The Gut Barrier–Microbiome–Immune Axis in Poultry: Comparative Mechanisms of Mucosal Defense and Tolerance

Modern poultry production operates at the intersection of host immunity, mucosal barrier biology, microbial ecology, nutrition, and environmental pressure. Nowhere is this integration more evident than in the gastrointestinal tract, where epithelial and immune cells continuously interpret dietary antigens, commensal microbes, and pathogens through pathogen-recognition receptors (PRRs) and downstream signaling networks. These interactions shape the balance between protective inflammation and tolerance, influence pathogen colonization resistance, and contribute to systemic physiological outcomes relevant to animal health and well-being.At the same time, birds offer a powerful comparative framework for immunology. Avian species share core innate and adaptive immune principles with mammals, yet display distinct features (e.g., specialized lymphoid tissues and avian-specific immune cell functions) and diverse ecological and domestication histories. The rapid growth of omics resources (metagenomics, metabolomics, transcriptomics, single-cell profiling) and improved experimental models now makes it feasible to move from descriptive associations toward mechanistic, comparative insights into how microbiomes and nutrition modulate mucosal immunity and barrier defense across birds and environments.This Research Topic aims to build a comparative, mechanism-driven framework for understanding the gut barrier–microbiome–immune axis in poultry, with a focus on how mucosal immune networks maintain tolerance to diet and commensals while mounting effective defense against enteric pathogens. We aim to move beyond “microbiome shifts” and performance-only endpoints to studies that identify specific immune pathways, cell networks, and microbial functions/metabolites that causally shape barrier integrity and immune tone.We welcome submissions (Original Research, Review, Mini Review, Perspective) on themes including, but not limited to:- comparative mucosal immune cell biology in birds (heterophils, macrophages, dendritic-like cells, T cell subsets, B cell responses)- avian pathogen recognition mechanisms and downstream signaling in gut epithelium and immune cells- mechanisms of tolerance to commensals and diet: regulatory pathways, IgA-like responses, epithelial–immune cross-talk- nutrition and immunology: amino acids, fatty acids, minerals, vitamins, fiber types, enzymes, phytogenics—linked to immune/barrier mechanisms- microbiome function and causality: metabolite–receptor–immune axes; gnotobiotic/defined communities; fecal/cecal microbiota transfers with immune phenotyping- host–pathogen–microbiome triads (e.g., Eimeria, Salmonella, Clostridium perfringens, Campylobacter) studied through immune mechanisms and barrier outcomes- multi-omics and systems immunology approaches (including single-cell/spatial transcriptomics) that connect microbial ecology to immune circuitry- environmental stressors (heat, ammonia, mycotoxins) as modulators of barrier immunity and microbial resilience in poultry Topic editors: Doyun Goo, Wongi Min Source: https://www.frontiersin.org/research-topics/77721/the-gut-barrier-microbiome-immune-axis-in-poultry-comparative-mechanisms-of-mucosal-defense-and-tolerance