Dietary supplementation with genistein enhances growth performance via attenuating intestinal inflammation in weaned...

As a soybean-derived isoflavone, genistein exhibits antioxidant as well as anti-inflammatory functions, but its effects on weaned piglets remain to be fully elucidated. The current work assessed the impacts of diet-supplied genistein on piglets' growth performance, along with its effects on regulating intestinal oxidative injury and inflammation. In Trial 1, seventy-two weaned piglets were assigned at random to four treatments and provided basal diets with genistein added at 0, 50, 100, or 150 mg/kg. Each treatment included six replicate pens with three piglets per pen, and the experiment lasted 42 days. Results indicated that genistein at 150 mg/kg remarkably enhanced BW on day 28 and average daily gain (ADG) during days 14-28 (P < 0.05). It also tended to elevate BW on day 42 and ADG throughout the 42-day period (0.05 ≤ P < 0.10). Genistein at 100 and 150 mg/kg showed a tendency to decrease the occurrence of diarrhoea during days 0-14 (0.05 ≤ P < 0.10). Moreover, 150 mg/kg genistein significantly increased plasma immunoglobulin G levels on day 42 (P < 0.05) and showed a trend towards enhanced plasma glutathione peroxidase activity on day 14 (0.05 ≤ P < 0.10). In Trial 2, the protective role of genistein in modulating responses to lipopolysaccharide (LPS) challenge was assessed. Twenty-four weaned piglets were randomised into four treatments: control, LPS challenge, genistein supplementation (150 mg/kg), and genistein (150 mg/kg) combined with LPS challenge. Each treatment included six replicate pens with one piglet per pen, and the experiment lasted 14 days. Results showed that pretreatment with genistein prior to LPS challenge evidently elevated the villus height in the ileum and downregulated the relative mRNA expression of interleukin-22 (IL-22) in the jejunal mucosa in comparison with the LPS group (P < 0.05). In addition, genistein inclusion markedly upregulated glutathione peroxidase 1 (GPX1) mRNA expression (P < 0.05) and displayed a potential upregulation of zonula occludens-1 (ZO-1) expression (0.05 ≤ P < 0.10) in the jejunal mucosa. Collectively, genistein inclusion in the diet promoted growth, lowered diarrhoea occurrence, and improved immune and antioxidant status, while effectively mitigating intestinal injury, inflammatory responses and oxidative stress in weaned piglets, supporting its potential as a functional feed additive during the weaning transition.