Fermented Rice Bran Mitigated the Syndromes of Type 2 Diabetes in KK-Ay Mice Model

<b>Background:</b> Diabetes is a devastating disease that causes millions of deaths. Fermented rice bran (FRB), made by fermenting rice bran with <i>Aspergillus kawachii</i> and a mixture of lactic acid bacteria, was hypothesized to b able to improve diabetes-related symptoms. This study aimed to investigate the effects of FRB supplementation in mitigating type 2 diabetes symptoms and identifying FRB bioactive compounds. <b>Methods</b>: In this study, KK-<i>A^y</i> mice (4 w.o. male) were used as a model for type 2 diabetes. Mice were divided into three different groups. The first group received a control diet, the second received a 12.5% non-fermented rice bran (RB) supplemented diet, and the last group was fed a 12.5% FRB-supplemented diet. Supplementation was done for 4 weeks. <b>Results</b>: FRB supplementation lowered the blood glucose level, OGTT, HOMA-IR, total cholesterol, liver RAGE protein, and <i>glucokinase</i> in KK-<i>A^y</i> mice. Metabolome analysis of RB and FRB showed that fermentation increased bioactive compounds in rice bran, such as GABA, L-theanine, and carnitine. It also increased the levels of various free amino acids while converting some amino acids such as arginine, tyrosine, and tryptophan into other metabolites. <b>Conclusions</b>: This research showed the potency of FRB supplementation as a preventive agent against type 2 diabetes.