Table 1.
Examples of human studies on the gut microbiota-derived metabolites in NAFLD and NASH.
| Study | Subjects | Type of metabolites | Type of sample | Results |
|---|---|---|---|---|
| Loomba et al. (46) | Adults with NAFLD (n = 86) | Short Chain Fatty Acids | Blood | ↑abundance of enzymes associated with lactate, acetate, and formate in mild/moderate NAFLD. ↑abundance of enzymes for butyrate, D-lactate, propionate, and succinate in advanced fibrosis. ↑serum 3-phenylpropanoate in advanced fibrosis. |
| Hoyles et al. (47) | Morbidly obese women (n = 105) | Amino Acids | Blood | ↑Phenylacetic acid, ↑ Valine, ↑Leucine, ↑ Isoleucine |
| Mouzaki et al. (48) | Adults with NASH (n = 22), SS (n = 11), healthy controls (n = 17) | Bile Acids | Fecal | ↑Primary to secondary BA ratio in NASH |
| Raman et al. (49) | Adults with NAFLD (n = 30), healthy controls (n = 30) | Ethanol, VOCs |
Fecal | ↑Butanoic acid, ↑Propanoic acid, ↑Acetic acid, and ↓2-butanone in NAFLD vs. healthy controls |
| Da Silva et al. (50) | Adults with SS (n = 15), NASH (n = 24), healthy controls (n = 28) | Short Chain Fatty Acids | Fecal and Blood | (Fecal) ↑Isobutyric acid, ↑Propionate (Serum) ↑2-hydroxy-butyrate, ↑L-lactic acid |
| Del Chierico et al. (51) | Children and adolescents (n = 61) with NAFLD, NASH, or obesity, healthy controls (n = 54) | VOCs | Blood | ↑2-butanone and ↑1-pentanol in NAFLD. ↑2-butanone and ↑4-methyl-2-pentanone in NASH |
↑, increase; ↓, decrease; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; SS, simple steatosis; BA, bile acids; VOC, volatile organic compounds.