副乾酪乳酸桿菌 NTU 101 與胚芽乳酸桿菌 NTU 102 對於 EL-4 T 細胞株與過敏原誘發之小鼠之免疫調節功效

Abstract

近年來，有過敏體質的人越來越多，其中最常見的第一型過敏反應為氣喘，尤以兒童族群最為嚴重。全台約每十個小孩就有一人患有氣喘或過敏反應，在大台北等都會區更高達 15-20%，且全台氣喘盛行率逐年攀升，不僅增加社會與醫療成本，更是家庭中的經濟與生活負擔。本研究以實驗室所分離之本土乳酸桿菌，包含副乾酪乳酸桿菌 NTU 101 與胚芽乳酸桿菌 NTU 102，以細胞平台與動物模式探討免疫調節之機轉。首先利用 EL-4 T 細胞株初步篩選出具免疫調節潛力的菌株，結果顯示副乾酪乳酸桿菌 NTU 101 除了能提升 Th1 細胞激素如 IFN-γ 之分泌外，能同時抑制 Th2 細胞激素如 IL-4、IL-5 與 IL-13之表現，效果皆優於胚芽乳酸桿菌 NTU 102，而主要活性之區分物存在於熱致死菌與酵素水解菌體後離心所得之沉澱物。此外以 OVA 刺激 BALB/c 小鼠誘導其成為過敏動物模式，研究顯示每日口服副乾酪乳酸桿菌 NTU 101 熱致死菌亦能調降體內血清與脾臟之 IgE 抗體的生成。在同時餵食乳酸菌與致敏的模式中，乳酸菌之主要調控機轉是藉由提升 IFN-γ 分泌與抑制 IL-4 及 IL-13 之表現，但對於 IL-5 則無顯著差異，因此顯示口服熱致死乳酸桿菌即可達到平衡 Th1/Th2 與緩解過敏症狀之功效。

Hypersensitivity has become more and more common around the world. Asthma is the most common type of hypersensitivity, especially in children. There are approximately 10% of children who suffered from asthma or hypersensitivity in Taiwan and more severe in metropolitan cities. The prevalence of asthma has markedly increased in Taiwan in recent decades which not only raised the social and medical costs but also deteriorated family burden and quality of life. This study focuses on the immunomodulatory effects of local lactic acid bacteria, namely Lactobacillus paracasei subsp. paracasei NTU 101 and Lactobacillus plantarum NTU 102, both in vitro and in vivo. We screened out potential immunomodulting candidates of Lactobacillus by EL-4 T cells. Lactobacillus paracasei subsp. paracasei NTU 101 exerted beneficial effects by increasing Th1 cytokine production of IFN-γ and by surpressing secretion of IL-4, IL-5 and IL-13. Additionally, effective hydrolysates were found in heat-killed and enzymatic hydrolyzed Lactobacillus. Moreover, the results showed that daily gavage of heat-killed Lactobacillus paracasei subsp. paracasei NTU 101 in OVA-induced allergic mice can reduce IgE secretion both in serum and spleen. Evidence for the basis of modulatory effects of Lactobacillus comes from increasing the expression of IFN-γ while decreasing the secretion of IL-4 and IL-13 at the same time in co-treatment of Lactobacillus with OVA-induced allergic mice. The results indicated that oral administration of heat-killed Lactobacilli can not only balance the activity of Th1/Th2 but also relieve the symptoms from hypersensitivity.