Preparation of gama-aminobutyric acid-enriched rice bran and its modulation on gut microbiota and cognitive function of rats in high-fat diet

In this study, gama-aminobutyric acid (GABA) in rice bran was promoted to be 8 times higher than its original one via anaerobic incubation. The GABA enriched rice bran (ERB) demonstrated a significantly increased anti-oxidant capacity following the incubation. The consumption of high-fat diet (HFD) with ERB was found to stimulate butyrate and propionate production by promoting Anaerostipes, Anaerostipes sp. and associated synthesizing enzymes. This altered short-chain fatty acids distribution further enhanced circulatory levels of leptin and glucagon-like peptide-1, controlling food intake by down-regulating orexigenic factors. Delightedly, the current study found GABA supplement delivered by rice bran significantly promoted hippocampal sulfatides synthesis, and reversed the HFD-induced sulfatides deficiency and oxidative-triggered mild cognitive impairment. Elevated GABA concentration in the hippocampus and the activation of GABA B-type receptors might be the primary contributors. This study highlights the potential of GABA enriched rice bran as a novel dietary supplement for benefiting the attenuation of chronic diseases.