Selected cellular-form breadth within Betaproteobacteria, shown as eight cells in four groupings. The class-level plate is non-exhaustive, non-diagnostic, and not a micrograph.
Scientific media record1 verified identifier
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- Betaproteobacteriataxon · class
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- NCBITaxon:28216
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- Editorial review completeIdentifiers authority-verified · Accessibility validated · · betaproteobacteria|betaproteobacteria-microbial-community-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
- Betaproteobacteria — NCBI TaxonomyParasutterella secunda type strainOxalobacter formigenes gen. nov., sp. nov.Neisseria gonorrhoeae type strain
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- CC BY-SA 4.0Created
A class of Gram-negative bacteria within the phylum Proteobacteria that has emerged as a causal risk factor for schizophrenia and bipolar disorder through Mendelian randomization studies.
Betaproteobacteria includes genera with notable metal tolerance—particularly within the order Burkholderiales—explaining their enrichment in heavy-metal-contaminated environments and potentially connecting environmental metal exposure to neuropsychiatric disease via the gut-brain axis.
Evidence map4 cited passagesInspect provenance +
Class Betaproteobacteria is causally linked to schizophrenia (OR = 1.13, 95% CI 1.01-1.27, p = 0.027). Betaproteobacteria has been previously associated with cognitive impairment in schizophrenia patients, suggesting a specific neurological pathway. Effective intervention requires suppressing both Betaproteobacteria and clostridia (OR 1.16) while restoring d
Class Betaproteobacteria is causally linked to bipolar disorder via a separate Mendelian randomization study, suggesting a shared gut-brain mechanism across psychotic spectrum disorders.
(Mendelian randomization, n=148,984)—Established Betaproteobacteria as a causal schizophrenia risk factor; bidirectional MR confirmed directionality.
(Mendelian randomization)—Causally linked Betaproteobacteria to bipolar disorder.
Contents
1. Taxonomy2. Metal Dependencies and Tolerance3. Ecological Role4. Conditions Associated5. Key Studies6. Open Questions7. Cross-ReferencesTaxonomy#
Class Betaproteobacteria, phylum Proteobacteria. Key gut-relevant orders: Burkholderiales (includes Oxalobacter, Parasutterella, Sutterella), Neisseriales (includes Neisseria Meningitidis).
Taxonomic note: some classification schemes have reclassified Betaproteobacteria as a subclass within Gammaproteobacteria based on phylogenomics; the traditional class-level designation is retained here for consistency with MR studies that used this taxonomy.
Metal Dependencies and Tolerance#
Iron. Betaproteobacteria encode diverse iron acquisition systems including siderophore receptors and TonB-dependent transporters. The class includes both iron-dependent commensals and aggressive iron competitors that thrive in iron-replete inflammatory environments.
Nickel and Heavy Metal Tolerance. Burkholderiales, the largest gut-relevant order within Betaproteobacteria, includes species that thrive in heavy-metal-contaminated soils and environments. Metal efflux pumps (CzcCBA for cadmium (Cd)/zinc (Zn)/cobalt (Co), NccCBA for nickel (Ni)/cobalt/cadmium) are widespread in Betaproteobacteria, providing survival advantages in metal-stressed environments.
This metal tolerance creates a potential pathway: environmental heavy metal exposure → selective enrichment of metal-tolerant Betaproteobacteria in the gut → neuropsychiatric effects via the gut-brain axis.
Ecological Role#
In the Healthy Gut#
Betaproteobacteria are minor members of the healthy gut microbiota, typically comprising <5% of the total community. Parasutterella and Oxalobacter are the best-characterized gut-resident genera.
In Dysbiosis#
Betaproteobacteria expansion is observed in neuropsychiatric conditions and in individuals with elevated heavy metal exposure. The class's metal tolerance mechanisms provide a competitive advantage when dietary or environmental metals create selection pressure against metal-sensitive commensals.
Conditions Associated#
Schizophrenia (Causal Risk Factor)#
Class Betaproteobacteria is causally linked to schizophrenia (OR = 1.13, 95% CI 1.01-1.27, p = 0.027).[1]Zhou 2024 — Gut Microbiome and Schizophrenia: Insights from Two-Sample Mendelian RandomizationKeer Zhou, Ancha Baranova, Hongbao Cao et al. · 2024Open reference 1 ↓ Betaproteobacteria has been previously associated with cognitive impairment in schizophrenia patients, suggesting a specific neurological pathway.
Effective intervention requires suppressing both Betaproteobacteria and Clostridia (OR 1.16) while restoring Desulfovibrio and Veillonellaceae—the two-sided ecological engineering principle.
Bipolar Disorder#
Class Betaproteobacteria is causally linked to bipolar disorder via a separate Mendelian randomization study,[2]Ni 2022 — Gut Microbiota and Psychiatric Disorders: A Two-Sample Mendelian Randomization StudyJing-Jing Ni, Qian Xu, Shan-Shan Yan et al. · 2022Open reference 2 ↓ suggesting a shared gut-brain mechanism across psychotic spectrum disorders.
Epilepsy#
Betaproteobacteria (class) and Burkholderiales (order) are MR risk factors for epilepsy (OR = 1.357 and 1.336 respectively), further supporting the class's role in neurological disease via the gut-brain axis.
Key Studies#
[1]Zhou 2024 — Gut Microbiome and Schizophrenia: Insights from Two-Sample Mendelian RandomizationKeer Zhou, Ancha Baranova, Hongbao Cao et al. · 2024Open reference 1 ↓ (Mendelian randomization, n=148,984)—Established Betaproteobacteria as a causal schizophrenia risk factor; bidirectional MR confirmed directionality.[2]Ni 2022 — Gut Microbiota and Psychiatric Disorders: A Two-Sample Mendelian Randomization StudyJing-Jing Ni, Qian Xu, Shan-Shan Yan et al. · 2022Open reference 2 ↓ (Mendelian randomization)—Causally linked Betaproteobacteria to bipolar disorder.
Open Questions#
Unresolved questions identified by the current evidence record.
01Does environmental heavy metal exposure drive Betaproteobacteria enrichment in neuropsychiatric patients?+
The metal tolerance of Burkholderiales provides a mechanistic hypothesis, but no study has measured both metal exposure and Betaproteobacteria abundance in psychiatric cohorts.
02Which Betaproteobacteria genera mediate the schizophrenia signal?+
Class-level MR data cannot distinguish between Parasutterella, Sutterella, Oxalobacter, and other gut-resident genera.
03Does Betaproteobacteria suppression improve cognitive outcomes in schizophrenia?+
The association with cognitive impairment suggests a specific intervention target, but no RCT has tested this.
Cross-References#
- Schizophrenia—causal risk factor via MR
- Clostridia—co-identified as schizophrenia risk taxon in the same MR study
- Veillonellaceae—causally protective counterpart in schizophrenia ecology
- Desulfovibrio—causally protective counterpart in schizophrenia ecology
- Parasutterella—a key gut-resident genus within Betaproteobacteria
- Oxalobacter—another gut-relevant genus; Burkholderiales order
- Neisseria Meningitidis—a pathogenic Betaproteobacteria outside the gut niche
- Epilepsy—Betaproteobacteria and Burkholderiales as MR risk factors
References 8
Numbered by first appearance in the article, then reconciled with its declared source list.
- 1
Keer Zhou, Ancha Baranova, Hongbao Cao et al. (2024). Zhou 2024 — Gut Microbiome and Schizophrenia: Insights from Two-Sample Mendelian Randomization. Schizophrenia (Nature Partner Journal).
- 2
Jing-Jing Ni, Qian Xu, Shan-Shan Yan et al. (2022). Ni 2022 — Gut Microbiota and Psychiatric Disorders: A Two-Sample Mendelian Randomization Study. Frontiers in Microbiology.
- 3
Ming Yuan, Dong Li, Zhe Zhang et al. (2018). Yuan 2018 — Endometriosis Induces Gut Microbiota Alterations in Mice. Human Reproduction.
- 4
Tung Hoang, Minjung Kim, Ji Won Park et al. (2023). Dysbiotic microbiome variation in colorectal cancer patients is linked to lifestyles and metabolic diseases. BMC Microbiology.
- 5
Fang L, Ning J (2024). Fang & Ning 2024 — Recent Advances in Gut Microbiota and Thyroid Disease: Pathogenesis and Therapeutics. Frontiers in Cellular and Infection Microbiology.
- 6
Wang M, Zhu Y (2025). Wang & Zhu 2025 — Gut Microbiome Versus Thyroid Cancer: Association and Clinical Implications (Review). Oncology Letters.
- 7
Ni JJ, Xu Q, Yan SS et al. (2022). Gut Microbiota and Psychiatric Disorders: A Two-Sample Mendelian Randomization Study. Frontiers in Microbiology.
- 8
Youjie Zeng, Si Cao, Heng Yang (2023). Roles of gut microbiome in epilepsy risk: a Mendelian randomization study. Frontiers in Microbiology.
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