Study found that Lactobacillus rhamnosus GCC-3 culture can improve intestinal and liver health and antiviral immunity of zebrafish

Researchers from the Aquatic Microbiology and Feed Innovation Team at the Feed Institute of the Chinese Academy of Agricultural Sciences have made a significant discovery regarding the benefits of incorporating Lactobacillus rhamnosus GCC-3 culture into the diet of zebrafish. Their findings indicate that this dietary addition can enhance the overall health of the zebrafish's liver and intestines while bolstering their antiviral immunity. This breakthrough has the potential to contribute to the advancement of aquaculture by offering valuable insights into areas such as liver lipid metabolism, liver and intestinal tissue health, and viral disease prevention. The research results have been published in the journal "Fish and Shellfish Immunology."

Probiotics have been utilized to effectively regulate the early interactions between gut microorganisms and their host, which, in turn, has long-lasting benefits in establishing and enhancing the digestive tract's immune function and overall production performance. However, the efficacy of probiotics in bolstering fish resistance to other infectious diseases, particularly viral infections, has remained a relatively unexplored area of study.

This particular study has unveiled some promising outcomes. The inclusion of 1% GCC-3 culture in the diets of zebrafish led to significant improvements in their growth performance. It also resulted in a marked reduction in the expression of pro-inflammatory genes like IL-1β in the livers of zebrafish and an upregulation of hypoxia-inducible factor (Hif-1α) in their intestines, along with an increase in the expression of tight junction proteins (ZO-1α and ZO-1β).

Bacterial sequencing data indicated that the group of zebrafish fed with 1% GCC-3 culture exhibited a substantial reduction in the abundance of Proteobacteria and an enrichment of Firmicutes in their intestinal flora.

Furthermore, when these zebrafish were challenged with Carp Spring Viremia Virus (SVCV), they displayed a higher survival rate compared to the control group. Additionally, their type I interferon antiviral immune response was significantly elevated. This study demonstrates the substantial probiotic benefits of incorporating 1% GCC-3 culture into the zebrafish diet, positively impacting their intestinal and liver health, as well as their antiviral immunity. These findings have the potential to pave the way for further research and development of GCC-3 culture as a functional feed additive in fish farming. The research was supported by funding from the National Natural Science Foundation of China.