A cross-sectional study conducted by Professor Li Xia’s research team from the Second Xiangya Hospital of Central South University was published online in the journal Cardiovascular Diabetology. By integrating oral and gut microbiota analyses, this study reveals the association between microbiota dysbiosis and chronic vascular complications in patients with long-duration type 1 diabetes (T1D), providing novel perspectives for relevant therapeutic strategies and mechanistic research. The co-first authors of this study are Tang Rong and Shi Mei, and the corresponding author is Professor Li Xia.
As the largest microbial community in the human body, the gut microbiota has been proven to participate in the pathogenesis of T1D by regulating immunity and intestinal permeability. However, its role in the long-term chronic course of T1D remains unclear. As the second-largest microbial community, the oral microbiota is regarded as a potential upstream source of the gut microbiota. Studies have confirmed that oral microbiota dysbiosis exists in the early stage of T1D, and periodontitis, a manifestation of oral microbiota dysbiosis, is independently associated with multiple chronic diabetic complications. The “oral-gut” microbial axis has been proven to play a crucial role in various systemic diseases such as rheumatoid arthritis and hypertension. Nevertheless, its function in the long-term course of T1D has not been explored, especially its impact on the occurrence and development of chronic T1D complications, which is currently unclear and often overlooked, necessitating in-depth investigation.
The study results definitively identified 26 gut microbiota and 8 oral microbiota associated with T1D vascular complications. Among them, butyrate-producing gut bacteria (such as Blautia wexlerae, Anaerobutyricum hallii, and Roseburia inulinivorans) and specific oral Neisseria species were enriched in T1D individuals without complications but significantly depleted in patients with complications, indicating their protective effects.
Multiple complication-related gut microbes were correlated with blood glucose and insulin resistance indicators (HbA1c, TIR, HGI, GRI, eGDR). Mediation analysis revealed that specific gut and oral microbiota may partially mediate the impact of metabolic disorders on complications, supporting the existence of the “metabolism-microbiota-complication” axis.
Models integrating oral-gut microbiota signatures significantly outperformed single-site (oral-only or gut-only) microbiota models in distinguishing T1D complications.
Predictive models combining oral and gut microbiota signatures can serve as non-invasive risk stratification tools, offering novel targets for the prevention and treatment of T1D vascular complications. In summary, these findings highlight the potential of microbiota-targeted strategies in preventing T1D-related complications and lay the foundation for developing microbiome-based risk prediction and intervention approaches.