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.
Figure 5D is extremely impressive! Glad my homemade synbiotic yogurt I have each day for breakfast is inoculated with bifidobacterium animalis subsp. lactis. Don’t want to look like those control mice ;)