Nitrogen-containing Compound Digestion

KEY Fermenters: Oxidation or fermentation by gut bacteria producing acid; Use: Utilisation or assimilation by gut bacteria; Common: Combined use and O/F for widespread, moderate and minor gut colonisers (total bacteria: 500);

nitrogen_compounds Common Species examples All consumers Prevalence in food Human digestion, metabolism, interactions Structure
Benzylamine 0 7 Elevated levels in corn and cabbage, with smaller amounts carrots, apples and lettuce. Has been used as for motion sickness. Metabolised by monoamine oxidase B to benzaldehyde.
Butylamine 0 8 Found in kale, cocoa, cucumbers, some cheeses and milk products, brown bread, fish and other seafood. A breakdown product of protein and amino acid metabolism. Accumulates in the gastric juices, along with numerous other aliphatic amines, of individuals with acute renal failure (Lichtenberger1993). Absorbed by gastric epithelial cells and can enter the blood stream. Probably eliminated through renal excretion or metabolised by CP450 to butyl hydroxylamine in the liver.
Ethanolamine 2 Citrobacter koseri; Enterobacter hormaechei subsp. hormaechei; 30 A food additive, but also found in lemon grass, dates, radishes and a wide variety of other foods. Detected throughout the body and is an essential compound available only through the diet. Present in blood at ~2 uM. Increased levels in the urine of non-typical neurodevelopment children (SoteloOrozco2023).
o-Aminobenzoate 0 7 Found in caraway, cinnamon, apples, and guava. A byproduct of tryptophan catabolism, which, at high levels can lead to kidney disease.
m-Aminobenzoate 0 0 Detected in cow's milk.
p-Aminobenzoate 1 Acidaminococcus fermentans; 5 Common in eggs, milk, meats (kidney and liver), mushrooms, spinach and whole grains. A non-essential compound in humans but essential for microbe-mediated folate biosynthesis.
Putrescine 6 Cronobacter sakazakii; Enterobacter cancerogenus; Enterobacter cloacae; Klebsiella pneumoniae; Klebsiella quasipneumoniae subsp. quasipneumoniae; Raoultella ornithinolytica; 52 High levels in citrus fruits (1.5 umol/g), green peppers (0.8 umol/g), wheat germ (0.7 umol/g) and soybean sprouts (MunozEsparza2019). Endogenously synthesised by ornithine decarboxylase-mediated decarboxylation of ornithine. Low acute toxicity.
Acetamide 0 12 Found in beetroot, milk, eggs, beef, chicory roots, and roasted coffee beans. Cronic levels of acetamide are known to result in the development of hepatocellular tumours in mice models (Dybing1987). Converted to N-hydroxyacetamide in the liver.
Urea 0 12 Has been used as a food additive. Low acute toxicity; main source of excreted nitrogen in humans. Blood urea levels are influenced by diet, level of hydration and liver function.
Lactamide 0 2 Not a normal human metabolite or nutrient.
Succinamate 0 18 Not a normal human metabolite or nutrient.
Creatinine 0 5 Some creatine is converted to creatinine during the cooking of red meat. Creatinine comes from the metabolism of creatine and the breakdown of normal muscle tissue. Typical levels range from ~50 - 120 umol/L and it is removed from the body through healthy kidneys. The buildup of creatinine can be a sign kidney function is impaired (Toyohara2010).
DL-Carnitine 0 3 Found in foods of animal origin (meat, milk, chicken and cheese). Humans require about 15 mg/day from diet or endogenous biosynthesis. Endogenously synthesised in the liver, kidney and brain from lysine and methionine. An essential cofactor involved in the transport of fatty acids to the mitochondria. Serum concentrations decline in patients with chronic kidney disease (Toyohara2010).
Urocanate 0 7 Foods high in histidine, such as cauliflower, promote formation of urocanic acid. Trans urocanic acid is also found in mushrooms. Formed by elimination of ammonia of histidine (via histidine ammonialyase). Metabolised further in the liver to 4-imidazolone-5-propionate, which can be transformed to glutamate.
Histamine 1 Enterobacter hormaechei subsp. hormaechei; 12 From tuna, mackerel, anchovy, spinach, wine, cheese, sausage and fermented foods. Also produced in the gut and endogenously (Neumann2021). Absorbed through the gut or synthesised from histidine, and metabolised by histamine N-methyltransferase/monoamine oxidase B route or diamine oxidase route (Neumann2021).
Tryptamine 1 Enterobacter hormaechei subsp. hormaechei; 9 Plants (particularly legumes), fungi and animals. tryptophan decarboxylase removes the carboxylic acid group on the α-carbon of tryptophan. Monoamine oxidases A and B are the primary enzymes involved in tryptamine metabolism to produce indole-3-acetaldehyde
Adenosine 0 14 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021).,Generally in fruits and vegetables. Adenosine and adenine are obtained from the corresponding NT after digestion. Enterocytes secret transporter proteins to aid in absorption. Small amounts of adenosine are reused, but most of it is catabolised in the liver.
Inosine 3 Anaerotruncus colihominis; Intestinimonas butyriciproducens; Lactobacillus gasseri; 42 Found in brewer's yeast, red meats, pork and poultry, organ meats, such as liver and kidney, as well as milk and cheese. Inosine and hypoxanthine are obtained from the the breakdown of tRNA or from the degradation of adenosine (intestinal adenosine deaminase).
Thymidine 3 Anaerotruncus colihominis; Intestinimonas butyriciproducens; Megamonas hypermegale; 32 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021). Also, asian pears, brassicas, japanese chestnuts, and apricots. Thymidine and thymine are obtained from the corresponding NT after digestion. Enterocytes secret transporter proteins to aid in absorption. Small amounts of thymidine are reused, but most of it is catabolised in the liver.
Uridine 2 Anaerotruncus colihominis; Intestinimonas butyriciproducens; 34 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021). Uridine and uracil are obtained from the corresponding NT after digestion. Enterocytes secret transporter proteins to aid in absorption. Small amounts of uridine are reused, but most of it is catabolised in the liver.
Adenosine-MP 0 3 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021). Intestinal alkaline phosphatase and ecto-5`-nucleotidase converts AMP to adenosine and adenine, which are absorbed (see above).
Thymidine-MP 1 Intestinimonas butyriciproducens; 6 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021). Intestinal alkaline phosphatase and ecto-5`-nucleotidase converts TMP to thymidine and thymine, which are absorbed (see above).
Uridine-MP 1 Intestinimonas butyriciproducens; 7 Human colostrum, milk, mushrooms, fish meal, fish soluble, legumes, animal protein soluble, and yeast extracts (Ding2021). Intestinal alkaline phosphatase and ecto-5`-nucleotidase converts UMP to uridine and uracil, which is absorbed (see above).
Glucosamine 14 Bacteroides eggerthii; Bacteroides fragilis; Bacteroides ovatus; Bacteroides thetaiotaomicron; Cronobacter sakazakii; Enterobacter cancerogenus; Enterobacter cloacae; 58 Obtained from the shells of shellfish, animal bones, bone marrow, and fungi. Glucosamine sulfate is well absorbed (~90%) and distributed to various sites in the body, including synovial fluid. However, ingested glucosamine is quickly incorporated into plasma globulins in the liver (Setnikar2001). Blood concentrations are normally around 40 umol/L.
N-Acetyl-glucosamine 18 Anaerotruncus colihominis; Bacteroides ovatus; Citrobacter farmeri; Citrobacter freundii; Citrobacter koseri; Cronobacter sakazakii; Enterobacter asburiae; 227 From the outer shells of shellfish and is taken as a medicine for IBD, osteoarthritis and multiple sclerosis. Also present in human milk (0.6-1.5 g/L). Administered GlcNAc has a half life of ~220 min in the blood, with about 50% being excreted in the urine. Blood levels are unaffected by insulin.
N-Acetyl-galactosamine 1 Bacteroides ovatus; 14 Present in beans, mulberry, red peppers, wheat and sour cherries.
N-Acetyl-mannosamine 2 Bacteroides ovatus; Subdoligranulum variabile; 17 Endogenous origin. ManNAc is synthesised from GlcNAc, which is catalysed by N-acylglucosamine 2-epimerase. It is a precursor of sialic acid. Readily absorbed and distributed (Carrillo2021).
N-Acetyl-neuraminate 2 Escherichia coli; Haemophilus influenzae; 5 Found in red meat and especially kidney. Neu5Ac makes up ~3% of human brain. Biosynthesised from ManNAc or GlcNAc. Added to the non-reducing hydroxyl groups of glycoproteins and glycolipids. High blood levels indicated kidney impairment.
Glucuronamide 1 Gordonibacter urolithinfaciens; 12
D-Glucosaminate 0 4 A component of bacterial lipopolysaccharides. Degradation product of chitosan.