Reference Number: 330
The gastrointestinal (GI) tract contains much of the body’s serotonin (5-hydroxytryptamine, 5-
HT), but mechanisms controlling the metabolism of gut-derived 5-HT remain unclear. Here we
demonstrate that the microbiota plays a critical role in regulating host 5-HT. Indigenous sporeforming bacteria (Sp) from the mouse and human microbiota promote 5-HT biosynthesis from
colonic enterochromaffin cells (ECs), which supply 5-HT to the mucosa, lumen and circulating
platelets. Importantly, microbiota-dependent effects on gut 5-HT significantly impact host
physiology, modulating GI motility and platelet function. We identify select fecal metabolites that
are increased by Sp and that elevate 5-HT in chromaffin cell cultures, suggesting direct metabolic
signaling of gut microbes to ECs. Furthermore, elevating luminal concentrations of particular
microbial metabolites increases colonic and blood 5-HT in germ-free mice. Altogether, these
findings demonstrate that Sp are important modulators of host 5-HT, and further highlight a key
role for host-microbiota interactions in regulating fundamental 5-HT-related biological processes.
What does this mean for a Baker?
While this study has no practical applications to baking, it is a very interesting study which provides us with more information on the action of gut microbes within our body. This study found that some bacterial species within our gut microbiome are responsible for regulating the production of serotonin, known as the ‘happy chemical’ in our brains. This highlights the importance of maintaining a healthy gut microbiome as microbial dysbiosis has links to depression.