The connection between gut bacteria and weight gain is a subject of great interest among researchers. It’s a topic of great interest to me, too! The search is on for probiotic therapies that prevent weight gain. In a recent study published in the Journal of Clinical Investigation, Vanderbilt University researchers discovered a protective effect against weight gain of a genetically modified probiotic bacteria, E. coli Nissle 1917.

Although most people think of food poisoning when they think of E. coli, only one specific E. coli strain causes disease (E. coli O157:H7). Most E. coli strains are actually harmless or even beneficial.

The researchers genetically modified the E. coli strain to produce a compound called NAPE (N-acylphosphatidylethanolamine), which is normally created in the small intestine in response to eating. NAPE is converted to NAE (N-acylethanolamine), which is known to reduce food intake and weight gain.

Mice eating a high-fat diet ingested NAPE-producing bacteria for eight weeks and were found to have lower food intake, body fat, insulin resistance, and fatty liver when compared to mice receiving bacteria not genetically modified to produce NAPE. The protective effects lasted at least four weeks after probiotics were no longer ingested. Twelve weeks later the mice still had lower body weight and body fat compared to control mice.

“Of course, it’s hard to speculate from mouse to human,” noted lead researcher Sean Davies, PhD, “But essentially, we’ve prevented most of the negative consequences of obesity in mice, even though they’re eating a high-fat diet.”

While this study is interesting, I must say that I have reservations about genetically modifying bacteria. We simply don’t know the long-term consequences. If this NAPE compound is something that we naturally produce in the intestines, it seems to me that we can find another way to optimize its production in the gut. Perhaps this research can help us to better understand how to affect weight gain, but without resorting to genetic modification. In all, this study still supports the connection between gut bacteria and weight gain. It shows that one simple chemical produced by gut bacteria has the ability to have many positive effects on weight loss-related health.