Using a unique bioinformatics technique developed at the University of Alabama at Birmingham, UAB researchers have detected the emergence of new strains of microbes in the human fecal microbiota after obesity surgery.
These new strains emerged after surgical disruption of the stomach and upper small intestine. In contrast, the researchers found that strains of the human gut fecal microbiota resembled those found pre-surgery following surgery in the colon, which is the lower part of the gastrointestinal, or GI, tract.
The UAB researchers studied patients undergoing two types of obesity surgery — Roux-en-Y gastric bypass and sleeve gastrectomy. In sleeve gastrectomy, the size of the stomach is reduced. Roux-en-Y gastric bypass also reduces the size of the stomach that receives food, but it additionally creates a surgical bypass of the rest of the stomach and the first part of the small intestine.
“Our results show that, when you change the upper GI tract with obesity surgery, you also change the gut environment, resulting in the emergence of new strains of microbes,” said Casey Morrow, Ph.D., leader of the research team and professor emeritus in UAB’s Department of Cell, Developmental and Integrative Biology. “In the microbial competition for nutrients and space in the GI tract, the winners are new strains that are more competitive in the new GI tract environment.”