GLOSSARY

Prevotella is a genus with varied species and sites, whose dietary associations do not establish universal benefit.

Phylum, family, genus, species and strain are different taxonomic levels; one strain's result cannot automatically represent its whole genus. Scientific revisions change names while older names remain in reports. Match current and historical names when comparing labels with studies. A ratio between two large phyla alone does not diagnose obesity, health or athletic readiness, and classification is not a ranking of universal benefit.

Microbiota refers to organisms in an environment; microbiome can also include their genes and ecological setting, depending on the definition. Gut communities contain more than bacteria, and intestinal regions differ. Stool offers a useful view of part of this system, not a complete map of small-intestinal or mucosal populations. Define the sample and terminology before interpreting a report as a description of the entire body.

Relative abundance is a share of the measured total, not an absolute count. A larger share may reflect declines elsewhere rather than growth of that organism. Extraction and analysis also influence estimates. Interpret before-and-after diet percentages with these constraints and the wider community. A colorful chart alone does not demonstrate causality, establish an ideal population size or justify trying to eliminate every low-abundance organism.