Immunomodulation by dietary supplements: A preventive health strategy for sustainable aquaculture of tropical freshwater fish, Labeo rohita (Hamilton, 1822)

Abstract

Dietary supplementation is an effective strategy for boosting the innate immune response in fishes. It involves the use of functional ingredients that bear the potential for mitigating the deleterious effects of chemotherapeutics (bioaccumulation and development of drug-resistant pathogens), as a more ecologically responsible approach to fish farming. With the emergence of probiotics, prebiotics, synbiotics and herbal immunostimulants; dietary supplementation has become an integral aspect of immunonutrition. In this review, we have compiled a list of dietary immunostimulants in rohu, based on the research carried over the last ten years. It should be noted that nearly 25% of the studies on dietary supplementation in Labeo rohita investigated probiotics species (either singly or as mixtures), followed by the use of herbal supplements or phytobiotics. In relation to stress, about 30% of the studies dealt with the supplementation of tryptophan, followed by the incorporation of lipotropes. Moreover, approximately 55-60% of the studies reviewed, were restricted to nutrition-based disease resistance against Aeromonas hydrophila infection. Commercially available probiotics and herbal feed additives have been helpful in the health management of L. rohita to some extent. Ongoing research is consistently exploring novel ingredients inducing favourable immunomodulation to survive stress and widespread A. hydrophila infection in L. rohita. However, further investigations aiming at broad-spectrum disease resistance and multiple stress resilience are recommended. Efforts must also be directed towards the elucidation of specifically targeted response in vivo. Overall, greater insights into the molecular mechanisms of dietary supplementation of immunostimulants warrants the use of downstream analytical techniques and highthroughput screening tools.

Bacteriophages in the Control of Aeromonas sp. in Aquaculture Systems: An Integrative View

“…Sustainably preventing aquaculture diseases is desirable, but not always possible since supplying the optimal conditions and feeding can be economically challenging. Furthermore, its success may require effective biocontrol techniques to reduce infections [ 97 , 98 ]. The rapid spread and the ubiquitous nature of fish pathogenic microorganisms mean that infection control and prevention can be difficult [ 99 , 100 ].…”

The effect and underlying mechanism of yeast β-glucan on antiviral resistance of zebrafish against spring viremia of carp virus infection

“…Glucans play a very important role in aquaculture as immunostimulant to improve the performance and health of farmed animals. β-Glucan has been found to induce immunity in various cultured fish species and resistance against different pathogens has been reported ( 8 , 37 , 38 ). Research have shown that β-glucan dosages, quality, route, and time of administration and duration of treatments may influence the its beneficial effects on growth, survival, and immunity of fish ( 39 ).…”

Dietary supplementation of Polygonum chinense improves the immunity of Asian seabass, Lates calcarifer (Bloch, 1790) against Vibrio harveyi infection

“…Oreochromis niloticus infected with A. hydrophila and fed a diet containing Withania sominefera extract showed increased lysozyme activity as well [81] . All of these findings suggested that plant extract supplementation diets can benefit fish with non-specific immune responses [82] .…”