Enhancing the resistant starch content of cassava starch via heat-moisture treatment for application as a prebiotic in chicken feed

This study aimed to increase the resistant starch (RS) content of cassava starch via heat-moisture treatment (HMT) and evaluate its prebiotic potential in chicken feed. The HMT involved autoclaving cassava starch at 20% moisture content and 121°C for 1 h (HMT-20), which yielded a high RS content (20.7%) in the cooked starch. In vitro fermentation with Limosilactobacillus reutters TBRC291 demonstrated the promising prebiotic potential of cooked HMT-20, comparable to that of commercial fructo-oligosaccharides, as indicated by enhanced bacterial growth, reduced pH, and increased short-chain fatty acid (SCFA) production. A 1% concentration of cooked HMT-20 was identified as optimal for prebiotic use. In the in vivo assessment, chickens were given feed supplemented with 1% cooked HMT-20 (HMT-Feed), displaying no adverse effects on growth performance over 35 days and significantly reducing relative abdominal fat and heart weight while increasing breast weight. Meat from the HMT-Feed group also exhibited increased yellowness and reduced cooking loss. Histological analysis revealed an improved intestinal morphology, including a greater villus height, reduced crypt depth, and higher villus-to-crypt ratio. Additionally, the HMT-Feed group exhibited a lower cecal pH and higher SCFA levels (notably butyric acid). Deep gut microbiota profiling revealed enriched levels of lactic acid- and butyrate-producing bacteria, indicating improved gut health. The HMT-modified product demonstrates potential applicability as a value-added and sustainable feed additive in the poultry industry.