“Chlorella vulgaris aquafeed supplementation as microbiota-gut-brain axis modulator in Dicentrarchus labrax (7229)”

Chlorella vulgaris aquafeed supplementation as microbiota-gut-brain axis modulator in Dicentrarchus labrax

Introduction: Aquaculture holds considerable potential to contribute to food security by meeting the nutritional requirements of the growing population worldwide and supporting the transition to healthier oceanic and freshwater ecosystems. It is expected to drive continued growth in global fish production, providing a decisive source of protein and nutrients for over three billion people. However, to sustainably intensify and expand aquaculture production systems, there is a need for technical innovation, appropriate governance, and regulatory frameworks across the value chain. One emerging solution is the development of sustainable aquafeed alternatives with a low carbon footprint and high nutritional and immunological boost value, such as microalgae. To optimize such alternatives, it is essential to understand how they influence physiological mechanisms such as the immune system. The intestinal microbiota, shaped by diet, acts as a functional “organ” that supports metabolism and immune balance. Disruption of this balance can lead to dysbiosis and increased disease risk. Importantly, the microbiota-gut-brain axis (MGBA) regulates numerous biological processes, including feed intake and immune responses, via interconnected pathways involving the immune and enteric nervous systems, the vagus nerve, and microbial metabolites such as short-chain fatty acids (SCFAs). Understanding how microalgae supplemented feeds influence these pathways can help improve fish health and affordability.

Methodology: To assess gut microbial communities, a whole 16S rRNA metabarcoding approach will be used via nanopore sequencing technology. Gene expression related to immune, neuroendocrine, and vagal pathways will be quantified using qPCR. ELISA will be employed to determine neurotransmitter concentrations, and Gas Chromatography–Mass Spectrometry (GC–MS) will be used to quantify SCFAs.

Results: The project will benefit: the aquaculture industry by improving fish health, thus lowering production costs; the consumer, as safe nutritious fish at affordable prices could be possible; the environment, with lower CO2 emissions and wild stock preservation; the scientific community, as new knowledge will be produced with a clear potential for the development of new sustainable functional aquafeeds based on MGBA modulation; and the general public, as chemically free fish will help to raise cultured fish acceptance.

Conclusion: A deeper understanding of the MGBA’s role in fish physiology and disease will support the development of novel therapeutic strategies focused on microbiota modulation. Ultimately, the targeted manipulation of gut microbiota can enhance resistance to pathogens, improve growth and lipid metabolism, stimulate immune responses, and contribute to overall gut health—advancing both aquaculture sustainability and fish welfare.

1. SARAIVA, MARCIA, CIIMAR, Presenter
2. Peixoto, Diogo, CIIMAR, Author
3. Hinzman, Mariana, CIIMAR, Author
4. Carvalho, Inês, CIIMAR, Author
5. Barbosa, Helena, CIIMAR, Author