人体肠道真菌的体外模拟培养

Simulated Culture of Human Intestinal Fungi in vitro

肠道真菌对人体健康具有重要影响。研究适用于人体肠道真菌体外发酵的培养基具有重要意义,这将为利用体外模拟发酵技术研究人体肠道真菌的组成和功能奠定坚实基础。本研究采用人体肠道菌群体外发酵、ITS(Internal transcribed spacer)高通量测序等方法,对VI(Veal infusion)培养基和DI(Dixon)培养基单独或混合在体外影响人体肠道真菌菌群结构进行研究。在属水平,VI和DI单独或混合能对人粪便样品中53.10%、47.79%和48.67%的肠道真菌进行体外培养。如果同时考虑到菌属相对丰度差异,VI、DI和VD(VI-DI)培养液与粪便样品的真菌组成的Pearson相关系数分别为0.70、0.55和0.54。另外,3种培养基可在体外富集培养部分肠道真菌,VI培养基显著富集曲霉菌(Aspergillus),VD和DI培养显著富集Gloeotinia。菌群相对丰度相关性分析发现,DI和VD发酵液中子囊菌门(Ascomycota)和担子菌门(Basidiomycota)呈显著负相关,DI发酵液中青霉属(Penicillium)和曲霉属呈显著正相关。总体来说,VI培养基能较好地模拟人体肠道真菌组成;3种培养基可富集不同种类的肠道真菌;肠道真菌在体外培养时存在一定的相互促进或拮抗作用。本研究将为人体肠道真菌的体外模拟和选择性富集培养提供参考。

Intestinal fungi have an important impact on human health.It is of great significance to study the culture medium suitable for the in vitro fermentation of human intestinal fungi,which will provide a theoretical foundation for learning the composition and function of human intestinal fungi by an in vitro simulated fermentation technology.In this study,the effects of Veal infusion(VI)medium and Dixon(DI)medium on human intestinal fungal flora in vitro were studied by the in vitro fermentation and high-throughput sequencing.At the genus level,VI and DI medium alone or mixed(DV)can simulate 53.10%,47.79%and 48.67%of human intestinal fungi in vitro.If considering the difference of relative abundance,the Pearson′s correlation coefficients between the fungal composition in VI,DI,VD culture samples and fecal samples were 0.70,0.55 and 0.54,respectively.In addition,these three media can enrich and culture some intestinal fungi in vitro.VI medium can significantly enrich Aspergillus,while VD and DI culture can significantly enrich Gloeotinia in vitro.The correlation analysis of intestinal fungal relative abundance showed that Ascomycota were significant negatively correlated with Basidiomycota in DI or VD fermentation broth,and Penicillium were significant positively correlated with Aspergillus in DI fermentation broth.Generally speaking,VI medium can better simulate the composition of human intestinal fungi;these three media can selectively enrich different kinds of intestinal fungi in vitro;intestinal fungi can promote or antagonize each other in vitro.This study will provide a reference for the in vitro simulation and selective enrichment culture of human intestinal fungi.