Peanut meal extract fermented with Bacillus natto attenuates physiological and behavioral deficits in a D-galactose-induced aging rat model

Our previous studies have shown that the nutritional properties of peanut meal after fermentation are markedly improved. In this study, in order to facilitate the further utilization of peanut meal, we investigated the effects of its fermentation extract by Bacillus natto (FE) on cognitive ability, antioxidant activity of brain, and protein expression of hippocampus of aging rats induced by D-galactose. Seventy-two female SD rats aged 4-5 months were randomly divided into six groups: normal control group (N), aging model group (M), FE low-dose group (FL), FE medium-dose group (FM), FE high-dose group (FH) and vitamin E positive control group (Y). Morris water maze (MWM) test was performed to evaluate their effects on learning and memory ability in aging rats. SOD activity and malondialdehyde (MDA) content of brain, HE staining and the expression of γ-aminobutyric acid receptor 1 (GABABR1) and N-methyl-D-aspartic acid 2B receptor (NMDAR2B) in the hippocampus of rats were measured. The results show that FE supplementation can effectively alleviate the decrease of thymus index induced by aging, decrease the escape latency of MWM by 66.06%, brain MDA by 28.04%, hippocampus GABABR1 expression by 7.98%, and increase brain SOD by 63.54% in aging model rats. This study provides evidence for its anti-aging effects and is a research basis for potential nutritional benefits of underutilized food by-products.

Changes in Functionality of Germinated and Non-Germinated Brown Rice Fermented by Bacillus natto

Germinated brown rice (GBR) is brown rice (BR) that has been germinated. GBR accumulates more nutrients and has a softer texture than BR. The aim of this study was to ferment GBR and BR using Bacillus natto and to investigate the functionality of the fermented products compared with white rice (WR) as a control. After fermentation with B. natto, the crude ash, total essential amino acids, and fat contents of each sample increased, while the crude protein content decreased. Moreover, the γ-aminobutyric acid and γ-oryzanol contents decreased, while the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging increased significantly in all fermented samples. The nattokinase activity (FU/g) of the fermented products was highest for GBR (43.11), followed by BR (19.62), and lowest for WR (12.24). Collectively, these results indicate that GBR fermented with B. natto yields better nutritional value and functional properties than fermented BR or WR.