Lactobacillus helveticus-fermented milk improves learning and memory in mice

Objectives: To investigate the effects of Calpis sour milk whey, a Lactobacillus helveticus-fermented milk product, on learning and memory. Methods: We evaluated improvement in scopolamine-induced memory impairment using the spontaneous alternation behaviour test, a measure of short-term memory. We also evaluated learning and working memory in mice using the novel object recognition test, which does not involve primary reinforcement (food or electric shocks). A total of 195 male ddY mice were used in the spontaneous alternation behaviour test and 60 in the novel object recognition test. Results: Forced orally administered Calpis sour milk whey powder (200 and 2000 mg/kg) significantly improved scopolamine-induced cognitive impairments (P < 0.05 and P < 0.01, respectively) and object recognition memory (2000 mg/kg; P < 0.05). Discussion: These results suggest that Calpis sour milk whey may be useful for the prevention of neurodegenerative disorders, such as Alzheimer's disease, and enhancing learning and memory in healthy human subjects; however, human clinical studies are necessary.