Metagenomic Insights into Gut Microbiota Alterations Following Dendrobium huoshanense Water Extract Intervention in Streptozotocin-Induced Type 1 Diabetic Rats

Dendrobium huoshanense water extract (DHWE) exhibits hypoglycemic effects in streptozotocin-induced type 1 diabetic (STZ-T1D) rats. However, its regulatory impact on the gut microbiota of T1D rats remains largely unclear. In this study, metagenomic sequencing was employed to characterize alterations in the gut microbiota of STZ-T1D rats following DHWE intervention, aiming to explore associations between DHWE-mediated gut microbial changes and T1D-related phenotypes. The results showed that 1300 mg/kg·BW/day DHWE did not significantly affect gut microbial α-diversity (p > 0.05), but drove the β-diversity structure toward that of normal rats. Meanwhile, DHWE significantly reduced the Bacteroidota/Bacillota ratio (p < 0.05), Megamonas (p < 0.01), Megamonas funiformis (p < 0.01), and notably increased the relative abundances of Adlercreutzia (p < 0.01), Adlercreutzia equolifaciens (p < 0.01) in STZ-T1D rats. Furthermore, functional annotation revealed that DHWE enriched multiple metabolic pathways, including streptomycin biosynthesis, ansamycins biosynthesis, galactose metabolism, ether lipid metabolism, and caprolactam degradation. Collectively, these findings demonstrate that DHWE reshapes gut microbiota composition and function in STZ-T1D rats, offering new clues regarding how gut microbial changes may contribute to the modulatory effects of Dendrobium huoshanense in T1D conditions.