When diabetes is caused by a damaged pancreas, it's not just about insulin. A new study looked at the gut bacteria of people with this type of diabetes, called type 3c, and compared them to people with type 1 diabetes and healthy people. They found the gut's bacterial community in type 3c diabetes is less diverse and has a distinct makeup. Specifically, two families of bacteria—Escherichia-Shigella and Streptococcus—were more common. Using a statistical model, the researchers could tell the difference between type 3c and type 1 diabetes with good accuracy based on the levels of five key bacteria. Their analysis suggests these bacterial changes are primarily linked to the pancreas not producing enough digestive enzymes, a condition called exocrine pancreatic insufficiency. This means the gut microbiome shifts in this form of diabetes seem to be driven more by the direct effects of the damaged pancreas on digestion, rather than by the general metabolic disturbances of diabetes itself.
Could gut bacteria reveal a hidden cause of diabetes? Study finds specific microbes linked to pancreatic damage.
Plain Language Summary
What this means for you:
In a form of diabetes caused by pancreatic damage, the gut microbiome changes appear to be driven by the pancreas itself, not just high blood sugar. What this means for you:
In a form of diabetes caused by pancreatic damage, the gut microbiome changes appear to be driven by the pancreas itself, not just high blood sugar. View Original Abstract ↓
Emerging evidence supports a bidirectional gut–pancreas axis in which microbial dysbiosis, barrier dysfunction, and altered metabolite fluxes contribute to pancreatogenic diabetes (T3cDM). Whether gut microbial changes reflect systemic metabolic disturbances or primarily arise from exocrine pancreatic insufficiency (EPI) remains unclear. We profiled the gut microbiome of 48 outpatients with T3cDM, type 1 diabetes (T1DM), and healthy controls. Genus-level 16S rRNA data were analyzed using cross-validated LASSO logistic regression and patient-specific community metabolic models. T3cDM showed reduced α-diversity and distinct β-diversity compared with T1DM and controls. Key compositional shifts included enrichment of Enterobacteriaceae (notably Escherichia–Shigella) and Streptococcaceae in T3cDM. LASSO models discriminated T3cDM from T1DM (AUC 0.867; accuracy 0.818), highlighting Blautia, Escherichia–Shigella, Streptococcus, Clostridium, and Faecalibacterium as predictors. Metabolic modelling indicated elevated Escherichia–Shigella growth in T3cDM and disease-specific metabolite fluxes. Gut microbial shifts in T3cDM predominantly reflect EPI rather than systemic metabolic disturbances characteristic of T1DM, underscoring the central role of exocrine pancreatic dysfunction in shaping the gut microbiome and its metabolic activity.