Dietary Acid Supplementation in Aquaculture Nutrition

Dietary acid supplementation encompasses the inclusion of organic acids and their derivatives in aquafeeds to optimise growth, health and resource utilisation in cultured aquatic species. Organic acids such as short‐chain fatty acids (SCFAs), including acetate, propionate and butyrate, as well as medium‐chain acids like fumaric and formic acid, serve multiple functions: they lower gut pH to enhance proteolytic and amylolytic enzyme activity, act as energy substrates for enterocytes, modulate gut microbiota composition and diversity, and influence host gene expression through epigenetic and signalling pathways. Microencapsulation technologies have been developed to protect acidifiers during feed processing and ensure targeted intestinal release. Dietary acids have been shown to reduce hepatic lipid deposition, stimulate antioxidant defence via Nrf2 activation, suppress pro‐inflammatory cascades mediated by NF-κB, and promote the maturation of intestinal mucosa. Across diverse taxa—finfish, crustaceans and reptiles—acid supplementation has improved feed conversion ratio, immune competence and resistance to bacterial and hypoxic challenges. This approach aligns with sustainable aquaculture objectives by reducing reliance on antibiotics and enhancing nutrient utilisations, thus contributing to reduced environmental impact and production costs on a global scale.

Research from Nature Portfolio

Recent studies have explored the synergistic effects of acidifiers with phytogenic bioactives and nature-identical compounds. In tilapia, combining a plant-derived phytogenic additive with potassium diformate resulted in enhanced weight gain, improved feed conversion and reduced mortality following a Francisella challenge, alongside modulation of gut bacterial communities towards a more balanced microbiome. In European sea bass, dietary microencapsulated blends of citric and sorbic acids with thymol and vanillin did not significantly alter growth but upregulated key immune markers (IL-8, IL-10, TGF-β), demonstrated prebiotic properties by enriching beneficial taxa such as Lactobacillus and Bacillus, and mitigated dysbiosis under thermal and hypoxic stress. These studies underline the capacity of combined acid–phytochemical strategies to reinforce mucosal immunity and maintain microbiome homeostasis under suboptimal rearing conditions.

Dietary Acid Supplementation in Aquaculture Nutrition publication trend

The graph below shows the total number of articles in dietary acid supplementation in aquaculture nutrition across all publications each year (not limited to Nature Index journals).

Technical terms

Short-chain fatty acids (SCFAs): Organic acids with fewer than six carbon atoms produced by microbial fermentation in the gut, serving as energy sources and signalling molecules.

Feed conversion ratio (FCR): A measure of feed efficiency calculated as the dry feed intake divided by weight gain over a feeding period.

Microencapsulation: A technology that encloses active compounds within microscopic carriers to protect them during feed processing and enable targeted release in the digestive tract.

Gut microbiota: The community of microorganisms residing in the gastrointestinal tract that influences nutrient assimilation, immune function and disease resistance.

Cytokine: A class of cell-secreted proteins that regulate inflammation and coordinate immune responses.

Histone deacetylase inhibitor: A compound that blocks enzymes removing acetyl groups from histones, thereby altering chromatin structure and gene transcription.

References

1. Effects of a phytogenic, alone and associated with potassium diformate, on tilapia growth, immunity, gut microbiome and resistance against francisellosis. Scientific Reports (2019).
2. Effects of dietary organic acids and nature identical compounds on growth, immune parameters and gut microbiota of European sea bass. Scientific Reports (2020).
3. Dietary sodium acetate and sodium butyrate improve high-carbohydrate diet utilization by regulating gut microbiota, liver lipid metabolism, oxidative stress, and inflammation in largemouth bass (Micropterus salmoides). Journal of Animal Science and Biotechnology (2024).
4. Effects of dietary sodium butyrate on growth performance, immune function, and intestinal microflora of Chinese soft-shelled turtle (Pelodiscus sinensis). Frontiers in Cellular and Infection Microbiology (2023).
5. Effects of Dietary Sodium Acetate on Growth Performance, Fillet Quality, Plasma Biochemistry, and Immune Function of Juvenile Golden Pompano (Trachinotus ovatus). Aquaculture Nutrition (2022).