Domestication of chickens from the wild red jungle fowl and modernisation of the poultry industry has changed both poultry and their intestinal microbiome, specifically the eimerian-microbiome-host relationship. Eimeria spp. represent an enteric parasite that has a long co-evolutionary history with their hosts. These parasites have adapted to suit an environment in which chickens thrive and the chickens’ intestinal environment, including the changing host microbiome. This review will delve into the changes in eimerian-host interactions with wild red jungle fowl versus domesticated chickens. The changing nature and composition of the intestinal microbiota as it followed the red jungle fowl into domestication and the relationship of this evolving microbiota with coccidia will be explored. Better comprehension of the web of interactions among the evolving eimerian-microbiome-host relationship will allow for the responsible exploitation of these relationships to maximise poultry health and productivity.
