Preliminary study on alleviation of heat-induced intestinal inflammation through compensatory effects of glucose oxidase.

1. The influence of glucose oxidase (GOD) supplementation on growth, gut inflammation and its compensatory effects in broilers was investigated before and after heat stress.2. Before heat stress, one-day-old broilers were divided into two groups: the control (CON) and GOD (100 g/t complete feed) groups. On d 21, the CON group was equally divided into CON1 and CON2 groups, and heat stress (35°C) was applied to the CON2 and GOD groups for 8 h/day to the end of the study, d 27 of age. The chickens were either killed before heat stress and 2 d after heat stress for the determination of cytokines in the liver and ileum, serum antioxidant enzymes and ileal microbiota. Growth performance was determined before and 7 d after heat stress.3. The GOD decreased Clostridiales and Enterobacteriaceae families of bacteria and increased ileal nuclear factor-κB, interleukin-1β, and interferon-γ (P < 0.05) before heat stress. The broilers exhibited compensatory effects, including increases in ileal sirtuin-1, heat shock protein 70 expression, liver nuclear factor erythroid 2-related factor 2 content, serum total antioxidant capacity and glutathione peroxidase level (P < 0.05). At 2 d after heat stress, inflammatory factors were increased in both the CON2 and GOD groups, but the levels were lower in the GOD than CON2 (P < 0.05). On d 7 after heat stress, GOS alleviated heat stress induced growth retardation (P < 0.05).4. These data suggested that GOD supplementation in broiler diets before heat stress stimulated intestinal oxidative stress and produced a compensatory response, which prevented a rapid increase in intestinal inflammatory factors and helped to maintain growth performance under heat stress.