Table 1. Examples of gut microbiota–derived metabolites and their beneficial effects on human health.
| Metabolite/pathway | Microbial agent | Health benefits |
|---|---|---|
| Butyrate (carbohydrate metabolism) | Clostridia (clusters IV and XIVa) | Increased intestinal barrier function (Kelly et al., 2015; Zheng et al., 2017) |
| F. prausnitzii | Modulate intestinal macrophage function (Chang et al., 2014) | |
| Eubacterium spp. | Regulation of colonic T reg cell homeostasis (Furusawa et al., 2013; Smith et al., 2013) | |
| Roseburia spp. | Induction of tolerogenic DCs that polarize naive CD4+ T cells toward IL-10–producing T reg cells (Kaisar et al., 2017) | |
| Coprococcus catus | Suppression of colonic inflammation (Singh et al., 2014; Simeoli et al., 2017) | |
| Anaerostipes hadrus | Improvements in insulin sensitivity (Khan and Jena, 2016) | |
| Propionate (carbohydrate metabolism) | Bacteroides spp. | Regulation of colonic T reg cell homeostasis (Furusawa et al., 2013; Smith et al., 2013) |
| Blautia obeum | Suppression of colonic inflammation (Tong et al., 2016) | |
| C. catus | Decreased innate immune responses to microbial stimulation (Ciarlo et al., 2016) | |
| Roseburia inulinivorans | Protection from allergic airway inflammation (Trompette et al., 2014) | |
| P. copri | Improvements in insulin sensitivity and weight control in obese mice (den Besten et al., 2015) | |
| Alistipes putredinis | ||
| Dialister invisus | ||
| A. muciniphila | ||
| Eubacterium hallii | ||
| Indole (tryptophan metabolism) | A variety of bacteria possessing tryptophanase, including: | |
| Lactobacillus spp. | Maintenance of host–microbe homeostasis at mucosal surfaces via IL-22 (Zelante et al., 2013) | |
| B. longum | Increased barrier function (Bansal et al., 2010) | |
| B. fragilis | Modulation of host metabolism (Chimerel et al., 2014) | |
| P. distasonis | ||
| Clostridium bartlettii | ||
| E. hallii | ||
| E. coli | ||
| I3A (tryptophan metabolism) | Lactobacillus spp. | Maintenance of mucosal homeostasis and intestinal barrier function via increased IL-22 production (Zelante et al., 2013) |
| Protection against intestinal inflammation in mouse models of colitis (Lamas et al., 2016) | ||
| IPA (tryptophan metabolism) | Clostridium sporogenes | Maintenance of intestinal barrier function and mucosal homeostasis (Venkatesh et al., 2014) |
| Increased production of antioxidant and neuroprotectant products (Hwang et al., 2009) | ||
| HYA (lipid metabolism) | Lactobacillus spp. | Maintenance of intestinal barrier function (Miyamoto et al., 2015) |
| Decreased inflammation (Kaikiri et al., 2017) | ||
| Increased intestinal IgA production (Kaikiri et al., 2017) | ||
| CLA (lipid metabolism) | Lactobacillus spp. | Decreased inflammation (Viladomiu et al., 2016) |
| Bifidobacterium spp. | Reduced adiposity (Segovia et al., 2017) | |
| F. prausnitzii | Improved insulin sensitivity (Garibay-Nieto et al., 2017) |
CLA, conjugated linoleic acid; HYA, 10-hydroxy-cis-12-octadecoate (linoleic acid derivative); I3A, indole-3-aldehyde; IPA, indole-3-propionate.