1.375116011 | 1.379766881 | Xenobiotics biodegradation and metabolism |
| Biotin metabolism | 1.629294232 | 1.353530461 | Metabolism of cofactors and vitamins |
| Cysteine and methionine metabolism | 1.252429753 | 1.319857082 | Amino acid metabolism |
| Histidine metabolism | 1.337980357 | 1.307807274 | Amino acid metabolism |
| Terpenoid backbone biosynthesis | 1.219721106 | 1.255154428 | Metabolism of terpenoids and polyketides |
| Pyruvate metabolism | 1.203718389 | 1.244340396 | Carbohydrate metabolism |
| Galactose metabolism | 1.304353556 | 1.241669162 | Carbohydrate metabolism |
| Amino sugar and nucleotide sugar metabolism | 1.187586374 | 1.204681509 | Carbohydrate metabolism |
| DNA replication | 1.121966036 | 1.175640842 | Replication and repair |
| Starch and sucrose metabolism | 1.152237336 | 1.160056586 | Carbohydrate metabolism |
| RNA polymerase | 1.107531898 | 1.154214975 | Transcription |
| Pyrimidine metabolism | 1.080985697 | 1.138523975 | Nucleotide metabolism |
| Glycolysis/Gluconeogenesis | 1.059329713 | 1.117924911 | Carbohydrate metabolism |
| Sulfur relay system | 1.037571692 | 1.115114503 | Folding, sorting, and degradation |
| Carbon fixation pathways in prokaryotes | 1.144409137 | 1.110323034 | Energy metabolism |
| Bacterial chemotaxis | 0.928965433 | 1.072521694 | Cell motility |
| Phenylalanine, tyrosine and tryptophan biosynthesis | 1.142041453 | 1.072385934 | Amino acid metabolism |
| Glycine, serine and threonine metabolism | 1.047522291 | 1.051897679 | Amino acid metabolism |
| Vitamin B6 metabolism | 1.095978252 | 1.036813495 | Metabolism of cofactors and vitamins |
| Fructose and mannose metabolism | 1.01269474 | 1.019973337 | Carbohydrate metabolism |
| Nicotinate and nicotinamide metabolism | 1.003934939 | 1.015386994 | Metabolism of cofactors and vitamins |
| Selenocompound metabolism | 0.996936885 | 0.997400288 | Metabolism of other amino acids |
| Citrate cycle (TCA cycle) | 0.980549374 | 0.937314932 | Carbohydrate metabolism |
| Base excision repair | 0.856127838 | 0.918980928 | Replication and repair |
| Folate biosynthesis | 1.039746113 | 0.889420937 | Metabolism of cofactors and vitamins |
| Sulfur metabolism | 0.881663768 | 0.853457984 | Energy metabolism |
| Purine metabolism | 0.805926888 | 0.83711679 | Nucleotide metabolism |
| Pentose and glucuronate interconversions | 0.944522721 | 0.831248327 | Carbohydrate metabolism |
| Lipoic acid metabolism | 0.870625718 | 0.804928953 | Metabolism of cofactors and vitamins |
| Riboflavin metabolism | 0.818374506 | 0.783066516 | Metabolism of cofactors and vitamins |
| Glycosaminoglycan degradation | 0.974747315 | 0.782333209 | Glycan biosynthesis and metabolism |
| Bacterial secretion system | 0.731754682 | 0.77750339 | Membrane transport |
| Nucleotide excision repair | 0.70397027 | 0.74313523 | Replication and repair |
| Arginine and proline metabolism | 0.759171318 | 0.731347955 | Amino acid metabolism |
| Flagellar assembly | 0.627106666 | 0.730554715 | Cell motility |
| Propanoate metabolism | 0.650482452 | 0.699075048 | Carbohydrate metabolism |
| Taurine and hypotaurine metabolism | 0.708283506 | 0.678809706 | Metabolism of other amino acids |
| Glyoxylate and dicarboxylate metabolism | 0.692037795 | 0.669965895 | Carbohydrate metabolism |
| Zeatin biosynthesis | 0.689302718 | 0.659106067 | Metabolism of terpenoids and polyketides |
| Butanoate metabolism | 0.618635253 | 0.648325375 | Carbohydrate metabolism |
| Nitrogen metabolism | 0.634023763 | 0.612675101 | Energy metabolism |
| Porphyrin and chlorophyll metabolism | 0.624160594 | 0.612572314 | Metabolism of cofactors and vitamins |
| ABC transporters | 0.563800651 | 0.609122585 | Membrane transport |
| RNA degradation | 0.574612652 | 0.593532487 | Folding, sorting, and degradation |
| Photosynthesis | 0.515066016 | 0.556433472 | Energy metabolism |
| Glycerophospholipid metabolism | 0.485024638 | 0.534990168 | Lipid metabolism |
| Lipopolysaccharide biosynthesis | 0.687742024 | 0.527040708 | Glycan biosynthesis and metabolism |
| Cyanoamino acid metabolism | 0.390200145 | 0.492359562 | Metabolism of other amino acids |
| Methane metabolism | 0.496294216 | 0.488184733 | Energy metabolism |
| Sphingolipid metabolism | 0.635235796 | 0.477936177 | Lipid metabolism |
| Chloroalkane and chloroalkene degradation | 0.425192334 | 0.470601084 | Xenobiotics biodegradation and metabolism |
| Oxidative phosphorylation | 0.46935296 | 0.465735567 | Energy metabolism |
| Glycerolipid metabolism | 0.430773874 | 0.461463402 | Lipid metabolism |
| Glutathione metabolism | 0.460205538 | 0.45430514 | Metabolism of other amino acids |
| beta-Alanine metabolism | 0.440959318 | 0.407775379 | Metabolism of other amino acids |
| Valine, leucine and isoleucine degradation | 0.359058929 | 0.369814577 | Amino acid metabolism |
| Tropane, piperidine and pyridine alkaloid biosynthesis | 0.388244182 | 0.359667083 | Biosynthesis of other secondary metabolites |
| Biosynthesis of unsaturated fatty acids | 0.335150603 | 0.357839165 | Lipid metabolism |
| Two-component system | 0.322106105 | 0.34651664 | Signal transduction |
| Synthesis and degradation of ketone bodies | 0.268429193 | 0.345131072 | Lipid metabolism |
| Fatty acid degradation | 0.346803712 | 0.342486857 | Lipid metabolism |
| Linoleic acid metabolism | 0.342898482 | 0.341448602 | Lipid metabolism |
| Phosphotransferase system (PTS) | 0.199207437 | 0.285320373 | Membrane transport |
| Bisphenol degradation | 0.35186384 | 0.274870063 | Xenobiotics biodegradation and metabolism |
| Phenylalanine metabolism | 0.300373933 | 0.273789072 | Amino acid metabolism |
| Ubiquinone and other terpenoid-quinone biosynthesis | 0.279629391 | 0.257149235 | Metabolism of cofactors and vitamins |
| Tyrosine metabolism | 0.246937361 | 0.256962574 | Amino acid metabolism |
| Tetracycline biosynthesis | 0.208775192 | 0.247854294 | Metabolism of terpenoids and polyketides |
| Ascorbate and aldarate metabolism | 0.202289911 | 0.208615133 | Carbohydrate metabolism |
| Inositol phosphate metabolism | 0.205902226 | 0.203389152 | Carbohydrate metabolism |
| Nitrotoluene degradation | 0.172897251 | 0.20173248 | Xenobiotics biodegradation and metabolism |
| Peroxisome | 0.235250149 | 0.201722271 | Transport and catabolism |
| Polyketide sugar unit biosynthesis | 0.183657223 | 0.196158763 | Metabolism of terpenoids and polyketides |
| Plant–pathogen interaction | 0.187462282 | 0.19510448 | Environmental adaptation |
| Primary bile acid biosynthesis | 0.174258783 | 0.194704611 | Lipid metabolism |
| Phosphonate and phosphinate metabolism | 0.210623597 | 0.193985285 | Metabolism of other amino acids |
| Dioxin degradation | 0.132156389 | 0.192271489 | Xenobiotics biodegradation and metabolism |
| Biofilm formation—Vibrio cholerae | 0.173235207 | 0.17739013 | Cellular community—prokaryotes |
| Lysine degradation | 0.156908886 | 0.163490452 | Amino acid metabolism |
| Benzoate degradation | 0.130709106 | 0.154388521 | Xenobiotics biodegradation and metabolism |
| Toluene degradation | 0.226951419 | 0.154343247 | Xenobiotics biodegradation and metabolism |
| Tryptophan metabolism | 0.134637556 | 0.154039866 | Amino acid metabolism |
| Epithelial cell signaling in Helicobacter pylori infection | 0.133630181 | 0.133210493 | Infectious disease: bacterial |
| beta-Lactam resistance (ko01501) | 0.116400133 | 0.129372715 | Drug resistance: antimicrobial |
| Aminobenzoate degradation | 0.099396758 | 0.11115085 | Xenobiotics biodegradation and metabolism |
| D-Arginine and D-ornithine metabolism | 0.075391048 | 0.100740543 | Metabolism of other amino acids |
| Geraniol degradation | 0.132655551 | 0.099248644 | Metabolism of terpenoids and polyketides |
| Insulin signaling pathway | 0.0775328 | 0.085309414 | Endocrine system |
| Lysosome | 0.122831158 | 0.076843656 | Transport and catabolism |
| Limonene and pinene degradation | 0.041696135 | 0.068942607 | Metabolism of terpenoids and polyketides |
| Chlorocyclohexane and chlorobenzene degradation | 0.049164205 | 0.067012044 | Xenobiotics biodegradation and metabolism |
| Xylene degradation | 0.060222967 | 0.066537537 | Xenobiotics biodegradation and metabolism |
| NOD-like receptor signaling pathway | 0.053602214 | 0.062017203 | Immune system |
| Penicillin and cephalosporin biosynthesis | 0.044010901 | 0.061981596 | Biosynthesis of other secondary metabolites |
| Metabolism of xenobiotics by cytochrome P450 | 0.087723182 | 0.058571569 | Xenobiotics biodegradation and metabolism |
| Protein digestion and absorption | 0.085504624 | 0.057502562 | Digestive system |
| Styrene degradation | 0.047308092 | 0.056042434 | Xenobiotics biodegradation and metabolism |
| RNA transport | 0.053502252 | 0.053393141 | Translation |
| Ethylbenzene degradation | 0.043423693 | 0.05273609 | Xenobiotics biodegradation and metabolism |
| Ribosome biogenesis in eukaryotes | 0.048701751 | 0.051376548 | Translation |
| Protein processing in endoplasmic reticulum | 0.049857189 | 0.051344231 | Folding, sorting, and degradation |
| Nonhomologous end-joining | 0.039577729 | 0.051092789 | Replication and repair |
| Steroid hormone biosynthesis | 0.057364299 | 0.049768089 | Lipid metabolism |
| Retinol metabolism | 0.052829295 | 0.041000788 | Metabolism of cofactors and vitamins |
| Apoptosis | 0.051068242 | 0.039806596 | Cell growth and death |
| N-Glycan biosynthesis | 0.051020131 | 0.039577794 | Glycan biosynthesis and metabolism |
| Biosynthesis of siderophore group nonribosomal peptides | 0.040949082 | 0.036467507 | Metabolism of terpenoids and polyketides |
| Naphthalene degradation | 0 | 0.03345037 | Xenobiotics biodegradation and metabolism |
| Staphylococcus aureus infection | 0.014941154 | 0.032990713 | Infectious disease: bacterial |
| Caprolactam degradation | 0.015081781 | 0.031192436 | Xenobiotics biodegradation and metabolism |
| Arachidonic acid metabolism | 0.00835724 | 0.015988998 | Lipid metabolism |
| Atrazine degradation | 0.012706409 | 0.012590907 | Xenobiotics biodegradation and metabolism |
| Amoebiasis | 0.010943335 | 0.010565855 | Infectious disease: parasitic |
| Pathways in cancer | 0.002348253 | 0.004687948 | Cancer: overview |
| African trypanosomiasis | 0.002658973 | 0.002975453 | Infectious disease: parasitic |
| Fluorobenzoate degradation | 0.003939606 | 0.00284413 | Xenobiotics biodegradation and metabolism |
| Flavonoid biosynthesis | 0.001518669 | 0.001969788 | Biosynthesis of other secondary metabolites |
| Steroid biosynthesis | 0.001710684 | 0.001934228 | Lipid metabolism |
| Polycyclic aromatic hydrocarbon degradation | 0.002108258 | 0.001597775 | Xenobiotics biodegradation and metabolism |
| Bacterial invasion of epithelial cells | 0.000977183 | 0.001439847 | Infectious disease: bacterial |
| Hypertrophic cardiomyopathy (HCM) | 0.000405166 | 0.001153199 | Cardiovascular disease |
| Carotenoid biosynthesis | 0.001092591 | 0.000980961 | Metabolism of terpenoids and polyketides |
| Betalain biosynthesis | 0.000516002 | 0.000457185 | Biosynthesis of other secondary metabolites |
| Parkinson disease | 0.000721022 | 0.000435491 | Neurodegenerative disease |
| Meiosis—yeast | 0.000594575 | 0.000424683 | Cell growth and death |
| Proteasome | 0.000137497 | 0.000225495 | Folding, sorting, and degradation |
| Photosynthesis—antenna proteins | 0.000522078 | 0.000196824 | Energy metabolism |
| Biosynthesis of type II polyketide backbone | 8.01E−05 | 9.25E−05 | Metabolism of terpenoids and polyketides |
| Isoflavonoid biosynthesis | 0.000141397 | 4.81E−05 | Biosynthesis of other secondary metabolites |
| Biosynthesis of type II polyketide products | 0 | 3.28E−05 | Metabolism of terpenoids and polyketides |
| Sesquiterpenoid and triterpenoid biosynthesis | 2.23E−05 | 2.79E−05 | Metabolism of terpenoids and polyketides |
| Systemic lupus erythematosus | 3.42E−05 | 1.26E−05 | Immune disease |
| Vibrio cholerae infection | 3.21E−05 | 1.09E−05 | Infectious disease: bacterial |
| Vasopressin-regulated water reabsorption | 3.70E−06 | 8.37E−06 | Excretory system |
| ECM–receptor interaction | 5.80E−06 | 6.84E−06 | Signaling molecules and interaction |
| Shigellosis | 1.18E−05 | 4.24E−06 | Infectious disease: bacterial |
| Endocytosis | 1.20E−06 | 2.17E−06 | Transport and catabolism |
| Spliceosome | 5.09E−07 | 1.46E−06 | Transcription |
| Phagosome | 1.30E−06 | 9.32E−07 | Transport and catabolism |
| Glycosphingolipid biosynthesis—lacto and neolacto series | 4.69E−07 | 3.37E−07 | Glycan biosynthesis and metabolism |
| Plant hormone signal transduction | 2.77E−07 | 1.99E−07 | Signal transduction |
| Various types of N-glycan biosynthesis | 4.06E−07 | 0 | Glycan biosynthesis and metabolism |
| Wnt signaling pathway | 4.14E−07 | 0 | Signal transduction |
The significance test method was Wilcoxon rank-sum test.
Further functional orthologs were predicted with level 3 KEGG pathway (Table 2B). Pentose and glucuronate interconversions (P = 4.988E−2), arginine and proline metabolism (P = 1.476E−2), phenylalanine metabolism (P = 3.792E−2), benzoate degradation (P = 3.792E−2), n-glycan biosynthesis (P = 1.041E−2), glyoxylate and dicarboxylate metabolism (P = 3.792E−2), riboflavin metabolism (P = 2.067E−2), biotin metabolism (P = 1.476E−2), folate biosynthesis (P = 3.792E−2), zeatin biosynthesis (P = 3.792E−2), nitrogen metabolism (P = 4.988E−2), caprolactam degradation (P = 2.067E−2), tropane, piperidine and pyridine alkaloid biosynthesis (P = 2.067E−2), biosynthesis of ansamycins (P = 2.813E−2), protein digestion and absorption (P = 1.476E−2), Staphylococcus aureus infection (P = 4.988E−2), phenylalanine, tyrosine, and tryptophan biosynthesis (P = 1.088E−3), beta-alanine metabolism (P = 6.993E−3), carbon fixation in photosynthetic organisms (P = 4.662E−3) and vitamin b6 metabolism (P = 6.993E−3) were less frequently expressed in the LPS group.
Correlation Between Changes in Hepatic Genes and Microbiota
The spearman correlation analysis between the microbiome and gene expression indicated that the relative abundance of Bifidobacterium, Lactobacillus were positively correlated (P < 0.05) while Eubacterium eligens group, Lachnospiraceae NC2004 group, ASF356, Lachnospiraceae NK4A136 group were negatively correlated with the changes of ACAA1, EHHADH, ALDH3A2 mRNA expression, which are associated with amino acid metabolism (P < 0.05) (Figure 6). In addition, Hibiscus syriacus and Blautia were strongly positively correlated while Slackia, Defluviitaleaceae UCG 011, and Leuconostoc negatively correlated with IL4I1 expression (P < 0.05). Blautia, ASF356, Lachnospiraceae NK4A136 group were profoundly correlated with inflammation-related genes such as ANXAl, CCL19, CXCLl3L2, EXFABP, ILlR2, and IL22RA2 (P < 0.05). However, Lactobacillus and Defluviitaleaceae UCG 011 were negatively correlated with the expression of inflammation-related mRNA (P < 0.05). As ALDH3A2, AOX2, ACAA1, ACOX1, PDPR, EHHADH, NOX4, DMGDH be genes related with oxidative stress, Slackia, Bifidobacterium, Escherichia-Shigella, Anaerostipes, Defluviitaleaceae UCG 011, and Lactobacillus had a positive association (P < 0.05) while Lachnospiraceae NC2004 group, Eubacterium eligens group, Blautia, and ASF356 a negative association with those mRNA expression (P < 0.05).
Figure 6.
Heatmap of Spearman's correlation between the gut microbiota and differentially expressed genes of liver. The intensity of the colors represented the degree of association (blue, positive correlation; red, negative correlation). Significant correlations are marked by *P < 0.05; **P < 0.01.
Correlation Between Changes in Metabolites and Microbiota
According to the results of Wilcoxon test, the top 20 significantly different bacterial genera were screened out. The correlations between bacterial genera and serum metabolites are represented in heatmaps (Figure 7). The result revealed that, among the bacteria at genus level, Bifidobacterium (P = 1.480E−2), Escherichia Shigella (P = 2.796E−2), and Anaerostipes (P = 1.205E−3) showed strong positive correlations with the myristoleic acid. In addition, Lachnospiraceae NK4A136 group (P = 4.877E−2), Blautia (P = 7.355E−3), and ASF356 (P = 1.587E−3) were negatively correlated with phenyllactic acid, while Leuconostoc (P = 2.836E−3), Anaerostipes (P = 3.407E−2), and Defluviitaleaceae UCG-011 (P = 4.886E−3) showed positive correlation.
Figure 7.
Heatmap of Spearman's correlation between the gut microbiota and serum metabolites. The intensity of the colors represented the degree of association (blue, positive correlation; red, negative correlation). Significant correlations are marked by *P < 0.05; **P < 0.01.
DISCUSSION
Immune stress in broiler chickens is generally characterized by declined appetite, injury of multiple organs, inducing growth inhibition. Bacterial infection and bacterial toxin are constantly responsible for immune stress (Wang et al., 2020; Tiku and Tan, 2021). Our previous study observed increased ACTH and CORT and decreased growth performance, which was consistent with the model of chronic stress (Beckford et al., 2020; Hu et al., 2021). We further identified amino acid metabolism, lipid metabolism of liver in relation to growth inhibition of broiler chickens mediated by immune stress (Bi et al., 2022a). Considering the potential involvement of intestinal microbiota mediating amino acid and lipid absorption and its role in poultry nutrition, 16S rRNA gene sequencing was applied to investigate the shaping of cecal microbiota in broiler chickens with immune stress (Xiao et al., 2017; Martinez-Guryn et al., 2018; Li et al., 2020b). In the present study, immune stress significantly altered the microbial community and function in cecum. After challenge, broilers showed enhanced diversity indices and variability of the microbiome, reduced abundance of SCFA-producing and butyrate-producing bacteria, as well as raised abundance of probiotics. Moreover, immune stress increased the activities of metabolism of cofactors and vitamins, as well as decreased the ability of energy metabolism and digestive system. Pearson's correlation analysis suggested that those bacteria were apparently correlated with the hepatic gene expression. The results may help us clarify the role of intestinal microbiota in growth inhibition induced by immune stress and search for potential therapeutic strategy.
As a component of gram-negative bacteria cell wall, LPS damages the gut barrier and disturbs the microbial composition, leading to impairment in nutrient utilization and the immune balance, thereby inhibiting growth of broilers (Chen and Yu, 2021; Zhang et al., 2021). Interestingly, supplement of jejunal microbiota can improve growth performance of chickens by suppressing intestinal inflammation (Zhang et al., 2022). However, the specific mechanism concerning the relationship between the microbiota and nutrient utilization needs to be elucidated. In this study, the challenge decreased the frequency of SCFA-producing bacteria including Blautia and butyrate producers including Faecalibacterium and Erysipelatoclostridiaceae. Blautia has activities of maintaining intestinal homeostasis such as preventing inflammation and is significantly reduced in patients with colorectal cancer (Nakatsu et al., 2015; Zou et al., 2022). Known as the major energy source to the colonic mucosa, Faecalibacterium plays a critical role in keeping gut balance (Luo et al., 2013). Clostridia vadinBB60 group, a member of the Clostridia class, which showed a positive correlation with the Treg cell counts, also declined after LPS challenge (Deng et al., 2022). Flavonifractor is found to strongly suppress Th2 immune response and attenuated inflammation (Mikami et al., 2020; Ogita et al., 2020). Butyricicoccus is a butyrate producing bacteria and its descent presents inflammatory bowel disease (Eeckhaut et al., 2013). In this study, the abundance of Flavonifractor and Butyricicoccus in the Model group showed a significant decline. The changes of microbiota population in LPS broilers are correlated with lower growth performance and increased inflammatory response (Bi et al., 2022). Therefore, regulating intestinal microbiota or supplementing specific probiotics will help reduce the influence that immune stress has on poultry production. Consistently, a recent study demonstrated that supplement of Blautia subtilis helps maintain normal growth performance in broiler chickens challenged by heat stress (Abdelqader et al., 2020).
It is interesting how microbial changes influence their host. Thus, to obtain more information on the functions performed by the microorganisms in the cecum, PICRUSt was used to compare Model with Control birds in the present study. We found that cecal microbiota were enriched with functions related to biosynthesis of ansamycins, glycan degradation, D-glutamine and D-glutamate metabolism, valine, leucine and isoleucine biosynthesis and biosynthesis of vancomycin group antibiotics. Besides, the LPS challenge promoted the activities of metabolism of cofactors and vitamins but receded the ability of energy metabolism and digestive system. The results obtained here are consistent with our previous work (Bi et al., 2022a). Thus, it is assumed that reduced food digest and nutrients metabolism induced declining feed utilization and growth performance via manipulating the bacterial community composition.
Gut–liver axis, which means a close functional and physiological link between the gut and the liver (Lin et al., 2021; Silveira et al., 2022; Yu et al., 2022). Approximately 70% of the blood that goes to the liver comes from the portal vein exit intestine, the liver is easily exposed to gut-derived compounds when the intestinal barrier is disrupted (Brescia and Rescigno, 2021; Zhong et al., 2021). On the other hand, liver injury impaired the bile acid metabolism and the promotion of intestinal dysmotility, thereby resulting in systemic inflammation and gut dysbiosis (Albillos et al., 2020). By RNA-seq, 129 DEGs were identified between the Model and the Control bird, which were enriched in process such as amino acid metabolism, lipid metabolism and inflammatory response (Bi et al., 2022). In this study, we examined the relationship between the relative abundance of gut microbiome and the liver DEGs using the Spearman correlation. In total, 182 positive correlations and 177 negative correlations were found. For instance, the DEGs including ACAA1, EHHADH, and ALDH3A2, which are involved in valine, leucine, and isoleucine metabolism, were significantly positively associated with the genus Bifidobacterium, Lactobacillus, while they had a strong negative correlation with the genus Eubacterium eligens group, Lachnospiraceae NC2004 group, ASF356, Lachnospiraceae NK4A136 group. Furthermore, ALDH3A2, AOX2, ACAA1, ACOX1, PDPR, EHHADH, NOX4, and DMGDH that are related to oxidoreductase activity had a significantly negative correlation with the genus ASF356. Interestingly, most DEGs related to inflammatory response were positively associated with the genus Blautia, Hibiscus syriacus, ASF356, Lachnospiraceae NK4A136 group. These results suggested that LPS challenge might induce increased inflammatory response, inhibited oxidoreductase activity and declined nutrient metabolism by regulating liver gene expression, which depends on gut microbiota.
Lactobacillus performed an anti-inflammatory effect mediated by TGF-β (Huang et al., 2015), IL-1β (Guo et al., 2015), and NLRP3 inflammasome (Wu et al., 2015; Ren et al., 2017). It was also reported that LPS-induced immune stress can be alleviated by adding Lactobacillus (Murray et al., 2020). In the present study, increased Lactobacillus aviaries was identified in the immune stress broilers. Lactobacillus can produce phenyllactic acid from 3-phenylpropanoic acid and phenyllactic acid. Due to the enhanced abundance of Lactobacillus that response to immune stress, upregulated phenyllactic and downregulated 3-phenylpropanoic acid in association with antibiotic and anti-inflammation were observed in our previous study (Bi et al., 2022c). Therefore, we presumed that Lactobacillus can remit LPS-induced inflammation by enhancing the phenylalanine metabolic bypass pathway. Similar results were reported in previous studies (Murray et al., 2019; Wang et al., 2019; Shini et al., 2020).
CONCLUSIONS
In summary, the results suggested discrepancy in terms of diversity and composition of the cecal microbiota in broiler chicks with immune stress. We also found decreased frequency of SCFA-producing bacteria and butyrate producers, as well as increased probiotic in immune stress birds. In addition, a high positive correlation between a few bacterial genera and DEGs was found in relation to inflammatory response and BCAA metabolism, whereas a high negative correlation was found between a few bacterial genera and these DEGs simultaneously. The results suggested potential microbiota involved in growth depression mediated by immune stress and provided strategies such as supplement of probiotic for alleviating immune stress in broiler chickens.
ACKNOWLEDGMENTS
This work was supported by the National Natural Science Foundation of China (32002325), Chongqing Research Program of Basic and Frontier Technology (cstc2020jcy-jmsxmX0418), and Fundamental Research Funds for the Central Universities (SWU-KT22011).
Availability of Data and Materials: All data generated or analyzed during this study are included in this published article.
DISCLOSURES
The authors declare no competing financial interests.
Footnotes
Supplementary material associated with this article can be found in the online version at doi:10.1016/j.psj.2023.102598.
Appendix. Supplementary materials
REFERENCES
- Abdelqader A., Abuajamieh M., Hayajneh F., Al-Fataftah A.R. Probiotic bacteria maintain normal growth mechanisms of heat stressed broiler chickens. J. Therm. Biol. 2020;92 doi: 10.1016/j.jtherbio.2020.102654. [DOI] [PubMed] [Google Scholar]
- Albillos A., de Gottardi A., Rescigno M. The gut-liver axis in liver disease: pathophysiological basis for therapy. J. Hepatol. 2020;72:558–577. doi: 10.1016/j.jhep.2019.10.003. [DOI] [PubMed] [Google Scholar]
- Beckford R.C., Ellestad L.E., Proszkowiec-Weglarz M., Farley L., Brady K., Angel R., Liu H.C., Porter T.E. Effects of heat stress on performance, blood chemistry, and hypothalamic and pituitary mRNA expression in broiler chickens. Poult. Sci. 2020;99:6317–6325. doi: 10.1016/j.psj.2020.09.052. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bi S., Qu Y., Shao J., Zhang J., Li W., Zhang L., Ni J., Cao L. Ginsenoside Rg3 ameliorates stress of broiler chicks induced by Escherichia coli lipopolysaccharide. Front. Vet. Sci. 2022;9 doi: 10.3389/fvets.2022.878018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bi S., Shao J., Qu Y., Hu W., Ma Y., Cao L. Hepatic transcriptomics and metabolomics indicated pathways associated with immune stress of broilers induced by lipopolysaccharide. Poult. Sci. 2022;101 doi: 10.1016/j.psj.2022.102199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bi S., Shao J., Qu Y., Xu W., Li J., Zhang L., Shi W., Cao L. Serum metabolomics reveal pathways associated with protective effect of ginsenoside Rg3 on immune stress. Poult. Sci. 2022;101 doi: 10.1016/j.psj.2022.102187. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bi S., Zhang J., Qu Y., Zhou B., He X., Ni J. Yeast cell wall product enhanced intestinal IgA response and changed cecum microflora species after oral vaccination in chickens. Poult. Sci. 2020;99:6576–6585. doi: 10.1016/j.psj.2020.09.075. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brescia P., Rescigno M. The gut vascular barrier: a new player in the gut-liver-brain axis. Trends Mol. Med. 2021;27:844–855. doi: 10.1016/j.molmed.2021.06.007. [DOI] [PubMed] [Google Scholar]
- Chen J.Y., Yu Y.H. Bacillus subtilis-fermented products ameliorate the growth performance and alter cecal microbiota community in broilers under lipopolysaccharide challenge. Poult. Sci. 2021;100:875–886. doi: 10.1016/j.psj.2020.10.070. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cole J.R., Wang Q., Cardenas E., Fish J., Chai B., Farris R.J., Kulam-Syed-Mohideen A.S., McGarrell D.M., Marsh T., Garrity G.M., Tiedje J.M. The Ribosomal Database Project: improved alignments and new tools for rRNA analysis. Nucleic Acids Res. 2009;37:D141–D145. doi: 10.1093/nar/gkn879. [DOI] [PMC free article] [PubMed] [Google Scholar]
- da Rosa G., Da Silva A.S., Souza C.F., Baldissera M.D., Mendes R.E., Araujo D.N., Alba D.F., Boiago M.M., Stefani L.M. Impact of colibacillosis on production in laying hens associated with interference of the phosphotransfer network and oxidative stress. Microb. Pathog. 2019;130:131–136. doi: 10.1016/j.micpath.2019.03.004. [DOI] [PubMed] [Google Scholar]
- Deng L., Wojciech L., Png C.W., Koh E.Y., Aung T.T., Kioh D.Y.Q., Chan E.C.Y., Malleret B., Zhang Y., Peng G., Gascoigne N.R.J., Tan K.S.W. Experimental colonization with Blastocystis ST4 is associated with protective immune responses and modulation of gut microbiome in a DSS-induced colitis mouse model. Cell. Mol. Life Sci. 2022;79:245. doi: 10.1007/s00018-022-04271-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edgar R.C. UPARSE: highly accurate OTU sequences from microbial amplicon reads. Nat. Methods. 2013;10:996–998. doi: 10.1038/nmeth.2604. [DOI] [PubMed] [Google Scholar]
- Eeckhaut V., Machiels K., Perrier C., Romero C., Maes S., Flahou B., Steppe M., Haesebrouck F., Sas B., Ducatelle R., Vermeire S., Van Immerseel F. Butyricicoccus pullicaecorum in inflammatory bowel disease. Gut. 2013;62:1745–1752. doi: 10.1136/gutjnl-2012-303611. [DOI] [PubMed] [Google Scholar]
- Guo S., Guo Y., Ergun A., Lu L., Walker W.A., Ganguli K. Secreted metabolites of bifidobacterium infantis and lactobacillus acidophilus protect immature human enterocytes from IL-1β-induced inflammation: a transcription profiling analysis. PLoS One. 2015;10 doi: 10.1371/journal.pone.0124549. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hu D., Li D., Shigeta M., Ochi Y., Okauchi T., Neyama H., Kabayama S., Watanabe Y., Cui Y. Alleviation of the chronic stress response attributed to the antioxidant and anti-inflammatory effects of electrolyzed hydrogen water. Biochem. Biophys. Res. Commun. 2021;535:1–5. doi: 10.1016/j.bbrc.2020.12.035. [DOI] [PubMed] [Google Scholar]
- Huang I.F., Lin I.C., Liu P.F., Cheng M.F., Liu Y.C., Hsieh Y.D., Chen J.J., Chen C.L., Chang H.W., Shu C.W. Lactobacillus acidophilus attenuates Salmonella-induced intestinal inflammation via TGF-β signaling. BMC Microbiol. 2015;15:203. doi: 10.1186/s12866-015-0546-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jami E., Israel A., Kotser A., Mizrahi I. Exploring the bovine rumen bacterial community from birth to adulthood. ISME J. 2013;7:1069–1079. doi: 10.1038/ismej.2013.2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jiang X.T., Peng X., Deng G.H., Sheng H.F., Wang Y., Zhou H.W., Tam N.F. Illumina sequencing of 16S rRNA tag revealed spatial variations of bacterial communities in a mangrove wetland. Microb. Ecol. 2013;66:96–104. doi: 10.1007/s00248-013-0238-8. [DOI] [PubMed] [Google Scholar]
- Jiang J., Qi L., Lv Z., Jin S., Wei X., Shi F. Dietary stevioside supplementation alleviates lipopolysaccharide-induced intestinal mucosal damage through anti-inflammatory and antioxidant effects in broiler chickens. Antioxidants. 2019;8:575. doi: 10.3390/antiox8120575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Konturek P.C., Harsch I.A., Konturek K., Schink M., Konturek T., Neurath M.F., Zopf Y. Gut-liver axis: how do gut bacteria influence the liver? Med. Sci. 2018;6:79. doi: 10.3390/medsci6030079. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li R.F., Liu S.P., Yuan Z.H., Yi J.E., Tian Y.N., Wu J., Wen L.X. Effects of induced stress from the live LaSota Newcastle disease vaccination on the growth performance and immune function in broiler chickens. Poult. Sci. 2020;99:1896–1905. doi: 10.1016/j.psj.2019.12.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li H., Xu H., Li Y., Jiang Y., Hu Y., Liu T., Tian X., Zhao X., Zhu Y., Wang S., Zhang C., Ge J., Wang X., Wen H., Bai C., Sun Y., Song L., Zhang Y., Hui R., Cai J., Chen J. Alterations of gut microbiota contribute to the progression of unruptured intracranial aneurysms. Nat. Commun. 2020;11:3218. doi: 10.1038/s41467-020-16990-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lin X., Zhang W., He L., Xie H., Feng B., Zhu H., Zhao J., Cui L., Li B., Li Y.F. Understanding the hepatoxicity of inorganic mercury through guts: perturbance to gut microbiota, alteration of gut-liver axis related metabolites and damage to gut integrity. Ecotoxicol. Environ. Saf. 2021;225 doi: 10.1016/j.ecoenv.2021.112791. [DOI] [PubMed] [Google Scholar]
- Luo Y.H., Peng H.W., Wright A.D., Bai S.P., Ding X.M., Zeng Q.F., Li H., Zheng P., Su Z.W., Cui R.Y., Zhang K.Y. Broilers fed dietary vitamins harbor higher diversity of cecal bacteria and higher ratio of Clostridium, Faecalibacterium, and Lactobacillus than broilers with no dietary vitamins revealed by 16S rRNA gene clone libraries. Poult. Sci. 2013;92:2358–2366. doi: 10.3382/ps.2012-02935. [DOI] [PubMed] [Google Scholar]
- Martinez-Guryn K., Hubert N., Frazier K., Urlass S., Musch M.W., Ojeda P., Pierre J.F., Miyoshi J., Sontag T.J., Cham C.M., Reardon C.A., Leone V., Chang E.B. Small intestine microbiota regulate host digestive and absorptive adaptive responses to dietary lipids. Cell Host Microbe. 2018;23:458–469. doi: 10.1016/j.chom.2018.03.011. .e5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mikami A., Ogita T., Namai F., Shigemori S., Sato T., Shimosato T. Oral administration of Flavonifractor plautii attenuates inflammatory responses in obese adipose tissue. Mol. Biol. Rep. 2020;47:6717–6725. doi: 10.1007/s11033-020-05727-6. [DOI] [PubMed] [Google Scholar]
- Munyaka P.M., Eissa N., Bernstein C.N., Khafipour E., Ghia J.E. Antepartum antibiotic treatment increases offspring susceptibility to experimental colitis: a role of the gut microbiota. PLoS One. 2015;10 doi: 10.1371/journal.pone.0142536. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murray E., Sharma R., Smith K.B., Mar K.D., Barve R., Lukasik M., Pirwani A.F., Malette-Guyon E., Lamba S., Thomas B.J., Sadeghi-Emamchaie H., Liang J., Mallet J.F., Matar C., Ismail N. Probiotic consumption during puberty mitigates LPS-induced immune responses and protects against stress-induced depression- and anxiety-like behaviors in adulthood in a sex-specific manner. Brain Behav. Immun. 2019;81:198–212. doi: 10.1016/j.bbi.2019.06.016. [DOI] [PubMed] [Google Scholar]
- Murray E., Smith K.B., Stoby K.S., Thomas B.J., Swenson M.J., Arber L.A., Frenette E., Ismail N. Pubertal probiotic blocks LPS-induced anxiety and the associated neurochemical and microbial outcomes, in a sex dependent manner. Psychoneuroendocrinology. 2020;112 doi: 10.1016/j.psyneuen.2019.104481. [DOI] [PubMed] [Google Scholar]
- Nakatsu G., Li X., Zhou H., Sheng J., Wong S.H., Wu W.K., Ng S.C., Tsoi H., Dong Y., Zhang N., He Y., Kang Q., Cao L., Wang K., Zhang J., Liang Q., Yu J., Sung J.J. Gut mucosal microbiome across stages of colorectal carcinogenesis. Nat. Commun. 2015;6:8727. doi: 10.1038/ncomms9727. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nolan L.K., Vaillancourt J.P., Barbieri N.L., Logue C.M. In: Pages 770–830 in Diseases of Poultry. 14th rev. ed. Swayne D.E., Boulianne M., Logue C.M., McDougald L.R., Nair V., Suarez D.L., editors. Wiley-Blackwell; Hoboken, NJ: 2020. Colibacillosis. [Google Scholar]
- Ogita T., Yamamoto Y., Mikami A., Shigemori S., Sato T., Shimosato T. Oral administration of flavonifractor plautii strongly suppresses Th2 immune responses in mice. Front. Immunol. 2020;11:379. doi: 10.3389/fimmu.2020.00379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ren D., Gong S., Shu J., Zhu J., Rong F., Zhang Z., Wang D., Gao L., Qu T., Liu H., Chen P. Mixed Lactobacillus plantarum strains inhibit Staphylococcus aureus induced inflammation and ameliorate intestinal microflora in mice. BioMed. Res. Int. 2017;2017 doi: 10.1155/2017/7476467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shini S., Zhang D., Aland R.C., Li X., Dart P.J., Callaghan M.J., Speight R.E., Bryden W.L. Probiotic Bacillus amyloliquefaciens H57 ameliorates subclinical necrotic enteritis in broiler chicks by maintaining intestinal mucosal integrity and improving feed efficiency. Poult. Sci. 2020;99:4278–4293. doi: 10.1016/j.psj.2020.05.034. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silveira M.A.D., Bilodeau S., Greten T.F., Wang X.W., Trinchieri G. The gut-liver axis: host microbiota interactions shape hepatocarcinogenesis. Trends Cancer. 2022;8:583–597. doi: 10.1016/j.trecan.2022.02.009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tiku V., Tan M.W. Host immunity and cellular responses to bacterial outer membrane vesicles. Trends Immunol. 2021;42:1024–1036. doi: 10.1016/j.it.2021.09.006. [DOI] [PubMed] [Google Scholar]
- Wang Y., Sheng H.F., He Y., Wu J.Y., Jiang Y.X., Tam N.F., Zhou H.W. Comparison of the levels of bacterial diversity in freshwater, intertidal wetland, and marine sediments by using millions of illumina tags. Appl. Environ. Microbiol. 2012;78:8264–8271. doi: 10.1128/AEM.01821-12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang G., Song Q., Huang S., Wang Y., Cai S., Yu H., Ding X., Zeng X., Zhang J. Effect of antimicrobial peptide Microcin J25 on growth performance, immune regulation, and intestinal microbiota in broiler chickens challenged with Escherichia coli and Salmonella. Animals. 2020;10:345. doi: 10.3390/ani10020345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang Y., Yan X., Han D., Liu Y., Song W., Tong T., Ma Y. Lactobacillus casei DBN023 protects against jejunal mucosal injury in chicks infected with Salmonella pullorum CMCC-533. Front. Vet. Sci. 2019;127:33–41. doi: 10.1016/j.rvsc.2019.09.010. [DOI] [PubMed] [Google Scholar]
- Wang H., Yang F., Song Z.W., Shao H.T., Bai D.Y., Ma Y.B., Kong T., Yang F. The influence of immune stress induced by Escherichia coli lipopolysaccharide on the pharmacokinetics of danofloxacin in broilers. Poult. Sci. 2022;101 doi: 10.1016/j.psj.2021.101629. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu Q., Liu M.C., Yang J., Wang J.F., Zhu Y.H. Lactobacillus rhamnosus GR-1 Ameliorates Escherichia coli-induced inflammation and cell damage via attenuation of ASC-independent NLRP3 inflammasome activation. Appl. Environ. Microbiol. 2015;82:1173–1182. doi: 10.1128/AEM.03044-15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Xiao Y., Xiang Y., Zhou W., Chen J., Li K., Yang H. Microbial community mapping in intestinal tract of broiler chicken. Poult. Sci. 2017;96:1387–1393. doi: 10.3382/ps/pew372. [DOI] [PubMed] [Google Scholar]
- Yu Y., Liu B., Liu X., Zhang X., Zhang W., Tian H., Shui G., Wang W., Song M., Wang J. Mesenteric lymph system constitutes the second route in gut-liver axis and transports metabolism-modulating gut microbial metabolites. J. Genet. Genomics. 2022;49:612–623. doi: 10.1016/j.jgg.2022.03.012. [DOI] [PubMed] [Google Scholar]
- Zhang X., Akhtar M., Chen Y., Ma Z., Liang Y., Shi D., Cheng R., Cui L., Hu Y., Nafady A.A., Ansari A.R., Abdel-Kafy E.M., Liu H. Chicken jejunal microbiota improves growth performance by mitigating intestinal inflammation. Microbiome. 2022;10:107. doi: 10.1186/s40168-022-01299-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang H., Yu X., Li Q., Cao G., Feng J., Shen Y., Yang C. Effects of rhamnolipids on growth performance, immune function, and cecal microflora in linnan yellow broilers challenged with lipopolysaccharides. Antibiotics. 2021;24:905. doi: 10.3390/antibiotics10080905. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhong G., Wan F., Lan J., Jiang X., Wu S., Pan J., Tang Z., Hu L. Arsenic exposure induces intestinal barrier damage and consequent activation of gut-liver axis leading to inflammation and pyroptosis of liver in ducks. Sci. Total Environ. 2021;788 doi: 10.1016/j.scitotenv.2021.147780. [DOI] [PubMed] [Google Scholar]
- Zou X.Y., Zhang M., Tu W.J., Zhang Q., Jin M.L., Fang R.D., Jiang S. Bacillus subtilis inhibits intestinal inflammation and oxidative stress by regulating gut flora and related metabolites in laying hens. Animal. 2022;16 doi: 10.1016/j.animal.2022.100474. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.







