Scientists Intrigued by Microbe That Makes Mice Swole

Researchers found a correlation between higher grip strength and abundance of Roseburia, especially Roseburia inulinivorans.

Older adults with R. inulinivorans showed 29% greater grip strength than those without the bacterium.

Introducing R. inulinivorans into mice increased forearm grip strength by about 30% and changed muscle fiber composition.

Human strains did not permanently colonize mouse guts, and human benefits remain unproven.

Authors suggested the bacterium could be developed as a probiotic to help preserve muscle strength with aging.