Synbiotic Goat Milk Kefir Lowered Peroxisome Proliferator Activated Receptor Gamma (PPARγ) Gene Expression in Rat Adipose and Liver Tissue
Abstract Background Kefir is a fermented milk product containing bacteria and yeast, whereas glucomannan from porang (Amorphophallus oncophyllus) tuber is known as a prebiotic in vivo. Diets with a high fat and high sugar will stimulate metabolic syndrome associated with changes in gene expression including peroxisome proliferator activated receptor gamma (PPARγ). The purpose of this study was to determine the effect of goat milk kefir enriched with porang glucomannan (synbiotic kefir) and goat milk kefir without glucomannan (probiotic kefir) on blood glucose, hemoglobin A1c (HbA1c), free fatty acid (FFA), tumor necrosis factor alpha (TNF-α), gene expression of peroxisome proliferator activated receptor gamma (PPARγ), and insulin-producing cells in rats fed a high-fat and high-fructose (HFHF) diet. Methods Male Sprague Dawley rats 8–12 weeks old (n = 30) treated with HFHF diets for two weeks, and then divided into five dietary groups (each group consisted of 6 rats): 1) normal control (received a standard diet only); 2) rats fed HFHF; 3) rats fed HFHF + probiotic kefir; 4) rats fed HFHF + synbiotic kefir; and 5) rats fed HFHF + simvastatin. The dose of kefir was 3.6 mL/200 g body weight/day and simvastatin was 0.72 mg/day. All of these treatments were carried out for 4 weeks. Results There were no significant differences in plasma blood glucose in HFHF rats after and before treatment, but decreased in plasma HbA1c and TNFα (p < 0.05) and inhibited the increase of FFA in rats after synbiotic kefir treatment (paired-samples t-test). Probiotic and synbiotic kefir decreased the gene expression of PPARγ2 (p < 0.05) in both of adipose and liver tissue in HFHF rats but had no effect on the total number of Langerhans islets and insulin-producing cells (one way ANOVA). Conclusions Synbiotic kefir could ameliorate the health of rats fed HFHF diet through decreasing HbA1c, TNFα, and PPARγ2 gene expression and preventing an increase in FFA. The results indicate that goat milk synbiotic kefir potentially improve metabolic syndrome.