WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
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 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…
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…
A Gram-negative, aerobic, non-fermenting coccobacillus and a member of the ESKAPE group of priority pathogens (Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter). Acinetobacter baumannii is among the most problematic nosocomial pathogens…
WHO Priority 1: Critical. A Gram-negative, strictly aerobic coccobacillus and one of the most dangerous nosocomial pathogens on the planet. A. baumannii belongs to the ESKAPE group and causes ventilator-associated pneumonia, wound infections, and bloodstream infections …
A Gram-negative, obligate anaerobic, mucin-degrading bacterium that colonizes the intestinal mucus layer and has emerged as one of the most important next-generation probiotics. A. muciniphila is consistently depleted in disease states associated with metal dyshomeostas…
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…
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; …
A Gram-negative, obligate anaerobic bacterium within the phylum Bacteroidetes and a common member of the healthy human gut microbiota. B. uniformis is a versatile polysaccharide degrader with emerging significance as an anti-inflammatory commensal whose depletion appear…
Bile acids are cholesterol-derived amphipathic molecules synthesized in the liver, secreted into the duodenum, and extensively modified by gut bacteria. The host-microbe co-metabolism of bile acids creates a signaling network with profound effects on lipid metabolism, g…
Cadmium is a toxic non-essential heavy metal (IARC Group 1 carcinogen) with a biological half-life of 17--30 years in mammals, primarily accumulating in the renal cortex via proximal tubular reabsorption of the Cd-metallothionein complex rasin 2025 cadmium exposure heal…
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…
Catalase is a heme-iron enzyme that decomposes hydrogen peroxide into water and oxygen. In microbial peroxide defense, it acts downstream of superoxide dismutase: superoxide dismutase converts superoxide to hydrogen peroxide, and catalase removes that hydrogen peroxide …
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…
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…
Dopamine is a catecholamine neurotransmitter central to reward, motivation, motor control, and executive function. Its synthesis is directly dependent on iron -- the rate-limiting enzyme tyrosine hydroxylase (TH) requires Fe2+ as a cofactor. This iron dependency makes d…
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: …
The most abundant bacterium in the healthy human colon (5-15% of total fecal microbiota), F. prausnitzii is the premier butyrate producer in the gut and a cornerstone of anti-inflammatory intestinal homeostasis. Its depletion is one of the most consistent microbiome sig…
The farnesoid X receptor (FXR), also known as NR1H4, is a nuclear receptor that functions as the primary bile acid sensor in the body. Activated by bile acids — especially chenodeoxycholic acid (CDCA) — FXR regulates bile acid synthesis, cholesterol metabolism, glucose …
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…
Ferroptosis is a form of iron-dependent regulated cell death driven by the accumulation of lipid peroxides on cellular membranes pendergrass 2026 microbial metallomics parkinsons ferroptosis, riederer 2021 iron concert master parkinsons. Unlike apoptosis or necrosis, fe…
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…
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-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…
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…
Hyperparathyroidism is the overproduction of parathyroid hormone (PTH), a master regulator of calcium homeostasis. While primary hyperparathyroidism (from parathyroid adenoma) is well described, the WikiBiome framework highlights secondary hyperparathyroidism -- the com…
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…
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…
A fundamental ordering of divalent transition metal ion binding affinities, established by Harry Irving and Robert Williams in 1953: Mg2+ < Mn2+ < Fe2+ < Co2+ < Ni2+ < Cu2+ Zn2+ This series holds for virtually all ligands and biological chelators. It means that copper b…
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…
Lipid metabolism — the synthesis, transport, and degradation of fats — is profoundly modulated by both the gut microbiome and metal homeostasis. The microbiome influences lipid metabolism through bile acid transformation, SCFA production, TMAO generation, and direct enz…
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…
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…
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 …
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…
An umbrella concept encompassing the metallomic dimensions of Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions. The brain is uniquely vulnerable to metal toxicity: it has high metabolic demand, limited regenerative capacity, region-specif…
A family of Gram-positive obligate anaerobes (formerly classified as the genus Oscillospira, now reclassified into Oscillibacter and related genera within Oscillospiraceae) that serve as keystone butyrate producers in the healthy human distal colonic microbiota (Konikof…
The second most common neurodegenerative disease, affecting over 10 million people worldwide dorsey 2018 parkinsons incidence meta analysis. Characterized by progressive loss of dopaminergic neurons in the substantia nigra, alpha-synuclein aggregation (Lewy bodies), and…
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…
Pneumonia is infection of the lung parenchyma, most commonly caused by streptococcus pneumoniae, Klebsiella pneumoniae, Haemophilus influenzae, and viruses (influenza, SARS-CoV-2). In the WikiBiome framework, pneumonia exemplifies the metal battleground at the host-path…
Roseburia intestinalis is a Gram-positive, obligate anaerobic member of the Lachnospiraceae family (Firmicutes). It is one of the most important butyrate producers in the human colon, converting dietary fiber into butyrate — the primary energy source for colonocytes and…
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…
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 genus of Gram-positive facultative anaerobes that occupy niches ranging from benign commensals (dental plaque, skin) to acute pathogens (pharyngitis, impetigo, invasive disease). Streptococci are uniquely manganese-dependent for catalytic scavenging of reactive oxygen…
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…
Type 2 diabetes (T2D) is a metabolic disease characterized by insulin resistance and progressive beta-cell dysfunction, affecting over 500 million people worldwide (IDF Diabetes Atlas 2021). The conventional framing centers on caloric excess and sedentary behavior. The …