Effects of nutraceuticals on the intestinal microbiota are receiving increased attention; however, there are few studies investigating their effects on broiler meat production. The aim of this study was to implement feeding strategies and carry out a comprehensive trial examining the interplay between natural biologically active compounds such as carotenoids, anthocyanins, fermentable oligosaccharides, and synbiotics and the gastrointestinal tract microbiota. Our feeding program was applied to an intensive production system with a flock of 1,080 Ross 308 broilers. Aging induced significant changes through the feeding experiment. Nutraceuticals were shown to modulate broiler intestinal diversity and differentially enriched Lactobacillus, Enterococcus, Campylobacter, and Streptococcus in the core microbiome during the different stages of broiler rearing. Additionally, they did not remarkably affect animal growth performance; nevertheless, a positive correlation was found between body weight and Corynebacteriales and Pseudomonadales. Furthermore, a diet high in carotenoid, fermentable oligosaccharide, and anthocyanin contents affected the number of beneficial genera such as Faecalibacterium, Lactobacillus, Blautia, and Ruminococcus. With this comprehensive trial, we revealed that nutraceuticals induced modulations in broiler gastrointestinal tract microbiota. We believe that plant-derived immunostimulants, recycled from plant food waste products, can supplement antibiotic-free broiler meat production.
IMPORTANCE In this trial, nutraceuticals were manufactured from waste products of food industry processing of Hungarian red sweet pepper and sour cherry and incorporated into the diet of poultry to investigate their effects on broilers’ growth and the broiler gastrointestinal tract microbiota. To avoid the generation of food waste products, we believe that this approach can be developed into a sustainable, green approach that can be implemented in commercial antibiotic-free poultry to provide safe and high-quality meat.