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.