Spirulina polysaccharide induces the metabolic shifts and gut microbiota change of lung cancer in mice.

A polysaccharide obtained from Spirulina (PSP) and its effect on lung cancer in mice was investigated. Our results indicate that the tumor volume and weight of the lung cancer-bearing mice treated with PSP decreased significantly. Metabolite analysis showed that 27 differential accumulated metabolites (DAMs) changed significantly, in which 24 DAMs increased while 3 DAMs decreased. KEGG enrichment results showed that these differential metabolites were enriched significantly in the high-affinity IgE receptor (FcεRI) signaling pathway and arachidonic acid metabolism. In addition, PSP modulated gut microbiota of the lung cancer-bearing mice. PSP increased the abundance of Lactobacillus, Allobaculum, Alloprevotella, and Olsenella, decreasing Bacteroides and Acinetobacter. The results might be related to suppressing lung cancer. Based on our study, we hypothesized that PSP inhibited lung cancer through FcεRI signaling pathway and arachidonic acid metabolism and regulated the balance of gut microbiota. Nevertheless, the relationship between these two pathways and gut microbiota needs further study.