Mixed
Long-term Roux-en-Y gastric bypass (RYGB) and vertical banded gastroplasty (VBG) induce durable, BMI-independent alterations in the gut microbiome that causally reduce fat mass deposition and shift host metabolism toward lipid oxidation.
Bariatric surgery (RYGB/VBG) causes long-lasting changes to gut bacteria that actively reduce fat storage and shift the body to burn more fat for energy. These changes persist for years and are not just due to eating less. The microbiome plays a direct causal role in reducing adiposity, independent of final BMI.
Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery... mice colonized with RYGB and VBG microbiota for 2 weeks accumulated 43% and 26% less body fat, respectively, than mice colonized with OBS microbiota
Why this rating
High-quality human observational data paired with causal germ-free mouse transplantation experiments, though the human cohort is small (n=14).
Source
Roux-en-Y Gastric Bypass and Vertical Banded Gastroplasty Induce Long-Term Changes on the Human Gut Microbiome Contributing to Fat Mass Regulation
Valentina Tremaroli et al. · Cell Metabolism · 2015
DOI 10.1016/j.cmet.2015.07.009
Related findings · Mixed
- Bariatric surgery (VSG and RYGB) is the most effective and sustainable treatment for obesity, producing marked and sustained weight loss that non-surgical interventions cannot match.Strong
- Severely protein-deficient diets (2–3% energy) induce lean body mass loss and metabolic imbalance, whereas adequate protein intake (0.66 g/kg/d minimum) is a prerequisite for maintaining muscle, bone, and physiological function.Strong
- For patients with Class III obesity (BMI >39.9 kg/m2), metabolic bariatric surgery (MBS) is significantly more effective than any currently approved medication, with BilioPancreatic Diversion (BPD) showing the highest estimated weight loss.Strong
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