Supplements · Metabolic & Cardiometabolic · Gut & Microbiome
Does a probiotic raise an appetite-and-blood-sugar hormone?
The claim, precisely: Lactobacillus reuteri increases GLP-1
Yes in one small human trial, but it rests on just 21 people and didn't improve insulin sensitivity or weight.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
L. reuteri SD5865 raised GLP-1 and GLP-2 release and insulin/incretin secretion in glucose-tolerant adults — the single best human-grade taxon->GLP-1 signal, but n=21 and no change in insulin sensitivity or weight.
The evidence (3)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Simon MC, et al. (Holst) 2015 · Diabetes Care | RCT | supports | moderate | n=21 RCT: increased GLP-1/GLP-2 and insulin/C-peptide secretion (Holst-lab assays); no change in IS or weight |
| Simon MC, et al. (Holst) 2015 · Diabetes Care | RCT | supports | moderate | [FT-verified] SD5865 DB-RCT n=21 +76% GLP-1 P<.01 +49% insulin; key human positive |
| Zeng 2024 · mBio | mechanism | supports | low | [FT-verified] mBio review microbiota-GLP1 crosstalk; mechanistic only |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.