Fig. 3: Rice bran peptides improve learning and cognitive abilities in mice.

A, B Analysis of alpha diversity among groups using Simpson and Shannon indices. Assessment of alpha diversity in young (4 months old) and old (24 months old) mice, with control groups and KF-8 intervention groups (treated from 14 to 16 months of age with KF-8 at a dosage of 30 mg/kg, twice weekly) (n = 3). C, D Visualization of fecal sample bacterial community characteristics among groups at the species level using Bray–Curtis distance matrix and principal coordinate analysis (PCoA) (n = 3). E Venn diagram illustrating the overlap of operational taxonomic units (OTUs) among groups (n = 3). F Heatmap of the most abundant features of differential gut bacteria at the genus level (n = 3). G Representative path plot during the MWM test phase (n = 5). H In the acquisition phase, the escape latency of the rice bran peptide treatment group was significantly reduced (n = 5). I The latency to reach the platform position (n = 5). J Number of crossings of the platform position by mice (n = 5). K Percentage of time spent in the platform quadrant by mice (n = 5). L Representative path plot of mice in the NOR test (n = 5). M Increase in the NOR index in mice of the rice bran peptide intervention group (n = 5). N, O In the NOR test, the time and frequency of activity in the natural peptide treatment group mice were significantly increased (n = 5). P Significant increase in the number of touches to new objects by mice in the rice bran peptide intervention group (n = 5). Q Representative path plot of mice in the open field test (n = 5). R, S Rice bran peptide promotes mouse movement, with significant increases in movement distance and speed (n = 5). T Time spent by mice in the central area (n = 5). U Increase in the percentage of mouse motor activity due to rice bran peptide intervention (n = 5). Differential bacteria were selected based on LEfSe analysis and the Kruskal–Wallis test. P < 0.05 indicates statistical significance. Statistical significance between groups was determined by Student’s t test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns not significant.