Gut microbiota: a factor in energy regulation.

Studies of germ-free and conventional mice revealed that the intestinal bacterial population of the latter contributed to the provision of calories to the host by hydrolysis of indigestible plant polysaccharides to absorbable monosaccharides. The gut microbiota at the same time caused the suppression of a circulating inhibitor of lipoprotein lipase, resulting in increased lipoprotein lipase activity and thus fat deposition. Both of these effects bring about a significantly increased body fat deposition in conventional mice compared with germ-free mice. Therefore, the intestinal microbiota, living in mutual beneficial symbiosis with the host organism, is an important regulator of energy uptake and storage.