The microbiome refers to the trillions of microorganisms that live in and on the human body. The microbiome plays a crucial role in human health, affecting functions of the immune system, digestive system, and other body systems. The microbiome is established early in life, beginning in the placenta and developing further during birth and through breastfeeding. Maintaining a healthy microbiome involves avoiding overuse of antibiotics, eating a high-fiber diet with fermented foods, limiting stress, and consuming prebiotic and probiotic supplements. Imbalances in the microbiome are linked to various diseases like IBS, IBD, and metabolic disorders.