Lose weight, gain it back. That’s the frustrating routine for many individuals who have experienced only short-term success with diets. To examine the microbial and metabolic factors underlying this weight loss-regain cycle, researchers at the Weizmann Institute of Science in Rehovot, Israel, ran a series of experiments using a mouse model of recurrent obesity. The composition of a mouse’s microbiome is predictive of post-diet weight regain, which is in part modulated by metabolites released by the bugs, the researchers found. Their results were published today (November 24) in Nature.
“This work adds some insight on how the microbiome acts as a buffer to changes in our diet,” study coauthor Eran Segal of the Weizmann Institute said during a press briefing this week (November 22).
In particular, the researchers found evidence to suggest that mice that were once obese tend to experience alterations in microbiome composition that persist during and after weight loss. They also linked the metabolic health of mice to levels of the dietary flavonoids apigenin and naringenin, among other metabolites exchanged between the host and microbiome.
There is hope, however. Segal and colleagues also reported that microbiome- and metabolite-mediating therapies—such as antibiotic treatment, fecal transplant, or postbiotic supplementation—can ameliorate the rate of weight regain in mice predisposed to recurrent obesity.
“It’s a combination of the microbiome and the diet” that contribute to exaggerated post-diet weight regain in mice, said Segal. “More and more, we and others are beginning to understand the interaction between the microbiome and the host, and how that interaction occurs. We, more and more, understand that this is going on—to a very large extent—at the level of molecules that are exchanged between the host and the microbiome.”
“The next obvious step is to study this in populations of humans that suffer similar relapsing obesity phenotypes,” coauthor Eran Elinav of the Weizmann Institute added during the press briefing, noting that such investigations are ongoing.