Metabolomic changes may explain kidney protection benefits after bariatric surgery

Bariatric surgery appears to contribute to several glomerular filtration rate (GFR)-independent metabolomic changes, which potentially explain the beneficial kidney effects of this procedure, suggests a recent study.

Twenty-seven adults with severe obesity who underwent bariatric surgery were included in this prospective, single-centre study. The research team performed serum metabolomics and measured GFR (mGFR) 1‒3 months prior to and 6 months after surgery. They used generalized estimating equation models to explore serum metabolite changes and MetaboAnalyst to conduct pathway analyses.

After adjustments, bariatric surgery showed a significant association with changes in 223 serum metabolites.

Several pathways were either downregulated (alpha-linoleic acid and linoleic acid, methionine, kynurenine, and alanine-glucose metabolism pathways; raw p<0.05) or upregulated (phenylacetate, bile acid biosynthesis, taurine and hypo-taurine metabolism, porphyrin metabolism pathways; raw p<0.05) after undergoing bariatric surgery.

Following surgery, creatinine also displayed a significant reduction independent of mGFR. N,N,N-trimethyl-alanyl proline betaine was the leading metabolite that had a significant association with mGFR, followed by creatinine.

“We discovered several GFR-independent metabolomic changes after bariatric surgery which may underlie its beneficial kidney effects including decreased inflammation, oxidation, and insulin resistance,” the researchers said. “Further studies are needed to investigate the potential mechanistic role of identified metabolites to clarify mechanisms of obesity-related kidney disease.”