WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
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 non-essential metal and the most abundant metallic element in the Earth's crust. Unlike manganese, iron, or selenium, aluminum has no known biological function in humans. Its significance in metal toxicology stems from two major concerns: proven neurotoxicity at eleva…
The process by which selection pressure from one agent — typically a heavy metal — simultaneously selects for resistance to a structurally unrelated agent such as an antibiotic, because the resistance determinants are genetically linked on the same mobile genetic elemen…
This page unifies the infant formula contamination, pregnancy complications, autism spectrum disorder, necrotizing enterocolitis, and neurodevelopmental toxicity threads around a single organizing insight: metal toxicity is disproportionately severe during specific deve…
arsenic (As) is unique among dietary heavy metals because it exists in two fundamentally different forms with dramatically different toxicities: inorganic arsenic (iAs, the dangerous form) and organic arsenic (arsenobetaine, arsenosugars — largely non-toxic). Understand…
cadmium (Cd) enters the human body primarily through food. Unlike nickel, which has high-concentration food categories that can be avoided, cadmium contamination is diffuse — embedded in staple crops, leafy greens, and grains that form the basis of most dietary patterns…
lead (Pb) has no safe level of exposure. Unlike most dietary metals, lead does not play any known biological role — every atom absorbed represents toxic burden. While environmental lead exposure (paint, soil, air) has decreased dramatically since leaded gasoline phase-o…
A synthesis of how dietary heavy metal exposure varies across the human lifespan, highlighting that the same metals present different risks at different developmental stages due to changing absorption rates, detoxification capacity, dietary patterns, and organ vulnerabi…
Food is the primary source of nickel exposure for the general (non-occupational) population. While food nickel poses minimal risk to most adults, children and nickel-sensitized individuals are high-risk groups.
Membrane-spanning protein complexes that actively export substrates from the bacterial cell, using energy from ATP hydrolysis or the proton motive force. In the context of metal-microbiome biology, efflux pumps serve a dual role that has profound clinical consequences: …
This page addresses the practical question: how do toxic metals get into people? Metal toxicology research identifies the mechanisms of harm, but understanding exposure routes -- dietary, occupational, environmental, and consumer product-mediated -- is essential for pre…
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 6-24 month developmental window — when infants transition from breast milk to solid foods — represents a convergence of maximum vulnerability and maximum exposure. Immature detoxification systems, rapid organ development, and high food-to-body-weight ratios mean tha…
Interleukin-10 is the primary anti-inflammatory cytokine, produced by Treg cells, macrophages, dendritic cells, and B cells. It suppresses pro-inflammatory cytokine production (IL-6, TNF-alpha, IL-1β), inhibits antigen presentation, and maintains immune tolerance. IL-10…
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…
Iron-sulfur (Fe-S) clusters are among the most ancient and ubiquitous metal cofactors in biology, present in all domains of life. These inorganic prosthetic groups -- typically [2Fe-2S] or [4Fe-4S] configurations -- mediate electron transfer, enzymatic catalysis, and re…
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…
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…
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…
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 …
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…
Streptococcus thermophilus is a Gram-positive, facultative anaerobic coccus that is the primary probiotic species used in commercial yogurt fermentation and thermophilic dairy fermentation worldwide. Distinct from pathogenic Streptococcus species, S. thermophilus produc…
TGF-beta is a pleiotropic cytokine with dual roles: immunosuppressive (driving regulatory T cell [Treg] differentiation and maintaining immune tolerance) and pro-fibrotic (promoting extracellular matrix deposition, wound healing, and tissue fibrosis). In the WikiBiome c…
The Th17/Treg balance is the immunological equilibrium between pro-inflammatory T helper 17 (Th17) cells and anti-inflammatory regulatory T (Treg) cells. This balance is the master switch between immune tolerance and autoimmune/inflammatory pathology — and the gut micro…
A non-essential metal with a dual toxicological profile: inorganic tin (from canned foods) causes primarily gastric irritation at high concentrations, while organotin compounds (tributyltin, trimethyltin) are far more toxic, acting as endocrine disruptors and neurotoxin…
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 …