Combined Analysis of Salivary Metabolomics and Microbiota in Type 1 Diabetics With Xerostomia: A Pilot Study

Given that the oral ecological environment undergoes alterations during the pathological progression of type 1 diabetes mellitus (T1DM) with xerostomia, this study employed microbiomics in conjunction with metabolomics to identify the distinct oral microbiota and salivary metabolites in patients with type 1 diabetic xerostomia and healthy individuals, aiming to elucidate the microorganisms, metabolites, and metabolic pathways potentially implicated in T1DM-associated xerostomia.

Saliva samples were obtained from individuals diagnosed with T1DM and xerostomia (patient group, n = 9) as well as from healthy volunteers (control group, n = 9), and were subsequently subjected to microbiota profiling and untargeted metabolomic analysis. Bioinformatics methodologies were applied to assess the microbiota and metabolomics datasets both independently and integratively.

A total of 88 differential metabolites were identified between the patient and control groups. These metabolites were predominantly enriched in the caffeine and Vitamin B6 metabolic pathways. Additionally, an average of 280 operational taxonomic units (OTUs) were detected, with species diversity found to be lower in the patient group compared to the controls. At the genus level, 20 significantly altered microbial taxa were identified. Differential genera, including Leptotrichia and Corynebacterium, exhibited higher abundance in the patient group, whereas genera such as Haemophilus and Streptococcus were predominantly present in the control group. Correlation analysis indicated that the differential microbiota did not exhibit strong associations with the identified differential metabolites. However, certain oral microorganisms were associated with specific metabolites enriched in the caffeine metabolic pathway.

In summary, the findings demonstrated notable differences in both oral microbiota composition and salivary metabolite profiles between T1DM patients with xerostomia and healthy individuals. Furthermore, a moderate degree of association between the oral microbiome and metabolome was observed, which may serve as a potential biomarker for T1DM-related xerostomia and contribute to the development of targeted therapeutic strategies.