The Interplay between Campylobacter and the Caecal Microbial Community of Commercial Broiler Chickens over Time.

is the most frequent foodborne zoonotic bacteria worldwide, with chicken meat being overwhelmingly the most important reservoir for human infections. Control measures implemented at the farm level (i.e., biosecurity or vaccination), which have been successfully applied to limit other pathogens, such as , have not been effective in reducing occurrence. Thus, new approaches are needed to fully understand the ecological interactions of with host animals to effectively comprehend its epidemiology. The objective of this study was to analyse longitudinally the gut microbiota composition of -infected and non-infected farms to identify any difference that could potentially be indicative of gut colonization by spp. Differences in the colonization rate and timing were observed at the farms that became positive for over the investigated time points, even though in positive tests, the occurrence of gut colonization was not observed before the second week of the life of the birds. Significant differences were observed in the abundances of specific bacterial taxa between the microbiota of individuals belonging to farms that became positive during the study and those who remained negative with particular reference to and , respectively. Moreover, colonization dramatically influenced the microbiota richness, although to a different extent depending on the infection timing. Finally, a key role of and genera on the microbial network was observed. Understanding the ecology of the interaction with host microbiota during infection could support novel approaches for broiler microbial barrier restoration. Therefore, evidence obtained through this study can be used to identify options to reduce the incidence of infection at a primary production level based on the targeted influence of the intestinal microbiota, thus helping develop new control strategies in order to mitigate the risk of human exposure to by chicken meat consumption.