Friend and Foe: Microbes in Orchestrating Immunity and Shaping Infection Dynamics

Microbial communities, or microbiota, are fundamental regulators of host immunity and infection outcomes across diverse body sites, including the gut, skin, respiratory tract, and vagina. Despite advances, infectious diseases remain a global challenge, exacerbated by antimicrobial resistance and emerging pathogens. This review explores the dynamic interplay between microbiota, host immune responses, and pathogens, highlighting how microbial interactions shape immune homeostasis and colonisation resistance. The review discusses therapeutic approaches leveraging probiotics, prebiotics, defined microbial consortia, and fecal microbiota transplantation to enhance resistance against bacterial, viral, fungal, and parasitic infections. These microbiome-based strategies represent promising, sustainable alternatives to conventional antibiotics, offering scalable and mechanism-driven interventions. This review further underscores the potential of microbiota-informed therapies to contribute to effective infectious disease prevention and management while addressing global health challenges.