Prevotellaceae

Taxonomy#

Family Prevotellaceae, order Bacteroidales, class Bacteroidia, phylum Bacteroidota. Key genera: Prevotella (including P. copri, P. melaninogenica), Alloprevotella, Paraprevotella, Hallella. Prevotella copri is the dominant species in non-Western, fiber-rich diets and is a primary driver of the "Prevotella enterotype."

Metal Dependencies#

Iron. Iron-dependent succinate dehydrogenase participates in the fumarate respiration pathway, a key anaerobic energy-generating strategy in Bacteroidales. Prevotellaceae encode iron uptake systems including TonB-dependent receptors for iron-siderophore complexes, though they are generally less aggressive iron competitors than Enterobacteriaceae.

In iron-depleted environments (host nutritional immunity), Prevotellaceae may lose competitive advantage to siderophore-producing pathobionts, contributing to their depletion in inflammatory conditions.

Key Enzymes and Metabolic Features#

Glycoside hydrolases: Prevotellaceae encode extensive polysaccharide utilization loci (PUL) for degrading plant-derived complex carbohydrates—xylan, arabinoxylan, pectin. This makes them indicators of fiber-rich diets.

Peptidases: Prevotella species also degrade host-derived glycoproteins, including mucin, which can trigger inflammatory responses when Prevotellaceae infiltrate the mucosal layer. Succinate dehydrogenase: Iron-dependent enzyme in fumarate respiration.

The Prevotellaceae Paradox#

The family's dual role as both beneficial (SCFA production, fiber fermentation) and potentially harmful (mucosal invasion, T-cell activation) depends on context.

Beneficial: In the gut lumen, Prevotellaceae ferment dietary fiber into SCFAs and maintain community diversity. Harmful: When Prevotellaceae infiltrate the mucosal layer, they can trigger T-cell and antibody responses, promoting Metal-Driven Inflammation.^{[1]Li 2023 — Gut Microbiota and Autism Spectrum Disorders: A Bidirectional Mendelian Randomization StudyZhi Li, Shuai Liu, Fang Liu et al. · 2023Open reference 1 ↓}

Key Studies#

^{[1]Li 2023 — Gut Microbiota and Autism Spectrum Disorders: A Bidirectional Mendelian Randomization StudyZhi Li, Shuai Liu, Fang Liu et al. · 2023Open reference 1 ↓} (Mendelian randomization)—Established Prevotellaceae as a causal ASD risk factor (OR 1.24); FDR-significant.^{[2]Microbial Metallomics and Parkinson's Disease: A Unified Metal-Driven Framework Linking Ferroptosis, Dysbiosis, and alpha-Synuclein PathologyKaren Pendergrass · 2025Open reference 2 ↓} (review)—Documented Prevotellaceae as the most consistently depleted family in PD.

^{[3]Romano 2021 -- Meta-analysis of the Parkinson's Disease Gut Microbiome Suggests Alterations Linked to Intestinal InflammationStefano Romano, George M Savva, Janis R Bedarf et al. · 2021Open reference 3 ↓} (meta-analysis)—Confirmed Prevotellaceae depletion across PD cohorts.