Table 2.
Studies showing the effect of dietary factors influencing the gut microbiome and its impact on the colonic mucosa and CRC progression.
| References | Human/in vivo/in vitro | Dietary factors or intervention | Influence on gut microbiome/bacterial species or strain | Impact on colon/CRC |
|---|---|---|---|---|
| Constante et al. (75) | In vivo (mice) | Heme iron (red meat) | ↓Firmicutes ↑ Proteobacteria |
↑ DSS induced Colitis ↑ Colitis induced adenoma |
| Fernández et al. (57) | In vivo (rat) | Processed meat mixed with polysaccharide inulin (functional food) | ↑ Blautia | CRC prevention ↑ SCFA production ↑ Anti-inflammatory action |
| Lagha and Grenier (49) | In vitro (U937-3xκB-LUC cell line and PMA treated U937 human monocytes) | Epigallocatechin-3-O-gallate and Theaflavins (Tea polyphenols) | ↓Fusobacterium nucleatum | ↓ Inflammation ↓ NF-κB activation |
| Kim et al. (61) | Human | Mango pulp polyphenols | ↑Lactobacillus | ↓ Intestinal inflammation ↓ IL-8, GRO and GM-CSF |
| Gong et al. (112) | In vivo (mice) | Neohesperidin (Flavonoid) | ↑Firmicutes ↑Proteobacteria ↓ Bacteroidetes |
↑ Apoptosis ↓ Angiogenesis |
| Chen et al. (50) | In vivo (mice) | Black raspberry anthocyanin (Flavonoid) | ↑Eubacterium rectale ↑Faecalibacterium prausnitzii ↑ Lactobacillus |
↓ Tumorigenesis ↓SFRP2 promoter methylation |
| Pan et al. (64) | In vivo (rat) | Black raspberry anthocyanin (Flavonoid) |
↑ Akkermansia ↑ Anaerostipes ↑ Desulfovibrio |
CRC prevention |
| Rodríguez-García et al. (73) | In vivo (mice) | Extra virgin olive oil | ↑ Firmicutes:Bacteroidetes ↑Akkermansia ↓Enterococcus ↓Staphylococcus ↓Neisseria ↓ Pseudomonas |
↓ Alteration in gut microbiota ↑ Anti-inflammatory effect |
| Watson et al. (115) | Human | n-3 PUFA | ↑Bifidobacterium ↑ Roseburia ↑ Lactobacillus |
CRC prevention (Increase butyrate producers) |
| Kim et al. (60) | In vitro (co-culture) | Fructooligosaccharides | Faecalibacterium prausnitzii ATCC 27768 strain and Bifidobacterium catenulatum KCTC 3221 strain | ↑ Butyrate production |
| In vivo (mice) | Fed with F. prausnitzii and B. catenulatum co-culture supernatant | ↑Akkermensia ↑ Verrucomicrobiales |
↑ Acetate, propionate and butyrate in the caecum ↑Il8 gene expression |
|
| Yuan et al. (108) | Human | Green tea extracts (Polyphenols) | ↑ Firmicutes:Bacteroidetes ↑ SCFA producers ↓ Fusobacterium |
CRC prevention |
| Farhana et al. (63) | In vivo (mice) | Essential turmeric oil-curcumin and vitamin E isomers | ↑Lactobacillaceae ↑ Bifidobacteriaceae ↑ Clostridium XIVa |
↓ CRC proliferation ↑ Probiotic action ↑ Anti-inflammatory effect |
| Greenhalgh et al. (119) | In vitro (HuMiX gut-on-a-chip model with synbionts) | Simulated high fiber diet (Prebiotic) | Lactobacillus rhamnosus Gorbach-Goldin (Probiotic) | CRC prevention ↓ Oncogenic pathways ↓ Lactate production ↓ Chemoresistance |
| Mehta et al. (44) | Human | Prudent diet (Whole grain and dietary fiber) | ↓Fusobacterium nucleatum | ↓ CRC risk |
| Oh et al. (120) | In vivo (mice) | Cudrania tricuspidate extracts in fermented milk (Prebiotic) | Lactobacillus gasseri 505 (Probiotic) |
↑ Lactobacillus ↑Bifidobacterium ↑Akkermansia ↓ Inflammatory cytokines ↑ Anti-inflammatory cytokines |
| Li et al. (51) | Human | Childhood calorie restriction | ↓Fusobacterium nucleatum | ↓ CIMP and ↓MSI which influences prognosis of CRC |
| Sobhani et al. (131) | In vivo (mice) | Fecal microbiota transplantation (of CRC subjects to germ free mice) | ↓ Coprococcus ↑ Bacteroides |
Enhanced DNA mutation and hypomethylation involving genes of pro-oncogenic Wnt and Notch pathway in mice |
| Alrafas et al. (132) | In vivo (mice) | Resveratrol (plant stilbenoid) | ↑ SCFA (butyrate and iso-butyrate) producers | CRC prevention ↓ HDAC ↑ Foxp3 ↑ Treg cells and IL-10 ↓ Th1 and Th17 cells |
CIMP, CpG island methylator phenotype; CRC, colorectal cancer; DSS, dextran sulfate sodium; Foxp3, forkhead box P3; GM-CSF, granulocyte-macrophage colony-stimulating factor; GRO, growth-regulated oncogene; HDAC, histone deacetylase; IL-8, interleukin-8; MSI, microsatellite instability; NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells; PUFA, polyunsaturated fatty acids; SCFA, short chain fatty acid; SFRP2, secreted frizzled related protein 2; Symbols, Enhanced (↑); Reduced (↓).