Campylobacter jejuni is a leading cause of bacterial foodborne gastroenteritis in the US and worldwide. Increase in antibiotic-resistant Campylobacter infections necessitates development of sustainable antibiotic-alternative approaches for the preharvest control in poultry and to reduce disease incidence in humans. Here, we evaluated the ability EcN (free and chitosan-microencapsulated, cM) to reduce C. jejuni colonization in chickens. Further, we measured the effect of EcN on intestinal morphology, gut microbiota, and immune responses in three-week-old C. jejuni infected chickens. Our results showed that treatment of infected chickens (three times/week; for 2 weeks) with either free- or cM EcN orally resulted in 2.1 and 2.6 log reduction of C. jejuni in the cecum, respectively, compared to the non-treated chickens (P0.05). Additionally, both free- or cM EcN did not impact the richness and evenness of the cecal microbiota; however, increased the villus height and crypts depth in jejunum and ileum. Chickens treated with either free- or cM EcN had higher C. jejuni-specific IgA and IgY antibodies compared to non-treated chickens (P0.05) and induced the expression of cytokines (IL-17A, IL-17F, IL-6, IL-1²) and chemokines (CXCLI1, CXCLI2) (1.6-4.3 folds; P0.05). Overall, our results showed that probiotic EcN can be used as an antibiotic-independent approach to control C. jejuni colonization in chickens. Our future experiment will test the EcN by supplementing in feed or water simulating field conditions to control Campylobacter colonization in chickens.