Type-species-anchored Fusobacterium fusiform rod forms, shown as ten bodies in six single and two paired groupings. This genus-level scientific reconstruction is representative, non-diagnostic, and not a micrograph.
Scientific media record1 verified identifier
- Subject
- Fusobacteriumtaxon · genus
- Identifiers
- NCBITaxon:848
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- Editorial review completeIdentifiers authority-verified · Accessibility validated · · fusobacterium|fusobacterium-morphology-v1.webp
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- Trained-algorithmic mediaCreated with a trained generative algorithm and reviewed by WikiBiome for subject identity, scientific framing, identifiers, provenance, and accessibility.
- Scientific basis
- Fusobacterium — NCBI TaxonomyFusobacterium — LPSNFusobacterium nucleatum — LPSNFusobacterium genus treatment
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- CC BY-SA 4.0Created
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 colorectal tumors where it promotes tumorigenesis through multiple virulence mechanisms.
It was the most frequently cancer-enriched genus across 45 cancer studies in a major meta-analysis.[1]Reproducible and opposing gut microbiome signatures distinguish autoimmune diseases and cancers: a systematic review and meta-analysisMd Zohorul Islam, Melissa Tran, Tao Xu et al. · 2022Open reference 1 ↓
Evidence map3 cited passagesInspect provenance +
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 colorectal tumors where it promotes tumorigenesis through multiple virulence mechanisms. It was the
FadA adhesin binds host E-cadherin on colonocytes, disrupting cell-cell junctions and activating the Wnt/beta-catenin signaling pathway. This promotes uncontrolled epithelial proliferation and is the primary oncogenic mechanism.
Fap2 also binds the TIGIT inhibitory receptor on NK cells and T cells, directly suppressing anti-tumor immune surveillance. This represents a microbial immune checkpoint exploitation.
Contents
1. Mechanisms of Colorectal Carcinogenesis2. Iron Dependency3. Oral-Gut Translocation4. Disease Associations Beyond CRC5. Key Metabolites6. ConnectionsMechanisms of Colorectal Carcinogenesis#
F. nucleatum drives CRC through a convergence of adhesion, immune evasion, and pro-tumorigenic signaling:
Adhesion and Invasion#
FadA adhesin binds host E-cadherin on colonocytes, disrupting cell-cell junctions and activating the Wnt/beta-catenin signaling pathway. This promotes uncontrolled epithelial proliferation and is the primary oncogenic mechanism.[2]Immune System, Microbiota, and Microbial Metabolites: The Unresolved Triad in Colorectal Cancer MicroenvironmentHanus M, Parada-Venegas D, Landskron G et al. · 2021Open reference 2 ↓
Fap2 lectin binds the Gal-GalNAc sugar moiety overexpressed on CRC tumor cells, enabling selective homing to tumor tissue rather than normal mucosa.
Immune Evasion#
Fap2 also binds the TIGIT inhibitory receptor on NK cells and T cells, directly suppressing anti-tumor immune surveillance. This represents a microbial immune checkpoint exploitation.[2]Immune System, Microbiota, and Microbial Metabolites: The Unresolved Triad in Colorectal Cancer MicroenvironmentHanus M, Parada-Venegas D, Landskron G et al. · 2021Open reference 2 ↓
LPS-TLR4 interaction activates NF-kB signaling, promoting chronic Metal-Driven Inflammation in the tumor microenvironment. Induces autophagy pathways (ULK1/ATG7) in CRC cells, contributing to chemotherapy resistance (5-FU, oxaliplatin).
Pro-inflammatory Signaling#
Activates NF-kB and STAT3 pathways, creating a self-reinforcing inflammatory tumor niche. Recruits myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) to the tumor microenvironment.
Iron Dependency#
F. nucleatum has an obligate iron requirement for growth, relying on FeoB and other iron acquisition systems. Thrives in the iron-rich tumor microenvironment created by hemorrhagic necrosis in advanced CRC. Iron supplementation in the gut may inadvertently promote Fusobacterium expansion, linking Iron overload to CRC risk.
Forms iron-dependent Biofilm communities in colorectal tumors, creating a protected niche resistant to host immunity and antibiotics.
Oral-Gut Translocation#
The oral cavity is the primary reservoir; F. nucleatum reaches the colon via hematogenous spread or direct swallowing. Oral health (periodontitis, gingivitis) is a risk factor for CRC, mediated partly through Fusobacterium translocation. Strain-specific analysis confirms identical clones in matched oral and tumor samples, establishing the oral-gut-tumor migration pathway.
Disease Associations Beyond CRC#
IBD: enriched in Crohn's disease and ulcerative colitis tissue, particularly in inflamed segments. Pancreatic cancer: detected in pancreatic tumor tissue; associated with poor prognosis. Esophageal and gastric cancers: enriched in upper GI malignancies.
Adverse pregnancy outcomes: F. nucleatum hematogenous spread linked to preterm birth and chorioamnionitis.
Key Metabolites#
Hydrogen sulfide (H2S)—produces H2S via cysteine desulfhydrase, contributing to DNA damage and Oxidative Stress in colonocytes. Formate and Butyrate—mixed acid fermentation products; butyrate paradoxically fuels CRC cells exhibiting the Warburg effect. Short-chain fatty acids—metabolic cross-feeding with other tumor-associated bacteria sustains the CRC microenvironment.
Connections#
- Colorectal Cancer—THE defining CRC-associated bacterium; FadA/Fap2 virulence mechanisms
- Iron—obligate iron requirement; thrives in iron-rich tumor environments
- inflammation—activates NF-kB/STAT3; chronic inflammatory signaling in tumors
- Biofilm—forms iron-dependent biofilms in colorectal tumors
- Dysbiosis—its enrichment is a hallmark of cancer-associated dysbiosis
- oxidative stress—H2S production drives DNA damage in colonocytes
- Cardiovascular Disease—oral Fusobacterium contributes to systemic inflammation
- Enterobacteriaceae—co-enriched in cancer and inflammatory disease states
- Faecalibacterium prausnitzii—inversely correlated; F. prausnitzii depletion accompanies Fusobacterium expansion
- Gut-Metal-Microbiome Interactions—iron availability in the gut modulates Fusobacterium competitive advantage
- Gastric Cancer—enriched in gastric tumor tissue alongside H. pylori
- Ovarian Cancer—enriched in ovarian tumor tissue; FadA-mediated E-cadherin/beta-catenin activation
References 5
Numbered by first appearance in the article, then reconciled with its declared source list.
- 1
Md Zohorul Islam, Melissa Tran, Tao Xu et al. (2022). Reproducible and opposing gut microbiome signatures distinguish autoimmune diseases and cancers: a systematic review and meta-analysis. Microbiome.
- 2
Hanus M, Parada-Venegas D, Landskron G et al. (2021). Immune System, Microbiota, and Microbial Metabolites: The Unresolved Triad in Colorectal Cancer Microenvironment. Frontiers in Immunology.
- 3
Appunni S, Rubens M, Ramamoorthy V et al. (2021). Emerging Evidence on the Effects of Dietary Factors on the Gut Microbiome in Colorectal Cancer. Frontiers in Nutrition.
- 4
Shaomin Zou, Chao Yang, Jieping Zhang et al. (2024). Multi-omic profiling reveals associations between the gut microbiome, host genome and transcriptome in patients with colorectal cancer. Journal of Translational Medicine.
- 5
Wantong Song, Leaf Huang (2025). Targeting tumor-associated microbiome: A new aspect of modulating tumor microenvironment for cancer therapy. Advanced Drug Delivery Reviews.
Article network
Mentioned here 14
Pages linking here 13
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- published revision
Revised “Connections”: now reads “the gut modulates Fusobacterium competitive advantage - gastric cancer -- enriched in gastric tumor tissue alongside H. pylori - ovarian cancer -- enriched in ovarian tumor tissue; FadA-mediated…”.
Revised “Connections”: changed “the gut modulates Fusobacterium competitive advantage” to “the gut modulates Fusobacterium competitive advantage - gastric cancer -- enriched in gastric tumor tissue alongside H. pylori - ovarian cancer -- enriched in ovarian tumor tissue; FadA-mediated…”. · WikiBiome Deploy Bot · +2 −0
Inspect exact Git diff ↗ - published revision
Revised “Fusobacterium”: now reads “45 cancer studies in a major meta-analysis.”.
Revised “Fusobacterium”: changed “45 cancer studies in a major meta-analysis ].” to “45 cancer studies in a major meta-analysis.”. Revised “Adhesion and Invasion”: changed “proliferation and is the primary oncogenic mechanism ]. - Fap2 lectin binds the Gal-GalNAc” to “proliferation and is the primary oncogenic mechanism. - Fap2 lectin binds the Gal-GalNAc”. Revised “Immune Evasion”: changed “This represents a microbial immune checkpoint exploitation ]. - LPS-TLR4 interaction activates NF-kB signaling,” to “This represents a microbial immune checkpoint exploitation. - LPS-TLR4 interaction activates NF-kB signaling,”. Added “Key Sources”: - - - Added citations to “Fusobacterium”: islam 2022 opposing microbiome signatures autoimmune cancer. Removed citations from “Fusobacterium”: [islam 2022 opposing microbiome signatures autoimmune cancer. Added citations to “Adhesion and Invasion”: hanus 2021 immune microbiota metabolites crc triad. Removed citations from “Adhesion and Invasion”: [hanus 2021 immune microbiota metabolites crc triad. Added citations to “Immune Evasion”: hanus 2021 immune microbiota metabolites crc triad. Removed citations from “Immune Evasion”: [hanus 2021 immune microbiota metabolites crc triad. Added citations to “Key Sources”: appunni 2021 dietary factors gut microbiome crc; zou 2024 multi omic microbiome genome transcriptome crc; song 2025 targeting tumor associated microbiome editorial. · WikiBiome Deploy Bot · +12 −3
Inspect exact Git diff ↗ - published revision
Created “Fusobacterium”: 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,…
Created “Fusobacterium”: 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,… Published sections: Fusobacterium; Mechanisms of Colorectal Carcinogenesis; Adhesion and Invasion; Immune Evasion; Pro-inflammatory Signaling; Iron Dependency; Oral-Gut Translocation; Disease Associations Beyond CRC; Key Metabolites; Connections. · WikiBiome Deploy Bot · +70 −0
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