Research

Hormonal

Metformin's primary glucose-lowering mechanism involves altering gut microbiota composition to increase butyrate and propionate production and enhance GLP-1 secretion, rather than solely acting via hepatic pathways.

If you take metformin, its effectiveness is partly driven by how it changes your gut bacteria to boost GLP-1. If you experience stomach issues, ask about delayed-release formulations (MetDR) which target the lower gut specifically, potentially reducing side effects while maintaining efficacy.

GoodSupportsHIGH confidence
the pharmacological action of metformin was observed to include alterations in bile acid recirculation and gut microbiota, resulting in enhanced glucagon-like polypeptide-1 (GLP-1) secretion
Louise Brunkwall et al. · Diabetologia · 2017

Why this rating

Supported by multiple human studies, meta-analyses, and delayed-release trials, though the paper notes large-scale Phase III trials are still needed for the specific delayed-release formulation.

Source

The gut microbiome as a target for prevention and treatment of hyperglycaemia in type 2 diabetes: from current human evidence to future possibilities

Louise Brunkwall et al. · Diabetologia · 2017

DOI 10.1007/s00125-017-4278-3

narrative_reviewCited 355×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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