<i>Aronia melanocarpa</i> extract modulates gut microbiota and induces dose-dependent metabolic shifts in broiler chickens

1. Following the ban on prophylactic antibiotic use in feed for poultry, interest in natural alternatives has increased, particularly plant-derived extracts. In this study, the effects of Aronia melanocarpa fruit extract (AMF) on growth performance, serum biochemistry and caecal microbiota in broilers were evaluated.2. A total of 360 male Ross-308 broiler chicks were randomly allocated to one of the four treatment groups for 35 days. These included a control group (CON) receiving the basal diet and three treatment groups supplemented with 50 mg/kg (AMF1), 100 mg/kg (AMF2) or 200 mg/kg (AMF3) of AMF extract.3. Antioxidant capacity and phenolic profile were determined by DPPH and UHPLC-ESI-MS/MS analyses. Because the ethanol extract had the highest antioxidant activity (94.5%), it was used in the experiment. Chlorogenic acid, quercetin, hesperidin and cyanidin-3-O-glucoside were the major phenolic compounds identified.4. The AMF supplementation had no significant effect on growth performance (p > 0.05). In contrast, serum triglyceride (TG), phosphorus, sodium and iron concentrations exhibited statistically significant quadratic dose – response relationships (p < 0.05). Serum TG levels were significantly reduced in the AMF3 group, whereas serum iron levels were significantly increased in the AMF1 and AMF2 groups (p < 0.05). Phosphorus and sodium levels were found to be lower in the control group compared to the other groups (p < 0.091 and p < 0.063, respectively).5. The 16S rRNA sequencing showed that low and medium dose AMF applications supported caecal microbial diversity by increasing the relative abundance of beneficial bacteria such as Bacillus spp. and Lactobacillus jensenii. The high supplementation dose led to the dominance of the Morganella morganii population.6. In conclusion, AMF can modulate the gut microbiota in broiler chickens in a dose-dependent manner without negatively affecting growth performance. Moderate inclusion rates have the potential to positively impact gut health and metabolic balance by increasing beneficial bacteria populations.