Impact of bariatric surgery on the gut microbiota and metabolomic profile of the enterohepatic axis in an experimental model of obesity

Abstract

Obesity is a complex metabolic disease associated with alterations in the gut microbiota and the metabolism of fatty acids and bile acids. Bariatric surgery can modify this axis, contributing to benefits beyond weight loss, and the response may differ between surgical techniques. This study investigates this differential impact in an experimental model of obesity. Both surgical procedures reduced body weight, although gastric bypass (GB) induced a more sustained weight loss and deeper metabolic changes. GB significantly decreased butyrate levels while increasing bile acids and the abundance of beneficial bacteria such as Akkermansia muciniphila and Bacteroides. Only GB reduced serum TMAO levels, a metabolite linked to cardiovascular risk, possibly through modulation of the hepatic enzyme FMO3. The results indicate that GB exerts a markedly distinct metabolic impact compared to sleeve gastrectomy (SG), which may largely explain its greater clinical efficacy.