Nutritional immunity of fish intestines: important insights for sustainable aquaculture

• Published in: Reviews in aquaculture Vol. 13; no. 1; pp. 642 - 663
• Main Author: Dawood, Mahmoud A.O.
• Format: Journal Article
• Language: English
• Published: Burwood Wiley Subscription Services, Inc 01-01-2021
• Subjects: Adaptive immunity; Animals; Aquaculture; Aquaculture feeds; aquafeed; Aquatic animals; Bacteria; Balanced diets; balanced feed; Correlation analysis; Diet; Digestive enzymes; Feed additives; Fish; Food additives; gut microbiota; Immune system; Immunity; Individual rearing; Industrial development; Intensive aquaculture; intestinal barriers; Intestinal flora; Intestine; Intestines; local immunity; Microbiota; Nutritional requirements; Optimization; outbreaks; Secretion; Sustainable aquaculture
• ISSN: 1753-5123; 1753-5131
• DOI: 10.1111/raq.12492

Intensive culture systems are usually employed to increase the production, but we suspect that, in such systems, fish suffer infection and stress, which weakens their health. However, such systems may fail due to lack of resources or difficulty in controlling the rearing conditions’ optimization. When intensive culture systems fail, aquatic animals gradually stop feeding. Accordingly, their physiological status deteriorates, and their immunity is suppressed. Through some strategies, it is possible to protect fish from disease by providing balanced food that maintain intestinal health and improve digestion, thereby increasing immunity. Protecting the health of the intestinal barriers is the primary guarantee of fish health. The local immunity of the intestine is associated with the innate and adaptive immunity of the fish’s entire body. Thus, it is necessary to understand the interaction between the gut microbiota and the general immune system, as well as the most important reasons that can increase or suppress intestinal immunity. Many studies have confirmed that balanced diets containing basic nutritional requirements are the primary factor for maintaining intestinal health in aquatic animals. Another strategy for improving the intestine’s local immunity is to use some non‐nutritional food additives that increase the activity of beneficial bacteria and the secretion of digestive enzymes and decrease the harmful bacteria. This review article aimed to clarify the relationship between a balanced aquafeed and the intestinal health of aquatic animals by discussing the findings of related studies. Awareness of this correlation between diet and intestinal health is expected to aid the aquaculture industry to develop proper nutritional strategies that ensure the protection of fish health.