WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
Inflammation is a broad concept, but in the metallomics context it has a specific character: heavy metals and pathogens activate overlapping inflammatory pathways, creating convergent pathology where distinguishing the metal contribution from the microbial contribution …
Neuroinflammation is an immune response within the central nervous system (CNS)—the brain and spinal cord. It involves changing states of microglia, astrocytes, cells of the neurovascular unit, and, in some settings, immune cells recruited from the circulation. The resp…
Harm potential: YELLOW — True iron deficiency anemia requires supplementation.
Systemic inflammation is the state in which inflammatory mediators — IL-6, TNF-alpha, CRP, IL-1beta — circulate throughout the body rather than remaining confined to a local injury site. In the WikiBiome framework, systemic inflammation is the final common pathway throu…
An acidic microenvironment is a local drop in pH — typically into the 4.5–6.5 range — inside a tissue, organ, or ecological niche. Acidification arises from three recurring sources: bacterial fermentative metabolism that releases short-chain fatty acids and lactate (lou…
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that functions as a master sensor at the intersection of gut microbial metabolism, environmental chemical exposure, and immune regulation. It is expressed broadly across immune cells, intesti…
The most common form of dementia, affecting an estimated 55 million people worldwide and projected to triple by 2050 zhang 2024 recent advances alzheimers mechanisms trials. Characterized by progressive memory loss, cognitive decline, amyloid-beta plaques, and neurofibr…
Arachidonic acid (AA) is a 20-carbon omega-6 polyunsaturated fatty acid (20:4n-6) that serves as the primary substrate for prostaglandin and leukotriene synthesis via COX-2 and 5-LOX pathways. It is the dominant pro-inflammatory lipid mediator — and its balance with ant…
Aromatase (CYP19A1) is the cytochrome P450 enzyme that catalyzes the final and rate-limiting step of estrogen biosynthesis — the conversion of androgens (testosterone, androstenedione) to estrogens (estradiol, estrone). It is expressed in the ovaries, placenta, adipose …
This page serves as a cross-reference point for the existing ahr concept page, which provides comprehensive coverage of AhR signaling, microbiome-derived ligands, and immune regulation. The aryl hydrocarbon receptor is a ligand-activated transcription factor that integr…
Progressive inflammatory disease of the arterial wall characterized by lipid accumulation, immune cell infiltration, and fibrous plaque formation. In the metallomics framework, atherosclerosis sits at the convergence of three interacting systems: heavy metal toxicity, g…
Atherosclerosis is a chronic inflammatory disease of arterial walls characterized by lipid-laden plaque formation, endothelial dysfunction, and progressive vascular occlusion. It is the pathological substrate underlying coronary artery disease, stroke, and peripheral ar…
A neurodevelopmental condition affecting approximately 1 in 36 children (US CDC 2023 estimate), characterized by differences in social communication, restricted interests, and repetitive behaviors. From a metallomics perspective, ASD presents a compelling convergence of…
The bacterial contamination hypothesis proposes that bacterial endotoxin (LPS) contamination of menstrual blood and endometrial tissue is a key driver of endometriosis pathogenesis. First formalized by Khan et al. (2018), this hypothesis shifts endometriosis from a pure…
A Gram-negative obligate anaerobe and the most clinically significant member of the Bacteroides genus. B. fragilis occupies a unique dual position in gut microbiology: as a non-toxigenic commensal (NTBF), it produces polysaccharide A (PSA) that shapes immune tolerance; …
Barrett's esophagus (BE) is a premalignant condition in which the normal squamous epithelium of the distal esophagus is replaced by intestinal-type columnar epithelium (intestinal metaplasia). It is the primary risk factor for esophageal adenocarcinoma (EAC), a cancer w…
Bilophila wadsworthia is a Gram-negative, obligate anaerobic, sulfite-reducing bacterium that has emerged as a key pathobiont linking high-fat diets, taurine metabolism, hydrogen sulfide production, and inflammatory disease. Its unique metabolic niche -- using taurine-c…
Bipolar disorder is a chronic neuropsychiatric condition characterized by recurrent episodes of mania (or hypomania) and depression, affecting approximately 1-2.4% of the global population. It carries significant morbidity -- reduced life expectancy by 10-15 years, high…
A selective semipermeable border formed by brain endothelial cells connected by tight junctions, pericytes, and astrocytic end-feet. The BBB restricts passage of most molecules from blood to brain, protecting the CNS from toxins, pathogens, and inflammatory mediators. M…
A heterodimer of S100A8 and S100A9 calcium-binding proteins that constitutes approximately 60% of the cytosolic protein content of neutrophils. Calprotectin is a central effector of nutritional immunity, sequestering essential transition metals from invading pathogens a…
Cardiovascular disease (CVD) -- encompassing atherosclerosis, coronary artery disease, hypertension, myocardial infarction, heart failure, and stroke -- is the leading cause of death globally. The gut-heart axis has emerged as a central paradigm linking microbial metabo…
Cerebral palsy (CP) is the most common motor disability in childhood, affecting 2-3 per 1,000 live births allen 2021 multi organ dysfunction cerebral palsy. Characterized by non-progressive disturbances in movement and posture arising from injury to the developing brain…
The major copper-carrying protein in human blood, binding approximately 95% of circulating copper. Ceruloplasmin is far more than a passive transport vehicle -- it is a multicopper oxidase with ferroxidase activity, an acute-phase reactant that rises with inflammation, …
Christensenellaceae is a family of Gram-negative, strictly anaerobic bacteria within the order Clostridiales (phylum Firmicutes) that has emerged as one of the most consistently health-associated and heritable members of the human gut microbiome. First formally describe…
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, disabling condition characterized by profound fatigue not relieved by rest, post-exertional malaise (PEM -- symptom worsening after physical or cognitive exertion), unrefreshing sleep, cognitive d…
Cirrhosis is end-stage liver fibrosis characterized by nodular regeneration, portal hypertension, and progressive hepatic failure. The gut-liver axis is central: portal venous blood delivers gut-derived LPS, bacterial DNA, and viable bacteria directly to the liver, and …
Clostridium symbiosum is a Gram-positive, obligately anaerobic bacterium within the Clostridium cluster XIVa — a taxonomic group enriched for short-chain fatty acid (SCFA) producers and specialized bile acid metabolizers. Despite its ambiguous name (suggesting symbiotic…
Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer death. Over 90% of cases are sporadic, driven by a complex interplay between genetic predisposition, dietary habits, gut microbiome composition, and environmental ex…
The co-occurrence of multiple diseases in the same individual at rates exceeding chance. Comorbidity patterns are a central puzzle in medicine -- why do IBD patients develop CVD? Why does PCOS cluster with T2D? Why do neurodegenerative diseases associate with depression…
An essential trace element with a striking dual nature: required for survival as a cofactor for critical enzymes (SOD1, cytochrome c oxidase, ceruloplasmin), yet toxic in excess through Fenton-like redox cycling and mis metallation of iron-sulfur clusters. Copper is ele…
Perhaps the most pervasive metallomic finding across human disease: copper is elevated in nearly every pathological condition examined in this wiki -- cancer (pan-cancer), PCOS, cardiovascular disease, depression, schizophrenia, IBD, and rheumatoid arthritis. Simultaneo…
Cyclooxygenase-2 (COX-2) is the inducible enzyme that converts arachidonic acid to prostaglandin H₂ — the precursor of prostaglandin E₂ (PGE₂), prostacyclin, and thromboxane. Unlike COX-1 (constitutive, homeostatic), COX-2 is transcriptionally induced by nf kappa b duri…
A chronic, relapsing-remitting inflammatory bowel disease (IBD) characterized by transmural inflammation of the gastrointestinal tract, most commonly affecting the terminal ileum and colon but capable of involving any segment from mouth to anus zhang 2017 intestinal mic…
Depression is the most prevalent mental health disorder globally, affecting over 280 million people zhu 2025 microbiota gut brain axis depression review, and one of the most metal-sensitive conditions in this wiki. It sits at the convergence of nearly every pathway cata…
A genus of Gram-negative, obligate anaerobic, sulfate-reducing bacteria (SRB) that produces hydrogen sulfide (H2S) as its primary metabolic end-product. H2S is a potent cytotoxin that disrupts colonocyte energy metabolism, damages the gut barrier, and promotes chronic i…
Diabetic kidney disease (DKD), also known as diabetic nephropathy, is the leading cause of end-stage renal disease (ESRD) worldwide, affecting 30-40% of patients with type 2 diabetes and type 1 diabetes. DKD is defined by progressive albuminuria, declining glomerular fi…
Disruption of the normal composition and metabolic function of microbial communities, particularly the gut microbiome. In the metallomics context, dysbiosis is both a consequence of metal toxicity and an amplifier of further disease -- creating vicious cycles where meta…
Dysmenorrhea -- painful menstruation -- is the most common gynecological complaint, affecting 50-90% of reproductive-age women. It is classified as primary (no identifiable pelvic pathology) or secondary (caused by conditions such as endometriosis, adenomyosis, or fibro…
Endometriosis is a chronic estrogen-dependent inflammatory condition affecting approximately 10% of reproductive-age women, characterized by the growth of endometrial-like tissue outside the uterus colonetti 2023 gut vaginal microbiota endometriosis meta analysis. The c…
Endothelial dysfunction is the impairment of the vascular endothelium's ability to produce nitric oxide (NO), regulate vascular tone, and prevent thrombosis. It is the earliest detectable stage of atherosclerosis and the mechanistic link between gut dysbiosis, systemic …
Endotoxemia is the presence of bacterial endotoxin (lipopolysaccharide, LPS) in the bloodstream. Metabolic endotoxemia — chronic, low-grade LPS translocation from the gut — is a central mechanism linking dysbiosis to systemic disease across dozens of conditions in this …
Moderate-to-vigorous exercise (~90 min/week) as adjunctive therapy alongside antipsychotics. The strongest evidence base of any non-pharmacological intervention for schizophrenia, with meta-analytic support for both psychiatric symptom reduction and metabolic benefit.
Fermentative metabolism is the set of anaerobic metabolic pathways by which bacteria break down carbohydrates and amino acids in the absence of oxygen, producing short-chain fatty acids (SCFAs) (primarily butyrate, propionate, acetate), gases (H₂, CO₂, CH₄), and organic…
The primary intracellular iron storage protein, capable of sequestering up to 4,500 iron atoms in a single molecule as a mineralized ferric oxyhydroxide core. Ferritin is one of the most elegant solutions evolution has produced for the iron paradox: iron is essential fo…
A Gram-negative obligate anaerobe that occupies a paradoxical niche in the gut microbiota: as a weak butyrate producer (short-chain fatty acid), it has anti-inflammatory potential; as a virulent invasive pathobiont in inflammatory bowel disease (particularly ulcerative …
The fifth most common cancer worldwide and third leading cause of cancer death, with over 1 million new cases annually. Gastric cancer stands unique in this wiki as the disease where a single microorganism -- helicobacter pylori -- provides the dominant causal pathway, …
Gastroesophageal reflux disease (GERD) is a chronic condition in which stomach acid or bile flows back into the esophagus, causing mucosal damage and symptoms such as heartburn and regurgitation. Affecting approximately 20% of Western populations, GERD is conventionally…
Alphabetical definitions of specialist terms used throughout this wiki. Where a full concept page exists, the term links to it. --- AhR (aryl hydrocarbon receptor) -- A ligand-activated transcription factor that senses microbial metabolites (especially indoles from tryp…
Gut barrier dysfunction -- colloquially "leaky gut" -- is the pathological increase in intestinal permeability that permits translocation of bacteria, bacterial products (LPS, peptidoglycan), metals, and dietary antigens from the gut lumen into the systemic circulation.…
Bidirectional communication between the gut microbiota and the central nervous system, mediated by neural (vagus nerve, enteric nervous system), immune (cytokines, microglia), endocrine (HPA axis), and metabolic (SCFAs, neurotransmitter precursors, tryptophan metabolite…
The gut-penis axis is an emerging concept describing the systemic pathway by which gut microbiome dysbiosis impairs erectile function through endothelial nitric oxide (NO) suppression and chronic inflammation. Though less established than the gut-brain or gut-heart axes…
The gut-prostate axis describes the bidirectional communication between the gut microbiome and the prostate gland. Gut-derived microbial metabolites, inflammatory mediators, and immune signals influence prostatic health, while prostatic disease states alter systemic inf…
The gut-thyroid axis describes the bidirectional communication between the gut microbiome and the thyroid gland. The thyroid regulates metabolism, energy homeostasis, and immune function -- and the microbiome influences thyroid physiology at every level: mineral absorpt…
heavy metals exert some of their most devastating effects on the nervous system. lead, mercury, and arsenic are the three metals with the most extensively documented neurotoxic mechanisms, but cadmium, manganese, aluminum, and nickel also contribute to neurological dama…
Hepatitis (liver inflammation) encompasses viral (HBV, HCV, HAV), autoimmune, alcoholic, and toxin-induced forms. In the WikiBiome framework, the gut-liver axis is central — portal blood delivers gut-derived microbial products (LPS, bacterial DNA) directly to the liver …
The master regulator of systemic iron homeostasis. Hepcidin is a 25-amino-acid peptide hormone produced primarily by hepatocytes that controls iron absorption, recycling, and distribution by binding to and degrading ferroportin (SLC40A1/FPN) -- the only known cellular i…
HIV (Human Immunodeficiency Virus) causes progressive CD4+ T cell depletion leading to AIDS. In the WikiBiome framework, HIV is notable for the gut-centric model of disease progression: HIV preferentially destroys gut-associated lymphoid tissue (GALT) early in infection…
Interleukin-1 beta (IL-1β) is a master pro-inflammatory cytokine and the primary product of the NLRP3 inflammasome. Unlike IL-6 and TNF-alpha (which are transcriptionally regulated by nf kappa b), IL-1β requires a two-step activation: (1) NF-kB-driven transcription of p…
IL-8 (CXCL8) is the primary neutrophil chemokine — it recruits neutrophils to infection sites and activates their antimicrobial functions (oxidative burst, degranulation, NET formation). In the WikiBiome context, IL-8 is notable for its vulnerability to gingipain degrad…
The immune system is not a monolith but a dynamic equilibrium between pro-inflammatory effector responses (Th1, Th2, Th17) and anti-inflammatory regulatory responses (Treg, IL-10, TGF-beta). Metals and the microbiome are two of the most potent environmental modulators o…
An umbrella term for chronic relapsing-remitting inflammatory conditions of the gastrointestinal tract, principally crohns disease (CD; transmural, any GI segment) and ulcerative colitis (UC; mucosal, colon only). Approximately 6 million patients worldwide. IBD represen…
Interleukin-22 (IL-22) is an immune signaling protein that helps coordinate host responses at epithelial surfaces. In the gut evidence represented by WikiBiome, group 3 innate lymphoid cells (ILC3s) are a prominent source, while Th17-associated responses can also includ…
Interleukin-6 is a pleiotropic cytokine that sits at the crossroads of innate immunity, adaptive immunity, and metabolism. It is one of the most frequently elevated inflammatory mediators across conditions in this wiki — appearing in disease signatures spanning IBD, aut…
The intestinal epithelium is a single-cell-thick barrier separating the lumen -- home to trillions of microbes and ingested metals -- from the systemic circulation. When this barrier fails, the consequences cascade: microbial products translocate, metals gain unrestrict…
Kynurenine is the primary metabolite of the kynurenine pathway, which handles ~95% of tryptophan catabolism in the body. While serotonin gets more attention, the kynurenine pathway is quantitatively dominant -- and its downstream metabolites span the range from neuropro…
The kynurenine pathway (KP) is the dominant route of tryptophan catabolism, accounting for approximately 95% of dietary tryptophan degradation. It produces a cascade of neuroactive, immunomodulatory, and potentially neurotoxic metabolites whose balance determines whethe…
Lachnospira is a genus of Gram-positive, obligate anaerobic bacteria within the lachnospiraceae family (Firmicutes phylum). L. pectinoschiza, the type species, is a specialist pectin fermenter that produces short chain fatty acids from plant-derived polysaccharides. The…
An iron-binding glycoprotein of the transferrin family that sequesters iron (and potentially other metals) from pathogens at mucosal surfaces and sites of inflammation. Lactoferrin is a key effector of nutritional immunity, complementing calprotectin's role in metal res…
Leptin is an adipokine (hormone produced by adipose tissue) that signals satiety to the hypothalamus — suppressing appetite and increasing energy expenditure. Leptin resistance (elevated leptin with impaired signaling) is a hallmark of obesity, paralleling insulin resis…
Lipopolysaccharide (LPS), also called endotoxin, is a major structural component of the outer membrane of Gram-negative bacteria. When released into circulation through a compromised gut barrier, LPS triggers potent inflammatory signaling via Toll-like receptor 4 (TLR4)…
Post-acute sequelae of SARS-CoV-2 infection (PASC), affecting an estimated 10-30% of COVID-19 survivors (WHO and CDC post-acute surveillance estimates) with symptoms persisting 12 weeks. Characterized by fatigue, cognitive dysfunction ("brain fog"), exercise intolerance…
Major depressive disorder (MDD) is a psychiatric condition characterized by persistent depressed mood, anhedonia, and cognitive/somatic symptoms. In the WikiBiome framework, MDD is a paradigm case for the gut brain axis: gut dysbiosis drives systemic inflammation and ne…
The biological processes by which organisms maintain proper intracellular and systemic concentrations of essential metals -- importing what is needed, storing excess safely, and exporting or sequestering surplus. Both host and microbial systems have evolved elaborate me…
Microbial metallomics is the study of how metals and microorganisms interact at the systems level — how metal availability shapes microbial communities, how microbes acquire and weaponize metals for virulence, and how this bidirectional metal-microbe interface drives di…
Microglia are the resident immune cells of the central nervous system, constituting 5-12% of all brain cells. They function as the brain's surveillance and defense system -- scanning for damage, clearing debris, pruning synapses during development, and mounting inflamma…
Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system, with a global prevalence of approximately 2.8 million attfield 2022 immunology ms nature review. The conventional framing centers on genetic susceptibility (HLA-DRB115:0…
Necrotizing enterocolitis (NEC) is the most common and lethal gastrointestinal emergency in premature infants, affecting 5-12% of very low birth weight neonates (<1500 g) with mortality rates of 20-30%. Characterized by intestinal inflammation, necrosis, and perforation…
Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) is a family of transcription factors that regulate inflammation, immune responses, cell survival, and proliferation. NF-kB is a convergence point where metal toxicity, pathogen signaling, and chronic…
The NLRP3 inflammasome is a host innate-immune signaling complex that connects cellular danger signals to caspase-1 activation. In the canonical pathway represented in WikiBiome's evidence vault, caspase-1 processes the inflammatory cytokines IL-1beta and IL-18 and clea…
Nrf2 is a master transcription factor that regulates the expression of antioxidant and cytoprotective genes. It plays a central role in cellular defense against oxidative stress, electrophilic stress, and inflammation. Under normal conditions, Nrf2 is sequestered in the…