Ecological and metabolic shifts of synthetic bacterial communities using sea cucumber sulfated polysaccharide as the sole carbon source

Sulfated polysaccharide from sea cucumber Stichopus japonicus (SCSPsj) is one of the major biological activity components in sea cucumber and is used to benefit host health by targeting the gut microbiota. However, the specific ecological and metabolic changes involved in the microbial communities after supplementation of SCSPsj remain unclear. Herein, a synthetic bacterial community containing defined species has been used to reduce the complexity of the natural gut microbial community. The results revealed that SCSPsj significantly modulated the composition of the synthetic bacterial community, such as increasing the abundance of Parabacteroides distasonis, Bacteroides vulgatus and Bifidobacterium animalis. SCSPsj significantly influenced the metabolites of the synthetic bacterial community, such as acetic acid, propionic acid, acetyl-CoA and glutamine. In addition, the presence of P. distasonis in the synthetic bacterial community has been found to affect the biomass and metabolites of the synthetic bacterial community in the medium using SCSPsj as the sole carbon source. These findings provide new insight into the application of SCSPsj in targeting the gut microbiota.