The role of the gut-brain axis in bariatric surgery

Bariatric surgery is the gold standard for sustained weight loss. Despite common misconceptions, bariatric surgery remodels gut-brain physiology in more complex ways than simply reducing stomach size or causing nutrient malabsorption. Bariatric surgery induces weight loss primarily by reductions in food intake and alterations in feeding patterns, macronutrient preference, and the rewarding aspects of food. Bariatric surgery also enhances nutrient-induced brain activation, alters nutrient processing, enhances gut hormone secretion, and increases bile acids. However, which of these signals directly link to improved satiety and altered reward pathways remains unclear. While state-of-the-art tools are now available to manipulate specific subpopulations of peripheral sensory neurons, work is needed to apply these tools to obesity and bariatric surgery. This will be critical for advancing the understanding of the role of the gut-brain axis in the success of surgery and allowing for the continued expansion of therapeutic options for obesity.