Gastrointestinal tract microbiota (None. Widely referred to as “gut microbiota,” but no standardized abbreviation as for molecular targets)

The gastrointestinal tract microbiota refers to the ecosystem of trillions of microorganisms (including bacteria, archaea, viruses, and fungi) inhabiting the human gut from the stomach to the colon. These microbes carry out essential physiological functions for their host, such as metabolizing dietary fiber, synthesizing vitamins, tuning immune responses, maintaining gut barrier integrity, and protecting against pathogens. The composition and activity of the gut microbiota is highly variable between individuals and can profoundly influence the effectiveness and toxicity of drugs, susceptibility to disease, and the outcome of therapies such as cancer immunotherapy. While the gut microbiota can be manipulated by antibiotics, probiotics, prebiotics, or fecal microbiota transplantation, it is not itself a molecular drug target; rather, it represents a complex and dynamic biological system whose balance is fundamental to health and disease.

Other names

Gut microbiotaGut floraIntestinal floraGut microbial communityGut microflora (older usage; now largely deprecated)Gastrointestinal microbiota

Restoration or modulation of microbial diversity (e.g., FMT) Direct suppression or promotion of specific bacteria (antibiotics, probiotics, prebiotics) Inhibition of specific bacterial enzymes (e.g., β-glucuronidase inhibitors to prevent irinotecan toxicity) Enhancement or suppression of host immune response by altering microbiota composition