The effect of Weissella confusa on the intestinal structure of rainbow trout (Oncorhynchus mykiss)

In recent decades, several studies have been performed on the evaluation of probiotics in fish and their positive has been reported on different species. In this study, rainbow trout (Oncorhynchus mykiss) with 115±2 g average initial weight were randomly assigned to tanks and fed with different levels of Weissella confusa (0 [control] and 3 g W. confuca powder per 10 Kg diet [3× 107 CFU/g count]) for 8 weeks. At the end of the experiment, tissue samples were taken from different parts of the intestine and fixed in 10% formalin. After tissue preparation, sections were stained with hematoxylin-eosin. The results showed that morphology parameters including villi length and width in the anterior and posterior intestines of the treatment group were significantly increased compared to the control group (P<0.05). According to the results, W. confusa probiotic can have positive effects on intestinal morphology and its absorptive surface area in rainbow trout.