Additionally, KEGG pathway enrichment analysis showed that the host genes of the identified DE circRNAs were mainly related to protein processing in the endoplasmic reticulum, other glycan degradation, lysine degradation, homologous recombination, epithelial cell signaling in Helicobacter pylori infection, neurotrophin signaling pathways, biosynthesis of nucleotide sugars, aminoacyl-tRNA biosynthesis, endocytosis, and yersinia infection (Figure 3(a)). Here, BDNF is linked to Yersinia infectious disease.