该研究以小米、糯米等谷物作为主要原料，利用从自然发酵的甘薯酸浆和豆腐酸浆中筛选得到的两株益生菌Lactobacillus paracasei L1和Lactobacillus casei YQ336作为发酵菌种，采用非靶向代谢组学技术，对谷物饮料在发酵前后的小分子物质进行差异性分析。通过主成分分析和正交偏最小二乘判别分析等方法发现，发酵前后饮料中显著变化（VIP>1且p<0.05）的差异代谢产物为25类145种，主要包括34种有机酸及其衍生物、21种黄酮类化合物、20种糖类及其衍生物、16种生物碱、10种核苷酸及其衍生物、10种氨基酸及其衍生物。其中发酵后含量显著提高的生物活性物质包括：提高36668倍的1-羟基-2-萘甲酸、1000倍的二氢白藜芦醇、800倍的2-羟基戊酸、517倍的大豆苷、488倍的牡荆素、238倍的芹菜素、148倍的异芥酸、130倍的染料木素等；通过KEGG代谢通路分析表明，差异显著的代谢通路有19条，推测谷物基质可能对L. paracasei L1和L. casei YQ336次级代谢的合成和积累具有一定影响，该研究将为利用乳酸菌发酵植物基质食品及其对植物基质的代谢机理研究奠定理论基础。

Millet, glutinous rice and other cereals were used as main raw materials. Two probiotics, L. paracasei L1 and L. casei YQ336, isolated from naturally fermented sweet potato sour liquid and tofu sour liquid were used as fermentation bacteria. Non targeted metabonomics technology was used to analyze the differences of small molecular substances in cereal drinks before and after fermentation. Through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA), it was found that there were 25 categories and 145 differential metabolites with significant changes (VIP > 1 and p < 0.05) in beverages before and after fermentation, mainly including 34 organic acids and their derivatives, 21 flavonoids, 20 sugars and their derivatives, 16 alkaloids, 10 nucleotides and their derivatives 10 amino acids and their derivatives. The bioactive substances with significantly increased content after fermentation include 36668 times of 1-hydroxy-2-naphthoic acid, 1000 times of dihydroresveratrol, 800 times of 2-hydroxyvaleric acid, 517 times of daidzein, 488 times of vitexin, 238 times of apigenin, 148 times of isoerucic acid, 130 times of genistein, etc. The analysis of KEGG metabolic pathway showed that there were 19 metabolic pathways with significant differences. It is speculated that grain substrate may have certain effects on the synthesis and accumulation of secondary metabolism of L. paracasei L1 and L. casei YQ336. This study will lay a theoretical foundation for the fermentation of plant matrix food by lactic acid bacteria and the metabolic mechanism of plant matrix.

辽宁省高等学校创新人才支持计划（2020）；辽宁省自然科学基金项目（2019-ZD-0600）