WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
Antimicrobial metals are metal ions and metal-based materials that kill or inhibit microorganisms. Copper, silver, zinc, and gallium are the principal agents, each exploiting different aspects of microbial metal biology. What makes this field particularly relevant to Wi…
Autoimmunity occurs when the immune system attacks the body's own tissues. What has emerged over the past two decades is that the gut microbiome is not merely associated with autoimmune disease -- it is a mechanistic driver of immune tolerance breakdown. Metals add a se…
Structured microbial communities encased in a self-produced extracellular polymeric substance (EPS) matrix. Biofilms are the predominant mode of bacterial and fungal growth in chronic infections, device-associated infections, and the gut. From a metallomics perspective,…
A genus of spirochete bacteria transmitted by Ixodes ticks, best known as the causative agent of Lyme disease -- the most common tick-borne illness in the Northern Hemisphere. Borrelia burgdorferi sensu lato comprises approximately 20 genospecies, with B. burgdorferi se…
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…
Chitotriosidase (CHIT1) is a human chitinase that degrades chitin — the structural polysaccharide of fungal cell walls, insect exoskeletons, and parasitic helminths. It is the most abundant chitinase in human serum and represents a direct arm of innate nutritional immun…
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…
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…
iron occupies a unique position among dietary metals: it is both an essential nutrient and a selective pressure that shapes the gut microbial ecosystem. The form, quantity, and bioavailability of dietary iron determines which microbes thrive and which are competitively …
The pathological disruption of normal metal homeostasis — the tightly regulated balance of essential trace elements (iron, zinc, copper, manganese, selenium, cobalt) and the effective exclusion of toxic metals (cadmium, lead, mercury, arsenic). Dyshomeostasis is a conve…
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…
The only known cellular iron exporter in mammals. Encoded by the SLC40A1 gene, ferroportin (FPN) sits on the basolateral membrane of enterocytes, the surface of macrophages, and the membrane of hepatocytes, controlling the flow of iron from these cells into the bloodstr…
Gene regulation in bacteria is the process by which cells control when and how much of each gene product is made. In the metallomics context, gene regulation is the mechanism by which bacteria respond to the metal environment -- sensing metal availability and adjusting …
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…
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…
Interferon gamma (IFN-γ) is the signature Th1 cytokine and the primary activator of macrophage antimicrobial functions. In the WikiBiome framework, IFN-γ is critical for two reasons: it drives nutritional immunity (iron restriction against intracellular pathogens) and i…
Innate immunity is the body's first-line, non-specific defense against pathogens — comprising physical barriers (epithelium, mucus), antimicrobial molecules (calprotectin, lactoferrin, defensins), pattern recognition receptors (TLRs, NOD-like receptors), and phagocytic …
Microbial communities do not acquire and use metals in isolation. Within biofilms, polymicrobial infections, and the gut microbiome, microbes engage in complex cooperative and competitive relationships mediated by metals -- sharing metallophores, concentrating metals in…
The most abundant transition metal in the human body and arguably the most consequential metal in biology. Iron sits at the center of a paradox that drives pathology across virtually every disease domain: organisms need it for oxygen transport, energy metabolism, DNA sy…
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…
Research summary — not medical advice. This page synthesizes published research on a mechanism-level intervention. It is not a clinical recommendation. Consult a qualified healthcare provider before making any changes to diet, supplementation, or treatment.
Lipocalin-2 (also known as NGAL — neutrophil gelatinase-associated lipocalin, or siderocalin) is a 25 kDa secreted protein produced by activated neutrophils, epithelial cells, and other innate immune cells. Its primary antimicrobial function is to sequester bacterial si…
Research summary — not medical advice. This page synthesizes published research on a mechanism-level intervention. It is not a clinical recommendation. Consult a qualified healthcare provider before making any changes to diet, supplementation, or treatment.
Manganese is an essential trace element with a narrow therapeutic window: required as a cofactor for critical enzymes including Mn-SOD (SOD2), pyruvate carboxylase, arginase, and ribonucleotide reductase, yet profoundly neurotoxic at elevated levels martin 2022 manganes…
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…
Metal sensing is the set of regulatory mechanisms bacteria use to detect intracellular metal concentrations and adjust gene expression accordingly. Because metal ions cannot be synthesized or degraded -- only imported, exported, sequestered, or trafficked -- sensing and…
Transition metals serve as essential cofactors for pathogen virulence factors across virtually all domains of microbial life. The dependence of pathogens on metals they must scavenge from the host environment creates a fundamental tension at the heart of infectious dise…
Protein-based transcription factors that sense intracellular metal concentrations and regulate gene expression accordingly. Metalloregulators are the decision-making layer of bacterial metal homeostasis -- they read the labile metal pool, determine whether a specific 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…
A transition metal occupying a central position in this wiki's evidence base. Nickel is toxic and carcinogenic to humans, yet an essential cofactor for pathogen virulence enzymes. It is the most frequent contact allergen worldwide and drives a wide spectrum of systemic …
Pathogens deploy dedicated cellular machinery to import, store, regulate, and when necessary export transition metals. These systems complement the extracellular siderophores metallophores that scavenge metals from the host environment by providing the membrane transpor…
Postpartum depression (PPD) affects 10-20% of women after delivery, with profound consequences for maternal health, infant bonding, and child neurodevelopment chao 2025 microbiota gut brain perinatal depression. The standard framing centers on hormonal withdrawal (estro…
Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. In the WikiBiome framework, sepsis represents the catastrophic failure of both colonization resistance (pathogen invasion) and nutritional immunity (metal restriction). Inf…
Small, high-affinity iron-chelating molecules secreted by bacteria and fungi to scavenge ferric iron (Fe3+) from the environment. Siderophore competition is a fundamental ecological force in the gut microbiome: organisms with superior iron acquisition systems gain a dec…
Siderophores are small, high-affinity iron-chelating molecules secreted by bacteria, fungi, and some plants to scavenge ferric iron (Fe3+) from their environment. In the context of infection, siderophores are the molecular weapons pathogens deploy to break through nutri…
Siderophores and metallophores are small-molecule chelators secreted by pathogens to scavenge metals from the metal-scarce host environment. They represent the extracellular arm of pathogen metal acquisition -- how pathogens reach out into the surrounding milieu to capt…
Small regulatory RNAs (sRNAs) are non-coding RNA molecules, typically 50-500 nucleotides long, that regulate gene expression post-transcriptionally in bacteria. In the context of metal biology and microbial pathogenesis, sRNAs serve as rapid-response coordinators that h…
A genus of Gram-positive, facultative anaerobic cocci that includes some of the most clinically significant human pathogens. Staphylococci are defined by their exceptionally comprehensive metal acquisition arsenal -- arguably the most thoroughly characterized of any bac…
A versatile Gram-positive pathogen with one of the best-characterized nutritional immunity evasion systems known. S. aureus requires nickel, iron, zinc, and manganese for virulence and has evolved dedicated acquisition systems for each, including the novel metallophore …
Research summary -- not medical advice. This page synthesizes published research on why a commonly prescribed intervention may be counterproductive in this specific clinical context. Consult a qualified healthcare provider before making any changes to treatment.
Warning: Clinical Disclaimer: This STOP page represents a hypothesis based on mechanistic evidence and should NOT replace clinical judgment. Always consult with a qualified healthcare provider before modifying any treatment plan.
Harm potential: YELLOW — True iron deficiency anemia requires supplementation regardless of inflammatory state.
Warning: Clinical Disclaimer: This STOP page represents a hypothesis based on mechanistic evidence and should NOT replace clinical judgment. Always consult with a qualified healthcare provider before modifying any treatment plan. Evidence quality ratings reflect the str…
This knowledge-base record is being expanded from WikiBiome’s evidence graph.
Warning: Clinical Disclaimer: This STOP page represents a hypothesis based on mechanistic evidence and should NOT replace clinical judgment. Always consult with a qualified healthcare provider before modifying any treatment plan. Evidence quality ratings reflect the str…
Warning: Clinical Disclaimer: This STOP page represents a hypothesis based on mechanistic evidence and should NOT replace clinical judgment. Always consult with a qualified healthcare provider before modifying any treatment plan. Evidence quality ratings reflect the str…
Harm potential: YELLOW — True iron deficiency anemia requires supplementation.
Research summary -- not medical advice. This page synthesizes published research on why a commonly prescribed intervention may be counterproductive in this specific clinical context. Consult a qualified healthcare provider before making any changes to treatment.
A Gram-positive pathogen (the "pneumococcus") that depends on iron, manganese, and zinc for virulence and has evolved dedicated transport systems for each. Iron is required for viability itself, manganese powers the superoxide dismutase needed to survive the oxidative b…
Superoxide dismutases are metalloenzymes that catalyze the dismutation of superoxide radical (O2-) into hydrogen peroxide (H2O2) and molecular oxygen -- the first line of defense against oxidative damage in all aerobic organisms. What makes SOD uniquely important in mic…
Transferrin is a glycoprotein (β₁-globulin, ~80 kDa) synthesized primarily by the liver that functions as the principal iron-transport protein in blood plasma. It binds ferric iron (Fe³⁺) with extraordinarily high affinity (Kd ~10⁻²³ M) and delivers it to cells via tran…
Tuberculosis is caused by mycobacterium tuberculosis, an intracellular pathogen that survives inside macrophage phagosomes. In the WikiBiome framework, TB exemplifies the intracellular metal battleground: M. tuberculosis deploys mycobactins (lipophilic siderophores) and…
Virulence factors are the molecular tools that enable a microorganism to colonize, invade, evade immune defenses, and cause damage to the host. They include toxins, adhesins, invasins, immune evasion molecules, and metabolic enzymes that provide competitive advantages i…
Zinc is the most widely utilized transition metal cofactor in biology. Approximately 9-10% of the eukaryotic proteome and 5-6% of the bacterial proteome consists of zinc-binding proteins capdevila 2024 bacterial metallostasis sensing trafficking. An estimated one-third …