Alterations in Ileal Microbiota and Fecal Metabolite Profiles of Chickens with Immunity to Eimeria mitis

Coccidiosis, caused by different species of parasites, is an economically important disease in poultry and livestock worldwide. This study aimed to investigate the changes in the ileal microbiota and fecal metabolites in chickens after repeated infections with low-dose . The chickens developed solid immunity against a high dose of infection after repeated infections with low-dose . The composition of the ileal microbiota and the metabonomics of the -immunized group and the control group were detected using 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC-MS). The relative abundance of , , , , , , and the group declined in the -immunized chickens, whereas , , , and increased. Furthermore, 286 differential metabolites (including N-undecylbenzenesulfonic acid, 1,25-dihydroxyvitamin D3, gluconic acid, isoleucylproline, proline, and 1-kestose) and 19 significantly altered metabolic pathways (including galactose metabolism, ABC transporters, starch and sucrose metabolism, the ErbB signaling pathway, and the MAPK signaling pathway) were identified between the -immunized group and the control group. These discoveries will help us learn more about the composition and dynamics of the gut microbiota as well as the metabolic changes in chickens infected with spp.