Research
Mixed
Supplementation with Lactobacillus probiotics after Roux-en-Y gastric bypass increases weight loss and reduces bacterial overgrowth compared to placebo.
If you have had Roux-en-Y gastric bypass, taking Lactobacillus probiotics may help you lose more weight and reduce bacterial overgrowth compared to not taking them. This is a specific benefit for surgical patients, not necessarily for the general population. Discuss probiotic supplementation with your surgeon.
GoodSupportsHIGH confidence
Our group showed that, in post-RYGB patients, supplementation with lactobacillus probiotics (phylum Firmicutes) led to greater weight loss and less bacterial overgrowth (as measured by the hydrogen breath test) than in RYGB patients given placebo.
Why this rating
Based on a prospective randomized trial cited in the paper.
Source
The Human Gut Microbiome
Timothy E. Sweeney et al. · JAMA Surgery · 2013
DOI 10.1001/jamasurg.2013.5
narrative_reviewCited 245×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Surgical weight loss via Roux-en-Y gastric bypass (RYGB) induces a distinct gut microbiome shift characterized by a 52-fold increase in phylum Proteobacteria and a decrease in the Firmicutes-to-Bacteroidetes ratio, which correlates with improved insulin sensitivity and weight loss.Moderate
- Obesity is associated with an elevated Firmicutes-to-Bacteroidetes ratio in the gut, which decreases following weight loss, although some studies show conflicting results.Moderate
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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