Date: 27/10/2025

Did you know that fish gut health is directly linked to their immunity and productive performance in aquaculture? In recent years, research in fish nutrition and immunology has revealed that the gut microbiota plays a central role in the immunocompetence of aquatic organisms.

Despite considerable scientific interest, most studies have focused only on the composition of the microbiome, failing to explore its functional potential in host physiology and immunity. Today, it is known that modulating the gut microbiota through functional nutrition, including highly digestible and bioactive ingredients, is a promising strategy for improving pathogen resistance and fish welfare.

How can we ensure that fish are healthy and immunologically prepared? It is precisely in this interaction that science has pointed to promising solutions.

In this blog, you will find the following topics:

How the microbiota influences the immune response of fish

The gastrointestinal tract of fish performs functions beyond digestion and nutrient absorption, serving as an active immune organ. In this environment, there is a complex interaction between immune system cells—such as lymphocytes, macrophages, and antigen-presenting cells—and the resident microbiota, which plays an essential role in modulating innate and adaptive immune responses, directly contributing to resistance against aquatic pathogens (Thakur et al., 2025).

The article “Probiotics in fish farming” highlights that a balanced intestinal microbiota enhances fish defend themselves better against disease. It increases the production of immunoglobulins, strengthens the intestinal barrier, and activates defense cells, making fish more resistant to common problems in aquaculture, such as streptococcosis and franciscellosis. In contrast, when there is an imbalance in the microbiota, known as dysbiosis, immunity is weakened, leaving fish more vulnerable to infections.

In addition, diet plays a key role in intestinal health. Functional and bioactive ingredients present in well-formulated diets can stimulate beneficial microorganisms, strengthen the intestinal barrier, and increase the immune resilience of fish (Zhou et al., 2021).

This knowledge highlights that maintaining intestinal health is not only a nutritional issue but a central strategy for preventing disease and improving productive performance in aquaculture systems.

Functional nutrition and bioactive ingredients: boosting performance and immunity

Functional nutrition has established itself as a strategic tool in modern aquaculture, especially in supporting the intestinal health and immunocompetence of farmed fish. Diets formulated with highly digestible ingredients and bioactive compounds promote better utilization of essential nutrients, such as proteins, amino acids, vitamins, and minerals, reducing metabolic overload and promoting intestinal homeostasis (Zhang et al. 2024).

Bioactive compounds such as prebiotics, probiotics, and functional extracts have a direct influence on the intestinal microbiota, stimulating the growth of beneficial microorganisms, reinforcing the integrity of the epithelial barrier, and modulating innate and adaptive immune responses. Studies show that the administration of probiotics such as Bacillus subtilis, Lactococcus lactis, and Saccharomyces cerevisiae promotes intestinal architecture regeneration, improves digestibility, and increases resistance to pathogens in intensive farming systems (Abareethan & Amsath, 2015; Hasan & Banerjee, 2020).

In addition to immunological effects, functional nutrition directly impacts zootechnical performance, reducing mortality losses and optimizing parameters such as weight gain, feed conversion, and overall well-being. According to Fracalossi & Cyrino (2012), the incorporation of functional ingredients in diets allows for greater production efficiency and sustainability, especially in high-density systems.

Therefore, the adoption of nutritional strategies based on highly digestible and bioactive ingredients represents an integrated approach to promoting intestinal health, robust immunity, and consistent productive performance in aquaculture.

BioActio Efficiency in aquaculture: how it acts on intestinal health

BioActio Efficiency, developed by MBRF Ingredients, is an enzymatic feather hydrolysate rich in bioactive peptides that support efficient nutrition and enhanced performance in aquaculture.

Its formulation acts directly on the intestinal microbiota, contributing to nutrient digestion, strengthening the intestinal barrier, and supporting the immune response of fish.

Zootechnical benefits observed:

● Weight gain and feed conversion: The peptides present in BioActio Efficiency are rapidly absorbed and metabolized, contributing to increased growth rates and improved feed conversion in tilapia.

● Palatability and digestibility: The presence of low molecular weight nitrogen compounds makes the ingredient more attractive and highly digestible, promoting voluntary consumption and nutritional efficiency.

● Apparent Digestibility Coefficient (ADC): Studies with red tilapia indicate that ingredients with high digestibility can achieve an ADC of up to 89%, as observed by Torres Novoa et al. (2013), which reinforces the ability to utilize the nutrients present in the hydrolysate.

With these attributes, BioActio Efficiency allows producers to maintain the intestinal health and immunity of fish preventively, with a direct impact on the productivity and well-being of the fish.

Final considerations

Intestinal health is at the heart of immunity and productive performance in farmed fish. Maintaining a balanced microbiota not only strengthens the immune response, but also ensures better nutrient utilization, consistent growth, and greater resistance to common diseases in aquaculture.

Functional nutrition, with highly digestible and bioactive ingredients, plays a strategic role in this process, stimulating beneficial microorganisms, strengthening the intestinal barrier, and increasing immune resilience.

In this context, solutions such as BioActio Efficiency from MBRF Ingredients, with low molecular weight bioactive peptides, offer clear and measurable benefits: improved digestion, palatability, weight gain, feed conversion, and immunity support.

Investing in strategies that integrate intestinal health, functional nutrition, and bioactive compounds means adopting a preventive, sustainable, and efficient approach, ensuring that fish grow with health, resistance, and consistent productive performance.

Want to learn more about functional ingredients and innovative solutions for aquaculture? Explore the complete MBRF Ingredients portfolio and discover how to enhance your formulations, ensuring efficiency, transparency, and quality for your products.