Trichinella spiralis infection decreases the diversity of the intestinal flora in the infected mouse

Background Trichinella spiralis is a kind of intestinal nematode that can strongly modulate the host immune system. However, the effects of T. spiralis infection on the intestinal flora are poorly understood. This study aimed to explore the effect of T. spiralis infection on the intestinal flora. Methods The intestinal contents of T. spiralis infected mice were examined through high-throughput sequencing (Illumina) of the V3–V4 hypervariable region in bacterial 16S rRNA gene. The sequences were analyzed using the QIIME software package and other bioinformatics methods. Results Altogether 2,899,062 sequences were generated from the samples collected from different intestinal regions at various infection time points; the 44,843 Operational Taxonomic Unit (OTUs) analysis showed that T. spiralis infection would decrease the diversity of intestinal flora in the infected mice relative to that in the uninfected ones, especially in the large intestine and feces. Further analysis indicated that, the genera Oscillospira from the phylum Firmicutes showed a higher abundance in the helminth-infected small and larger intestines; the genera Bacteroides from the phyla Bacteroides, the genera Lactobacillus from the phyla Firmicutes, the genera Escherichia from the phyla Proteobacteria, and the genera Akkermansia from the phyla Verrucomicrobia displayed increased abundances in the T. spiralis positive fecal samples compared with those in the negative samples. Conclusions T. spiralis infection decreases the diversity of the intestinal flora in the infected mouse. However, it remains unclear about the association between the changes in intestinal flora caused by T. spiralis infection and the parasite pathogenesis, which should be further examined.