Aquaculture, the fastest growing food production sector, has the potential to strengthen global food security, meet the nutritional needs of a growing population, and support the transition toward healthier ocean and freshwater ecosystems. Global fish production is expected to continue rising, with aquaculture projected to reach 106 million metric tonnes by 2030—up from 87.5 million metric tonnes in 2020—an increase of more than 30%. This growth will provide an essential source of protein and other nutrients for more than three billion people. However, achieving sustainable intensification and expansion of aquaculture systems will require technological innovation, appropriate incentives, and effective governance and regulation throughout the value chain. Timely and well designed actions are therefore critical to ensure the sector develops sustainably.
Among the emerging strategies, sustainable aquafeed alternatives with a low carbon footprint and high nutritional and immunological value—such as microalgae—are gaining attention. Microalgae, such as Chlorella vulgaris, offer a rich supply of bioactive compounds, balanced amino acid profiles, and essential long chain omega 3 fatty acids. These components can enhance immune responses, antioxidant capacity, and overall nutritional quality in fish. Diet also plays a central role in shaping the intestinal microbiota, which functions as an additional organ contributing to metabolism, immune defence, and gut homeostasis. Disruptions in microbial communities can lead to dysbiosis, impaired intestinal barrier function, and increased disease susceptibility. Understanding how new aquafeed ingredients influence physiological processes such as nutrient absorption and immune modulation will be key to improving feed formulations and producing healthier, more nutritious fish at accessible prices.
The microbiota–gut–brain axis (MGBA) further highlights the complexity of these interactions. This bidirectional communication network links the gut microbiota, immune signalling pathways, and the central nervous system through neural, metabolic, and immune routes. Microbial metabolites—particularly short chain fatty acids—along with neurotransmitters and bacterial products, play crucial roles in regulating immune function, maintaining intestinal integrity, and influencing feeding behaviour. Disruptions in the MGBA can trigger inflammation, weaken the blood–brain barrier, and contribute to disease development.
Therefore, the main goal of the MiMo project is to provide a better understanding of the underpinning MGBA machinery of fish fed C. vulgaris supplemented diets and to deliver a deeper understanding of the basic mechanisms involved during disease using the European seabass (Dicentrarchus labrax) as a model. A more detailed understanding of the underlying mechanisms and physiological roles of the MGBA in the etiopathology of diseases will help to design novel therapeutics based on MGBA activities modulation.