# Effect of Toxocara canis infection on liver and lung microbial flora diversity and composition in dogs

## TL;DR

This study shows that Toxocara canis infection alters the microbial diversity in dogs' livers and lungs, potentially affecting infection development.

## Contribution

The study reveals that T. canis infection increases opportunistic pathogens in liver and lung microbiota, independent of the parasite's adult stage.

## Key findings

- T. canis infection increases abundance of opportunistic pathogens in host liver and lungs.
- Changes in liver and lung microbiota are independent of T. canis adults' microbial flora.
- Microbiota changes may influence tissue homeostasis and immune responses during infection.

## Abstract

Toxocariasis is a zoonotic parasitic disease that is widely prevalent in the world. Toxocara canis adults are parasitic in the small intestinal tract of canids, and the larvae migrate to the liver and lungs before reaching the final destination. Our previous experiments have confirmed that T. canis infection could affect the composition of host intestinal microbial flora. In this experiment, we further analyze the potential effects of T. canis infection on host liver and lung microbial flora. Utilizing 16s rRNA high-throughput sequencing, coupled with various bioinformatics analysis techniques, our study revealed that T. canis infection significantly elevated the abundance of certain opportunistic pathogens in the host’s liver and lungs. This marked elevation contributes to the establishment of infection. Through cluster analysis, we found that the changes in the microbiota of the liver and lungs were independent of the microbial flora carried by T. canis adults. However, whether the changes are due to the migration of larvae remains to be explored. In short, T. canis infections have a significant impact on the abundance and diversity of flora in the host tissues, and the changes in microbiota abundance and diversity could further influence tissue homeostasis and immune responses, thus regulating the establishment of infection.