藉由小鼠與犬隻模式探討Lactobacillus kefiranofaciens M1於異位性皮膚炎之研究

Abstract

異位性皮膚炎是一種與遺傳有關的皮膚疾病，其由第一型過敏反應引起，並造成皮膚紅腫、發炎、濕疹、苔蘚化等症狀。目前，口服抗組織胺或外用類固醇為治療異位性皮膚炎主要之方法，然而其可能會造成嗜睡、腸胃不適和肝腎功能異常等副作用。本試驗藉由小鼠與犬隻模式探討本實驗室所分離出之益生菌Lactobacillus kefiranofaciens M1是否對於異位性皮膚炎具有預防或改善之功效。 小鼠試驗中，分別以卵白蛋白（ovalbumin, OVA）及塵螨（house dust mites, HDM）致敏小鼠，並於試驗期間餵予5x108 CFU/mL Lb. kefiranofaciens M1。結果顯示，餵食Lb. kefiranofaciens M1並以OVA致敏之小鼠其血清中OVA特異性免疫球蛋白（immunoglobulin, Ig）E之濃度有較未給予Lb. kefiranofaciens M1組別下降之趨勢，並且能顯著減少Th1與Th2細胞激素之分泌（P<0.05）。小鼠以OVA與HDM致敏並餵予Lb. kefiranofaciens M1後，其Peyer’s patches中之CD4+CD25+ T 細胞分布比例亦顯著較無餵予Lb. kefiranofaciens M1組別提高（P<0.05）。 而在犬隻模式部分，第一階段試驗中，正常米格魯犬隻餵飼109和1010 CFU/dog Lb. kefiranofaciens M1菌粉12週，每4週採集血液與糞便，測定周邊血液單核球（peripheral blood mononuclear cells, PBMC）分泌細胞激素與非特異性抗體濃度變化，以及糞便中微生物菌相是否改變。在給予Lb. kefiranofaciens M1之組別中，介白素（interleukin, IL）-2較控制組有下降之趨勢，而腫瘤壞死因子（tumor necrosis factor, TNF）-α和IL-10則較控制組有提高之趨勢；非特異性抗體方面，IgG有提高之趨勢而IgE則有下降之現象，然而兩者與控制組之間並無顯著差異。微生物菌相方面，餵飼109和1010 CFU/dog Lb. kefiranofaciens M1菌粉之組別，其革蘭氏陽性菌Lactobacillus與Bifidobacterium 菌屬比例有提高之現象，而革蘭氏陰性菌Escherichia coli與Clostridium perfrigens之數量則遭受抑制。在第二階段試驗中，犬隻分為控制組，與分別給予賦形劑和Lb. kefiranofaciens M1菌粉22週之2組。除了控制組之外，試驗第6週時犬隻於其腋窩及鼠蹊部塗抹0.25 g/mL塵螨溶液致敏。第22週時，致敏犬隻患部有紅斑、丘疹、膿皰、脫毛和搔癢造成之創傷等症狀，餵予Lb. kefiranofaciens M1組別之症狀評分有較無餵予Lb. kefiranofaciens M1組別為低之趨勢，然而兩者之間並無顯著差異。餵予Lb. kefiranofaciens M1組之干擾素（interferon, IFN）-γ和TNF-α亦有較無餵予Lb. kefiranofaciens M1組降低之現象。在HDM特異性IgE方面，餵予Lb. kefiranofaciens M1組之濃度有較無餵予Lb. kefiranofaciens M1組為低之趨勢，然而組別之間亦無顯著差異。 綜觀上述，從小鼠試驗中，餵食Lb. kefiranofaciens M1可能具有提高CD4+CD25+ T細胞分布比例、降低特異性IgE濃度以及調節Th1和Th2細胞激素分泌之作用。而在犬隻模式方面，Lb. kefiranofaciens M1具有調節免疫力和改變腸道微生物組成之能力。然而，在預防犬隻異位性皮膚炎臨床症狀的部分則未發現顯著之效果。

Atopic dermatitis (AD) is an allergic skin disease which causes skin itching and inflammation. AD is resulted from immunological hypersensitive reaction. Medicines such as antihistamine and antibiotics are used for AD treatment. However, these medicines might also induce adverse side effects. Lactobacillus kefiranofaciens M1 (M1) is a probiotic which has been proved to be effective in treatment of allergy and asthma in mice. Thus, the aim of this study was to further investigate the effects of M1 on preventing or curing AD in mouse and canine models. In mouse model, mice were assigned randomly to five groups (normal, ovalbumin (OVA), OVA+M1, house dust mites (HDM) and HDM+M1 groups). OVA+M1 and HDM+M1 groups were fed with 5x108 CFU/mL M1 throughout the experiment period. The results showed that feeding of M1 had the tendency to decrease the OVA-specific IgE concentration, and significantly reduced the production of T helper type 1 (Th1) and Th2 related cytokines (P<0.05). CD4+CD25+ T cells were significantly increased in Peyer’s patches of OVA+M1 and HDM+M1 groups (P<0.05). To further investigate the effects of M1 on preventing or curing AD in canine atopic dermatitis (CAD), beagles were used for experiment. In the first stage of canine model, canine were assigned into control, 109 and 1010 groups, and latter two groups were administrated 109 or 1010 CFU/dog M1 powder daily for 12 weeks. Blood and feces were collected every 4 weeks for analysis. Canine fed with M1 had the tendency to decrease Th1 and Th2 cytokine production of peripheral blood mononuclear cells (PBMC) on week 12. In immunoglobulin (Ig) concentration, IgG concentration and IgG2/IgG1 ratio were growing up in 1010 group, while IgE were not significantly different. In fecal microbiota study, the ratio of Lactobacillus and Bifidobacterium to Escherichia coli and Clostridium perfrigens was increased in 109 and 1010 groups. In the second stage of canine model, canine were assigned into control, HDM and HDM+M1 groups. HDM and HDM+M1 groups had clinical signs such as erythema, papules, pustules, alopecia and self-traumatized lesions. In canine atopic dermatitis extent and severity index (CADESI) score on week 18, HDM+M1 group had lower score than HDM group, while there were not significantly different. HDM+M1 group also decreased the production of interferon-γ and tumor necrosis factor-α. In HDM-specific IgE concentration, HDM+M1 group had the tendency to decrease compared with HDM group, although there were not significantly different, either. In conclusion, administration of M1 appeared to increase the population of CD4+CD25+ T cells, decrease specific IgE concentration and balance Th1 and Th2 cytokine production in mouse model. It can also improve the immunomodulation and alter gut microbiota composition in canine model. However, the benefits of prevent the development of CAD were not significant.