The Role of Microorganisms in Human Health and Disease

Abstract

Microorganisms are fundamental components of the human biological environment and include bacteria, fungi, viruses, archaea, and other microscopic organisms. Many microorganisms coexist with humans without causing disease and contribute to digestion, metabolism, immune development, and protection against harmful organisms. The human microbiota is particularly important at body sites such as the gastrointestinal tract, skin, oral cavity, and respiratory system. At the same time, pathogenic microorganisms can cause infectious diseases, while disruptions in microbial communities may be associated with inflammatory, metabolic, and other chronic conditions. This paper examines nine major aspects of microorganisms in human health and disease, including the human microbiome, beneficial microbial functions, immune interactions, pathogenic microorganisms, antimicrobial resistance, microbiome imbalance, nutrition, probiotics and therapeutics, and emerging microbiome research.