Nitrate {60000092}

Shared Reference Notes

• [1.1] 
  - Foods that naturally contain significant amounts of nitrate are fruits and vegetables, which are both unequivocally associated with health benefits. It is estimated that we obtain more than 80% of nitrate from vegetables. - Nitrate-reducing oral bacteria, including representatives of Neisseria, Rothia, Veillonella, Actinomyces, Corynebacterium, Haemophilus, and Kingella reduce nitrate to nitrite . -nitrate prevented acidification by oral bacteria and the nitrate reduction capacity (NRC) of the oral microbiota correlated negatively with caries abundance. - nitrate reduction prevented acidification and the resulting overgrowth of cariogenic bacteria by increasing lactate consumption and ammonia production. Additionally, nitrate increased health-associated nitrate-reducing genera, while decreasing strictly anaerobic periodontal diseases- and halitosis-associated bacteria
• [1.2] 
  - Lack of #Butyrate signaling results in nitrate electron acceptors being released into the colon, which facultative anaerobes can also use for cell respiration, breaking down carbohydrates into carbon dioxide rather than fermenting them.
• [1.3] [#High Fat Diet] 
  - The abundance of #Firmicutes and the ratio of #Firmicutes to #Bacteroidetes increased in mice fed an HFD, but this increase was prevented by dietary nitrate.
• [#Fecal Microbiota Transplantation, #High Fat Diet] - fecal microbiota transplant (FMT) from mice fed an HFD in the presence, but not absence, of dietary nitrate appears sufficient to prevent HFD-induced metabolic derangement and cardiac functional changes without increasing serum NOx concentrations.
• [1.4] [#Atherosclerosis] [#Streptococcus] 
  - issimilatory nitrate reduction > CACS-associated species > converts nitrate to #Ammonia, and having an increased activity of this pathway in the colon could potentially inhibit the potential positive cardiovascular effects of nitrate.
• - Dietary nitrate is absorbed in the intestines and excreted back into the gastrointestinal tract by the salivary glands at high concentrations, forming the so-called entero-salivary circulation of nitrate. - Denitrifying oral bacteria are important for converting nitrate (NO3−) into nitrite (NO2−), which can be further converted into #Nitric Oxide (NO) in the acidic pH of the stomach. - The generation of NO contributes to gastric protection by increasing blood flow and mucus thickness. - The nitrate and nitrite that are not converted to NO in the stomach are absorbed into the bloodstream and tissues, where they might act as reservoir for NO, which appears to be important for vasodilation under hypoxia and modulation of mitochondrial respiration.
• [1.5] [#Veillonella parvula] 
  - nitrate, a signature metabolite of inflammation, allows V. parvula to transition from fermentation to anaerobic respiration. - Nitrate respiration was fundamental for ectopic colonization in a mouse model of colitis
• [1.6] [#Short Chain Fatty Acid] 
  - accumulation of nonfermentable nitrate further inhibits the growth of short-chain fatty acid- (SCFA-) producing microbes, as they are unable to utilize this substrate.
• [#Ulcerative Colitis] - increased abundance of nitrate-reducing bacteria in UC patients. - persistent inflammation in UC patients accumulates nonfermentable nitrate. - #Bifidobacterium and #Lactobacillus can utilize nonfermentable forms of nitrate.
• [#Ulcerative Colitis] [#Short Chain Fatty Acid] - A significant loss of SCFA-producing microbes and the concurrent increase in nitrate-reducing bacteria in UC patients favor a shift towards a proinflammatory microbiome > enrichment of #Lactic acid-producing bacteria is a consequence of increased inflammation.
• [1.7] [#End-stage renal disease] 
  - Nitrate treatment boosted the nitrate-nitrite-NO pathway, which ameliorated UUO-induced renal dysfunction and #Fibrosis in mice, represented by improved glomerular filtration and morphological structure and decreased renal collagen deposition, pro-fibrotic marker expression, and inflammation.
• - treatment with nitrate (in vivo) or nitrite (in vitro) decreased lipid accumulation, which was associated with dampened NADPH oxidase activity and mitochondria-derived #Oxidative stress.
• [1.8] 
  - Nitrate also altered oral microbiome metabolism, causing an increase in pH levels, which is beneficial to limit #Caries development.
• - acute and chronic nitrate exposure decreased #Caries-associated #Veillonella and #Streptococcus decreased .
• - acute and chronic nitrate exposure increased (representatives of) health-associated #Neisseria and #Rothia whilst reducing #Periodontal disease-associated #Prevotella .

References Notes