Preventive effect of peptides derived from fermented milk on chronic stress-induced brain damage and intestinal dysfunction in mice

Abstract

This study investigated the preventive effects of peptides derived from milk fermented with the probiotic strain Lactobacillus gasseri 505 (505) against stress-related brain damage and anxiety-like behavior. The peptides MKPWIQPKTKVIPYVRYL (Pep14) and VYQHQKAMKPWIQPKTKVIPYVRYL (Pep21), which exhibit high antioxidant and anti-inflammatory activities, were administered to stressed mice. The results showed that the stress mechanism in the gut-brain axis was regulated by pretreatment with both peptides, leading to inhibition of neurodevelopment and neuroinflammation through the hypothalamic-pituitary-adrenal (HPA) axis, based on the expression of related mRNA and proteins. The expression of colonic inflammation-related mRNA and proteins was also reduced. Moreover, anxiety-like behavior was significantly reduced in mice treated with Pep14 and Pep21. These results indicate that the bioactive peptides Pep14 and Pep21, derived from milk fermented with 505, may prevent stress-induced brain damage and anxiety-like behavior via regulation of the HPA axis.