Research

Hormonal

Roux-en-Y gastric bypass (RYGB) surgery produces distinct circulating metabolite signatures (specifically higher propionate and conjugated bile acids in good responders) that correlate with weight loss response, independent of gut microbiota composition or hunger/satiety hormone levels.

If you are considering or have had gastric bypass surgery, know that 'success' isn't just about how much weight you lose. The surgery changes your body's chemistry (specifically bile acids and gut byproducts like propionate) in ways that might improve your metabolism even if the scale doesn't move as much as expected. This means metabolic health improvements can happen independently of massive weight loss, and tracking these internal markers might be more important than just the number on the scale.

ModerateQualifiesMEDIUM confidence
While fecal and circulating metabolite analyses showed higher levels of propionate (p = 0.0001) in good and valerate (p = 0.04) in bad responders, respectively, conjugated primary and secondary bile acids were higher in good responders in the fasted (p = 0.03) and postprandial state... Differences in weight loss did not reflect in metabolic outcome after RYGB.
Charlotte Fries et al. · Metabolites · 2022

Why this rating

Observational cohort study with a small sample size (n=23) and long post-operative timeframes (4+ years), limiting causal inference regarding the timing of metabolite changes.

Source

Metabolic Profile and Metabolite Analyses in Extreme Weight Responders to Gastric Bypass Surgery

Charlotte Fries et al. · Metabolites · 2022

DOI 10.3390/metabo12050417

cohort · n=23Cited 5×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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