Xylanase and phytase as modulators of gut microbiota and phytate degradation in wheat-based diets for meat quail

This study evaluated the interactive effects of xylanase and phytase in corn- or wheat-based diets on growth performance, phytate degradation, digesta pH, and gut microbiota of meat-type quail. A total of 224 European quail were assigned to a 2 × 2 × 2 factorial arrangement with two basal diets (corn-soybean meal or wheat-soybean meal), two xylanase levels (0 or 16,000 BXU/kg), and two phytase levels (0 or 2,000 FTU/kg). Growth performance was evaluated from 7 to 42 d of age, and carcass traits, intestinal pH, inositol phosphate (InsP) concentrations, and gut microbiota were assessed at 42 d. Birds fed wheat-based diets exhibited greater body weight gain and improved feed conversion compared with those fed corn-based diets (P < 0.05). Phytase and xylanase supplementation enhanced phytate degradation, reduced concentrations of higher-order inositol phosphates (InsP6-InsP4), and modified digesta pH (P < 0.05), with more pronounced effects in wheat-based diets. Alpha diversity analysis indicated no effect of treatments on bacterial richness (Chao1), whereas Shannon diversity differed markedly among treatments (P < 0.001), indicating changes in microbial evenness. Beta diversity analyses revealed a clear separation of microbial communities according to basal diet and enzyme supplementation (PERMANOVA, P = 0.001). Correlation network analysis demonstrated matrix-dependent reorganization of microbial interactions in response to phytase and xylanase. In conclusion, phytase and xylanase supplementation modulated gut microbial community structure and phytate degradation in a basal diet-dependent manner. Productive performance responses were influenced by interactions between enzyme supplementation and diet composition. These findings highlight the importance of enzyme-matrix interactions in shaping nutrient availability and intestinal microbial ecology in meat-type quail.