Yeast β-Glucans as Fish Immunomodulators: A Review

Simple Summary The beta-glucan obtained from yeast-a very important molecule for fish production-activates the immune system of fish by different mechanisms and induces protection against pathogens. However, most previous related studies have focused on the use of commercial beta-glucan from the yeast Saccharomyces cerevisiae to understand the activation pathways. Experimental beta-glucans extracted from other yeasts show other interesting biological activities even at lower doses. This review article analyzes the current information and suggests perspectives on yeast beta-glucans. Administration of immunostimulants in fish is a preventive method to combat infections. A wide variety of these biological molecules exist, among which one of the yeast wall compounds stands out for its different biological activities. The beta-glucan that forms the structural part of yeast is capable of generating immune activity in fish by cell receptor recognition. The most frequently used beta-glucans for the study of mechanisms of action are those of commercial origin, with doses recommended by the manufacturer. Nevertheless, their immune activity is inefficient in some fish species, and increasing the dose may show adverse effects, including immunosuppression. Conversely, experimental beta-glucans from other yeast species show different activities, such as antibacterial, antioxidant, healing, and stress tolerance properties. Therefore, this review analyses the most recent scientific reports on the use of yeast beta-glucans in freshwater and marine fish.

Automated summary

This review analyzes the immune and biological activities of yeast beta-glucans in fish, highlighting the inefficiency of commercially available beta-glucans in some fish species and the potential adverse effects of increased dosage. However, experimental beta-glucans from other yeast species show interesting activities such as antibacterial, antioxidant, and healing properties.