WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions, filtered to mechanism.
Butyrate is a four-carbon short-chain fatty acid produced when anaerobic gut microorganisms ferment dietary substrates. In the colon, it participates in epithelial energy metabolism, barrier maintenance, immune signaling, and gene regulation. Its effects depend on conce…
Competitive exclusion is the ecological principle that two species competing for the same limiting resource cannot coexist indefinitely — one will outcompete the other. In the gut microbiome, competitive exclusion is the primary mechanism by which commensal bacteria pre…
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…
The transfer of processed stool from a healthy donor into a recipient's gastrointestinal tract to restore a disrupted microbial community. FMT is the most direct form of microbiome intervention -- replacing the entire community rather than supplementing individual strai…
Functional shielding is the phenomenon in which one microorganism — typically a fungus — physically and immunologically protects a co-resident pathogen from host immune attack, antimicrobial agents, and oxidative stress. The shielding organism's biofilm matrix acts as a…
Heavy metals is a widely used but chemically imprecise umbrella term for elements discussed because of their density, persistence, environmental occurrence, or toxicity. One common convention uses density above 5 g/cm3, but density alone does not determine biological ha…
A condition in which cells fail to respond normally to insulin, requiring progressively higher insulin levels to maintain glucose homeostasis. Insulin resistance is central to PCOS, type 2 diabetes, and metabolic syndrome, and has extensive but complex connections to me…
Mendelian randomization (MR) is a statistical method that uses genetic variants as instrumental variables to infer causal relationships between an exposure (e.g., gut microbiome composition) and an outcome (e.g., disease). Because genetic variants are randomly allocated…
Metallomics is the systematic study of metals and metalloids in a biological system. The metallome is the set of metal and metalloid species present in a defined organism, tissue, cell, fluid, or microbial community; metallomics is the measurement and interpretation of …
Microbiome-derived metabolites are small molecules made, consumed, or chemically transformed through activity in the gut microbiome and other host-associated communities. They connect community function to host biology, but the phrase covers several kinds of provenance:…
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…
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…
Parenteral nutrition (PN) -- the delivery of nutrients directly into the bloodstream via intravenous infusion -- is a life-saving intervention for patients who cannot absorb nutrition enterally. However, PN presents unique challenges for the metal-microbiome axis: it in…
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 …
Non-digestible food substrates that selectively stimulate the growth and/or activity of beneficial gut microorganisms, conferring health benefits to the host. Distinct from probiotics (live organisms) and postbiotics (microbial metabolic products), prebiotics act as fue…
A synbiotic is a combination of a probiotic (live beneficial microorganism) and a prebiotic (substrate that selectively feeds beneficial microbes), designed to work synergistically — the prebiotic supports the survival and colonization of the probiotic organism. Synbiot…
A synbiotic is a combination of live microorganisms (probiotics) and substrates selectively utilized by host microorganisms (prebiotics) that confers a health benefit. The rationale is additive or synergistic: the prebiotic component (typically inulin, fructo-oligosacch…
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…
Toll-like receptor 4 (TLR4) is a cell-surface pattern-recognition receptor in the toll like receptors family. It is best known for detecting particular forms of bacterial lipopolysaccharide (LPS) through a receptor complex and converting that detection into innate immun…