Weight-focused trials found limited evidence of changes in overall gut microbiome diversity
A systematic review found some changes in specific bacterial groups, but little clear evidence connecting microbiome changes to lasting weight or metabolic improvements.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Most interventions did not produce statistically significant changes in overall microbial diversity. The review did find associations between some supplements and particular bacterial groups, and probiotic intake was associated with lower body weight and body fat. Those observations do not establish that changing the microbiome caused weight loss or produced lasting metabolic improvements.
Methods and outcomes varied widely, and the abstract does not provide pooled effect sizes. The authors called for standardized methods and reporting before confirmation through meta-analysis; a causal link to lasting benefits remains uncertain.
Specific bacteria and overall diversity differed
Prebiotic consumption was associated with greater abundance of Actinobacteria and Bifidobacterium, while probiotics were associated with more Lactobacillus. These shifts in named bacterial groups occurred alongside mostly nonsignificant findings for overall microbiome diversity.
The proposed pathway remains unproven
The review found no strong evidence linking short-chain fatty acid levels, gut microbes and obesity. It also emphasized limited causal evidence for microbiome changes leading to sustained weight loss or metabolic improvements.
The original publication
Impacts of Lifestyle and Microbiota-Targeted Interventions for Overweight and Obesity on the Human Gut Microbiome: A Systematic Review.
Lee YT, Akan A, Önel DB et al.
Obes Rev · 2026
- PubMed ID
- 41372103
- Record checked
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