Microbiota (or Microbiome; “Normal human microbiota” may be used for the human context, e.g., “Intestinal microbiota”) (None. Common abbreviations are context-specific (e.g., GM for “gut microbiota”) but not standardized or canonical.)

Microbial flora (now termed microbiota or microbiome) refers to the ecological community of microorganisms that inhabit particular environments, such as the skin, gut, or mucous membranes of humans. This community consists primarily of bacteria, but also includes archaea, fungi, and protists. The human microbiota plays critical roles in digestion, immune function, and protection against harmful microbes, and disruptions can contribute to disease states ranging from gastrointestinal disorders and metabolic diseases to infections and neurodegenerative conditions. While not a molecular therapeutic target like a protein or receptor, the structure and function of the microbiota is a major focus for current interventions—including antibiotics, probiotics, prebiotics, and microbiota transplantation—with important implications for drug metabolism and safety. The correct term to use in 2025 scientific context is microbiota (or microbiome) rather than microbial flora.

Other names

MicrofloraNormal floraCommensal floraResident microbiotaGut microbiota (when referring specifically to the intestinal microbial community)

Modulation of community structure (promotion, depletion, or rebalancing of certain strains by probiotics, prebiotics, or antibiotics); Inhibition or promotion of microbial metabolic pathways (e.g., β-glucuronidase inhibition to prevent drug-induced toxicity); Restoration of eubiosis and prevention of dysbiosis; Delivery of therapeutics using live microbes (“bacterial chassis” therapies)