Research

Mixed

Obesity is associated with a gut microbiota composition characterized by a lower proportion of Bacteroidetes and a higher proportion of Firmicutes compared to lean individuals, a pattern observed in both murine models and human studies.

Focus on a diverse, fiber-rich diet rather than trying to target specific bacterial ratios, as the relationship between microbiota and obesity is complex and not fully understood in humans. Dietary patterns that support microbial diversity (e.g., high fiber) are more actionable than trying to manipulate specific phyla ratios.

ModerateSupportsMEDIUM confidence
obese individuals possessing a lower proportion of Bacteroidetes and higher levels of Firmicutes than their lean counterparts, thus resembling the patterns established in previous murine studies.
Siobhan F. Clarke et al. · Gut Microbes · 2012

Why this rating

The paper reviews multiple studies showing consistent trends in animals and some in humans, but also highlights conflicting human data and lack of statistical significance in some cohorts.

Source

The gut microbiota and its relationship to diet and obesity

Siobhan F. Clarke et al. · Gut Microbes · 2012

DOI 10.4161/gmic.20168

narrative_reviewCited 460×
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DOI resolved against Crossref · corpus check 2026-06-10

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