Search bioRxiv⌕ Search

bioRxiv · 10.64898/2026.01.09.697679

Gut-derived GLP-1 released by rare sugar D-allulose cooperates with insulin to activate left-sided vagal afferents and enhance insulin sensitivity

Abstract

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) ameliorate hyperglycemia by directly stimulating insulin secretion from the pancreas. In contrast, the physiological role of short-lived endogenous GLP-1 remains unclear, largely because of its limited access to pancreatic {beta} cells. Here, we show that D-allulose-induced intestinal GLP-1 secretion (AIGS) cooperates with insulin to reduce blood glucose levels by enhancing insulin action, rather than insulin secretion, in male mice. This cooperation and remote signaling require left-sided vagal afferents forming the common hepatic branch, but not right-sided afferents. AIGS-enhanced insulin action required both GLP-1 receptors and insulin receptor substrate 2 in these neurons. Remarkably, AIGS improved insulin resistance and hyperglycemia more rapidly and potently than the GLP-1RA exendin-4. These findings reveal that a subclass of vagal afferent neurons synergistically activated by endogenous intestinal GLP-1 and insulin does not stimulate insulin secretion but augments insulin action to improve glucose tolerance. This novel extra-pancreatic GLP-1 action mediated by vagal afferents provides a promising basis for innovative type 2 diabetes therapies. ARTICLE HIGHLIGHTO_LICompared with GLP-1 receptor agonists, the physiological roles and mechanisms of endogenous, short-lived GLP-1 in glucose metabolism remain poorly understood. C_LIO_LIWe utilized the rare sugar D-allulose, a noncaloric GLP-1 secretagogue, as a tool to elucidate the physiological actions of endogenous GLP-1. C_LIO_LID-allulose-induced intestinal GLP-1 release cooperates with insulin to activate left-sided vagal afferents, enhancing insulin action rather than insulin secretion and thereby regulating glycemic control. C_LIO_LIBecause this acute mechanism improved hyperglycemia in type 2 diabetes more effectively than GLP-1 receptor agonists, targeting GLP-1/insulin-vagal signaling may inform novel therapies and dietary or nutritional interventions for T2DM. C_LI

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ohbayashi, K., Tanida, M., Abe, C., Ishihara, H., Omi, W., Kubota, N., Drucker, D. J., Yada, T., Iwasaki, Y.. 2026-01-09. Gut-derived GLP-1 released by rare sugar D-allulose cooperates with insulin to activate left-sided vagal afferents and enhance insulin sensitivity. https://doi.org/10.64898/2026.01.09.697679

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

The canine hair metabolome encodes age and coat exposure in over 700 dogs

Hair can be collected noninvasively and stored for years, making it a practical sample for studying physiology and environmental exposure. Yet the chemical information it carries in dogs remains largely unexplored. We profiled 782 banked hair samples from 700 Golden Retrievers by untargeted liquid chromatography-mass spectrometry, detecting 4,533 compound groups and revealing an unexpectedly rich chemical profile. Prominent signals reflected skin-surface and hair chemistry, including amino acids, peptides and urocanic acid, alongside surfactants, plasticizers and pesticides detectable despite washing. A signal annotated as imidacloprid distinguished dogs receiving topical products containing this insecticide from dogs receiving no flea or tick preventive (AUC 0.865). Hair chemistry also varied with age, most strongly between puppyhood and early adulthood. Oxidized lipids generally declined, whereas amino acids and peptides remained largely stable. A multivariate model estimated age with moderate accuracy (cross-validated r = 0.66) and assigned a higher age to the later sample in 64 of 75 repeatedly sampled dogs. Because age and collection date were strongly correlated, their effects could not be fully separated, although date-restricted analyses supported an age-related contribution. Together, these findings establish banked dog hair as a promising resource for studying chemical exposure and life-stage-associated changes in chemistry.

physiology↗

Dietary Human HSP90 Promotes Longevity and Healthspan in Caenorhabditis elegans via a Multi-Branched Stress Signaling Pathway

The loss of proteostasis is one of the primary drivers of aging. Despite the important role of the molecular chaperone HSP90 in maintaining proteostasis, its systemic role in aging appears contradictory because its inhibitors can effectively extend lifespan across diverse species. This study showed that dietary HSP90 supplementation via Escherichia coli significantly extended lifespan and healthspan of Caenorhabditis elegans without fertility trade-offs. Exogenous HSP90 likely acts as an extracellular signaling ligand that engages downstream kinase networks to drive the activation of three major longevity-associated transcription factors: DAF-16, SKN-1, and HSF-1. In addition, we demonstrated the additive effect of combining dietary HSP90 supplementation with the senolytic HSP90 inhibitor tanespimycin, indicating that extracellular proteostatic signaling and the intracellular inhibition of HSP90 can work together to enhance longevity. Finally, we engineered an antibiotic-free E. coli Nissle 1917 probiotic that constitutively expresses HSP90, which successfully extended the lifespan of C. elegans.

physiology↗

Sex differences in myocardial ketone oxidation capacity in cardiometabolic disease with coincident ischemic heart disease

Background: Myocardial infarction (MI) in patients with heart failure with preserved ejection fraction (HFpEF) is associated with worse outcomes than MI in individuals without HFpEF. However, the molecular mechanisms underlying this increased vulnerability remain poorly understood. We investigated sex differences in cardiac ketone body (KB) metabolism in patients with diabetes-associated ischemic heart disease, and in a mouse model of HFpEF complicated by MI (HFpEF-MI). Methods: Cardiac BDH1 and OXCT1 expression was assessed in male and female patients with diabetes, with or without ischemic heart disease. Male and female mice received a high-fat diet and L-NAME for 10 weeks to induce HFpEF, followed by coronary artery ligation to induce MI. Glucose tolerance, cardiac function, survival, cardiac KB oxidative capacity, and circulating KB levels were evaluated. Results: Cardiac BDH1 and OXCT1 abundance was significantly reduced in male patients with diabetes-associated ischemic heart disease but preserved in female patients. In mice, 10 weeks of high-fat diet and L-NAME administration increased fasting blood glucose and impaired glucose tolerance. MI reduced systolic function in control and HFpEF mice of both sexes. Male HFpEF-MI mice exhibited higher mortality than female HFpEF-MI mice. Consistent with our human results, male HFpEF-MI mice showed reduced cardiac ketolytic enzyme expression alongside elevated circulating KB levels, whereas female mice maintained cardiac KB oxidative capacity. Conclusion: Reduced cardiac ketolytic enzyme expression and impaired KB oxidative capacity are associated with greater mortality in male HFpEF-MI mice, whereas female mice exhibit preserved KB oxidative capacity and improved survival. Similar sex differences in ketolytic enzyme expression were observed in patients with diabetes-associated ischemic heart disease. These findings identify cardiac ketone metabolism as a potential therapeutic target warranting further investigation in HFpEF complicated by MI.

physiology↗