The potential of encapsulated inuloprebiotics from domestic Jerusalem artichokes (Helianthustuberosus) as natural antibacterial growth promotor for an antibiotic replacement in broiler chickens was presently assessed through assays of growth performance, serum immunoglobulin production and influence on caecal microflora. Two hundred-forty, 1-day-old, male broilers (Ross 308) were randomly allotted to four treatments (T1–T4), with three replicate pens per treatment and 20 chicks per pen. Broiler chicks were fed a basal diet (T1: control) or basal diet plus antibiotics (T2: Chlorotetracycline, 0.10%), 300 ppm of the inuloprebiotics (T3), or 450 ppm of the inuloprebiotics (T4) for 35 days. Body weight, dressing percentage or weight of breast and thigh muscles relative to carcass weight of T3 and T4 broiler chickens was significantly (P＜0.05) higher than T1 and T2 broiler chickens. The weight of abdominal fat from T3 and T4 broiler chickens were significantly (P