Probiotics in aquaculture benefit both animal and human health
Disease outbreaks are a major challenge in aquaculture, and the use of certain treatments leads to drug bioaccumulation in fish and the development of antibiotic-resistant bacterial strains.
Aquaculture, the production of aquatic organisms under controlled conditions, is an important food production sector for many countries around the world.1 It can meet the nutritional food needs of a growing world population, while having a lower demand on natural resources compared to other sources of animal protein.2
Disease outbreaks are a major challenge in aquaculture, and it is well known that the use of antibiotics leads to drug bioaccumulation in fish and the development of antibiotic-resistant bacterial strains. Antibiotic resistant bacteria and their antimicrobial resistance genes can spread from farmed aquatic to terrestrial animals to human environments, causing adverse health effects in humans, animals and aquatic ecosystems.
In 2008, the World Health Organization proposed probiotics for aquaculture and as an environmentally friendly method to prevent disease. Over years of use and research in aquatic animals, probiotics have been associated with improved growth performance, disease resistance, immune function, epithelial barrier integrity and increased increase of beneficial microbes in animal gut and surrounding water.
Probiotics have multiple mechanisms of action to produce these health benefits, such as the following:
- Lactic acid-producing bacteria belonging to the Firmicutes phylum have been shown to colonize the intestinal mucus of fish, where they aid in the processing and absorption of food, promoting fish growth.
- Pediococcus acidilactici the bacteria are bioactive against common fish pathogens due to their production of bacteriocin, thereby enhancing disease resistance.
- S.putrefaciens Pdp11 can modulate fish gut microbiota and immune system-related gene expression during high storage-induced stress, thereby enhancing immune function.
Other suggested mechanisms of action include antagonistic activity against pathogens; membership site contest; contribution to macro and micronutrients; competition for nutrients, chemicals or energy; and reduction of virulence through manipulation of quorum sensing.
All of these benefits are important findings when it comes to limiting the use of antibiotics in aquaculture. The use of probiotics holds promise not only for the aquaculture industry and animal health, but also for minimizing the spread of antibiotic-resistant bacteria to humans. Ongoing research should be conducted to determine the appropriate selection and effectiveness of the probiotic strain(s) needed to achieve optimal results in fish and minimal impacts in humans.3
Aboli Ghatpande is a 2022 PharmD candidate at the University of Connecticut at Storrs.
The references
- Farming: Farming. United States Department of Agriculture. Accessed March 15, 2022. https://www.usda.gov/topics/farming/aquaculture
- Bourne JK. How to raise a better fish. National geographic. Accessed March 15, 2022. https://www.nationalgeographic.com/foodfeatures/aquaculture/
- El-Saadony MT, Alagawany M, Patra AK, et al. The functionality of probiotics in aquaculture: an overview. Fish Crustacean Immunol. 2021;117:36-52. doi: 10.1016/j.fsi.2021.07.007.