Reference entry

Keystone Species

Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.

Glossary context

Defined

in the site-wide microbiome glossary

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Definition

A bacterial species that has a disproportionately large effect on the structure and function of the microbial community relative to its abundance. The loss of keystone species can trigger cascading changes in the entire microbiome ecosystem.

Related terms

Microbiome Diversity

The variety and abundance of different microbial species in a given environment. Greater diversity is consistently associated with better health outcomes, while reduced diversity is linked to obesity, inflammatory bowel disease, and other chronic conditions.