WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions, filtered to microbe.
A genus of Gram-positive, obligate anaerobic bacteria within the lachnospiraceae family that produces short chain fatty acids and plays a significant role in bile acid metabolism. Key species include B. obeum, B. wexlerae, B. hydrogenotrophica, and B. producta. While pr…
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 genus of Gram-positive, facultatively anaerobic, filamentous bacteria that are among the most abundant colonizers of the human oral cavity. Actinomyces species, particularly A. naeslundii, play dual roles as early dental plaque colonizers and as opportunistic pathogen…
Aerococcus is a genus of Gram-positive, alpha-hemolytic, catalase-negative cocci. The primary species of clinical relevance are A. urinae (a cause of urinary tract infections, particularly in elderly men) and A. christensenii (a vaginal commensal). In the WikiBiome vaul…
A Gram-negative, obligate anaerobic genus within the Bacteroidetes phylum (family Rikenellaceae). Alistipes occupies a complex and context-dependent role in the gut ecosystem — some species carry well-documented anti-inflammatory properties, while the genus is paradoxic…
A genus of Gram-positive obligate anaerobes in the family Lachnospiraceae (Clostridium cluster XIVa) that occupy a critical metabolic relay position in gut ecosystem stability: converting lactate to butyrate. Anaerostipes is one of the most consistently depleted genera …
Bacteroidales is an order of obligate anaerobic, Gram-negative bacteria within the phylum Bacteroidetes. It includes the families Bacteroidaceae (bacteroides), Prevotellaceae (prevotella), Rikenellaceae, and Porphyromonadaceae (porphyromonas). Bacteroidales are among th…
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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; …
This knowledge-base record is being expanded from WikiBiome’s evidence graph.
Bifidobacterium adolescentis is a Gram-positive, obligate anaerobic species within the phylum Actinobacteria and the dominant Bifidobacterium species in the adult human gut. It is a specialist degrader of resistant starch and dietary fiber, producing acetate and lactate…
Bifidobacterium breve is a Gram-positive, obligate anaerobic species within the phylum Actinobacteria, predominantly found in the infant gut and breast milk. It is among the earliest colonizers of the neonatal intestine and plays a key role in human milk oligosaccharide…
Bifidobacterium longum subsp. infantis (commonly called B. infantis) is the premier human milk oligosaccharide (HMO)-utilizing bacterium and the dominant species in the breastfed infant gut. It drives immune maturation, Treg induction, and pathogen exclusion in early li…
Bilophila wadsworthia is a Gram-negative, obligate anaerobic, sulfite-reducing bacterium that has emerged as a key pathobiont linking high-fat diets, taurine metabolism, hydrogen sulfide production, and inflammatory disease. Its unique metabolic niche -- using taurine-c…
A genus of spirochete bacteria transmitted by Ixodes ticks, best known as the causative agent of Lyme disease -- the most common tick-borne illness in the Northern Hemisphere. Borrelia burgdorferi sensu lato comprises approximately 20 genospecies, with B. burgdorferi se…
Candida auris is an emerging multidrug-resistant fungal pathogen first identified in 2009 (Satoh et al. 2009, from a Japanese patient's ear canal) and now classified as a critical-priority pathogen by the WHO (WHO Fungal Priority Pathogens List 2022) and CDC (CDC 2019 A…
A haploid, asexual yeast and the second most common cause of invasive candidiasis after Candida albicans. Recently reclassified into the genus Nakaseomyces (as N. glabratus), though the name C. glabrata remains in widespread clinical use. Unlike C. albicans, C. glabrata…
Citrobacter is a genus of Gram-negative, facultatively anaerobic bacteria in the Enterobacteriaceae family, named for its ability to utilize citrate as a sole carbon source. Species include C. freundii, C. koseri, and C. rodentium (a mouse model for EHEC infection). In …
A class of Gram-positive, obligate anaerobic bacteria within the phylum Firmicutes that represents the most functionally diverse and clinically significant taxonomic class in the human gut microbiome. Clostridia encompasses the dominant butyrate producers sustaining col…
Clostridium butyricum is a spore-forming, obligate anaerobic, Gram-positive bacterium and one of the leading next-generation probiotic candidates. The MIYAIRI 588 strain (CBM 588) is approved as a pharmaceutical probiotic in Japan and has expanding clinical evidence acr…
This page redirects to clostridioides difficile. Clostridium difficile was reclassified as Clostridioides difficile in 2016 based on phenotypic and phylogenomic analyses that demonstrated it belonged to a distinct clade within the former Clostridium genus. The reclassif…
A Gram-positive, obligate anaerobic genus within the lachnospiraceae family (Firmicutes phylum). Dorea occupies a mixed role in the gut ecosystem -- while it is a core member of the healthy human microbiome, several species are consistently enriched in autoimmune and ne…
A genus of Gram-positive bacteria (primarily E. faecalis and E. faecium) that exemplifies the metal-antibiotic resistance co-selection crisis. Enterococci carry diverse metal tolerance genes for mercury, arsenic, copper, and cadmium on the same mobile genetic elements a…
Erysipelotrichaceae is a family within the phylum Firmicutes that has drawn increasing attention for its consistent enrichment in metabolic disorders. Members of this family are Gram-positive, obligate anaerobes found throughout the mammalian gastrointestinal tract, whe…
A Gram-negative bacterium that spans the commensal-pathogen spectrum, with pathogenic variants (UPEC, STEC, EHEC) deploying nickel-dependent enzymes as virulence factors. E. coli is the model organism for nickel transport biology -- the NikABCDE system was first charact…
A Gram-positive obligate anaerobe in the family Ruminococcaceae (Clostridium cluster IV) whose defining metabolic activity is the degradation of dietary flavonoids — the very polyphenols that serve as anti-inflammatory, antioxidant, and antimicrobial agents. When Flavon…
An order of Gram-negative, obligate anaerobic bacteria within the phylum Fusobacteriota (formerly Fusobacteria). This order-level page covers the broader taxonomic group that includes the well-characterized genus fusobacterium and its key species fusobacterium nucleatum…
A Gram-negative opportunistic pathogen and member of the ESKAPE group of antibiotic-resistant priority pathogens. K. pneumoniae deploys multiple nickel-dependent enzymes for virulence and relies on the dual-function metallophore yersiniabactin for both iron and nickel s…
Lachnospira is a genus of Gram-positive, obligate anaerobic bacteria within the lachnospiraceae family (Firmicutes phylum). L. pectinoschiza, the type species, is a specialist pectin fermenter that produces short chain fatty acids from plant-derived polysaccharides. The…
A family within the Firmicutes phylum (order Clostridiales, formerly Clostridium cluster XIVa) that serves as a sentinel indicator of gut health -- its depletion is the single most consistent microbiome signature across nearly every disease represented in this wiki. The…
This page serves as the family-level hub for Lachnospiraceae, connecting the individual genus and species pages (roseburia, blautia, anaerostipes, eubacterium rectale) with the overarching ecological and metabolic framework that defines the family. For the primary entit…
Lactobacillus jensenii defines Community State Type V (CST-V) in the vaginal microbiome. It produces hydrogen peroxide and lactic acid, contributing to vaginal defense against pathogens, though less dominant than lactobacillus crispatus (CST-I).
Lactococcus lactis is a Gram-positive, facultatively anaerobic, lactic acid bacterium best known as the workhorse of the dairy fermentation industry. It holds GRAS (Generally Recognized As Safe) status and has emerged as a versatile platform for probiotic and therapeuti…
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…
A Gram-negative, obligate anaerobic genus within the Firmicutes phylum (family Acidaminococcaceae, class Negativicutes). The primary species P. faecium and the recently characterized P. succinatutens are specialized propionate producers that utilize succinate as their m…
A Gram-negative, obligately anaerobic, black-pigmented bacterium and one of the classical periodontopathogens. P. intermedia belongs to the "orange complex" of periodontal pathogens (Socransky classification) and is distinguished by its iron and heme dependency -- the c…
A family of Gram-negative, obligate anaerobic bacteria within the phylum Bacteroidota (formerly Bacteroidetes) that includes the genus prevotella and the recently described alloprevotella. Prevotellaceae are specialist fiber fermenters producing short-chain fatty acids,…
Propionibacterium (largely reclassified as Cutibacterium for skin species) is a genus of Gram-positive, anaerobic to aerotolerant bacteria that produce propionic acid as their primary fermentation product. P. acnes (now Cutibacterium acnes) is the dominant skin commensa…
A Gram-negative uropathogen whose Ni-dependent urease is the central driver of catheter-associated urinary tract infection (CAUTI) pathogenesis. Urease-mediated urea hydrolysis alkalinizes urine, triggering precipitation of struvite (magnesium ammonium phosphate) and ap…
A genus of Gram-positive, obligate anaerobic cocci within the Firmicutes phylum that exemplifies dual-nature microbiology — containing both keystone beneficial species and disease-associated pathobionts within the same genus. The genus spans multiple former taxonomic gr…
A Gram-positive obligate anaerobe that has emerged as a pro-inflammatory pathobiont enriched across multiple disease states including crohns disease, depression, and multiple sclerosis. R. gnavus produces a species-specific inflammatory polysaccharide that activates int…
A genus of ascomycete yeasts that includes both a proven therapeutic probiotic (S. boulardii) and species associated with disease states (S. cerevisiae enriched in CRC mycobiome). This dual nature -- commensal/probiotic versus disease-associated -- parallels the bacteri…
See also: saccharomyces (genus page) Saccharomyces boulardii is a non-pathogenic yeast strain used as a probiotic across a wide range of gastrointestinal and inflammatory conditions. Taxonomically a strain of S. cerevisiae, it is phenotypically distinct — optimally acti…
Saccharomyces cerevisiae is a unicellular budding fungus (ascomycete) ubiquitous in fermentation, brewing, bread-making, and increasingly used as a pharmaceutical probiotic (Hatoum et al. 2012). The strain S. boulardii (also called S. cerevisiae var. boulardii) is the m…
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-negative, microaerophilic genus within the Proteobacteria phylum (family Sutterellaceae). The primary species S. wadsworthensis is classified as a pathobiont due to its IgA-degrading capacity and associations with neurodevelopmental and inflammatory conditions. H…
A Gram-positive, facultatively anaerobic genus within the class Erysipelotrichia (phylum Firmicutes) that has become one of the most frequently identified taxa in gut-brain and gut-immune Mendelian randomization studies. Turicibacter sanguinis, the type species, possess…
Tyzzerella is a genus of Gram-positive, strictly anaerobic bacteria within the family Lachnospiraceae (order Clostridiales, phylum Firmicutes). It was recently reclassified from Clostridium cluster XIVa and remains poorly characterized at the species level. The genus in…
A Gram-negative, obligate anaerobic genus within the Firmicutes phylum (class Negativicutes, family Veillonellaceae). The primary species V. parvula is a specialized lactate utilizer that occupies a unique metabolic niche by cross-feeding with lactate-producing bacteria…
A family of Gram-negative, obligate anaerobic bacteria within the Firmicutes phylum (class Negativicutes) that occupies a unique metabolic niche as specialized lactate utilizers. Veillonellaceae cannot ferment sugars directly -- instead, they cross-feed on lactate produ…