Effects of different feeding strategies on ion-transporting, energy metabolism and intestinal health of Nile tilapia (Oreochromis niloticus) under saline-alkaline stress

This study investigated the impact of different feeding strategies on energy metabolism, intestinal health, and gut microbiota composition in Nile tilapia (Oreochromis niloticus) under saline-alkaline stress. Nile tilapia was exposed to saline-alkaline conditions and subjected to three distinct feeding strategies: continuous feeding (control), 5-day feeding followed by 2-day fasting, and 18-hour intermittent fasting. Physiological and molecular analyses revealed that saline-alkaline stress significantly impaired ion transporting, liver glucose metabolism, and intestinal integrity, leading to reduced growth performance and increased oxidative stress. However, the intermittent fasting regimens, particularly the 18-hour intermittent fasting strategy, effectively alleviated these adverse effects. This feeding strategy improved growth rates, enhanced hepatic enzyme activities related to glucose metabolism, and restored antioxid18-hour fasting regimen mitigates growth suppression and oxidative stress under saline-alkaline exposureant capacity. Furthermore, 18-hour intermittent fasting significantly modulated the gut microbiota, increasing the abundance of beneficial bacteria such as Firmicutes and Fusobacteria, while reducing pathogenic Proteobacteria, which are linked to inflammatory responses. Additionally, this strategy enhanced gut health by improving digestive enzyme activities and strengthening the intestinal barrier. These findings suggest that optimized feeding strategies, such as intermittent fasting, can mitigate the negative effects of saline-alkaline stress in Nile tilapia, and offered a promising approach to enhance resilience and productivity in saline-alkaline aquaculture environments.