Broad bean (Vicia faba L.) caused abnormal lipid metabolism in grass carp (Ctenopharyngodon idellus) liver: Insight from the gut microbiota-liver axis

Broad bean (Vicia faba L.) has received attention from the food and animal feed industries as a sustainable, inexpensive and versatile plant-based protein source. However, long-term consumption of broad bean, especially unprocessed ones, can lead to hepatic lipid accumulation. To investigate how broad bean affected hepatic lipid metabolism and its underlying mechanisms, we conducted a multi-omics analysis of crisp grass carp (Ctenopharyngodon idellus C. et V) model with hepatic steatosis after feeding with single broad bean for 120 d. The glycolysis inhibition, increased de novo lipogenesis, abnormalities in lipid metabolism and activation of oxidative stress were the key processes involved in broad bean-induced hepatic lipid accumulation. Disturbances in intestinal flora caused, damage to the intestinal barrier, and increased lipopolysaccharide caused by broad bean promoted hepatic lipid accumulation. Reduction of anti-nutritional factors and balanced diet offer potential strategies to mitigate the liver damage caused by broad bean consumption. Overall, our findings provided a theoretical basis for the wide application of broad bean as animal feeds.