TABLE 1.

Investigations into NAFLD and microbiota composition and function in humans.

Study	Design and participant details	Microbial findings and summary of results	Upregulated microbiota	Downregulated microbiota
Caussy et al. (63)	• Prospective discovery cohort • 203 participants were divided into NAFLD- cirrhosis, NAFLD without AF, non-NAFLD controls	Identified a specific stool microbiome-derived signature of NAFLD-cirrhosis Assessed microbial biomarker could present an adjunct tool to determine stage of liver disease.	Streptococcus, Megasphaera, Enterobacteriaceae, Streptococcus, Gallibacterium	Bacillus and Lactococcus, Pseudomonas, Faecalibacterium prausnitzii, Catenibacterium, Rikenellaceae, Mogibacterium, Peptostreptococcaceae
Behary et al. (39)	• Prospective discovery cohort • 90 subjects were divided into: 32 with NAFLD-HCC, 28 with NAFLD-cirrhosis and 30 non-NAFLD control	Gut dysbiosis characterizes liver Cirrhosis NAFLD-HCC was characterized by expansion of Proteobacteria compared to non-NAFLD controls.	Proteobacteria, Coriobacteriaceae	Oscillospiraceae, Erysipelotrichaceae, Bacteroidetes, Muribaculaceae, Odoribacteraceae, Prevotellaceae
López-Salazar et al. (109)	• Animal model • SO, OO, CO was fed with NAFLD C57BL/6 mice, respectively	SO showed the highest microbial diversity, high insulin sensitivity and low grade inflammation. CO showed the lowest bacterial diversity, increase in the LPS concentration, hepatic steatosis, increased lipogenesis.	Akkermansia muciniphila, Bifidobacterium, Bacteroides acidifaciens, Faecalibacterium prausnitzii, Mucispirillum schaedleri	Verrucomicrobia phyla
Ding et al. (26)	• Animal model • Mice were randomized into: CHOW, CHOW + NAC, HFD + NAC	NAC potentially alleviated HFD-induced NAFLD via the homeostasis of the gut microbiota.	Firmicutes norank_f_Erysipelotrichaceae, Coriobacteriaceae_UCG-002	Bacteroidetes, Enterorhabdus, Lachnoclostridium, Alistipes
Liu et al. (50)	• Prospective discovery cohort • Female NAFLD patients and normal controls. • Female C57BL/6 mice were divided into: normal diet, sham-operated + HFD, OVX + HFD, OVX + HFD + FMT.	The structure of the gut microbiota was changed in NAFLD patients and mice induced by OVX. FMT attenuated estrogen deficiency induced NAFLD in mice.	Bacteroidetes, Proteobacteria, Bacteroides, Alistipes, Verrucomicrobia, Faecalibaculum, Helicobacter, Epsilonbacteraeota	Muribaculaceae, Lactobacillus
Zeybel et al. (4)	• Prospective discovery cohort • MAFLD were classified into: no steatosis, mild steatosis, moderate steatosis, severe steatosis.	The alterations in the microbial compositions start at early stages of the clinical spectrum and cause metabolic disturbances underlying HS.	Firmicutes (Streptococcus mitis and Roseburia inulinivorans) and Bacteroidetes (Barnesiella intestinihominis and Bacteroides uniformis)	Bacteroidetes (Prevotella sp. CAG 520, Prevotella sp. AM42 24, Butyricimonas virosa, and Odoribacter splanchnicus), Proteobacteria (Escherichia coli), Lentisphaerae (Victivallis vadensis), and Firmicutes (Holdemanella biformis, Dorea longicatena, Allisonella histaminiformans, and Blautia obeum)
Zhang et al. (38)	• Animal model • Male C57BL/6 were fed with NC, HFLC, HFHC	High dietary cholesterol induces spontaneous and progressive development of NAFLD–HCC in male mice by modulating the gut microbiota.	M. schaedleri_Otu038, Desulfovibrio_Otu047, Anaerotruncus_Otu107, Desulfovibrionaceae_Otu073	Akkermansia, Lactobacillus, Bifidobacterium, Bacteroides
Carbajo-Pescador et al. (56)	• Wistar rats were separated into: Control, semi-purified high fat diet (HFD)	The consumption of oils with high monounsaturated and polyunsaturated fats and probably the presence of phenolic compounds that protects gut barrier integrity allows the maintenance of healthy gut microbiota.	Firmicutes Clostridia (Firmicutes phylum), Deltaproteobacteria and Gammaproteobacteria (Proteobacteria phylum)	Bacteroidetes, Bacteroidia (Bacteroidetes phylum) and Bacilli (Firmicutes phylum)
Zhang et al. (84)	• C57BL/6J male mice were divided into: normal diet, HFD, HFID (high-fat plus resistant dextrin diet)	Resistant dextrin mitigates hepatic steatosis through modifying the intestinal microbiome and fecal metabolome in mice.	Bifidobacteriaceae, Dietziaceae, and Prevotellaceae, Firmicutes phylum, Turicibacter, Faecalibaculum, and Streptococcus	Bifidobacterium, Dietzia, Globicatella, Enterococcus, Lactobacillus, Leuconostoc, Lactococcus, Streptococcus, Lachnoclostridium, Parabacteroides, Catabacter, Blautia, Dubosiella, Erysipelatoclostridium, unidentified_ Erysipelotrichaceae
Li et al. (28)	• Male C57BL/6 mice were divided into: normal diet, HFHC diet, HFHC diet supplemented with UCDA.	UDCA could resistance hepatic inflammation in a dose dependent pattern and improve the dysbiosis of the gut microbiota induced by HFHC.	Firmicutes, Verrucomicrobiota	Bacteroidetes, Actinobacteriota, Proteobacteria

SO, soybean oil; OO, olive oil; CO, coconut oil; NAC, N-acetylcysteine; CHOW, chow diet; HFD, high-fat diet; NC, normal chow; HFLC, high-fat/low-cholesterol diet; HFHC, high-fat/high-cholesterol diet; OVX, ovariectomy.