The nitrate (NO3)-nitrite (NO2)-nitric oxide (NO) pathway, as a storage reservoir for endogenous NO production, is dependent on the oral bacteria with NO3- reducing capacity. Undesirable changes of oral microbiota towards a decreased load of health-related NO3-reducing bacteria and an overgrowth of pathogenic species, leading to subsequent decreased NO2 production in the oral cavity and decreased systemic NO availability, are now considered risk factors for the development of insulin resistance and type 2 diabetes (T2D). This chapter discusses available evidence focusing on oral microbiota dysbiosis in T2D, especially NO3-reducing bacteria and their metabolic activity (including NO3-reductase and NO2-reductase activity), affecting net oral NO2 accumulation and the NO3-NO2-NO pathway.
Keywords: Nitrate, Nitrite, Nitric oxide, Nitrate reductase, Nitrite reductase, Oral microbiota, Type 2 diabetes.
