The human microbiome includes bacteria, fungi, and viruses that live on and inside the body. These communities influence digestion, immune function, and sometimes drug metabolism.
Microbiome studies must separate correlation from causation: a microbial shift can be a driver of disease, a consequence, or both. Diet, antibiotics, and environment can strongly reshape microbial composition.
Future therapies may include targeted probiotics, phage treatments, or personalized nutrition based on microbial profiles.