The еffect of аdding мealworm, рrobiotics, and мealworm рlus рrobiotics on IL-8 gene expression in liver and spleen tissues of broiler chickens

Abstract

Interleukin-8 (IL-8), a pro-inflammatory cytokine, plays a critical role in immune modulation in poultry and has potential applications in veterinary and human medicine. This study investigated the effects of dietary supplementation with mealworm (Tenebrio molitor), probiotics, or their combination on IL-8 gene expression in the livers and spleens of broiler chickens. A total of 160 one-day-old broiler chickens (Ross 308 strain) were assigned to four treatments (basal diet, basal diet + 0.2 g/kg probiotic, basal diet + 0.5% mealworm, and basal diet + 0.2 g/kg probiotic + 0.5% mealworm) in a completely randomized design. After 42 days, RNA was extracted from liver and spleen tissues, and IL-8 expression was quantified using qRT-PCR. High RNA integrity was confirmed by clear 18S and 28S rRNA bands (2:1 ratio) on agarose gel electrophoresis, with specific IL-8 amplification verified by a single 200 bp band and a melting curve peak at 81.5°C. All treatments significantly increased IL-8 expression compared to the control (P < 0.05), with the combined mealworm and probiotic treatment showing a significantly greater effect in both tissues, indicating a synergistic interaction. These findings suggest that mealworms and probiotics enhance immune competence in broiler chickens, likely through modulation of antimicrobial peptides and the gut microbiota. Although IL-8 is a pro-inflammatory cytokine, its moderate upregulation in healthy birds represents beneficial immune activation and improved readiness against pathogens rather than harmful inflammation. This immune stimulation is specific to the chickens themselves and does not imply that consuming their meat or products would increase IL-8 or enhance immunity in humans. The synergistic effect of mealworms and probiotics highlights their potential as functional feed additives for improving poultry health. Further research is needed to identify the underlying bioactive components and to confirm these effects under diseasechallenge conditions.