Lactobacillus pentosus var. plantarum C29 ameliorated D-galactose-induced memory impairment, reversed the inhibition of BDNF and doublecortin expression and cAMP response element-binding protein activation, and reduced the inhibition of aging p16 and inflammatory markers p-p65, p-FOXO3a, cyclooxygenase (COX)-2 and inducible NO synthase (iNOS). Here, NOS2 is linked to memory impairment.