ABSTRACTDespite reducing the prevalent foodborne pathogenCampylobacter jejuniin chickens decreases campylobacteriosis, few effective approaches are available. The aim of this study was to use microbial metabolic product bile acids to reduceC. jejunichicken colonization. Broiler chicks were fed with deoxycholic acid (DCA), lithocholic acid (LCA), or ursodeoxycholic acid (UDCA). The birds were also transplanted with DCA modulated anaerobes (DCA-Anaero) or aerobes (DCA-Aero). The birds were infected with human clinical isolateC. jejuni81-176 or chicken isolateC. jejuniAR101. Notably,C. jejuni81-176 was readily colonized intestinal tract at d16 and reached an almost plateau at d21. Remarkably, DCA excludedC. jejunicecal colonization at 100, 99.997, and 100% at 16, 21, and 28 days of age. Neither chicken ages of infection nor LCA or UDCA alteredC. jejuniAR101 chicken colonization level, while DCA reduced 91% of the bacterium in chickens at d28. Notably, DCA diet reduced phylum Firmicutes but increased Bacteroidetes compared to infected control birds. Importantly, DCA-Anaero attenuated 93% ofC. jejunicolonization at d28 compared to control infected birds. In conclusion, DCA shapes microbiota composition againstC. jejunicolonization in chickens, suggesting a bidirectional interaction between microbiota and microbial metabolites.