Importance of human microbiome: an update

Millions of microorganisms—including bacteria, viruses, fungi, archaea, and protists—reside on and within the human body, collectively forming the human microbiota. This complex and dynamic community plays a crucial role in modulating physiological processes, particularly the development and regulation of the immune system. Modern behaviors such as frequent washing, excessive hygiene, and widespread use of antimicrobial agents can disrupt the natural composition and functional balance of the microbiota, leading to altered immune responses and increased susceptibility to disease. In this review, we focus primarily on the bacterial component of the human microbiome. While we acknowledge the importance of viruses, fungi, archaea, and protists, these components are beyond the scope of the current review. We highlight recent advances in bacterial microbiome research that are reshaping our understanding of host–microbe interactions, immune modulation, and the health consequences of microbiota dysbiosis.