In conclusion, we observed that dietary Capsicum and C. longa oleoresins regulate susceptibility to experimental avian NE and alter the intestinal microbiota of commercial broiler chickens. This study demonstrates that dietary phytonutrients exert beneficial effects on gut health
to reduce the negative consequences of NE and nutratherapeutic mechanism may involve altering gut microbial communities. These new findings increase our understanding of 1) the positive effect of dietary phytonutrient as alternatives to antibiotics, 2) host genetics on the interaction of host–pathogen in NE and 3) the possible role of gut microbiota in local immune regulation in broiler chickens. This study is the first to report on the effects of dietary phytonutrients on gut microbiota in commercial broiler breeds and opens a new way to reduce the use of antibiotics in poultry disease control. Future studies on the role of the avian
intestinal microbiome in immune regulation and host–pathogen interactions are expected to shed new light on the host response to NE that will be beneficial for practical poultry husbandry.