Bile Acids: Major Regulator of the Gut Microbiome.
Level 5 - mechanism / opinion, no new human data
Bench (in vitro) and animal (rodent) experimental study with no human data
PubMed 36144395 · doi:10.3390/microorganisms10091792
What was done
Researchers evaluated the antimicrobial effects of five human bile acids (ursodeoxycholic acid, cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid) using in vitro disc diffusion assays against various microorganisms. They subsequently created a rodent model administering these bile acids and measured changes in fecal bacterial populations in the colon and cecum using real-time polymerase chain reaction (qPCR).
What was found
The abstract reports no numerical values, effect sizes, or statistical significance levels. Qualitatively, each bile acid displayed distinct microbial inhibitory profiles; inhibitory activity was low against native gastrointestinal and biliary microbiota, but significant against normal flora from other organ systems. In the rodent model, changes in microbial counts following bile acid administration differed between the colon and cecum, reflecting the selectivity observed in vitro.
Why it matters
This study shows that bile acids exert selective antimicrobial effects that spare native gut microbiota while inhibiting non-gastrointestinal flora, clarifying how endogenous bile acid pools shape intestinal microbial composition.
Limits
This is purely bench and animal research without human subjects. The abstract omits sample sizes (n), specific bacterial taxa evaluated, dosages administered, and quantitative outcome measurements.
Cited by
- supports TUDCA is an antibacterial bile salt.