It is a component of the dietary peptide anserine. Anserine is beta-alanyl-1-methyl-L-histidine, and it is known to come from chicken, turkey, duck, rabbit, tuna and salmon.

1-methylhistidine is derived from the dipeptide anserine (which consists of the amino acids 1-methylhistidine and beta-alanine). Anserine and its derivatives are associated with the consumption of poultry and fish. Both 1-methylhistidine and 3-methyl

2-Methylhippuric Acid (2MHA), 3-Methylhippuric Acid (3MHA), 4-Methylhippuric Acid (4MHA) -- These are metabolites of xylenes, solvents found in paints, lacquers, cleaning agents, pesticides, and gasoline. Exposure to xylenes generates methy

Methylsuccinic acid is a normal metabolite found in human fluids. Increased urinary levels of methylsuccinic acid (together with ethylmalonic acid) are the main biochemical measurable features in ethylmalonic encephalopathy, a rare metabolic dis

- 3,4-dihydroxyphenylpropionic acid is found in red beetroot, common beet, olives, and correlated with coffee intake. - One of the most abundant phenolates, formed by microbial transformation of dietary polyphenols and endogenous metabolites such

3,5-Dihydroxybenzoic acid was highly correlated with intake of whole-grain bread and breakfast cereals, and a primary metabolite of alkylresorcinols, a biomarker for whole-grain intake. Alkylresorcinols are a naturally occurring type of phenolic l

3-Methylhistidine is an amino acid which is excreted in human urine. The measurement of 3-methylhistidine provides an index of the rate of muscle protein breakdown. 3-Methylhistidine is a biomarker for meat consumption, especially chicken. It is a

Phenylpropionylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these met

(p-Hydroxybenzoate or 4-HB) - One of the most abundant phenolates formed by the microbiota. It is a product of microbial transformation of dietary polyphenols and endogenous metabolites such as dopamine, phenylalanine, tyrosine, and tryptophan.

4-Hydroxyphenylacetate is a tyrosine metabolic product of certain Clostridia bacteria. Elevated levels are associated with Clostridia overgrowth, small intestinal bowel overgrowth (SIBO), or small bowel disease. May also indicate celiac disease.

AKA: 4-Hydroxyphenylpyruvate, 4-HPPA 4-hydroxyphenylpyruvic acid is an intermediate in the breakdown of phenylalanine. 4-hydroxyphenylpyruvic acid is converted to homogentisate; a blockage at this step results in increased homogentisate, which

5-Hydroxyindoleacetic acid (5HIAA) is a breakdown product of serotonin that is excreted in the urine. Serotonin is a hormone found at high levels in many body tissues. Serotonin and 5HIAA are produced in excess amounts by carcinoid tumors, and levels

8-hydroxy-2-deoxyguanosine measures the oxidative impact to DNA. 8-hydroxy-2-deoxyguanosine levels will be high if your total antioxidant protection is inadequate.

a-hydroxybutyric acid (2-hydroxybuturic acid [2-HB]) is a marker that relates to oxidative stress. a-hydroxybutyric acid is an organic acid produced from a-ketobutyrate via the enzymes lactate dehydrogenase (LDH) or a-hydroxybutyrate dehydrogenase

a-Keto-b-Methylvaleric Acid is a B-Complex Vitamin Marker. Vitamins are compounds that your body needs to be healthy. Vitamins are “essential” for proper function, which means that they are not made inside your body and mus

- Alpha-ketobutyric acid results from the breakdown of threonine or methionine during glutathione production. - Specifically, cystathionine is metabolized to alpha-ketobutyric acid and cysteine. - a- ketobutyric acid enters the mitochondrial ma

Alpha-Ketoglutarate is an organic acid that is important for the proper metabolism of all essential amino acids. It is formed in the Krebs cycle, the energy-producing process that occurs in most body cells.

2-Ketoisocaproic Acid is a B-Complex Vitamin Marker (Leucine catabolism). 2-Ketoisocaproic Acid is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids.

Alpha-Ketoisovalerate (together with Alpha-Ketoisocaproate and Alpha-Keto-Beta-methylvalerate) requires Vitamins B1, B2, B3, B5 and lipoic acid to be metabolized.

- An intermediate metabolite of lysine metabolism, produced primarily under oxidative stress (metal-catalyzed oxidation). - In adolescents, α-aminoadipic acid was associated with adipogenesis and insulin resistance. - Higher plasma &alpha

Adipic Acid, together with Suberate and Ethylmalonate are all functional markers for deficiency of carnitine.

- In a review of 46 studies higher plasma alanine was a potential predictor of insulin resistance and diabetes. - In a review of baseline urine markers and conventional metabolic assessments, with a 5-year follow up, elevated baseline urine alanin

Aldosterone is a mineralcoritcoid and a hormone. It allows the transport of sodium across the cell membrane. Aldosterone is important in blood pressure regulation and also for the volume of blood found in the blood vessels.

Anserine is part of a group of Beta-Amino Acids and Derivatives. Anserine is beta-alanyl-1-methyl-L-histidine, and it is known to come from chicken, turkey, duck, rabbit, tuna and salmon.

Other names: Anthranilate - Several clinical studies have reported increased excretion of anthranilic acid and other metabolites in bladder cancer patients. - Anthranilic acid was one of nine markers that positively correlated with protein

- Evaluate for consumption of foods and pharmaceuticals that contain arabinitol. - Because a common substrate for the production of arabinitol in the body is glucose, reduced intake of dietary sugars is a key therapeutic area for elevated arabinit

→ Arginine is a precursor of urea, nitric oxide, polyamines (putrescine, spermidine, spermine and agmatine), proline, glutamate, and creatine. → Levels may drop with increased need, or in renal or small intestine dysfunction.

Asparagine is a non-essential protein amino acid that is present in many fruits and vegetables including asparagus, from which it gets its name. Other dietary sources include meat, potatoes, eggs, nuts, and dairy. It can also be formed from aspartic

Aspartic acid is a nonessential amino acid that plays roles in many important metabolic processes, such as energy production (citric acid cycle), hormone metabolism, CNS activation, and the urea cycle. It is found in many protein sources such as oyst

b-hydroxybutyrate is one of the ketone bodies.  The term ketone body describes any of 3 molecules: acetoacetate, b-hydroxybutyrate, or acetone. Acetoacetate is produced by acetyl-CoA metabolism, b-hydroxybutyrate is the result of ac

b-­Hydroxyisovaleric Acid [aka 3-Hydroxyisovaleric Acid (3-HIA)] is formed from the metabolism of the branched-chain amino acid leucine. Methylcrotonyl-CoA carboxylase catalyzes an essential step in this pathway and is biotin dependent. Reduced a

β-alanine is a breakdown product of carnosine and anserine, which are dipeptides from meat consumption. Although β-alanine’s properties are limited, its relationship to carnosine makes it important. Both have antioxidant properties. C

→ Benzoic acid is primarily made endogenously by gut bacteria acting upon dietary polyphenols. → Benzoic acid acts as an acidifier and can inhibit pathogenic microorganisms. → Benzoic acid is found in broccoli, pep

Benzoylform is also known as Phenylglyoxylic Acid and a marker for Styrene exposure. Styrene is a chemical used to make latex, synthetic rubber, and polystyrene resins. These resins are used to make plastic packaging, disposable cups a

- Each of the BCAAs is catabolized by a dehydrogenase enzyme forming branched-chain keto acids (BDKA), or 2-oxo acids. The dehydrogenase enzyme is heavily dependent on B-complex vitamins, the lack of which may decrease pathway function, possibly lead

Carnosine (beta-alanyl-L-histidine) is a urinary biomarker which comes from the consumption of beef, pork, and to a lesser extent, poultry. It is a dipeptide consisting of the amino acids histidine and beta-alanine and is concentrated in skeletal

Cis-Aconitic Acid is involved in both energy production and removal of toxic ammonia.

- Diet has a significant impact on citric acid levels:     » Increased acid load due to diets high in animal-based proteins, carbonated drinks, and in severe carbohydrate restriction can lead to mild metabolic acidosis, h

→ Citrulline comes from dietary sources and plasma amino acid precursors such as arginine, ornithine, glutamine, glutamate, or proline. → Enterocytes are the main site of citrulline production, making small intestine function a

Cortisol is a stress hormone produced by the adrenal glands and is the primary agent used in our body’s flight or fight response to threatening stimuli. Levels naturally peak in the morning and then reach their lowest point at night. A high blo

Cortisone is the inactive form of cortisol. Cortisone shows minimal biological activity per se, reflecting negligible affinity for the glucocorticoid and aldosterone receptors. The kidney, colon and saliva gland have lots of activity for changing cor

As a waste product, creatinine is filtered out of the blood by the kidneys and removed from the body in urine. The amount of creatinine formed daily is based on muscle mass, which varies with age, gender, and ethnicity. It is usually produced at a fa

Cystathionine is an intermediate dipeptide within the process of transsulfuration. Transsulfuration is the main route for irreversible homocysteine disposal, glutathione production, and energy. The initial step involves the enzyme cystathionine &beta

Cystine is rate limiting for glutathione production. Cystine is the oxidized form of cysteine. → Low cystine may be reflective of reduced glutathione levels and has also been noted in those with celiac disease and lower BMD. →&nb

Cystine is rate limiting for glutathione production. Cystine is the oxidized form of cysteine. Cystine is formed from the oxidation of cysteine, or from the degradation of glutathione oxidation products. It is two cysteines linked together with a

- Only elevated is of concern. D-lactic acid is generally produced in minimal quantities by human cells. It comes from three sources,     1. from human methylglyoxal (MGO) pathway (assumed to be the sole source of blood D-lacta

- Equol is a bacterial-derived metabolite with estrogenic and antioxidant activity. Reductase enzymes secreted by the gut microbiota convert daidzein into equol. Daidzein is an isoflavone from soy, tofu, soy milk, tempeh, miso. - The ability to pr

Ethanolamine is an intermediary metabolite in the serine-to-choline sequence. It can be used to synthesize phosphatidylethanolamine (PE), a very important membrane phospholipid. Ethanolamine is not only a precursor, but also a breakdown product of PE

Ethylmalonate, together with Adipate and Suberate, gives information about your ability to process fatty acids. Note: These tests are used to check for rare metabolic disorders, usually in infants. There is no apparent reason nor benefit to c

Formiminoglutamic Acid (FIGlu) is an intermediary organic acid in the conversion of the amino acid histidine to glutamic acid. This enzymatic conversion requires tetrahydrofolic acid.

Emerging research seems to show a relationship between the rise in metabolic diseases and the increased consumption of fructose—particularly consumption of non-natural sources of fructose found in sugar-sweetened beverages and other processed f

Fumarate (together with Succinate and Malate) is used in the body’s metabolic pathway that generates cellular energy – the Citric Acid Cycle.

Gamma-aminobutyric acid (GABA) is an amino acid that functions as an inhibitory neurotransmitter. It serves one-third of brain neurons and is involved in depression and mania. Although there are some dietary supplement and food sources for GABA (c

Gamma-aminobutyric acid (GABA) is an amino acid that functions as an inhibitory neurotransmitter. It serves one-third of brain neurons and is involved in depression and mania. Although there are some dietary supplement and food sources for GABA (c

AKA: Glucarate / D-Glucaric Acid - Urinary glucaric acid has been used as an indicator of induced hepatic drug metabolization and elevated with exposure to xenobiotics. - Levels may indirectly represent P-450 activity or an end-product of the g

- Glucose identifies processing of overall diet. Small amounts of glucose may be found in the urine of healthy individuals. - Researchers found that those with a high waist-to-hip ratio (WHR), but no history of diabetes, had significantly lower ur

Glutamine is the most abundant amino acid in the blood and is an important source of energy for many tissues in the body. It is derived from the amino acids histidine and glutamic acid.

- Glutamic acid has been associated with higher BMI, blood pressure, and insulin resistance, while glutamine levels were inversely associated. - A high plasma glutamine-to-glutamic acid ratio was associated with lower risk of diabetes in the Frami

Glutaric Acid (Glutarate) is endogenously produced in the catabolism of lysine and tryptophan. - Increased Glutaric acid is associated with secondary carnitine deficiency. - Glutaryl-CoA (from lysine or tryptophan) normally enters the Krebs cy

→ Patients with pressure sores had significantly increased glycylproline, finding positive predictive value for pressure sores of 70%. → In an older (1964) review of bone markers of patients with bone disease, researchers found

- Patients with pressure sores had significantly increased glycylproline, finding positive predictive value for pressure sores of 70%. - In an older (1964) review of bone markers of patients with bone disease, researchers found glycylproline only

Urinary hexanoylglycine is a specific marker for the diagnosis of Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. 

→ Benzoic acid is metabolized to hippuric acid and excreted. → Hippuric acid is a normal urinary metabolite associated with microbial degradation of certain dietary components. → Levels of hippuric acid rise with t

Histidine is involved in one-carbon units for conversion of formiminoglutamic acid (FIGLU) to glutamic acid. - High plasma histidine has been associated with increased plasma glutamic acid, alanine and glutamine, and decreased branched-chain amino

→ Plasma homocystine is higher in those with cystathionine-beta-synthase deficiency. → Plasma homocystine, as well as taurine, were significantly lower in insufficient methotrexate therapy responders. → Homocystine

Homocystine is a common amino acid in your blood. You get it mostly from eating meat. High levels of it are linked to early development of heart disease.

Homogentisic acid is a breakdown product of 4-Hydroxyphenylpyruvic Acid (4-HPPA).  Elevated in the genetic disease homogentisic aciduria (alkaptonuria).

Homovanillate (aka Homovanillic Acid) is a dopamine metabolite. Homovanillate and Vanilmandelate are breakdown products from neurotransmitters involved in hormone and nerve impulse transmission, called catecholamines.

3-Hydroxykynurenine is a metabolic intermediate of the kynurenine pathway that elicits neurotoxic effects.

- Hydroxyproline is the key factor in stabilizing collagens. - Hydroxyproline is abundant in meat and low in plant-based foods. Meat intake increases levels of proline and hydroxyproline. - Increased hydroxyproline has been found in collagen ca

Hydroxyproline is the key factor in stabilizing collagens. - Hydroxyproline is abundant in meat and low in plant-based foods. Meat intake increases levels of proline and hydroxyproline. - Increased hydroxyproline has been found in collagen cata

- A product of tryptophan fermentation. If elevated, decrease protein intake and address digestion and GI issues. Bacteroides, Clostridia, and E. coli ferment tryptophan to produced indoleacetic acid. - It has been found elevated in liver disease

Citric acid, cis-aconitic acid, and isocitric acid are the first three metabolites in the Krebs Citric Acid energy production cycle, which operates in the mitochondria of your cells. 

Branched Chain Amino Acids (Isoleucine, Leucine, Valine) are the three branched chain amino acids (BCAAs). Branched chain amino acids (BCAA) are essential amino acids and must be obtained from the diet (mainly meat, grains, and dairy). Branched-Ch

KT Ratio stands for Kynurenine/Tryptophan Ratio (KTR). What is Tryptophan? Tryptophan is involved in serotonin production and is the least abundant amino acid. What is Kynurenine? Kynurenine is primary breakdown product of tryptophan.

KT Ratio stands for Kynurenine/Tryptophan Ratio (KTR). What is Tryptophan? Tryptophan is involved in serotonin production and is the least abundant amino acid. What is Kynurenine? Kynurenine is primary breakdown product of tryptophan.

Kynurenic Acid is product of the metabolism of L-Tryptophan and appears in urine in Vitamin B6 deficiencies. Your body needs vitamin B6 (pyridoxine) to utilize amino acids derived from dietary protein.

Kynurenine is the primary breakdown product of tryptophan. - Kynurenine blood levels have been found higher in type 2 diabetes, obesity, CVD, ADHD in children, HOMA-IR. - Higher kynurenine increases Treg cell differentiation via the AhR (a

Kynurenine is the primary breakdown product of tryptophan. - Kynurenine blood levels have been found higher in type 2 diabetes, obesity, CVD, ADHD in children, HOMA-IR. - Higher kynurenine increases Treg cell differentiation via the AhR (a

- Lactic acid is produced endogenously under anaerobic conditions. - Main route of lactic acid disposal is conversion to pyruvic acid or excretion via urine. - Higher urine lactic acid levels have been associated with diabetes, fasting glucose,

Branched Chain Amino Acids (Isoleucine, Leucine, Valine) are the three branched chain amino acids (BCAAs). Branched chain amino acids (BCAA) are essential amino acids and must be obtained from the diet (mainly meat, grains, and dairy). - Activator

Lysine catabolism leads to collagen and carnitine production. - Higher plasma valine, lysine, and tyrosine were independently and positively associated with gestational diabetes mellitus and insulin activity. - Increased urinary lysine was asso

Malic Acid is involved in the citric acid cycle (aka. Krebs cycle). The citric acid cycle is a series of reactions that occur in the mitochondrion to generate chemical energy that fuels the metabolism.

→ Mandelic acid and benzoylformate are major metabolites of styrene and ethylbenzene exposure. → Styrene is a key component in consumer products. Occupational exposure has been associated with increased rates of pulmonary, neur

Methionine is an essential amino acid that plays an important role in the methylation cycle. Methionine is obtained from dietary intake or through homocysteine remethylation. Methionine’s dietary sources include eggs, fish, meats, Brazil nuts,

Methylmalonic Acid (MMA) is formed from propionylCoA via methylmalonyl-CoA. Major dietary sources of propionyl-CoA include valine, isoleucine, methionine, threonine, and odd chain fatty acids. MethylmalonylCoA is converted to succinyl-CoA to feed the

Albumin is not normally found in urine. Temporary dysfunction of the filtration barrier can occur under certain conditions, including fever, dehydration, a urinary tract infection (UTI), and after vigorous exercise, allowing small amounts of albumin

→ It is a key substrate for the synthesis of proline, polyamines, and citrulline. → Higher ornithine blood levels were associated with lower breast cancer risk; also found higher in those with Alzheimer’s and Parkinson&rs

Orotic Acid is a sensitive marker of your liver’s capacity to convert toxic ammonia to non-toxic urea that you can excrete. That capacity can be increased by additional arginine. Ammonia toxicity can also be reduced by

Oxalic acid may be associated with dysbiosis from Aspergillus, Penicillium, Candida, or high dose vitamin C. If yeast or fungal markers are elevated, antifungal therapy may reduces oxalates. Also associated with anti-freeze (ethylene glycol) poisonin

Produced from bacterial degradation of unabsorbed phenylalanine.

Final products include: DOPA, dopamine, norepinephrine, epinephrine, thyroid hormones, melanin, in TCA cycle, or 4-hydroxyphenylacetic acid.

Phosphoethanolamine is an intermediate in the serine-to-choline sequence. It is both a precursor and byproduct of phospholipid biosynthesis and breakdown. As a precursor to the phospholipid phosphatidylethanolamine, phosphoethanolamine plays a key ro

Other names: Picolinate From the breakdown of hydroxykynurenine via ACMS decarboxylase - Decreased picolinic acid and increased quinolinic acid blood levels noted in suicidal subjects. - A tryptophan metabolite produced through non-enzymatic

Pimelic acids are excreted in elevated amounts in urine in disorders of mitochondrial beta-oxidation and disorders of peroxisomal beta-oxidation, for which they are of significant diagnostic value. Pimelic acid originating from fatty acid synthesi

Collagen Catabolism: Collagen contains proline, hydroxyproline, and glycine. → Sarcopenia (low muscle mass) was associated with higher plasma proline. → Proline was significantly lower in esophageal cancer patients comp

Proline is a nonessential amino acid. It contains a secondary α-imino group and is sometimes called an α-imino acid. Proline, and its metabolite hydroxyproline, constitute a third of the total amino acids found in collagen. Lysine, prolin

- Pyridoxic acid (4-Pyridoxate) is a catabolic product of vitamin B6 that is excreted in the urine. Pyridoxic acid represents > 90% of vitamin B6 species excreted in the urine, and 40-60% of dietary vitamin B6 intake. Urine 4-pyridoxic acid correl

Pyroglutamic acid (5-oxoproline) is produced and utilized in the gamma-glutamyl cycle. This cycle is needed to assist in the production and recycling of glutathione (GSH), a powerful antioxidant. Glutathione is a tripeptide, consisting of glutamat

Pyruvic Acid feeds into the citric acid cycle & converts into acetyl CoA. Pyruvate is formed from carbohydrate via glucose or glycogen & secondarily from fats (glycerol) & glycogenic amino acids.

Research has noted antidiabetic, anti-inflammatory, antioxidant, antimicrobial, anti-Alzheimer's, antiarthritic, cardiovascular, and wound-healing effects.

Kynurenic acid and Quinolinic acid are tryptophan metabolites formed through the kynurenine pathway. Tryptophan is the amino acid precursor to serotonin; its major route for catabolism is the kynurenine pathway. Important products of the kynurenine p

Sarcosine is also known as N-methylglycine. It is an intermediate and byproduct in the glycine synthesis and degradation. Sarcosine is metabolized to glycine by the enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generate

Increased urinary products of the omega fatty acid metabolism pathway may be due to carnitine deficiency, fasting, or increased intake of triglycerides from coconut oil, or some infant formulas.

- Plasma serine was found higher in depression, and psychoses including schizophrenia. - Methionine supplementation significantly increased plasma serine. - Serine is involved in cysteine and methionine metabolism. - Blood serine was lower i

- Suberic acid is present in the urine of people with fatty acid oxidation disorders. - A metabolic breakdown product derived from oleic acid. - Elevated levels of this unsaturated dicarboxylic acid are found in individuals with medium-chain ac

Suberylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites

Succinate (or succinic acid) is an important metabolite that is involved in several chemical processes in the body.

Sulfocysteine is the product of sulfite-dependent cleavage of cystine. In the pathway, cysteine becomes sulfite, which converts to sulfate via sulfite oxidase + Mo. If the pathway is blocked, sulfocysteine builds up.

Sulfocysteine is the product of sulfite-dependent cleavage of cystine. In the pathway, cysteine becomes sulfite, which converts to sulfate via sulfite oxidase + Mo. If the pathway is blocked, sulfocysteine builds up.

- Tartaric acid is a compound found in plant foods. It has been identified as a biomarker of grape intake, though it has also been identified in other foods. Tartaric acid levels peak at 4–8 hours after intake. Levels in foods vary significantl

Taurine differs from other amino acids because a sulfur group replaces the carboxyl group of what would be the nonessential amino acid, β-alanine. It takes part in biochemical reactions and is not fully incorporated into proteins. In most tissue

- BCAAs are key nitrogen donors in the form of glutamic acid, glutamine, and alanine. - Elevated total BCAAs have been associated with obesity, weight loss, insulin resistance, and NAFLD. - Elevated plasma BCAAs were associated with an increase

Three pathways: - Kynurenine Pathway (primary pathway) – leading to niacin production - Serotonin/Melatonin - Indoles Tryptophan is involved in serotonin production via vitamin B6-dependent pathways resulting in the intermediate 5-h

Three pathways: - Kynurenine Pathway (primary pathway) – leading to niacin production - Serotonin/Melatonin - Indoles Tryptophan is involved in serotonin production via vitamin B6-dependent pathways resulting in the intermediate 5-h

- A higher protein intake or supplementation results in increased levels. - Low protein intake or inflammation can lead to lower levels. - Nutrient cofactors of tyrosine pathways include BH4, non-heme iron, vitamins B6 and B3, copper, niacin, v

- A higher protein intake or supplementation results in increased levels. - Low protein intake or inflammation can lead to lower levels. - Nutrient cofactors of tyrosine pathways include BH4, non-heme iron, vitamins B6 and B3, copper, niacin, v

Valine is a branched-chain amino acid (BCAA). BCAA’s are nitrogen donors, facilitate glucose uptake by liver and skeletal muscle, and enhance glycogen synthesis. Branched-Chain Amino Acids (BCAAs) are required for protein synthesis and ar

Metabolite of epinephrine and norepinephrine. Often elevated due to stress induced catecholamine output or lead toxicity.

Xanthurenic acid is produced as part of the kynurenine pathway of tryptophan catabolism, along with kynurenic and quinolinic acid. From the breakdown of hydroxykynurenine via kynurenine aminotransferases (KAT) +B6 - Elevated xanthurenic acid ha