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

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. We evaluated the metabolic capabilities of the gut microbiome of twelve T2DM and six healthy individuals through shotgun metagenomics using MiSeq platform. 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 P6.5%) 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 (