腸管感染症におけるヒト腸内細菌叢：関連から応用まで

Enteric infections remain a leading global cause of morbidity, mortality and economic loss, increasingly compounded by the rise of antimicrobial resistance. The gut microbiome - spanning bacteria, archaea, fungi, protists and viruses - is now recognized as an important mediator that shapes susceptibility to infection, pathogen expansion and disease severity through mechanisms such as colonization resistance, resource competition and immune modulation. Conversely, the gut microbial community can facilitate enteric infection through other processes such as cross-feeding and horizontal gene transfer. In this review, we synthesize correlative and mechanistic evidence currently available on microbiome-pathogen interactions; outline host, environmental and socioeconomic modifiers that affect disease risk across the life course; and evaluate current clinical applications. We highlight key limitations in the field and identify priority areas for future research to refine causal models of microbiome-pathogen ecology and enable targeted diagnostics and therapeutics for preventing and managing enteric infections.