Supplements · Metabolic & Cardiometabolic · Gut & Microbiome
Lactobacillus reuteri increases GLP-1
In plain terms: Does the probiotic L. reuteri raise the appetite-and-blood-sugar hormone GLP-1?
Yes in one small human trial, but it rests on just 21 people and didn't improve insulin sensitivity or weight.
📅 Last reviewed: 2026-07-15 ⓘ
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 (9)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Hsieh FC, Lee CL, Chai CY, Chen WT, Lu YC, Wu CS 2013 · Nutr Metab | animal | supports | low | L. reuteri GMNL-263 improved insulin resistance in high-fructose rats (GLP-1 indirect) |
| Natividad JM, Agus A, Planchais J, Lamas B, Jarry AC, Martin R, Michel ML, Chong-Nguyen C, Roussel R, Straube M, Jegou S, McQuitty C, Le Gall M, da Costa G, Lecornet E, Michaudel C, Modoux M, Glodt J, Bridonneau C, Sovran B, Dupraz L, Bado A, Richard ML, Langella P, Hansel B, Launay JM, Xavier RJ, Duboc H, Sokol H 2018 · Cell Metabolism | animal | supports | moderate | AhR-ligand Lactobacillus strain improves glucose dysmetabolism in mice via enhanced intestinal GLP-1 secretion |
| Nilsson A, Johansson-Boll E, Sandberg J, Björck I 2016 · Clin Nutr ESPEN | RCT | mixed | low | Commercial probiotic mix (incl lactobacilli) did not consistently augment barley-induced GLP-1 in humans |
| Verma S, Mishra AK, Mishra A, Y Thajudeen K, Singh H, Khan G 2026 · Probiotics Antimicrob Proteins | observational | mixed | low | Systematic review finds skin-derived Bifidobacterium (not L. reuteri) can stimulate GLP-1, indirect and off-organism support only. |
| Lai TT, Tsai YH, Liou CW, Fan CH, Hou YT, Yao TH, Chuang HL, Wu WL 2024 · npj Biofilms Microbiomes | animal | contradicts | moderate | Colonizing L. reuteri in microbiota-deficient mice SUPPRESSED elevated GLP-1 (directionally opposite the claim) |
| Wang JX, Chang SY, Jin ZY, Li D, Zhu J, Luo ZB, Han SZ, Kang JD, Quan LH 2025 · Journal of agricultural and food chemistry | animal | mixed | moderate | L. reuteri gavage in HFD/db-db mice raised fecal eicosatrienoic acid, which promoted GLP-1 secretion via CD36/PLC/IP3R/Ca2+ in intestinal cells, improving glucose homeostasis; in-vitro STC-1 cells confirmed. |
| Simon MC, Strassburger K, Nowotny B, Kolb H, Nowotny P, Burkart V, Zivehe F, Hwang JH, Stehle P, Pacini G, Hartmann B, Holst JJ, MacKenzie C, Bindels LB, Martinez I, Walter J, Henrich B, Schloot NC, Roden M 2015 · Diabetes Care | RCT | supports | moderate | SD5865 DB-RCT n=21 +76% GLP-1 P<.01 +49% insulin; key human positive |
| Zeng Y, Wu Y, Zhang Q, Xiao X 2024 · mBio | observational | supports | low | [FT-verified] mBio review microbiota-GLP1 crosstalk; mechanistic only |
| Tenorio-Jiménez C, Martínez-Ramírez MJ, Tercero-Lozano M, Arraiza-Irigoyen C, Del Castillo-Codes I, Olza J, Plaza-Díaz J, Fontana L, Migueles JH, Olivares M, Gil Á, Gomez-Llorente C 2018 · BMC Complement Altern Med | RCT | tested-null | low | RCT of L. reuteri V3401 in obese metabolic-syndrome adults found no significant improvement in insulin-resistance/incretin markers, tempering the GLP-1 claim. |
Disagree, or know a study we missed?
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.