Autochthonous potential probiotics improve the Tianchongyou feed utilization in spotted seabass (Lateolabrax maculatus)

Tianchongyou (TC), is a feed ingredient that contains defatted yellow mealworm and the medium during their growth with a crude protein content of more than 65 %. Our previous research found that TC utilization of spotted seabass (Lateolabrax maculatus) was limited. This research was conducted to examine whether indigenous intestinal probiotics can improve the utilization of TC in spotted seabass. The experiment includes a control group (TC, fed basal diet) and five treated groups, fed the diets prepared by supplementing the basal diet (TC) with Bacillus licheniformis (BL), Virgibacillus salarius (VS), Alkalihalobacillus clausii (AC), Virgibacillus pantothenticus (VP), and Bacillus safensis subsp. safensis (BS). The results indicated that the final body weight, weight gain, and specific growth rate of spotted seabass in both the VS and VP groups exhibited a significant increase compared to those in the TC group (P < 0.05). There were no statistically significant alterations observed in the levels of serum AKP, LZM, and complement 3 among the treated groups when compared to the TC group (P > 0.05). Intestinal health of spotted seabass in VS and VP groups were well than that of TC group. The VP and VS groups showed significant enhancements in intestinal morphology (P < 0.05) when compared to the TC group. Furthermore, there was a significant elevation in the relative mRNA expression level of claudin in the VS group (P < 0.05). The VS and VP groups exhibited a higher prevalence of potential probiotics, such as Bacillus, and Acinetobacter, in comparison to the TC group. In summary, V. salaries, V. pantothenticus could be further researched as potential probiotics to improve the intestinal health of aquatic animal fed TC diet.