Interaction between Bacteroidetes species in the fermentation of Lycium barbarum arabinogalactan

The present study investigated the utilization of an arabinogalactan from Lycium barbarum (LBP-3) by intestinal Bacteroidetes species. The mixed-culture assay showed 58.4 % LBP-3 was utilized, and Bacteroides caccae and Phocaeicola vulgatus utilized more LBP-3 in single-culture compared to others. During in vitro fermentation of LBP-3, P. vulgatus favored arabinose while B. caccae preferred galactose. Moreover, 9 and 25 oligosaccharides were identified by HPLC-MS n in conditioned media (CM) derived from B. caccae and P. vulgatus , respectively. All of 3 tested Parabacteroides species ( P. distasonis , P. goldsteinii , and P. johnsonii ) markedly proliferated in CM of B. caccae and P. vulgatus , and proliferations of B. uniformis , B. finegoldii , B. ovatus and B. thetaiotaomicron also increased significantly in CM of B. caccae. The study suggests that the ability of Bacteroidetes species to degrade LBP-3 and sheds light on cooperative interactions of Bacteroides, Phocaeicola , and Parabacteroides species in the presence of LBP-3.