Fishing for the right probiotic: host–microbe interactions at the interface of effective aquaculture strategies

Abstract

Effective aquaculture management strategies are paramount to global food security. Growing demands stimulate the intensification of production and create the need for practices that are both economically viable and environmentally sustainable. Importantly, pathogenic microbes continue to be detrimental to fish growth and survival. In terms of host health, the intestinal mucosa and its associated consortium of microbes have a critical role in modulating fitness and present an attractive opportunity to promote health at this interface. In light of this, the administration of probiotic microorganisms is being considered as a means to restore and sustain health in fish. Current evidence suggests that certain probiotic strains might be able to augment immunity, enhance growth rate, and protect against infection in salmonids, the most economically important family of farmed finfish. This review affirms the relevance of host-microbe interactions in salmonids in light of emerging evidence, with an emphasis on intestinal health. In addition, the current understanding of the mode of action of probiotics in salmonid fish is discussed, along with delivery systems that can effectively carry the living microbes.

Regulation of Host Gene Expression by Gastrointestinal Tract Microbiota in Chinook Salmon (Oncorhynchus tshawytscha)

“…Given the putative function of the responding genes, our work indicates a likely effect on host fitness as well. Indeed, many recent studies have shown that microbial symbionts are critical biological components for host traits closely associated with fitness, such as immune system development and function (Fuess et al, 2021;Langlois et al, 2021;Rosshart et al, 2017). This is the first study to consider and compare the impact of probiotics and antibiotics administered to captive fish on the rearing water microbial communities and we found that the aquatic microbial communities in the rearing tanks were significantly influenced by the feed treatments.…”

Probiotics Have the Potential to Significantly Mitigate the Environmental Impact of Freshwater Fish Farms

“…Probiotics can aid in the development of new fish feeds and lead to an improvement in gut health and feed conversion when used as supplements in conventional fish diets. Furthermore, probiotics can cause a reduction in the pathological issues occurring in the gut when alternative sources are used for the manufacture of fish feeds [20,27]. Likewise, gut function and immunity of beluga sturgeons fed a soya-bean-containing diet showed an improvement when experimental fish feed was supplemented with probiotics [42],…”

“…Probiotics can aid in the development of new fish feeds and lead to an improvement in gut health and feed conversion when used as supplements in conventional fish diets. Furthermore, probiotics can cause a reduction in the pathological issues occurring in the gut when alternative sources are used for the manufacture of fish feeds [20,27]. Likewise, gut function and immunity of beluga sturgeons fed a soya-bean-containing diet showed an improvement when experimental fish feed was supplemented with probiotics [42], illustrating the improvements that probiotics produce on fish health and growth, paving the way for the development of alternative fish feed, and therefore, reducing the reliance of the aquaculture fish feed industry on fisheries and fish meal [43,44].…”

“…LAB can also chelate iron to reduce Fe 2+ . Decreased O 2 levels in LAB cells can also inhibit Fe 2+ synthesis [20,21]. Other micronutrient factors and biochemical pathways, such as glutathione, thioredoxin, and vitamins C and E, enhance the antioxidant capacity of LAB cells, thus contributing to redox homeostasis [20].…”

Effects of dietary Metschnikowia sp. GXUS03 on growth, immunity, gut microbiota and Streptococcus agalactiae resistance of Nile tilapia ( Oreochromis niloticus )

“…Fishing for the right probiotic is key of effective aquaculture strategies (Langlois et al, 2021). We speculated that these yeasts could be used as an eco-friendly feed additive to reduce the problem of chemical abuse in tilapia farming.…”