Influence of Eimeria falciformis Infection on Gut Microbiota and Metabolic Pathways in Mice

Abstract

Coccidiosis, caused by different species of <i>Eimeria</i> parasites, is an economically important disease of poultry and livestock worldwide. Here we report previously unknown alterations in the gut microbes and metabolism of BALB/c mice infected with <i>Eimeria falciformis</i> Specifically, we observed a significant shift in the abundance of cecal bacteria and disrupted metabolism in parasitized animals. The relative abundances of <i>Lachnospiraceae</i> bacterium NK4A136, <i>Ruminiclostridium</i>, <i>Alistipes</i>, and <i>Lactobacillus</i> declined in response to <i>E. falciformis</i> infection, whereas <i>Escherichia</i>, <i>Shigella</i>, <i>Helicobacter</i>, <i>Klebsiella</i>, and <i>Bacteroides</i> were increased. Carbohydrate and amino acid metabolites in the serum samples of infected mice were significantly altered compared to naïve controls. Levels of amino acids, including asparagine, histidine, l-cysteine, tryptophan, lysine, glycine, serine, alanine, proline, ornithine, methionine, and valine, decreased on day 7 postinfection before returning to baseline on day 14. In addition, increased levels of indolelactate and mannitol and a reduced amount of oxalic acid indicated impaired carbon metabolism upon parasitic infection. These data demonstrate that intestinal coccidial infection perturbs the microbiota and disrupts carbon and nitrogen metabolism.