Oral Administration of Okara Soybean By-Product Attenuates Cognitive Impairment in a Mouse Model of Accelerated Aging

• Published in: Nutrients 2019-12, Vol.11 (12), p.2939
• Main Authors: Corpuz, Henry M, Arimura, Misa, Chawalitpong, Supatta, Miyazaki, Keiko, Sawaguchi, Makoto, Nakamura, Soichiro, Katayama, Shigeru
• Format: Article
• Language: English
• Subjects: Aging; Animal cognition; Animal Feed - analysis; Animals; Brain research; Brain-derived neurotrophic factor; Brain-Derived Neurotrophic Factor - genetics; Brain-Derived Neurotrophic Factor - metabolism; Cellulose; Cognitive ability; Cognitive Dysfunction - drug therapy; Cytokines; Diabetes; Diet; Diet - veterinary; Dietary fiber; Food; Gastrointestinal Microbiome - drug effects; Gene Expression Regulation - drug effects; Glycine max - chemistry; Hippocampus - drug effects; Hippocampus - metabolism; Interdisciplinary aspects; Male; Memory; Mice; Microbiota; Okara; Oral administration; Prebiotics; Probiotics; Senescence; Soybeans; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu11122939

The microbiota-gut-brain axis has attracted increasing attention in the last decade. Here, we investigated whether okara, a soybean by-product rich in dietary fiber, can attenuate cognitive impairment in senescence-accelerated mouse prone 8 (SAMP8) mice by altering gut microbial composition. Mice were fed either a standard diet, or a diet containing okara (7.5% or 15%, / ) for 26 weeks. In the memory test, the 7.5% okara-fed mice showed a longer step-through latency and the 15% okara-fed mice had a short escape latency compared with control mice. The 15% okara-fed mice displayed decreased body weight, increased fecal weight, and altered cecal microbiota composition compared with the control group; however, there was no significant difference in the serum lactic acid and butyric acid levels among these mice groups. The 7.5% okara-fed mice had significantly higher NeuN intensity in the hippocampus compared with control mice. Furthermore, a decrease in inflammatory cytokine TNF- and an increase in brain-derived neurotrophic factor (BDNF) was observed in the 7.5% okara-fed group. The expression of synthesizing enzyme of acetylcholine was increased by the okara diets, and the acetylcholine level in the brain was higher in the 7.5% okara-fed group than in the control. These suggest that oral administration of okara could delay cognitive decline without drastically changing gut microbiota.