山羊乳寡醣改善小鼠腸內細菌菌相與免疫調節功能之評估

Abstract

本試驗之目的在研究比較小鼠的日常飲食中添加山羊乳寡醣或半乳寡醣對其腸道菌相組成及免疫能力的影響。試驗中所使用的山羊乳寡醣是利用快速液態層析儀分離再濃縮後所得。本試驗使用40隻4週齡大的雄性BALB/c小鼠為受試對象，總飼養期間為兩個月。四個試驗組分別為1)對照組；2)半乳寡醣組；3)酸性山羊乳寡醣組與4)中性山羊乳寡醣組。三個寡醣處理組餵飼劑量均為每日500 mg/每公斤體重。餵飼四週後，所有小鼠均進行遲發性過敏反應（delayed-type hypersensitivity）檢測。隨後，利用腹腔注射卵白蛋白來對小鼠進行特異性免疫反應測試，追蹤血漿中免疫球蛋白G(IgG) 及免疫球蛋白M (IgM) 的濃度變化。隨後，當飼養滿八週後，採集小鼠血液樣本進行特異性免疫反應測試及血液血球計數分析試驗。接著犧牲所有小鼠，解剖取得其腸道與脾臟。在腸道取1)結腸絨毛；2)結腸內容物；3)盲腸絨毛及4)盲腸內容物後再加上5)糞便，分別檢測其菌數。檢測的菌種為1)Bifidobacterium spp.；2)Lactobacillus spp.；3) Clostridium perfringens及4) Escherichia coli。而脾臟則用以進行淋巴細胞增生能力的測試。本試驗結果顯示，在遲發性過敏反應上，三個寡醣處理組都較對照組有較小的腫脹程度。血液血球計數分析的結果，則呈現三寡醣處理組在單位血液量中的白血球、淋巴球與單核球三種細胞數目皆高於對照組。特異性免疫反應方面，半乳寡醣組與酸性山羊乳寡醣組的小鼠血漿中IgG及IgM濃度亦顯著較對照組為高。淋巴細胞增生能力上，半乳寡醣組與酸性山羊乳寡醣組有較對照組強的T淋巴球增生表現。最後，腸道菌數檢測的結果，半乳寡醣組與酸性山羊乳寡醣組相較於對照組，顯著的提昇腸道中Bifidobacterium spp. 和 Lactobacillus spp. 的數目，並使E. coli下降，但在對照組與中性山羊乳寡醣組之間則較無差異。綜合上述結果，山羊乳寡醣在提昇小鼠免疫能力和增加腸道益菌數目上與半乳寡醣有類似的正面結果。

The purpose of this study was to investigate the effect of dietary supplementation of goat milk OS on intestinal bacterial composition and immunity of mice. The goat milk OS were isolated and concentrated by FPLC in NTU Animal Nutrition Lab. Forty male BALB/c mice of 4 weeks age were used in this study. They were randomly allocated to 4 treatments of 10 mice each treatment. The four treatments were: (1)control, (2)galacto-oligosaccharides(GOS), (3)acidic goat milk oligosaccharides(AOS) and (4)neutral goat milk oligosaccharides(NOS). After four weeks of OS feeding, all mice were subjected to the delayed-type hypersensitivity test. After eight weeks, blood samples were collected for assay of the blood cells numbers, immunoglobulin G, immunoglobulin M and splenic lymphocyte proliferation, and samples of the (1)colic content, (2)colic villus, (3)cecal content, (4)cecal villus and (5)feces were taken for culturing count of Bifidobacterium, Lactobacillus, Clostridium perfringens and Escherichia coli. Results showed that all three OS treatments were higher in quantities of leukocytes, lymphocytes, and monocytes than the control group. In delayed-type hypersensitivity test, the swollen skin areas were smaller in the GOS, AOS, and NOS groups. Plasma IgG and IgM concentrations of mice in GOS or AOS group were significantly higher than those of control group. The lymphocyte proliferation competence in GOS and AOS groups was higher for T cell proliferation. In the intestinal bacterial composition, the number of Bifidobacterium spp. and Lactobacillus spp. increased significantly and E. coli decreased in the GOS and AOS groups, but there was not difference between NOS and control groups. In conclusion, goat milk oligosaccharides have ameliorative effect on immunity and intestinal bacterial composition, which was similar to the effects of GOS.