Research

Mixed

Obesity and overweight are associated with a gut microbiota profile characterized by a significantly higher Firmicutes-to-Bacteroidetes ratio, increased abundance of SCFA-producing Firmicutes taxa (e.g., Lachnospiraceae, Ruminococcus gnavus), and decreased abundance of Bacteroidetes taxa (e.g., Bacteroides uniformis, Flavobacteriaceae).

Your gut bacteria composition changes with obesity, specifically showing more Firmicutes and fewer Bacteroidetes. This isn't just a side effect; these bacteria influence how you harvest energy and store fat. To shift your microbiome toward a healthier profile, focus on increasing dietary fiber intake and physical activity, which are associated with higher Bacteroidetes abundance and lower Firmicutes dominance.

GoodSupportsHIGH confidence
The gut microbial community of OB patients exhibited a significant decrease in the relative abundance of several Bacteroidetes taxa... instead, several Firmicutes taxa were significantly increased in the same subjects... The Firmicutes/Bacteroidetes ratio... was significantly higher in OB, with a value more than twice that of NW
Vanessa Palmas et al. · Scientific Reports · 2021

Why this rating

Large sample size for a microbiome study (n=92), rigorous statistical controls (PERMANOVA, LEfSe, MaAsLin), but observational design limits causal inference.

Source

Gut microbiota markers associated with obesity and overweight in Italian adults

Vanessa Palmas et al. · Scientific Reports · 2021

DOI 10.1038/s41598-021-84928-w

cross_sectional · n=92Cited 375×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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