Lactobacillus paracasei subsp. paracasei NTU 101 菌粉對高脂高果糖飲食誘導葡萄糖不耐大鼠之血糖調節作用

Abstract

乳酸菌為常見之益生菌，目前已有許多文獻指出其具有改善肥胖、血脂異常及胰島素抗性等代謝異常之功效。本研究探討 Lactobacillus paracasei subsp. paracasei NTU 101 菌粉對高脂高果糖飲食所誘發之葡萄糖耐受不良是否具有預防及改善效果。以高脂高果糖飲食 [脂肪：24.5% (w/w)，果糖：10.2% (w/w)] 和 30% (w/v) 果糖水餵食 Sparque-Dawley (SD) 大鼠，誘發其產生葡萄糖不耐，預防模式同時介入高脂高果糖飲食及低、中、高劑量 (107、108、109 CFU/rat/day) 之 NTU 101 菌粉；治療模式則於誘發葡萄糖不耐後介入不同劑量之 NTU 101 菌粉。結果顯示高脂高果糖飲食會誘發大鼠產生高胰島素血症及葡萄糖不耐，而管餵介入低、中、高劑量 NTU 101 菌粉在預防及治療模式中皆可顯著降低血中胰島素濃度、HOMA-IR 及口服葡萄糖耐受試驗之曲線下面積。此外，餵食 NTU 101 菌粉可顯著提升糞便中 Bifidobacterium spp. 菌數，並增加結腸組織中緊密連接蛋白 (tight junction protein) occludin 之 mRNA 表現量，降低血中脂多醣 (lipopolysaccharide, LPS) 及發炎細胞激素 TNF (tumor necrosis factor)-α 和 IL (interleukin)-6 濃度，並增加肝臟及脂肪組織中葡萄糖轉運蛋白 (glucose transporter, GLUT) 的表現量。綜合以上結果，餵食不同劑量之 NTU 101 菌粉在預防及治療模式中可藉由改善腸道菌相，維持腸壁之完整性，進而降低腸道 LPS 進入體內所引起之發炎反應，進而改善周邊組織之胰島素抗性，達到調節血糖的效果，顯示 NTU 101 菌粉具有開發為第二型糖尿病患者輔助調節血糖保健食品之潛力。

Lactic acid bacteria (LAB) are frequently used as probiotics, and have been reported to improve various metabolic disorders such as obesity, dyslipidemia and insulin resistance. This study investigated the preventive and therapeutic effects of Lactobacillus paracasei subsp. paracasei NTU 101-fermented products (NTU 101) on impaired glucose tolerance (IGT) induced by high fat high fructose diet (HFFD). Sprague-Dawley (SD) rats were fed a HFFD [25% (w/w) fat and 10% (w/w) fructose in food (4.3 kcal/g) and fructose-enriched drinking water (30% (w/v)] for IGT with 107, 108 or 109 CFU/rat/day of NTU 101 for prevention or therapy. HFFD resulted in hyperinsulinemia and IGT, while NTU 101 administration significantly decreased insulin levels, homeostatic model assessment-insulin resistance (HOMA-IR) and glucose area under the curve (AUC) during oral glucose tolerance test (OGTT) in preventive and therapeutic models. Additionally, NTU 101 increased Bifidobacterium spp. in feces and tight junction protein expression in colon, therefore reduced serum lipopolysaccharide (LPS) and proinflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-6. Moreover, the expression of glucose transporter (GLUT) in liver and adipose tissue were elevated in NTU 101-treated groups. These results demonstrated that administration of different dose of NTU 101 exert both preventive and ameliorative effects on insulin resistance and IGT via preserving gut barrier integrity, decreasing the transfer of LPS into the circulatory system and LPS-induced inflammatory responses, suggesting its possible clinical application in type 2 diabetes mellitus (T2DM) prevention.