Gut Microbiota-Derived Extracellular Vesicles in Patients With Obesity Undergoing Gastric Bypass Surgery

Human gut microbiota is associated with obesity. Gut microbiota-derived extracellular vesicles (EVs), lipid coated nanoparticles secreted by bacteria, have been suggested as a communication mechanism between gut microbiota and the host. This study characterized the effect of Roux-en-Y gastric bypass (RYGB) on gut microbiota and gut microbiota-derived EVs in patients with obesity. Fecal samples were collected from 30 recruited patients at baseline and 6 months after surgery. EVs were isolated from fecal samples, and their origin and protein content were analyzed. The number of unique proteins was increased in gut microbiota-derived EVs after the surgery as compared to baseline. A significant difference in both microbiota composition (p = 0.001; PERMANOVA) and microbiota-derived EVs (p = 0.001; PERMANOVA) was observed in response to surgery. Based on 16S rRNA gene sequencing data, a random forest classifier accurately classified both gut microbiota (AUC = 0.93) and EVs (AUC = 0.80) to baseline and after surgery groups. This study found that gastric bypass surgery altered both the composition and characteristics of gut microbiota and gut microbiota-derived EVs in patients with obesity. Thus, gut microbiota-derived EVs may play a role in obesity and influence the health effects of bariatric surgery beyond the gut. Trial Registration: ClinicalTrials.gov identifier: NCT00950003.