Niacin {90000163}

Shared Reference Notes

• [1.1] [#Diabetes Type 2] [#Microencapsulated delayed-release Nicotinic Acid] 
  - Gut-targeted delayed-release NA but not NAM produced a significant increase in the abundance of #Bacteroidetes. - In the absence of systemic side effects, these favorable microbiome changes induced by microencapsulated delayed-release NA were associated with an improvement of biomarkers for systemic insulin sensitivity and metabolic inflammation.
• [1.2] [#Indole-3-carboxyaldehyde, #Indole-3-propionic acid, #Tryptophan] [#Ginseng] 
  - #Ginsenoside Rg1 could increase the levels of Trp metabolites in the serum, including indole-3-carboxaldehyde, #Indole-3-lactic acid, 3-indolepropionic acid and niacinamide. - In mice with high-fat diet-induced obesity, #Ginsenoside Rb1 significantly altered the gut microbiota composition and serum Trp
• [1.3] [#Colorectal cancer] 
  - Analogous to the activity of niacin, #Butyrate activates GPR109A to suppress colonic inflammation and colon cancer development
• [#Short Chain Fatty Acid] - Several receptors have been identified for SCFAs such as free fatty acid receptor 3 (FFAR3 or GPR41) and niacin receptor 1 (GPR109A) - GPR41 and GPR109A are G-protein coupled receptors (GPCRs) found on intestinal epithelial cells, immune cells, and adipocytes. - GPR41 is associated with increased energy expenditure, #Leptin hormone expression, and decreased food intake
• [1.4] 
  - #Bacteroides fragilis, #Prevotella copri, and #Ruminococcus lactaris can also produce vitamin B3 in the gut as they possess a vitamin B3 biosynthesis pathway
• - Lower plasma niacin levels have been observed in patients with #Crohn’s disease
• - Vitamin B3, known as nicotinamide, nicotinic acid, or niacin, is converted into its active form, nicotinamide adenine dinucleotide (NAD), which is essential for many critical metabolic processes, primarily as a redox cofactor
• - The bacterially synthesized vitamin B3 contributes to local colonocyte nutrition and maintains the morphology of intestinal stem cells
• - intestinal bacteria synthesize vitamin B3 mainly from amino acid #Tryptophan but using a unique pathway
• - Vitamin B3 plays a vital role in reducing inflammation and causes relapsing inflammatory bowel diseases such as #Ulcerative Colitis when deficient. - It controls inflammation by inhibiting vascular permeability in intestinal tissues by activating the PGD2/DP1 signal in endothelial cells. - vitamin B3 engages in various metabolic reactions that alter the cellular redox state and rapamycin signalling pathway, thus suppressing the colon’s inflammations
• [#Hydrocolon Therapy] - retention enema containing vitamin B3 effectively promoted mucosal healing in patients with #Ulcerative Colitis, most likely due to the downregulation of colonic inflammatory cytokines and suppression of proinflammatory gene expression
• [1.5] 
  - #Trigonelline (TG), a naturally occurring alkaloid compound (N-methyl nicotinic acid) found in various plants, including #Coffee beans, fenugreek, and Japanese radish
• [1.6] [#Covid-19] [#γ-Aminobutyric acid] 
  - Distinct metabolites, including nicotinic acid (Vitamin B) and γ-Aminobutyric acid, were correlated with immune durability in BNT162b2 vaccines, while L-#Tryptophan showed significance for CoronaVac vaccines.
• [1.7] 
  - Microbiota derived #Ribosyl nicotinamide (nicotinamide riboside or NR) is one of the main precursors of nicotinamide adenine dinucleotide (NAD+), which has been reported to be significantly reduced in individuals with #Rheumatoid Arthritis. - Administration of NR and other NAD+ precursors leads to improved clinical outcomes for #Rheumatoid Arthritis patients and for a range of other inflammatory, neurodegenerative and cardiovascular diseases
• [1.8] 
  - 3-HAA can be converted to #Quinolinic acid (QA), which is further catabolized into nicotinamide adenine dinucleotide (NAD+) and niacin. KA and QA are both neuroactive inflammatory mediators
• [1.9] 
  - Mitochondrial dysfunction and low nicotinamide adenine dinucleotide (NAD+) levels are hallmarks of skeletal muscle ageing and #Sarcopenia
• [#Alzheimer’s disease] - HCAR2 (GPR109A), a microglial receptor playing a protective role in AD, was activated by nicotinic acid derived from R. guavus.

References Notes