WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions, filtered to mechanism.
16S rRNA gene sequencing is the most widely used method for characterizing bacterial communities in this wiki. It targets the ~1,500 base pair 16S ribosomal RNA gene, which contains nine hypervariable regions (V1–V9) flanked by conserved sequences. Universal primers amp…
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…
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…
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…
Drug repurposing (also called drug repositioning) is the strategy of identifying new therapeutic uses for existing approved drugs. It dramatically accelerates the path from bench to bedside because safety, pharmacokinetics, and manufacturing are already established. In …
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: …
Endocrine-disrupting chemicals (EDCs) are exogenous substances that interfere with hormone synthesis, secretion, transport, binding, action, or elimination. The classical EDC list -- BPA, phthalates, dioxins, PCBs, pesticides -- is well established. What WikiBiome adds …
Exogenous chemicals that interfere with hormone synthesis, secretion, transport, binding, or elimination, mimicking or blocking endogenous hormones at physiologically relevant concentrations. In the metallomics-microbiome framework, endocrine disruptors occupy a critica…
Gingipains are the zinc-dependent cysteine proteases that serve as the master virulence factors of porphyromonas gingivalis. Three gingipains exist: RgpA and RgpB (arginine-specific) and Kgp (lysine-specific). They require zinc as a catalytic cofactor, making gingipain …
The third nickel-dependent enzyme class in human pathogens, after urease and hydrogenase. Glyoxalase I detoxifies methylglyoxal, a reactive and toxic byproduct of glycolysis. While less well-known than urease or hydrogenase as a virulence factor, GloI is emerging as a s…
The gut-gonadal axis describes the bidirectional communication between the intestinal microbiome and the reproductive endocrine system. Gut bacteria modulate sex hormone levels through enzymatic activity (particularly beta glucuronidase-mediated estrogen deconjugation),…
Horizontal gene transfer (HGT) is the movement of genetic material between organisms outside of parent-to-offspring inheritance. In the gut microbiome, HGT -- primarily mediated by mobile genetic elements (MGEs) including plasmids, transposons, integrons, and integrativ…
Interleukin-17 (primarily IL-17A and IL-17F) is the signature cytokine of Th17 cells. At physiological levels, IL-17 maintains mucosal barrier defense by recruiting neutrophils and inducing antimicrobial peptide production. At pathological levels (Th17/Treg imbalance), …
Immunotherapy harnesses the patient's own immune system to fight disease, most notably cancer. Immune checkpoint inhibitors (ICIs) -- antibodies that block PD-1, PD-L1, or CTLA-4 -- have revolutionized oncology since their introduction in the 2010s, producing durable re…
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…
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…
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…
The labile metal pool (LMP) is the fraction of intracellular metal that is bioavailable -- loosely coordinated with small molecules, transiently protein-bound, or truly "free" in solution. This pool is vanishingly small (often <1 free atom per cell for zinc and copper) …
Metabolomics is the comprehensive measurement of small-molecule metabolites (<1,500 Da) in a biological sample -- the functional readout of what the genome, transcriptome, and microbiome are actually doing. While genomics tells you what organisms are present and metagen…
Specialized proteins that escort metal ions from their point of entry to specific metalloenzyme targets, ensuring correct metalation in a cytoplasm crowded with competing metal-binding sites. Metallochaperones solve a fundamental problem in metal biology: how does the r…
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…
A family of small (6-7 kDa), cysteine-rich proteins that bind heavy metals with extraordinary affinity. Metallothioneins (MTs) are the cell's primary chemical defense against metal toxicity -- they sequester cadmium, mercury, lead, and other toxic metals, preventing the…
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…
Mitochondrial dysfunction refers to the impairment of mitochondrial energy production, redox balance, and signaling functions. Mitochondria are the primary targets of heavy metal toxicity in human cells, and they are also the organelles most dependent on metal cofactors…
Molecular mimicry occurs when microbial antigens share structural similarity with host proteins, triggering cross-reactive immune responses that attack host tissue. It is a primary mechanism linking infections and dysbiosis to autoimmune disease — the immune system corr…
Specialized membrane proteins that import nickel into bacterial cells, supplying the essential cofactor for virulence enzymes including urease, NiFe hydrogenase, and Ni-glyoxalase. Because mammals produce no known nickel-requiring proteins, these transporters represent …
Nickel-glyoxalase (Ni-GlxI) is a bacterial variant of the glyoxalase I enzyme system that depends on nickel as its essential metal cofactor. This enzyme detoxifies methylglyoxal (MG), a toxic glycolysis byproduct that accumulates under glucose fermentation. Unlike the h…
Nickel-urease (urease, EC 3.5.1.5) is a metalloenzyme that catalyzes the hydrolysis of urea (NH₂-CO-NH₂) to ammonia (NH₃) and carbon dioxide (CO₂). The active site contains two nickel ions (Ni²⁺) coordinated by histidine and cysteine residues. Nickel-urease is expressed…
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…
Phage therapy uses bacteriophages — viruses that infect and lyse specific bacteria — as precision antimicrobials. Unlike broad-spectrum antibiotics, phages target specific bacterial species or strains, sparing the commensal microbiome. In the WikiBiome framework, phage …
Phosphodiesterases (PDEs) are a family of enzymes that hydrolyze cyclic nucleotides (cAMP and cGMP), regulating intracellular signaling cascades. PDE5, the isoform targeted by sildenafil and tadalafil, is best known for its role in erectile dysfunction pharmacotherapy, …
Shotgun metagenomics is a sequencing approach that fragments and sequences all DNA in a sample -- bacterial, archaeal, fungal, viral, and host -- without prior amplification of a specific gene target. Unlike 16S rRNA amplicon sequencing, which identifies "who is there" …
Statins (HMG-CoA reductase inhibitors) are the most widely prescribed drug class globally, used primarily for cholesterol lowering and cardiovascular risk reduction. Over 200 million people take statins worldwide. Beyond their canonical mechanism of inhibiting cholester…
The exposome is the totality of environmental exposures an individual experiences from conception to death. Coined by Christopher Wild in 2005, it complements the genome by capturing the environmental side of the gene-environment equation. Metals are among the most quan…
A gut microbiome-derived metabolite that has emerged as one of the strongest microbial biomarkers for cardiovascular disease risk. TMAO exemplifies how microbial metabolism of dietary nutrients can generate systemically toxic products -- a fundamentally different paradi…
Tryptophan (Trp) is an essential amino acid metabolized via three competing pathways: the kynurenine pathway, the serotonin pathway, and the microbial indole pathway. The balance among these pathways is profoundly influenced by the gut microbiome, inflammation, and meta…
The most widespread nickel-dependent virulence factor across human pathogens. Urease is found in at least 40 prokaryotic and 9 eukaryotic pathogenic species, making it the single most important enzyme linking dietary/environmental nickel to infectious disease.
Uremic toxins are metabolic waste products that accumulate in the blood when kidney function declines. A striking proportion of the most clinically significant uremic toxins are produced not by human metabolism but by the gut microbiome -- making the gut-kidney axis a c…
Vancomycin is a glycopeptide antibiotic targeting Gram-positive bacteria by binding D-Ala-D-Ala of peptidoglycan precursors. It is the last-resort treatment for MRSA and oral vancomycin is first-line for severe clostridioides difficile infection. In the WikiBiome framew…
Vitamin B12 (cobalamin) is an essential cobalt-containing cofactor required for homocysteine metabolism, methylation reactions, and neurological function. Its core corrin ring chelates a cobalt ion, placing B12 at the intersection of metallomics and microbial ecology. C…
Zinc-metalloproteases are a large and functionally diverse family of proteolytic enzymes requiring zinc (Zn²⁺) in the active site for catalytic activity. They cleave peptide bonds in proteins, causing tissue destruction, immune evasion, and bacterial dissemination. Majo…