为探究具有预防龋齿功效的副干酪乳杆菌ET-22(Lactobacillus paracasei ET-22)活菌及其后生元组分(热灭活菌和分泌物)对白念珠菌的抑制作用,评价副干酪乳杆菌ET-22活菌及其后生元组分的抗氧化能力及白念珠菌菌丝转化抑制率后,采用注射免疫抑制剂和涂抹白念珠菌的方法建立ICR小鼠的口腔念珠菌病模型.造模前后,分别以饮水的方式连续给予18 d剂量为109 CFU/mL的ET-22活菌以及相对应的后生元组分,研究副干酪乳杆菌ET-22对小鼠舌部组织形态及炎症因子表达情况的影响.109 CFU/mL的副干酪乳杆菌ET-22对白念珠菌出芽抑制率最高,为37.84%;后生元组分中热灭活菌及分泌物抑制率分别为17.50%、28.00%.动物模型中,ET-22活菌及其后生元组分干预后,均显著降低了小鼠血清中IFN-γ含量;分泌物组显著降低了小鼠舌部组织中IFN-γ和TNF-α含量,活菌组只显著降低了 TNF-α含量,活菌组和热灭活菌组显著提高了小鼠舌部组织中CCL20趋化因子含量及舌苔菌群的丰富度和多样性.组织病理切片显示:ET-22活菌及分泌物组明显改善了小鼠舌表皮的棘层松懈和炎症细胞浸润;热灭活菌组对舌表乳头及表皮脱落有改善效果.实验结果显示,ET-22可通过减轻小鼠舌部组织的炎症浸润与转移,调节舌苔菌群组成,抑制口腔有害菌.研究表明,ET-22通过对白念珠菌的抑制,降低口腔念珠菌病的发病风险,有望进一步开发成为具有呵护口腔健康功能的口腔益生菌食品.
The inhibition effect of Lactobacillus paracasei(L.paracasei)ET-22 live bacteria,known for its efficacy in preventing dental caries,and postbiotic components(heat-inactivated bacteria and secretions)on Candida albicans was investigated.After evaluating the antioxidant capacity of L.paracasei ET-22 live bacteria and its postbiotic components and the inhibition rate of Candida albicans hyphae transformation,an oral candidiasis model of ICR mice was established by injection of immunosuppressants and application of Candida albicans.Before and after modeling,L.paracasei ET-22 live bacteria with a dose of 109 CFU/mL and corresponding postbiotic components were continuously administered through drinking water for 18 d to study the effects of L.paracasei ET-22 on the morphology of mouse tongue tissue and the expression of inflammatory factors.At a concentration of 109 CFU/mL of L.paracasei ET-22 live bacteria,the live bacteria exhibited the highest inhibition rate of 37.84%against the budding of Candida albicans.The heat-inactivated bacteria and secretions in the postbiotic components showed inhibition rates of 17.50%and 28.00%,respectively.In animal models,after intervention with live bacteria and postbiotic components,the concentration of IFN-γ in the serum was significantly reduced.In the secretion group,the content of IFN-γ and TNF-α in the tongue tissue was significantly reduced,while in the live bacteria group,only TNF-α content was significantly reduced.The live bacteria and heat-inactivated bacteria groups showed a significant increase in the CCL20 chemokine content and the richness and diversity of coated tongue microbiota.The histopathological sections showed that the ET-22 live bacteria and secretion group significantly improved the looseness of the mouse tongue epithelium and inflammatory cell infiltration,and the heat-inactivated bacteria group had a positive effect on the shedding of papillae and tongue epithelium.The experimental results showed that ET-22 could regulate oral microbiota composition and inhibit harmful bacteria to oral through alleviating the inflammatory infiltration and metastasis of tongue tissue.The study indicated that ET-22 could decrease the risk of oral candidiasis and could be further developed for oral probiotic food with the function of oral health caring.