Metabolic & Cardiometabolic · Gut & Microbiome
Akkermansia muciniphila P9 protein induces GLP-1
In plain terms: Can a protein from the gut microbe Akkermansia trigger release of the blood-sugar hormone GLP-1?
Yes, but only shown in animals and lab cells so far, never in people.
📅 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
A. muciniphila's secreted P9 protein induces GLP-1 from L-cells (ICAM-2/IL-6-dependent) and improves glucose tolerance in mice; independently reproduced in vitro. Mouse + cell-line only — no human GLP-1 evidence, and the bacterium is not encouraged by bread starch directly (it feeds on mucin).
The evidence (14)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Cani PD, Knauf C 2021 · Cell Metab | mechanism | supports | moderate | Cani commentary affirms P9->GLP-1; COI authors hold A.muciniphila/A-Mansia patents; commentary not data |
| Safari F, Golafshan F, Malekpour E, Mirzaei SA, Rouzbahani H, Hajarzadeh MO, Nasir Harandi S, Nasirharandi S, Noursina A 2025 · Probiotics Antimicrob Proteins | mechanism | supports | low | Review: Amuc_1631 (P9) enhances glucose homeostasis by promoting GLP-1 secretion, linking gut microbiota to metabolic regulation. |
| Depommier C, Everard A, Druart C, Plovier H, Van Hul M, Vieira-Silva S, Falony G, Raes J, Maiter D, Delzenne NM, de Barsy M, Loumaye A, Hermans MP, Thissen JP, de Vos WM, Cani PD 2019 · Nat Med | RCT | tested-null | moderate | Proof-of-concept human supplementation of A. muciniphila improved insulin sensitivity/markers; organism whose P9 secretion is proposed GLP-1 mediator. |
| Di W, Bai X, Tian S, Zhao L, Cao X, Hao Y, Zhai Z 2025 · 3 Biotech | in-vitro | supports | moderate | Engineered L. lactis secreting A. muciniphila P9 stimulated GLP-1 (GCG/PCSK1 up) in NCI-H716 L-cells; anti-obesity potential in HFD mice. |
| Dinkov B 2026 · Biomedicines | mechanism | supports | low | Narrative review, not evidence: 'a narrative review format was selected and no formal risk of bias assessment was performed.' Re-describes the P9 primary: 'In cell cultures of enteroendocrine L-cells, purified P9 protein can independently induce secretion of glucagon-like peptide-1 (GLP-1) [ 18 ].' Review — zero weight. |
| Han Y, Lu J, Bu X, Hu L, Niu C, Qiao J, Wu H, Caiyin Q 2026 · Microorganisms | in-vitro | supports | moderate | Narrative review: 'This review summarizes the disease-associated proteins of A. muciniphila reported to date', including P9 (Amuc_1631) acting via ICAM-2 on GLP-1 secretion, cited to ref 8. Review — zero weight. |
| Suenaert P, Segers A, Rymenans L, Devroye H, Moll JM, Cani PD, de Vos WM 2026 · Gut Microbes | RCT | supports | moderate | Pasteurized A. muciniphila in humans modulated metabolic endpoints consistent with P9/Amuc-driven GLP-1 axis; downstream clinical readout of the mechanism. |
| Long Z, Li J, Zhu F, Liu X, Zhou J, Li J, Xu W 2026 · Int J Biol Macromol | mechanism | supports | low | Mechanistic review: P9 mediates host metabolism through ICAM-2/IL-6 signaling driving GLP-1 secretion; biomanufacturing and delivery advances. |
| Yoon HS, Cho CH, Yun MS, Jang SJ, You HJ, Kim JH, Han D, Cha KH, Moon SH, Lee K, Kim YJ, Lee SJ, Nam TW, Ko G 2021 · Nat Microbiol | animal | supports | moderate | Yoon 2021 NatMicro P9 induces GLP-1, improves glucose in mice (ICAM-2/IL-6). ANIMAL-ONLY species caveat |
| Di W, Zhang Y, Zhang X, Han L, Zhao L, Hao Y, Zhai Z 2024 · World J Microbiol Biotechnol | in-vitro | supports | moderate | Di 2024 recombinant L.lactis P9 raised GCG/PCSK1 1.5-1.6x in NCI-H716; independent in-vitro |
| Arukha AP, Nayak S, Swain DM 2025 · Nutrients | in-vitro | mixed | low | VH A. muciniphila (Vidya Strain) bacterial cell extracts produced a dose-dependent, >2000% rise in GLP-1 secretion from NCI-H716 L-cells and a modest increase in insulin secretion from INS-1 beta cells. |
| Mazhar M, Zhu Y, Qin L 2023 · Foods | observational | tested-null | low | Narrative review: 'This review focuses on the effectiveness of dietary fiber in producing SCFAs'; GLP-1 point is SCFA-mediated ('SCFAs either enhance the release of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) from L-cells'), not the Akkermansia P9 protein. Review — zero weight (matches two sibling rows). |
| Nauck MA, Quast DR, Wefers J, Pfeiffer AFH 2021 · Diabetes Obes Metab | mechanism | supports | high | Establishes L-cell GLP-1 secretion physiology underpinning claim that a secreted bacterial protein acting on L-cells raises GLP-1. |
| He K, An F, Zhang H, Yan D, Li T, Wu J, Wu R 2024 · Foods | observational | supports | low | A. muciniphila functional-component review summarizing P9-mediated GLP-1 stimulation and glucose-homeostasis benefits. |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
Opens a short form. You'll sign in with Google so submissions are tied to a real account — we don't display your identity, and we only accept a link we can verify (PubMed, DOI, ClinicalTrials.gov).
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.