Robert Caesar

The human gut microbiota has gained interest as an environmental factor that may contribute to health or disease1. The development of next-generation probiotics is a promising strategy to modulate the gut microbiota and improve human health; however, several key candidate next-generation probiotics are strictly anaerobic2 and may require synergy with other bacteria for optimal growth.

By comparing GF and CONV-R mice, we recently identified tauro-beta muricholic acid (T?MCA) as a potent FXR antagonist and showed that FXR suppression is alleviated by microbial metabolism of T?MCA to ?MCA. 15 Similarly, modulation of the mouse gut microbiota using antibiotics or the antioxidant tempol increases the levels of T?MCA and suppresses FXR activity.

Objective The gut microbiota has been implicated as an environmental factor that modulates obesity, and recent evidence suggests that microbiota-mediated changes in bile acid profiles and signalling through the bile acid nuclear receptor farnesoid X receptor (FXR) contribute to impaired host metabolism. Here we investigated if the gut microbiota modulates obesity and associated phenotypes through FXR. Design We fed germ-free (GF) and conventionally raised (CONV-R) wild-type and Fxr?/?