Health Markers

3-Hydroxykynurenine (3-OH-kynurenine) is a metabolite in the kynurenine pathway, which reflects the breakdown of the amino acid tryptophan. It serves as an intermediate compound during the conversion of tryptophan into important molecules, including the essential coenzyme NAD+ (nicotinamide adenine dinucleotide).

5-Hydroxyindoleacetate (5-HIAA) is a measure that reflects the breakdown of serotonin, a key neurotransmitter in the body. It is primarily used as a clinical marker, particularly for detecting and monitoring carcinoid tumours that may overproduce serotonin. Urinary 5-HIAA levels can also serve as an approximate indicator of the body’s overall serotonin levels.

Anti-Thyroglobulin (A-TG) antibodies are immune system proteins that target thyroglobulin, an essential protein in the thyroid gland involved in the production of thyroid hormones. Elevated levels of A-TG often indicate autoimmune thyroid disorders such as Hashimoto’s thyroiditis or Graves’ disease. These conditions can impact thyroid function and overall health, making A-TG monitoring crucial for diagnosis and management.

Anti-Thyroid Peroxidase (A-TPO) antibodies are immune proteins that mistakenly attack thyroid peroxidase, an enzyme crucial for the production of thyroid hormones. Elevated levels of A-TPO antibodies are commonly linked to autoimmune thyroid disorders like Hashimoto’s thyroiditis and Graves’ disease, which can result in either hypothyroidism or hyperthyroidism and impact overall health.

Adipate, also known as adipic acid, is a compound involved in lipid metabolism and serves as a biomarker for metabolic dysfunctions, especially those related to fatty acid oxidation. Its presence, often detected in urine or blood tests, can aid in diagnosing and monitoring metabolic conditions.

ADMA is an endogenous inhibitor of nitric oxide synthase (NOS), the enzyme responsible for producing nitric oxide (NO), a key molecule for vascular tone and endothelial function. Elevated ADMA levels can reduce nitric oxide availability, potentially affecting blood vessel dilation and circulation. Increased concentrations have been associated with endothelial dysfunction and impaired blood flow regulation. Low or balanced ADMA levels generally indicate healthy nitric oxide production and vascular function.

Albumin is the most abundant protein in human blood plasma and plays a key role in maintaining oncotic pressure, helping to retain fluid within blood vessels. It also binds and transports various substances in the blood, such as hormones, vitamins, and drugs. Produced by the liver, albumin levels in the blood serve as important indicators of liver function and nutritional status.

Alkaline phosphatase (ALP) is an enzyme found in various tissues across the body, notably in the liver, bones, kidneys, and digestive system. ALP plays a crucial role in protein breakdown and dephosphorylation processes. In the liver, it is linked with bile ducts and is frequently used to assist in diagnosing liver and bone disorders. Raised ALP levels may suggest bile duct obstruction or bone diseases, while low levels might be associated with specific genetic conditions and malnutrition.

Alpha-ketoglutarate (AKG) is a key compound in the Krebs cycle, an essential metabolic pathway for energy production in cells. It plays a crucial role in converting nutrients into energy, amino acid metabolism, and nitrogen transport. Additionally, Alpha-ketoglutarate is involved in various cellular processes, including signaling and regulation....

ALT (Alanine Aminotransferase): ALT is an enzyme primarily found in the liver, where it assists in breaking down proteins. When liver cells are damaged or inflamed, ALT is released into the bloodstream, causing its levels to rise. Measuring ALT is a common way to assess liver health, as elevated levels may indicate liver injury or disease, while normal levels generally suggest healthy liver function.

Alanine aminotransferase (ALT) is an enzyme primarily located in the liver that plays a crucial role in protein metabolism and other vital metabolic functions. Raised ALT levels in the blood can indicate damage to liver cells or inflammation, making it a significant marker for evaluating liver health.

Amylase is an enzyme involved in digestion, produced by the pancreas and salivary glands. Its primary function is to break down complex carbohydrates — such as starches and glycogen — into simpler sugars like maltose and glucose, which the body can easily absorb.

Aspartate aminotransferase (AST) is an enzyme present in the liver, heart, muscles, and other tissues. It enters the bloodstream when cells are damaged, making it a valuable marker for evaluating liver injury and other tissue damage. Elevated AST levels are commonly observed in liver conditions such as hepatitis or fatty liver disease but can also indicate muscle injury or heart disease. AST is usually assessed alongside alanine aminotransferase (ALT) to more accurately determine the type and severity of liver damage.

Beta-hydroxybutyrate (BHB) is a ketone body that indicates the body’s transition to using fat as its main energy source. Produced by the liver from fatty acids during fasting, carbohydrate restriction, or intense physical activity, BHB serves as an alternative energy source—especially for the brain—when glucose availability is low. It is a crucial marker of ketosis, a metabolic condition linked to fat metabolism.

Betaine is a compound found in foods such as beets and spinach. It plays key roles in the body by acting as a methyl donor in methylation processes, helping regulate cellular fluid balance, supporting liver health by preventing fat accumulation, and lowering homocysteine levels, which contributes to cardiovascular health.

Bilirubin is a yellow compound that indicates the breakdown of red blood cells in the body. It is transported to the liver, where it is processed and excreted into the bile. Proper liver function ensures bilirubin is effectively filtered from the blood and converted into a form that can be eliminated through the digestive system. Blood bilirubin levels are an important marker of liver health, bile duct function, and red blood cell turnover.

Hematuria, or blood in the urine, refers to the presence of red blood cells in the urine. It may be visible, causing the urine to appear pink, red, or cola-colored, or microscopic, detectable only through laboratory analysis. This condition can result from a variety of causes, ranging from minor issues to serious underlying health problems.

Carnitine is a naturally occurring compound that plays a vital role in energy metabolism. It transports long-chain fatty acids into the mitochondria, where they are broken down to generate energy, and aids in removing metabolic waste from cells. Although the body can synthesize carnitine in the liver and kidneys, it is also acquired from dietary sources, mainly animal-based foods.

The cholesterol-to-HDL (Chol:HDL) ratio is a measure that reflects the balance between total cholesterol and high-density lipoprotein (HDL) cholesterol in the blood. This ratio is used to assess heart disease risk, with a lower ratio indicating a healthier balance and a reduced risk. It is often considered a more accurate indicator of cardiovascular health than total cholesterol levels alone.

Choline is an essential nutrient that plays a crucial role in many vital bodily functions. It helps maintain the structure of cell membranes, supports the production of the neurotransmitter acetylcholine for muscle control, memory, and mood, and aids in fat metabolism and liver health. Choline is also important for brain development, neural tube formation during pregnancy, DNA synthesis, and the healthy functioning of the nervous system.

Cis-aconitate is an intermediate in the Krebs cycle, a central metabolic pathway involved in cellular energy production. It is formed during the conversion of citrate to isocitrate, a reaction catalyzed by the enzyme aconitase. The Krebs cycle plays a vital role in oxidising nutrients to produce ATP, the main energy source for cells, and also supplies key building blocks for the synthesis of amino acids, nucleotides, and fatty acids.

Citramalate, also known as citramalic acid, is a compound that can be measured as a urinary marker to assess metabolic health. It is produced as a metabolic byproduct and may indicate bacterial imbalance or overgrowth in the gut. Elevated levels can also reflect potential disruptions in normal metabolic processes.

Citrate is a compound that plays a vital role in the citric acid cycle, essential for energy production in aerobic organisms. It helps break down carbohydrates, fats, and proteins to produce ATP (energy). Citrate also aids in regulating the body’s acid-base balance and helps prevent kidney stones by binding with calcium.

CK, or Creatine Kinase, is an enzyme found in the heart, brain, skeletal muscle, and other tissues. Elevated levels of CK in the blood can indicate muscle damage, as this enzyme leaks out of damaged muscle cells. There are different types of CK, including CK-MM found in skeletal muscle, CK-MB primarily in the heart, and CK-BB typically in the brain. Measuring CK levels is useful for diagnosing and monitoring muscle damage, including damage from myocardial infarction (heart attack)....

Creatinine is a compound produced through muscle metabolism and acts as a crucial indicator of kidney function. It is derived from creatine, a molecule vital for energy production in muscles, and is filtered from the blood by the kidneys before being eliminated in urine.

Cystathionine is a non-protein amino acid that acts as an important intermediate in the metabolism of the essential amino acids methionine and cysteine. It plays a crucial role in the transsulfuration pathway, where homocysteine is converted into cystathionine by the enzyme cystathionine β-synthase (CBS), and cystathionine is then further degraded into cysteine by the enzyme cystathionine γ-lyase (CSE).

This ratio indicates the balance between more cytotoxic bile acids (such as lithocholic and deoxycholic acid) and protective bile acids like ursodeoxycholic acid (UDCA). A higher ratio may indicate increased oxidative or inflammatory stress in the liver or intestinal environment. A lower ratio, characterized by elevated neuroprotective bile acids, reflects improved bile acid regulation and decreased cellular stress. Balanced levels promote optimal liver detoxification and metabolic resilience.

Anti-Thyroid Peroxidase (A-TPO) antibodies are proteins produced by the immune system that target thyroid peroxidase, an enzyme essential for thyroid hormone production. Elevated levels of A-TPO antibodies may indicate autoimmune thyroid disorders, such as Hashimoto's thyroiditis or Graves' disease, which can disrupt thyroid function and affect overall health.

EBNA IgG is a marker that reflects the presence of antibodies against EBV (Epstein-Barr virus) nuclear antigen (EBNA), a protein produced during the later stages of infection. The presence of EBNA IgG antibodies generally indicates a past infection, as these antibodies develop several weeks to months after the initial infection and typically remain detectable for life. Testing for EBNA IgG is often used alongside VCA antibodies to differentiate between a current and past infection and to evaluate the stage of the infection.

EBV VCA is a protein component of the Epstein-Barr virus (EBV) that appears early during infection. Testing for VCA is an important marker for diagnosing both acute and chronic EBV infections.

eGFR (Estimated Glomerular Filtration Rate) is a measure used to estimate how effectively the kidneys filter waste from the blood. It is calculated using serum creatinine levels along with factors such as age, body size, and gender. eGFR serves as a crucial indicator of kidney function, helping to assess how well the kidneys are performing. A lower eGFR indicates reduced kidney function, which may suggest kidney disease or damage.

Ethyl malonate (EM) is a compound that acts as a biomarker for certain metabolic disorders. High levels of ethyl malonate in the body may indicate inherited metabolic conditions such as ethylmalonic encephalopathy or impairments in fatty acid oxidation.

Gamma-glutamyl transferase (GGT) is an enzyme found throughout the body, with the highest levels in the liver. GGT plays a crucial role in glutathione metabolism, which is essential for antioxidant defense. It aids in the transfer of amino acids and peptides across cell membranes. Elevated GGT levels are commonly used as a marker to detect liver damage, particularly bile duct obstructions and liver conditions associated with alcohol consumption.

Globulin is a group of blood proteins that play important roles in the body, including transporting hormones, lipids, vitamins, and minerals. They are also key components of the immune system, with some globulins functioning as antibodies that help defend against infections. Produced by the liver and immune system, globulin levels can provide insight into immune health, liver function, and nutritional status.

Glucose is a simple sugar and the primary source of energy for the body’s cells. It plays a vital role in metabolism, supporting brain function, muscle activity, and overall energy production. Blood glucose levels are carefully regulated by hormones such as insulin and glucagon. Imbalances in glucose levels can lead to conditions like diabetes, hypoglycemia, and hyperglycemia, impacting overall health and requiring proper management.

GOT, or Gamma-Glutamyl Transferase (GGT), is an enzyme found in various tissues of the body, with the highest levels in the liver. It plays a key role in glutathione metabolism, a vital antioxidant, and is involved in the transport of amino acids across cell membranes. GOT is commonly measured in blood tests and serves as an important marker of liver and biliary tract function.

HbA1c (Glycated Hemoglobin) is a biomarker that indicates the average blood glucose levels over the last two to three months. It is formed when glucose attaches to hemoglobin in red blood cells and acts as a crucial marker for long-term blood sugar control. Raised HbA1c levels indicate poor glucose management and are routinely used to diagnose and monitor diabetes.

HDL (High-Density Lipoprotein) is a type of cholesterol commonly known as “good” cholesterol. It helps protect heart health by transporting excess cholesterol from the bloodstream to the liver, where it can be eliminated from the body. Higher HDL levels are linked to a reduced risk of heart disease and stroke.

Histamine is a bioactive compound derived from the amino acid histidine and plays key roles in immune defense, stomach acid secretion, and inflammatory responses. In the bloodstream, histamine reflects both mast cell activity and the body’s ability to degrade histamine via enzymes such as DAO and HNMT. Elevated histamine levels may indicate immune activation, allergic response, or reduced histamine breakdown capacity. Low or balanced histamine concentrations suggest normal regulation of histamine metabolism and immune function.

Homovanillic acid (HVA) is a metabolite that indicates the breakdown of dopamine, a key neurotransmitter in the body. HVA levels act as an important marker for assessing dopamine activity. Variations in HVA can signal changes in dopamine function and are used to track the effectiveness of treatments targeting dopamine metabolism.

High-sensitivity C-reactive protein (hs-CRP) is a blood test that measures low levels of C-reactive protein (CRP), an important marker of inflammation in the body. Unlike standard CRP tests, hs-CRP can detect subtle inflammation, making it particularly useful for assessing the risk of cardiovascular diseases like heart attacks and strokes. Elevated hs-CRP levels may indicate a higher risk of heart disease, even when other risk factors are absent.

Hydroxymethylglutarate (HMG), particularly as β-hydroxy β-methylglutaryl-CoA (HMG-CoA), is a compound that plays two crucial roles in the body. It acts as a key intermediate in cholesterol synthesis, essential for forming cell membranes, steroid hormones, and bile acids. Furthermore, in the liver, HMG-CoA aids in the production of ketone bodies, which function as an alternative energy source during fasting, low-carbohydrate diets, or intense physical activity when glucose levels are depleted.

IDO (Indoleamine 2,3-dioxygenase) is an enzyme involved in metabolising the amino acid tryptophan through the kynurenine pathway. By depleting tryptophan, it can modulate immune responses, a mechanism that some tumours may use to evade immune detection. IDO is also implicated in psychiatric and neurodegenerative disorders and is influenced by inflammation and stress.

IgG (Immunoglobulin G) is a type of antibody that indicates the body’s long-term immune response. It is the most abundant antibody in the bloodstream and plays a crucial role in protecting against infections. In the case of Lyme disease, caused by the bacterium Borrelia burgdorferi, IgG antibodies are tested to assess past exposure or the later stages of infection. Unlike IgM antibodies, which appear early, IgG antibodies develop more slowly and can remain in the body for a long time, providing lasting immunity.

IgM (Immunoglobulin M) is a type of antibody that acts as the body’s first line of defence against infections. It plays a crucial role in the immune system’s initial response by promptly recognising and targeting invading pathogens. In diagnostic testing, IgM levels are measured to identify recent infections, such as Lyme disease caused by Borrelia burgdorferi. The presence of IgM antibodies in the blood generally indicates recent exposure or an active infection, providing vital information about the early stages of the immune response.

Isocitrate is a crucial intermediate in the Krebs cycle, a vital metabolic pathway for cellular energy generation. It is produced from citrate and subsequently transformed into α-ketoglutarate, a process that contributes to the production of NADH utilised for ATP synthesis. Isocitrate also links various metabolic pathways, including the synthesis of amino acids, nucleotides, and fatty acids.

Ketones are substances produced when the body breaks down fats for energy, especially during low carbohydrate intake such as fasting or following a ketogenic diet. This process, called ketosis, primarily takes place in the liver and generates key ketones like beta-hydroxybutyrate, acetoacetate, and acetone. Ketones serve as an alternative energy source, particularly for the brain, but elevated levels can signal serious conditions like diabetic ketoacidosis (DKA) in people with diabetes.

KMO (Kynurenine 3-monooxygenase) is an enzyme that plays a key role in the kynurenine pathway, responsible for metabolising the amino acid tryptophan. It helps regulate the balance of metabolites within this pathway, influencing processes that can affect brain health. KMO activity has been linked to neurological conditions such as Alzheimer’s disease, Huntington’s disease, and schizophrenia.

Kynurenic acid is a metabolite produced in the kynurenine pathway during the breakdown of the amino acid tryptophan. It acts in the nervous system as a neuroprotective agent and is a subject of interest in neurological and psychiatric research. Imbalances in kynurenic acid levels have been linked to conditions such as schizophrenia and depression.

Kynurenine is a key metabolite in the breakdown of the essential amino acid tryptophan. It serves as a precursor to several important compounds, including the neuroprotective kynurenic acid and the neurotoxic quinolinic acid, and plays a vital role in various physiological and pathological processes in the body.

Lactate, also known as lactic acid, is a byproduct of anaerobic metabolism — the process of breaking down glucose for energy without enough oxygen, commonly occurring during intense exercise. It is associated with muscle fatigue and the characteristic “burn” sensation experienced during strenuous activity. Lactate also plays a role in the Cori cycle, where it is converted back into glucose in the liver.

LDL (Low-Density Lipoprotein) is a type of cholesterol commonly known as “bad” cholesterol. It transports cholesterol particles through the bloodstream, and elevated levels can lead to plaque accumulation in the arteries. This accumulation, called atherosclerosis, can narrow and harden the arteries, raising the risk of heart disease and stroke.

The measurement of histamine in stool is a diagnostic test used to evaluate gastrointestinal conditions. Histamine is a compound involved in immune responses and inflammation. Elevated histamine levels in stool may indicate allergic reactions, infections, or disorders affecting the gut’s immune system. Monitoring stool histamine can help assess digestive health and guide treatment approaches.

Urinary leukocytes are white blood cells present in urine. They are usually absent or found in very small amounts, and elevated levels often indicate infection or inflammation in the urinary tract or kidneys. Their presence is a key indicator for diagnosing urinary tract infections (UTIs) and other kidney-related disorders.

Malate, or malic acid, is a crucial compound involved in cellular metabolism, particularly within the Krebs cycle in the mitochondria. It plays a vital role in energy production by being converted into oxaloacetate, a process that produces NADH, which is subsequently used to generate ATP, the primary energy currency of the cell.

Methylmalonic acid (MMA) is a substance produced in the body during the metabolism of certain fats and proteins. It is a byproduct of methionine breakdown and is influenced by vitamin B12 levels. Elevated MMA levels can serve as an indicator of vitamin B12 deficiency.

Neopterin is a molecule produced by immune cells, especially macrophages, in response to stimulation by interferon-gamma. It is regarded as a marker of immune system activation and inflammation. Elevated neopterin levels in urine or blood can indicate increased immune activity, commonly observed in infections, autoimmune disorders, or chronic inflammatory conditions. Since it reflects cellular immune response, neopterin is sometimes used to monitor disease progression or the status of the immune system.

Nicotinamide adenine dinucleotide (NAD) is a crucial coenzyme found in all living cells. It plays a key role in cellular metabolism, particularly in redox reactions, by cycling between its oxidised form (NAD⁺) and reduced form (NADH). Beyond energy production, NAD⁺ is essential for cell signalling, DNA repair, and regulating gene expression, making it vital for maintaining cellular health and function.

Urinary nitrates are chemical compounds usually not found or present only in trace amounts in urine. Their presence may indicate a bacterial infection, such as a urinary tract infection (UTI), because certain bacteria can convert urinary nitrite into nitrate. Nitrate testing is a common diagnostic method used to detect UTIs.

Non-HDL cholesterol measures all harmful types of cholesterol, including LDL (low-density lipoprotein), VLDL (very low-density lipoprotein), and other lipid particles that lead to plaque accumulation in your arteries. It is calculated by subtracting your HDL (high-density lipoprotein) or "good" cholesterol level from your total cholesterol count. Non-HDL cholesterol is regarded as a more comprehensive indicator of heart disease risk than LDL cholesterol alone, as it accounts for all atherogenic particles.

Primary bile acids – cholic acid (CA) and chenodeoxycholic acid (CDCA) – are synthesized in the liver and constitute the initial phase of bile acid metabolism. They play a crucial role in emulsifying dietary fats and aiding the absorption of fat-soluble vitamins. Elevated levels may indicate disrupted bile acid synthesis or cholestasis, whereas decreased levels can suggest diminished hepatic production or impaired bile flow. Balanced levels are indicative of normal liver function and bile acid metabolism.

Urinary protein, also known as proteinuria, refers to the presence of an abnormal amount of protein in the urine. Proteins, such as albumin, are vital components of blood, but they're not normally found in urine in significant amounts. The presence of protein in urine can be an indicator of kidney damage or disease, as healthy kidneys typically prevent significant protein loss through urine.

PSA (Prostate-Specific Antigen) is a protein produced by the prostate gland and is commonly measured in the blood as an indicator of prostate health. Elevated PSA levels may suggest prostate cancer but can also be caused by non-cancerous conditions such as benign prostatic hyperplasia or prostatitis.

PSA, or Prostate-Specific Antigen, is a protein produced by the prostate gland. Measuring PSA levels in the blood helps screen for prostate health, as elevated levels may indicate prostate cancer. However, higher PSA can also result from non-cancerous conditions such as benign prostatic hyperplasia or prostatitis.

The PSA ratio, or free-to-total PSA ratio, is a measure that indicates the proportion of free prostate-specific antigen (PSA) to total PSA in the blood. It is calculated by dividing the free PSA (not bound to proteins) by the total PSA (free plus protein-bound), then multiplying by 100 to express it as a percentage. This ratio aids in differentiating between benign prostate conditions and prostate cancer, particularly in men with moderately elevated total PSA levels.

Pyruvate is a key compound in cellular metabolism formed as the end product of glycolysis when glucose is broken down. It plays a central role in energy production by entering the citric acid cycle under oxygen-rich conditions. When oxygen is low, such as during intense exercise, pyruvate is converted into lactate to support continued ATP (energy) production. Additionally, pyruvate is involved in gluconeogenesis and serves as a precursor for amino acid synthesis.

Quinolinic acid is a metabolite in the kynurenine pathway, which is involved in the metabolism of the amino acid tryptophan. It plays a key role as an excitotoxin in the central nervous system. Elevated levels of quinolinic acid have been linked to neurological conditions such as Alzheimer’s disease, Huntington’s disease, epilepsy, and certain psychiatric disorders including depression.

S-Adenosylmethionine (SAMe) is a naturally occurring compound found in all cells, formed from methionine and ATP. It plays a vital role in methylation processes, neurotransmitter production affecting mood, joint health, and liver function. SAMe is commonly used as a supplement to support conditions such as depression, osteoarthritis, and liver disorders.

The SAMe/SAH ratio is a measurement that indicates the balance between two crucial compounds in the body — S-Adenosylmethionine (SAMe) and S-Adenosylhomocysteine (SAH). SAMe acts as a primary methyl donor in numerous biochemical reactions, while SAH is formed after SAMe donates its methyl group. A higher SAMe/SAH ratio signifies a strong capacity for methylation, which promotes healthy cellular function and overall well-being.

SDMA is a methylated derivative of the amino acid arginine and is primarily excreted by the kidneys. Unlike ADMA, SDMA does not directly inhibit nitric oxide synthase but reflects similar metabolic and renal processes. Elevated SDMA levels can indicate reduced kidney clearance or altered amino acid metabolism. Stable or optimal SDMA values suggest efficient renal function and normal arginine turnover.

This ratio reflects the conversion of primary bile acids by intestinal bacteria into secondary bile acids. A higher ratio may indicate increased microbial conversion or slowed bile acid turnover, while a lower ratio can reflect reduced bacterial activity or impaired bile flow. Maintaining balance is important for gut–liver communication, lipid metabolism, and overall digestive health.

Suberic acid, also known as octanedioic acid, is a dicarboxylic acid that acts as a metabolic marker in the body. In biological and physiological contexts, it is primarily linked to fatty acid metabolism. Increased levels of suberic acid may indicate metabolic disorders, especially those involving fatty acid oxidation, such as medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency.

Succinate is a crucial metabolic intermediate that plays a vital role in the Krebs cycle, the process by which cells generate energy. It assists in converting nutrients into ATP, the main energy source for cellular activities. Apart from energy production, succinate also takes part in amino acid and fatty acid synthesis and functions as a signalling molecule that affects inflammation and the body’s response to low oxygen levels.

Tertiary bile acids are secondary bile acids that have undergone further modification in the liver, such as ursodeoxycholic acid (UDCA). They are generally considered less cytotoxic and may have protective, anti-inflammatory effects on the liver and bile ducts. Elevated tertiary bile acids can indicate adaptive responses to oxidative or metabolic stress. Adequate levels reflect efficient bile acid recycling and hepatobiliary balance.

Total bile acids represent the combined concentration of all bile acids circulating in the blood. They are synthesised in the liver from cholesterol and play a central role in fat digestion, nutrient absorption, and detoxification. Elevated total bile acid levels may reflect reduced bile flow, liver dysfunction, or impaired reabsorption in the intestine. Normal concentrations indicate balanced bile acid synthesis and efficient hepatic and intestinal function.

Cholesterol is a waxy, fat-like substance found in all cells of the body and is essential for producing hormones, vitamin D, and digestive substances. While the body produces all the cholesterol it needs, it is also found in animal-based foods such as meat and dairy. There are two main types: low-density lipoprotein (LDL), or “bad” cholesterol, which can lead to plaque buildup in arteries, and high-density lipoprotein (HDL), or “good” cholesterol, which helps remove excess cholesterol from the bloodstream.

Total Iron Binding Capacity (TIBC) is a blood test that indicates the blood's ability to bind and carry iron through transferrin — the primary iron-transport protein. It offers an indirect measurement of available transferrin and is often used alongside other iron tests to evaluate iron deficiency, anaemia, or iron overload conditions.

Total protein is a measure that reflects the combined levels of two major blood proteins — albumin and globulin. Albumin, the most abundant protein in blood plasma, helps maintain oncotic pressure and transports various substances, while globulins play key roles in immune response, blood clotting, and other functions. Total protein levels provide important insights into nutritional status as well as liver and kidney health.

Transferrin saturation is a measure that reflects the percentage of transferrin — a blood protein that transports iron — that is actually bound to iron. It helps assess how effectively iron is being carried and utilized in the body. This marker is useful for identifying iron deficiency or iron overload, and is typically calculated using serum iron and total iron-binding capacity (TIBC). Low levels may suggest iron deficiency, while high levels can indicate conditions such as hemochromatosis.

Transglutaminase IgG (tTG-IgG) is a blood test that detects IgG antibodies against tissue transglutaminase, an enzyme found in the intestinal lining. It is primarily used to assist in diagnosing celiac disease, particularly in individuals with IgA deficiency or inconclusive tTG-IgA results, by identifying an immune response to gluten.

Triglycerides are a type of fat (lipid) present in the bloodstream and act as a primary form of energy storage. Extra calories from food are transformed into triglycerides and stored in fat cells, which are then released by hormones to provide energy between meals. High triglyceride levels, especially when paired with elevated LDL or low HDL cholesterol, are associated with an increased risk of atherosclerosis, heart attack, and stroke.

Trimethylamine (TMA) is a volatile organic compound produced in the gut by bacterial fermentation of dietary nutrients such as choline, L-carnitine, and lecithin. Normally, TMA is rapidly converted in the liver to trimethylamine N-oxide (TMAO), which is less toxic. However, elevated TMA levels can indicate imbalances in the gut microbiome or impaired liver detoxification capacity. High TMA is also associated with trimethylaminuria, a rare metabolic disorder that causes a strong body odor. Monitoring TMA provides insight into gut microbial activity, protein metabolism, and liver function.

Trimethylamine N-oxide (TMAO) is a compound produced in the liver from trimethylamine (TMA), which is generated by gut bacteria during the digestion of nutrients like choline, L-carnitine, and phosphatidylcholine. Elevated levels of TMAO have been linked to an increased risk of cardiovascular disease, kidney dysfunction, and inflammation. TMAO serves as a valuable marker for assessing metabolic health and the impact of gut microbiota on systemic disease risk. Lifestyle and diet, especially red meat and eggs, can significantly influence TMAO levels. Monitoring TMAO may help identify hidden risks even when other conventional markers appear normal.

Urea is a waste product formed in the liver through the breakdown of proteins. After formation, it is transported to the kidneys and eventually excreted in the urine. Measuring urea levels in the blood, often called blood urea nitrogen (BUN), is a common test used to evaluate kidney function. Elevated blood urea levels can indicate impaired kidney function or other issues affecting waste processing and excretion.

Urine density, also known as urine specific gravity, measures the concentration of solutes in urine. It reflects the kidneys' ability to concentrate or dilute urine and acts as an indicator of hydration status and kidney function. Although normal values may vary, deviations can signal dehydration, overhydration, or underlying kidney problems.

Urobilinogen in urine is a by-product of red blood cell breakdown, formed in the intestines from bilirubin and excreted in the urine. It is normally found in low concentrations and serves as an indicator of liver function and health. Abnormally high or low levels may indicate liver disease or blood-related conditions.

Vanillylmandelic acid (VMA) is a metabolite produced from the breakdown of catecholamines like adrenaline, noradrenaline, and dopamine. It serves as a clinical marker to evaluate catecholamine activity, with levels usually measured in urine. Various factors, including certain foods and medications, can affect VMA levels.

Xanthurenate is a metabolite produced during the breakdown of the amino acid tryptophan via the kynurenine pathway. Its levels can indicate vitamin B6 (pyridoxine) status, as this vitamin serves as an essential cofactor in the process. Elevated xanthurenate may suggest a vitamin B6 deficiency.