genes

Analysis of Commensal Host-Microbial Relationships in the Intestine

I know this title sounds a little confusing, but the really, really important take home message in this study is that bacteria in the gut may actually affect the way genes are expressed. The genes that are modulated involve the body’s ability to break down environmental toxins, maintain the barrier functions of the gut and many others. This study was done on mice, but if this holds true in humans, than this is truly an amazing finding. All of us in medicine need to wake up an realize that the bacteria in our gut play a major role in our health, as well as our disease.

Science Hooper et al. 291 (5505):881 Human beings contain complex societies of indigenous microbes, yet little is known about how resident bacteria shape our physiology. We colonized germ-free mice with Bacteroides thetaiotaomicron, a prominent component of the normal mouse and human intestinal microflora. Global intestinal transcriptional responses to colonization were observed with DNA microarrays, and the cellular origins of selected responses were established by laser-capture microdissection. The results reveal that this commensal bacterium modulates expression of genes involved in several important intestinal functions, including nutrient absorption, mucosal barrier fortification, xenobiotic metabolism, angiogenesis, and postnatal intestinal maturation. These findings provide perspectives about the essential nature of the interactions between resident microorganisms and their hosts.