Two types of weight-loss surgeries lead to shifts in patients' gut microbiomes, researchers from the University of Gothenburg report in Cell Metabolism.
Using shotgun metagenomic sequencing, Gothenburg's Fredrik Bäckhed and his colleagues examined the fecal microbiomes of 14 women with stable weights nine years after their surgeries and those of women matched to patients' pre- and post-surgery BMI. Half of the patients underwent Roux-en-Y gastric bypass and half vertical banded gastroplasty.
From this, they found that both procedures led to changes in patients' gut microbiomes. Patients who underwent Roux-en-Y gastric bypass had higher levels of Gammaproteobacteria and of Escherichia, Klebsiella, and Pseudomonas, but lower levels of Clostridium difficile, Clostridium hiranonis, and Gemella sanguinis.
The researchers also noted changes in the gene content of the gut microbiomes of women who underwent surgery as compared to those who did not. In particular, they found they harbored an enrichment of genes implicated in fatty acid metabolism, nitrogen metabolism, and the two-component system, among other processes.
Further, the researchers report that germ-free mice treated with stool samples from women who underwent surgery could better metabolize fat than mice that received samples from controls.
"Our findings are important in light of the growing epidemic of obesity and associated diseases," Bäckhed says in a statement. "Since surgery always confers a risk, it is critical to identify non-surgical strategies. One potential strategy would be to devise novel probiotics based on our findings that can be supplied to obese individuals."