Chewing Well During Meals May Benefit Health Via the Enterosalivary Nitrate–Nitrite–Nitric Oxide Pathway

Abstract

Saliva contains nitrates recycled from ingested foods (e.g., vegetables) via the enterosalivary pathway. During meals, thorough chewing enhances salivary flow and the reduction of salivary nitrate to nitrite by oral commensal bacteria and thus leads to a nitrite-rich gastric environment. Subsequently, nitric oxide (NO) and S-nitrosothiols, rather than N-nitroso compounds, are generated in the acidic stomach. These molecules may confer gastric and systemic health benefits by transducing NO-mediated signals, particularly in patients with vascular endothelial dysfunction and metabolic syndrome, which is associated with reduced endogenous NO generation consequent to impaired NO synthase activity. This article reviews literature suggesting that the thorough chewing of food produces a nitrite-rich gastric environment and promotes health benefits by enhancing NO bioavailability via the enterosalivary nitrate-nitrite-NO pathway.