Dynamic Succession and Development of the Gut Microbiota in Specific Pathogen-Free Chickens During Early Life: A Comprehensive Review

The vertebrate gastrointestinal tract hosts a complex and dynamic microbial ecosystem essential for host physiology, immune maturation, and disease resistance. In poultry, the early post-hatch period represents a critical window for microbial colonization, with long-lasting implications for health and productivity. While the gut microbiota of commercial chickens has been extensively characterized, successional patterns in specific pathogen-free (SPF) chickens during early life remain inadequately understood. This review synthesizes current knowledge on gut microbiota establishment in chickens, emphasizing SPF birds during the initial weeks post-hatch. We examine taxonomic composition, diversity dynamics, and ecological succession from days ۱۱ to ۱۷, identifying day ۱۷ as a critical turning point in community assembly. The functional implications of these microbial shifts are explored, including effects on immune system maturation, nutrient metabolism, and pathogen resistance. Additionally, we discuss factors influencing microbial colonization, such as environmental conditions, host genetics, and management practices. The identification of critical developmental windows for microbiota modulation offers opportunities for targeted interventions to optimize gut health and improve poultry production efficiency. Future research directions, including metagenomic and metabolomic approaches, are proposed to elucidate the functional capacity of the developing microbiota and its interactions with the host.

کلیدواژه ها:

gastrointestinal ، microbial ، poultry ، health