Table 1.
The role of bile acids in shaping the microbiota composition.
| Bile acid | Effect on the microbiome (in vivo) | Mechanism (in vitro) | Reference |
|---|---|---|---|
| Primary BAs | UDCA decreases the abundance of Escherichia and enhances the abundance of Lactobacillus when administered to neonatal mice | Directly inhibits the growth of Escherichia | (20) |
| UDCA promotes the growth of Bacteroidaceae, Clostridium cluster XIVa and Akkermansia during the DSS model of colitis | Unknown | (25) | |
| Conjugated BAs | βTMCA decreases the abundance of Escherichia and enhances the abundance of Lactobacillus when administered to neonatal mice; βTMCA and TCA increase microbiota richness when administered to neonatal mice | Directly promotes the growth of L. johnsonii and L. reuteri | (20) |
| glycine-conjugated UDCA (GUDCA) promotes the growth of Bacteroidaceae, and A. muciniphila during the DSS model of colitis; taurine-conjugated UDCA (TUDCA) promotes the growth of Prevotellaceae and A. muciniphila during the DSS model of colitis | Unknown | (25) | |
| Secondary BAs | Adoptive transfer of DCA and LCA-producing bacterial consortium or C. scindens enhances resistance to C.difficile infection | DCA and LCA each inhibit the growth of C. difficile directly; DCA and LCA enhance the activity of antimicrobials produced by C. scindens | (16), (17) |
| Antibiotic treatment targeting secondary bile acid-producing bacteria enhances the outgrowth of C. difficile | LCA, DCA and HDCA (hyodeoxycholic acid) directly inhibit the growth of C. difficile | (18) | |
| – | Conversion of DCA by E. lenta to a less bacteriostatic isoDCA favors the growth of Bacteroides ovatus | (9) | |
| LCA promotes biofilm formation and intestinal colonization of vancomycin-resistant E. faecium | LCA induces MgCl2-dependent morphotype switch to chained growth | (19) |