GLOSSARY

Interindividual Microbiome Variation is between-person variation linked to diet, medicines, age or environment, not necessarily disease.

Microbial responses to food, training or supplements vary between people and depend on baseline and timing within a person. Useful personalization begins with a goal, history and response assessment; one commercial report does not provide an established precise menu. Athletes should assess performance, tolerance and adequate food alongside data. Resembling a reference population alone is not success if practical outcomes or nutritional adequacy do not improve.

Microbiomes vary between people and over time within one person, influenced by diet, medicines, geography, age and bowel habits. Stability concerns limited change over an interval; resilience concerns recovery or adaptation after disturbance. Record sampling conditions and recent events for personal comparisons. Being different from a teammate is not by itself unhealthy or a reason to copy that athlete's diet, supplements or presumed microbial target.

An association between microbes and health or performance does not alone establish microbial causation. Diet and training can influence both, and culture or animal findings are not direct human prescriptions. Sports-benefit claims need relevant human outcomes for the actual intervention. An axis name or biological pathway cannot replace evidence of a practical effect, especially when a product is marketed using results from a different population or formulation.