Metagenomic Analysis of the Gut Microbiome Reveals Enrichment of Menaquinones (Vitamin K2) Pathway in Diabetes Mellitus

Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with a high prevalence worldwide, especially among overweight and obese populations. T2DM is multifactorial with several genetic and acquired risk factors that lead to insulin resistance. Mounting evidence indicates that alteration of gut microbiome composition contribute to insulin resistance and inflammation. However, the precise link between T2DM and gut microbiome role and composition remains unknown. Methods: We evaluated the metabolic capabilities of the gut microbiome of twelve T2DM and six healthy individuals through shotgun metagenomics using MiSeq platform. Results: We identified no significant differences in the overall taxonomic composition between healthy and T2DM subjects when controlling for differences in diet. However, results showed that T2DM enriched in metabolic pathways involved in menaquinone (vitamin K2) superpathway biosynthesis (PWY-5838) as compared to healthy individuals. Covariance analysis between the bacterial genera and metabolic pathways displaying difference in abundance (analysis of variance P<0.05) in T2DM as compared to healthy subjects revealed that genera belonging Firmicutes, Actinobacteria, and Bacteroidetes phyla contribute significantly to vitamin K2 biosynthesis. Further, the microbiome corresponding to T2DM with high glycosylated hemoglobin (HbA1c) (>6.5%) exhibit high abundance of genes involved in lysine biosynthesis and low abundance of genes involved in creatinine degradation as compared to T2DM with lower HbA1c (<6.5%). Conclusion: The identified differences in metabolic capabilities provide important information that may eventually lead to the development of novel biomarkers and more effective management strategies to treat T2DM.

Automated summary

The study found that Gut microbiome of T2DM patients are enriched in metabolic pathways associated with vitamin K2 biosynthesis, which may be related to insulin resistance. T2DM patients with high glycosylated hemoglobin levels have different gene abundances in metabolic pathways, which could be significant for the development of new biomarkers and better management strategies for T2DM in the future.