WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
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,…
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…
Atopobium is a genus of obligate anaerobic, Gram-positive bacteria in the phylum Actinobacteria. The primary species of clinical relevance is A. vaginae (recently reclassified as Fannyhessea vaginae), which is one of the hallmark organisms of bacterial vaginosis (BV) an…
Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age, affecting an estimated 29% of women globally. Rather than an infection by a single pathogen, BV represents a polymicrobial dysbiotic state -- a collapse of the protective Lactoba…
Candida tropicalis is an opportunistic fungal pathogen and occasional gut commensal, increasingly recognized as one of the most clinically significant non-albicans Candida (NAC) species. Once considered a distant runner-up to C. albicans, it has emerged as a major drive…
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 …
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…
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…
Curli are functional amyloid fibers produced by escherichia coli, salmonella, and other Enterobacteriaceae as the primary protein component of their extracellular biofilm matrix. The curli subunit CsgA polymerizes into cross-beta-sheet amyloid fibrils that are structura…
Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene, producing defective chloride and bicarbonate transport across epithelial membranes. While the genetic defect affects multiple organ systems, chronic lung infection is the prima…
Debaryomyces is a genus of ascomycetous fungi, with D. hansenii being the most clinically relevant species, that represents a prominent opportunistic pathobiont enriched in inflammatory bowel disease, particularly crohns disease. Unlike many commensal fungi, Debaryomyce…
Dental caries (tooth decay) is the most prevalent chronic disease worldwide, driven by acid-producing biofilm bacteria — primarily Streptococcus mutans and Lactobacillus species — that demineralize tooth enamel. In the WikiBiome framework, dental caries connects to the …
Endometriosis is a chronic estrogen-dependent inflammatory condition affecting approximately 10% of reproductive-age women, characterized by the growth of endometrial-like tissue outside the uterus colonetti 2023 gut vaginal microbiota endometriosis meta analysis. The c…
Enterobacter cloacae is a Gram-negative, facultatively anaerobic member of the Enterobacteriaceae. Ubiquitous in soil, water, and the mammalian gut, it is a leading cause of nosocomial infections and carries clinically significant antibiotic resistance through inducible…
Enterococcus faecalis is a Gram-positive, facultatively anaerobic coccus that inhabits the gastrointestinal tract, oral cavity, and genitourinary tract of humans. It is a commensal in the healthy gut at low abundance but is one of the most clinically significant opportu…
Essential oils are volatile aromatic compounds extracted from plants, composed primarily of terpenes, phenylpropanoids, and their oxygenated derivatives. In the WikiBiome context, essential oils are relevant not as aromatherapy but as sources of bioactive molecules with…
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…
A Gram-negative, obligate anaerobic bacterium that has emerged as the most consistently CRC-associated microorganism in human gut microbiome studies. F. nucleatum is the primary species of concern, originally a commensal of the oral cavity that translocates to colorecta…
A Gram-negative obligate anaerobe that has emerged as a major pathogen in colorectal cancer (CRC) and inflammatory bowel disease. F. nucleatum is significantly enriched in CRC tissue and tumors compared to healthy mucosa, making it one of the strongest microbe-cancer as…
A Gram-negative obligate anaerobe that occupies a paradoxical niche in the gut microbiota: as a weak butyrate producer (short-chain fatty acid), it has anti-inflammatory potential; as a virulent invasive pathobiont in inflammatory bowel disease (particularly ulcerative …
Gardnerella vaginalis is a Gram-variable, facultatively anaerobic bacterium that is the key organism in bacterial vaginosis (BV), the most common vaginal infection in women of reproductive age. Its sialidase production, biofilm-forming capacity, and associations with he…
See also the genus page: gardnerella Gardnerella vaginalis is the primary causative agent of bacterial vaginosis (BV), the most common vaginal infection worldwide. This species page focuses on the species-level biology — particularly the vaginolysin cytotoxin and biofil…
Gordonibacter urolithinfaciens is a Gram-positive, obligate anaerobic bacterium belonging to the family Eggerthellaceae that plays a specialized and critical role in polyphenol metabolism and conversion of ellagic acid to urolithin A. This microbial conversion is one of…
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…
Research summary — not medical advice. This page synthesizes published research on a mechanism-level intervention. It is not a clinical recommendation.
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…
A Gram-negative obligate anaerobe traditionally considered an oral commensal, but increasingly recognized as an opportunistic pathobiont with the ability to translocate from oral biofilms to the gastrointestinal tract and bloodstream. Leptotrichia species are prominentl…
Methanobrevibacter smithii is the dominant methanogenic archaeon in the human gut, responsible for consuming hydrogen gas produced by fermentative bacteria and converting it to methane. Despite being an archaeon rather than a bacterium, it represents 0–15% of gut microb…
N-acetylcysteine (NAC) is the acetylated form of the amino acid L-cysteine and serves as the rate-limiting precursor for glutathione synthesis — the body's primary intracellular antioxidant and a critical cofactor for phase II detoxification of heavy metals. In the micr…
N-glycosylation is a post-translational modification in which glycan chains are attached to asparagine residues on proteins. This modification is critical for protein folding, cell-cell recognition, and immune system signaling. In the context of host-microbe interaction…
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 …
NiFe-hydrogenase (also called [Ni-Fe] hydrogenase or nickel-iron hydrogenase) is a class of enzymes that catalyze reversible hydrogen (H₂) oxidation. The active site contains both nickel (Ni) and iron (Fe) metal atoms arranged in a sophisticated bimetallic cluster. The …
Parvimonas micra is a small (0.5–1.0 µm), Gram-positive, obligately anaerobic coccus originally isolated from the human oral cavity that has emerged as one of the most consistent and universally enriched pathobionts in colorectal cancer across all geographic regions, ag…
Periodontitis is a chronic inflammatory disease of the periodontal tissues (gingiva, periodontal ligament, alveolar bone) driven by a dysbiotic polymicrobial biofilm in the subgingival pocket. The keystone pathogen is porphyromonas gingivalis, whose zinc-dependent gingi…
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, …
A Gram-negative obligate anaerobe and keystone pathogen of the oral microbiome that causes chronic periodontitis and is increasingly implicated in systemic diseases including alzheimers disease and cardiovascular disease. P. gingivalis virulence is fundamentally depende…
A Gram-negative uropathogen whose Ni-dependent urease is the central driver of catheter-associated urinary tract infection (CAUTI) pathogenesis. Urease-mediated urea hydrolysis produces ammonia and alkalinizes urine, triggering precipitation of struvite (magnesium ammon…
Quorum sensing (QS) is cell-density-dependent communication in which bacteria produce, secrete, and detect small signaling molecules (autoinducers) to coordinate group behaviors — including biofilm formation, virulence factor production, siderophore synthesis, and antib…
Serratia is a genus of Gram-negative, facultatively anaerobic bacteria in the Enterobacteriaceae family. The primary species is S. marcescens, famous for its red pigment prodigiosin and its role as a nosocomial opportunistic pathogen. In the WikiBiome vault, Serratia ap…
Serratia marcescens is a Gram-negative, facultatively anaerobic member of the Enterobacteriaceae, historically recognized by its distinctive red pigment prodigiosin. Once considered a harmless environmental saprophyte, S. marcescens is now recognized as a significant op…
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 …
Staphylococcus epidermidis is a Gram-positive, facultative anaerobic coagulase-negative staphylococcus and one of the most abundant commensals of human skin and mucosal surfaces. While generally benign, it is a leading cause of nosocomial infections associated with indw…
Research summary -- not medical advice. This page synthesizes published research on why broad-spectrum antibiotics may worsen gut dysbiosis rather than correct it. This does NOT apply to life-threatening infections requiring antibiotic treatment. Consult a qualified hea…
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…
Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a Gram-positive, facultatively anaerobic coccus that exists in two clinical contexts: (1) as a major neonatal pathogen causing life-threatening meningitis and sepsis in newborns, and (2) as an enric…
The primary architect of dental caries -- the most prevalent chronic infectious disease worldwide. S. mutans is a Gram-positive, facultative anaerobe that colonizes tooth surfaces and produces the acid-rich, metal-managed biofilms known as dental plaque. What sets this …
A genus of ascomycete yeasts (formerly classified as Zygosaccharomyces) found in fermentation environments (bread, wine, kombucha) and increasingly detected as a component of the human gut mycobiome. While typically at low abundance in healthy individuals, Torulaspora d…
Trichosporon asahii is a basidiomycetous yeast found in soil, water, and on human skin. It is the primary cause of invasive trichosporonosis in immunocompromised patients, particularly those with neutropenia or hematologic malignancies. It is inherently resistant to ech…
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.
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-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…