Background: The human microbiota is all microorganisms that live on and in humans as gut microbiota, vaginal microbiota, skin microbiota and so. The human microbiome consists of the human microbiota and the genes these cells harbor. The human microbiome is characterized by the huge number and wide diversity. The multi-omic approaches, including phylogenetic marker-based microbiome profiling, shotgun metagenomics, metatranscriptomics, metaproteomics, and metabolomics, have enabled the efficient characterization of microbial communities. The human microbiome produces a high amount of metabolites that can affect its host to the degree some scientists have considered it especially the gut microbiome as an extraorgan. The human microbiome accomplishes many vital processes. It maintains intestinal integrity and supports its barrier function. It provides essential nutrients like vitamin K and vitamin B. The human microbiome is vital to the innate and adaptive immune system. Disturbance of human microbiome can lead to somatic diseases as autoimmune diseases, obesity, metabolic syndrome, DM type II, and the development of cancer. Besides, the somatic disorders, dysbiosis was associated with autism and psychiatric disorders. This review article aims to shed light on updates on human microbiomes and its importance to human health. It will discuss the relation of dysbiosis to human diseases.