Abstract:
Lychee pulp phenolics (LPP) is mainly catabolized in the host colon, increasing the abundances of Bacteroides and Lactobacillus. Herein, five selected gut microbial strains (Bacteroides uniformis, B. thetaiotaomicron, Lactobacillus rhamnosus, L. plantarum, and L. acidophilus) were separately incubated with LPP to ascertain the specific strains participating in phenolic metabolism and the corresponding metabolites. The results indicated that B. uniformis, L. rhamnosus, and L. plantarum were involved in LPP utilization, contributing to 52.37, 28.33, and 45.11% of LPP degradation after 48 h fermentation, respectively. Unprecedentedly, the metabolic pathway of the major phenolic compound quercetin-3-O-rutinose-7-O-α-L-rhamnoside by L. plantarum, appeared to be the direct fission of C-ring at C2-O1 and C3-C4 bonds, which was proved from the occurrence of two substances with the deprotonated molecule [M-H]- ion at m/z 299 and 459, respectively. Meanwhile, it was fully confirmed that B. uniformis participated in the catabolism of isorhamnetin glycoside and procyanidin B2. In the B. uniformis culture, kaempferol was synthesized through dehydroxylation of quercetin which could be catabolized into alphitonin by L. rhamnosus. Furthermore, LPP metabolites exerted higher antioxidant activity than their precursors and gave clues to understand the interindividual differences for phenolic metabolism by gut microbiota.
摘要:
荔枝果肉酚类物质(LPP)主要在宿主结肠中分解代谢,增加拟杆菌和乳酸菌的丰度。在这里,五种选定的肠道微生物菌株(均匀拟杆菌,B.Thetaiotaomicron,鼠李糖乳杆菌,植物乳杆菌,和嗜酸乳杆菌)分别与LPP孵育,以确定参与酚类代谢的特定菌株和相应的代谢物。结果表明,均匀芽孢杆菌,L.鼠李糖,植物乳杆菌参与了LPP的利用,发酵48小时后,LPP降解的比例为52.37、28.33和45.11%,分别。前所未有的,植物乳杆菌对主要酚类化合物槲皮素-3-O-木偶糖-7-O-α-L-鼠李糖苷的代谢途径,似乎是C2-O1和C3-C4键的C环的直接裂变,这是从两种物质的发生证明的去质子化分子[M-H]-离子分别在m/z299和459。同时,完全证实了异鼠李素苷和原花青素B2的分解代谢。在马形芽孢杆菌文化中,山奈酚是通过槲皮素的脱羟基作用合成的,槲皮素可以被鼠李糖乳杆菌分解代谢为字母素。此外,LPP代谢物比它们的前体具有更高的抗氧化活性,并为了解肠道微生物群的酚类代谢的个体差异提供了线索。