WikiBiomeThe human microbiome encyclopediaRanked matches across titles, topics, categories, and article introductions.
A Gram-negative obligate anaerobe identified as a histamine-producing bacterium enriched in dysbiotic microbiota associated with obesity, metabolic syndrome, and metabolic endotoxemia. Allisonella is a minor but functionally significant genus whose primary clinical rele…
Anaerococcus is a genus of Gram-positive, obligate anaerobic cocci within the phylum Firmicutes. It is a normal inhabitant of the human vaginal, skin, and gastrointestinal microbiota, but is recognized as an opportunistic pathogen in dysbiotic states, particularly when …
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 …
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…
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 anaerobe that exemplifies the commensal-pathobiont spectrum. B. vulgatus is a common component of the healthy gut microbiota, yet is significantly enriched in colorectal cancer and depression, suggesting a context-dependent pathogenic potential.…
Barnesella is a genus of obligate anaerobic, Gram-negative bacteria in the phylum Bacteroidetes. It is a relatively understudied gut commensal that appears in the WikiBiome vault primarily in the context of endometriosis microbiome studies, where it is part of the compl…
This knowledge-base record is being expanded from WikiBiome’s evidence graph.
Clostridium perfringens is a Gram-positive, strictly anaerobic, spore-forming bacterium infamous for causing gas gangrene, food poisoning, and necrotizing enterocolitis (NEC) in premature infants. It is one of the most widely distributed pathogenic bacteria in nature, f…
Clostridium symbiosum is a Gram-positive, obligately anaerobic bacterium within the Clostridium cluster XIVa — a taxonomic group enriched for short-chain fatty acid (SCFA) producers and specialized bile acid metabolizers. Despite its ambiguous name (suggesting symbiotic…
An order of Gram-negative, strictly anaerobic sulfate-reducing bacteria (SRB) within the class Deltaproteobacteria. The defining metabolic feature of Desulfovibrionales is dissimilatory sulfate reduction -- using sulfate as a terminal electron acceptor and producing hyd…
Eggerthella is a genus of Gram-positive, strictly anaerobic, non-spore-forming bacteria in the family Eggerthellaceae (phylum Actinobacteria). The most studied species, Eggerthella lenta, was originally classified as Eubacterium lentum before reclassification. It is a n…
A Gram-positive obligate anaerobe and key estrobolome member that links metabolic dysbiosis to hormone-driven diseases, particularly endometriosis. E. lenta is remarkable for its ability to inactivate cardiac glycosides (like digoxin) and to produce beta-glucuronidase, …
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…
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…
This knowledge-base record is being expanded from WikiBiome’s evidence graph.
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 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 …
Haemophilus is a genus of small, Gram-negative, facultatively anaerobic coccobacilli that inhabit the upper respiratory tract, oral cavity, and gastrointestinal tract. The genus name literally means "blood-loving" -- a direct reference to its absolute requirement for he…
--- title: Hungatella type: entity subtype: microbe created: 2026-04-10 updated: 2026-04-16 lastsubstantiveupdate: 2026-04-16 sources: [altinok-dindar-2023-gut-microbiota-breast-cancer-diet, qin-2024-consistent-microbiome-signatures-old-young-onset-crc, zhang-2025-gut-v…
Research summary — not medical advice. This page synthesizes published research on a mechanism-level intervention. It is not a clinical recommendation.
--- title: Intestinibacter type: entity subtype: microbe created: 2026-04-10 updated: 2026-04-16 lastsubstantiveupdate: 2026-04-16 sources: [dai-2024-gut-microbiota-cvd-bidirectional-mr, xiang-2023-host-gene-microbiome-crc-mr, wu-2017-metformin-gut-microbiome-t2d-nature…
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…
Post-acute sequelae of SARS-CoV-2 infection (PASC), affecting an estimated 10-30% of COVID-19 survivors (WHO and CDC post-acute surveillance estimates) with symptoms persisting 12 weeks. Characterized by fatigue, cognitive dysfunction ("brain fog"), exercise intolerance…
Megasphaera is a genus of obligate anaerobic, Gram-negative bacteria in the family Veillonellaceae (class Negativicutes, phylum Firmicutes). The genus occupies two distinct ecological niches — the vaginal microbiome (where it is a hallmark of bacterial vaginosis) and th…
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…
--- title: Oxalobacter type: entity subtype: microbe created: 2026-04-10 updated: 2026-04-16 lastsubstantiveupdate: 2026-04-16 sources: [duan-2020-gut-microbiota-heavy-metal-probiotic-strategy, zhang-2022-causal-gut-microbiome-cvd-mr, dai-2024-gut-microbiota-cvd-bidirec…
This knowledge-base record is being expanded from WikiBiome’s evidence graph.
Paraprevotella is a genus of obligate anaerobic, Gram-negative bacteria in the family Prevotellaceae, related to prevotella. It is a gut commensal with emerging associations across neuropsychiatric and reproductive conditions. - Schizophrenia: Altered in gut-brain axis …
--- title: Parvimonas type: entity subtype: microbe created: 2026-04-10 updated: 2026-04-16 lastsubstantiveupdate: 2026-04-16 sources: [qin-2024-consistent-microbiome-signatures-old-young-onset-crc, saito-2019-metagenomic-gut-microbiota-colorectal-adenoma, wu-2021-micro…
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…
Peptostreptococcus stomatis is a Gram-positive, obligately anaerobic coccus originally isolated from the human oral cavity (oral streptococcal species) that has emerged as a carcinogenic oral pathobiont enriched in colorectal cancer, particularly in advanced stages. Unl…
See also: porphyromonas (genus page), porphyromonas gingivalis (species page) Porphyromonas bennonis is an obligate anaerobic, Gram-negative bacterium related to the periodontal pathogen porphyromonas gingivalis. Unlike its oral relative, P. bennonis is primarily associ…
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 obligate anaerobe that occupies a unique context-dependent niche in the human gut microbiome. P. copri is significantly enriched in rheumatoid arthritis patients and is associated with metabolic syndrome and obesity, yet in other contexts it can function…
Rikenella is a genus of obligate anaerobic, Gram-negative bacteria in the family Rikenellaceae (phylum Bacteroidetes). The primary species is R. microfusus. In the WikiBiome vault, Rikenella is consistently depleted across disease states — a protective commensal whose l…
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…
Sneathia is a genus of obligate anaerobic, Gram-negative bacteria in the phylum Fusobacteriota (formerly Fusobacteria). The primary species is S. sanguinegens (formerly Leptotrichia sanguinegens), with S. amnii also clinically significant. Sneathia is a member of the BV…
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 …