The human microbiota, comprising diverse microorganisms, plays a critical role in maintaining health and modulating immune responses. Its influence on infection development is profound, with a balanced microbiota acting as a barrier against pathogenic invasions through competitive exclusion, antimicrobial production, and immune system regulation. Dysbiosis—microbial imbalance—disrupts these protective mechanisms, increasing susceptibility to infections such as Clostridioides difficile, respiratory infections, and viral diseases. The microbiota also affects infection severity and outcomes, emphasizing the importance of microbial diversity.

Microbiota, dysbiosis, infections, immune modulation, probiotics, fecal microbiota transplantation, microbial diversity, antimicrobial resistance.

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