Periodic Reporting for period 1 - Reprogram (Nutritional epigenetic programming of gut mucosal health in first-feeding fish)
Reporting period: 2021-06-01 to 2023-05-31
Aquaculture is expected to provide 70% of the fish for human consumption by 2030, as most wild fisheries are either stagnant or grossly over-exploited. To meet future global food demands, aquaculture is expected to intensify production, delivering fish that will have to thrive at high densities in less space. Such intensification can compromise the capacity of fish to respond to pathogens, making them more susceptible to diseases. Enhancing fish immunity and disease resistance is a solution towards sustaining the fast-growing aquaculture sector. Shaping fish health during the critical window of early life to achieve immune competence later in life- the aim of Reprogram – can be a step towards better aquaculture health management. The project aims to explore the concept of nutritional programming using dietary ingredients to enhance gut mucosal health during the first-feeding stages when fish still lack a fully mature immune system. The ultimate aim is to assess the interaction and relative roles of immune-related genes, gut microbes and nutritional programming on subsequent resistance to pathogens. Specifically, the focus is on applying natural dietary immunomodulating ingredients to improve fish disease resistance. As the implications of such ingredients during the early life stages via nutritional programming have not been extensively explored, evaluating the potential of early life programming of fish immune-competence is of great importance for increasing fitness throughout life.
During the project, different health-modulating ingredients such as sodium butyrate, beta-glucans and mannan-oligosaccharides were included in the diets of Nile tilapia first-feeding larvae. Fish performance, immune-related gene expression and microbiome composition from the larval stage to juvenile were evaluated to understand potential early nutritional programming effects. The results indicated that beta-glucans have a positive effect on gut microbiome development, while butyrate was shown not to be favourable for larvae performance when applied at early stages. Moreover, the impact of the aquaculture environment and the use of probiotics was also evaluated showing an important influence on the microbiome development in tilapia larvae, suggesting that such aspect needs to be taken into account when evaluating the microbiome composition and fish health, especially in relation to nutritional supplements. The results so far have been disseminated in wider aquaculture audiences, including conferences in Europe and Asia, and published in open-access journals, while there are also available open-access datasets.
Successful outcomes of early nutritional programming will not only assist in reducing antibiotic use in aquaculture in accordance with the EU One Health Action Plan for environmentally friendly ways of combating diseases, but will also assist in understanding how the impacts of early-life nutrition could be incorporated into programmes for disease resistance, thus improving fish health and welfare in aquaculture.