Mice treated with the probiotic Bifidobacterium lactis had a significantly increased lifespan & lower inflammation.

Mice treated with the probiotic Bifidobacterium lactis lived significantly longer than controls, had decreased levels of inflammation, healthier colons, and a stronger gut barrier. Part of the positive benefits of this probiotic were mediated by increased production of spermidine (which also improves lifespan in mice) in the colon.