title: Enterosalivary nitrate metabolism and the microbiome: Intersection of microbial metabolism, nitric oxide and diet in cardiac and pulmonary vascular health.
abstract: Recent insights into the bioactivation and signaling actions of inorganic, dietary nitrate and nitrite now suggest a critical role for the microbiome in the development of cardiac and pulmonary vascular diseases. Once thought to be the inert, end-products of endothelial-derived nitric oxide (NO) heme-oxidation, nitrate and nitrite are now considered major sources of exogenous NO that exhibit enhanced vasoactive signaling activity under conditions of hypoxia and stress. The bioavailability of nitrate and nitrite depend on the enzymatic reduction of nitrate to nitrite by a unique set of bacterial nitrate reductase enzymes possessed by specific bacterial populations in the mammalian mouth and gut. The pathogenesis of pulmonary hypertension (PH), obesity, hypertension and CVD are linked to defects in NO signaling, suggesting a role for commensal oral bacteria to shape the development of PH through the formation of nitrite, NO and other bioactive nitrogen oxides. Oral supplementation with inorganic nitrate or nitrate-containing foods exert pleiotropic, beneficial vascular effects in the setting of inflammation, endothelial dysfunction, ischemia-reperfusion injury and in pre-clinical models of PH, while traditional high-nitrate dietary patterns are associated with beneficial outcomes in hypertension, obesity and CVD. These observations highlight the potential of the microbiome in the development of novel nitrate- and nitrite-based therapeutics for PH, CVD and their risk factors.
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA. Electronic address: kochcd@upmc.edu.
authors.forename: Carl D
authors.initials: CD
authors.lastname: Koch
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA 15261, USA.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Gladwin
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA 15261, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Freeman
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden.
authors.forename: Jon O
authors.initials: JO
authors.lastname: Lundberg
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden.
authors.forename: Eddie
authors.initials: E
authors.lastname: Weitzberg
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA 15261, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden.
authors.forename: Alison
authors.initials: A
authors.lastname: Morris
mesh_terms: D000818:Animals; D002318:Cardiovascular Diseases / Q000378:metabolism / Q000382:microbiology*; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D064307:Microbiota; D009055:Mouth / Q000382:microbiology*; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D011652:Pulmonary Circulation; D015398:Signal Transduction
chemical_list: D005227:Fatty Acids; D009566:Nitrates; D009569:Nitric Oxide
keywords: Cardiovascular disease; Inflammation; Microbiome; Nitrate; Nitrated fatty acids; Nitric oxide; Nitrite; Pulmonary hypertension