Research

Hormonal

Metformin treatment alters gut microbiota composition (increasing Escherichia coli and decreasing Intestinibacter bartlettii) to enhance the production of short-chain fatty acids (propionate and butyrate) and modulate bile acid pools, which mediates glucose-lowering effects.

If you take metformin, your gut bacteria are actively helping lower your blood sugar by producing beneficial fatty acids. This is a key part of how the drug works, though it can cause temporary stomach upset for some people.

GoodSupportsHIGH confidence
Support for the causal effects of these GM differences in type 2 diabetes has been provided by randomized trials and studies in drug-naive individuals demonstrating that the GM compositional changes translate to enhanced production of propionate and butyrate (20,21) and modulation of bile acid pools (21), which may mediate some of the glucose-lowering effects of metformin (Fig. 3) (20–22,24).
Mariana X. Byndloss et al. · Diabetes · 2024

Why this rating

Supported by randomized trials and large metagenomic studies, though individual variability exists.

Source

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications—2023 <i>Diabetes</i>, <i>Diabetes Care</i>, and <i>Diabetologia</i> Expert Forum

Mariana X. Byndloss et al. · Diabetes · 2024

DOI 10.2337/dbi24-0028

narrative_reviewCited 17×
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DOI resolved against Crossref · corpus check 2026-06-10

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