he gut microbiota enhances the host’s metabolic capacity for processing nutrients and drugs and modulate the activities of
multiple pathways in a variety of organ systems.
Acquisition of the gut microbiota was associated with rapid increase in body weight (4%) over the first 5 days of
colonization
The colonization process stimulated
glycogenesis in the liver prior to triggering increases in hepatic triglyceride synthesis
modifications of hepatic Cyp8b1 expression and the subsequent alteration of bile acid metabolites
Expression and activity of major drug-metabolizing
enzymes (Cyp3a11 and Cyp2c29) were also significantly stimulated
The gut microbiota (GM) exhibits a relatively low level of diversity compared to those of most soil ecosystems and in humans
it is comprised of usually no more than nine phyla of microorganisms, of which only two are dominant: the Firmicutes and the Bacteroidetes
colonization of a germfree gut was rapid and remarkably stable, establishing within only
a week after first exposure
a study conducted on germfree rats by Nicholls et al. showed that 3 weeks were necessary
to obtain a stabilization and “normalization”
the microbiota status affects
the systemic metabolism of the host, modulating the metabolic fingerprint of topographically remote organs such as the liver
and the kidney
Gut colonization induces a rapid weight gain associated with stimulation of hepatic glycogenesis and triglyceride synthesis
Gut colonization alters bile acid metabolite profiles via modulation of hepatic Cyp8b1 expression
Bile acids are well-known contributors to glucose and lipid metabolism in the liver
GM is known to alter bile metabolism
GM is also known to exert a strong influence on the metabolism of xenobiotics
The effects of gut microbiome are not confined to the gut. They alter bile acid metabolism and thus lipid/glucose metabolism. They alter CYP450 activity. They effect metabolism. They effect the metabolism, and thus effects, of other drugs.