Linking the microbiome to a higher BMI

A recent study done at the University of Utah has shown that an increased level of the Desulfovibrio bacteria next to a decreased level in Clostridia bacteria may result in an increase in weight. In lean mice, the researchers observed more Clostridia whilst obese mice had relatively less Clostridia in their microbiome. However, the obese mice had relatively more Desulfovibrio bacteria present in their gut. Both species have a prominent role in the absorption of fats in the intestinal system, as an effect of the genes that they encode that compel the body to absorb fats. 

An interesting finding of this research was that the immune system could modulate the effects of these bacteria. Previous findings had shown that the deactivation of a certain immune-system gene could cause an increase in body weight. When the researchers provided Clostridia bacteria to mice with this gene deactivated, the mice remained lean as they were able to efficiently resorb fats from the intestinal system. However, when these mice received a dose of Desulfovibrio, these mice became obese.

The researchers plan to further elucidate the molecular mechanisms that underlie these weight-gain and -loss effects due to these bacteria, to potentially identify a key molecule that could have implications in the treatment of Diabetes Type 2.