Anaerobic Bacteria and Clostridia in Health and Disease: From Gut Microbiota to Zoonotic Risk

Anaerobic bacteria—especially members of the Clostridium and Clostridioides groups—are dominant residents of the mammalian gut and key drivers of intestinal physiology. Their capacity to metabolize complex substrates, reshape bile acids, and generate bioactive metabolites makes them central to host nutrition, mucosal barrier function, immune education, and colonization resistance. At the same time, clostridial lineages include major toxin-producing pathogens and pathobionts that can expand under antibiotic pressure, dietary shifts, or inflammatory conditions, linking microbiome disturbance to clinically important disease outcomes.Recent advances in anaerobic cultivation, strain-resolved sequencing, and multi-omics have revealed that risk and function often sit at the strain level, where small genetic differences can separate beneficial commensals from virulent or highly transmissible variants. This Research Topic will bring together cellular, molecular, ecological, and translational studies that clarify how clostridial and other anaerobic lineages influence host physiology and infection susceptibility, how virulence and toxin systems emerge and persist, and how zoonotic or food/feed-associated routes contribute to exposure and disease risk across humans, animals, and the environment. By integrating clinical, veterinary, and environmental perspectives, the collection aims to support a One Health view of clostridial biology—from gut ecology to spillover risk.To ensure strong mechanistic and infection-microbiology relevance, we particularly encourage submissions that include functional validation (e.g., experimental models, strain-level genomic/phenotypic characterization, or demonstrated links to host responses and disease endpoints), rather than descriptive surveys alone.We welcome articles addressing, but not limited to, the following themes:-Comparative biology and ecology of Clostridium and Clostridioides species across hosts and habitats-Anaerobe-driven metabolic networks (e.g., fermentation pathways, bile acid transformations, SCFA production) and their impact on gut homeostasis and host defense-Host–microbiota interactions shaping mucosal immunity, barrier function, and inflammation in the presence of anaerobic bacteria-Strain-level diversity, adaptation, and persistence mechanisms (sporulation, biofilms, stress tolerance, niche competition)-Molecular mechanisms of virulence, toxin regulation, and toxin–host cell interactions-Zoonotic transmission routes and reservoirs, including livestock, companion animals, and wildlife interfaces, supported by genomic epidemiology and/or virulence/toxin profiling where possible-Food/feed-associated risks, contamination pathways, and control strategies across the farm-to-fork continuum, with clear links to infection risk and microbial determinants (e.g., spores, toxins, resistance, or transmissibility)-Clinical and veterinary perspectives on diagnosis, treatment, recurrence, and prevention of clostridial infections-Environmental drivers of clostridial spread (wastewater, soil, manure, antimicrobial use) and One Health surveillance approaches, ideally integrating isolate/strain characterization or mechanistic inference-Emerging methods and models (culturomics, anaerobic co-culture, organoids, gnotobiotics, multi-omics) to resolve causality and mechanism-Clinical and veterinary perspectives on diagnosis, treatment, recurrence, and prevention of clostridial infections and toxications.-We aim to include toxin-mediated diseases, which are highly relevant from both medical and veterinary perspectives, and align with the One Health approach. Topic editors: Tomasz Grenda, Piotr Domaradzki Source: https://www.frontiersin.org/research-topics/77647/anaerobic-bacteria-and-clostridia-in-health-and-disease-from-gut-microbiota-to-zoonotic-risk