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Impact of Autolysed Brewer’s Yeast and Soluble Dried Yeast Extract on Growth Performance and Mucosal Health of Atlantic Salmon (Salmo salar) Parr
by
, , , , ,
Sheu G. Odu-Onikosi
1,2,*,
Taofik A. Momoh
1,
Sherilyn T. Abarra
1,
Noah E. Wood
1,
Folasade D. Amulejoye
3,
Matthew Emery
1,
Glenn M. Harper
1,
Benjamin Eynon
1,
Victor Kuri
1
,
Holger Kühlwein
4 and
Daniel L. Merrifield
1,* 1
Fish Health and Nutrition Research Group, School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
2
Department of Fisheries and Aquaculture, Lagos State University of Science and Technology, Ikorodu 104101, Nigeria
3
Department of Fisheries and Aquaculture Technology, Olusegun Agagu University of Science and Technology, Okitipupa P.M.B. 353, Nigeria
4
Leiber GmbH, 49565 Bramsche, Germany
*
Authors to whom correspondence should be addressed.
Animals 2025, 15(3), 323; https://doi.org/10.3390/ani15030323
Submission received: 31 December 2024
/
Revised: 18 January 2025
/
Accepted: 21 January 2025
/
Published: 23 January 2025
(This article belongs to the Special Issue Gut Microbiota in Aquatic Animals)
Simple Summary
The aquaculture industry is increasingly pursuing sustainable practices, including the use of functional feed additives (FFAs) to enhance fish health and growth, and reduce reliance on antibiotics usage in aquafeeds. Brewer’s yeast-derived additives have emerged as promising FFAs, showing significant potential in promoting sustainable aquaculture development. In this study, the use of commercial brewer’s yeast-derived feed additives was explored to improve the health and performance of Atlantic salmon. The salmon were fed diets supplemented with autolysed brewer’s yeast (ABY) or soluble dried yeast extract (SDYE) for nine weeks to assess their impact on skin and intestinal health, immune response, intestinal bacterial communities, and growth. The results showed that the brewer’s yeast additives, particularly ABY, improved intestinal structure, enhanced immune-related gene expression, and positively influenced the bacterial community in the intestine, all while maintaining healthy blood parameters and growth rates. These findings suggest that the yeast additives can support fish health and resilience, offering a sustainable way to boost aquaculture productivity while reducing reliance on antibiotics. This has potential benefits for both environmental sustainability and global food security.
Abstract
Yeast-based feed additives have emerged as promising functional feed additives (FFAs) to promote sustainable aquaculture development through enhanced gut health and immune modulation in fish. The present study evaluated the impact of autolysed brewer’s yeast (ABY) and soluble dried yeast extract (SDYE) in improving the intestinal and skin histology, immune response, and intestinal microbiome of Atlantic salmon parr (Salmo salar) over a 9-week feeding trial. Three experimental diets were produced: a control diet, a diet supplemented with ABY at 2.5 g/kg, and a diet supplemented with SDYE at 2.5 g/kg. These diets were administered to triplicate tanks of Atlantic salmon. The yeast-supplemented diets, especially ABY, improved intestinal mucosal fold length, lamina propria width, microvilli density, and intestinal goblet cell counts, as well as skin goblet cell counts. The yeast additives had no detrimental effects on the fish haematology, with no significant differences in haemoglobin concentration, red blood cell counts, and white blood cell counts among the treatment groups. Gene expression analysis revealed upregulation of il-1β and muc-2 in fish fed the ABY diet, indicating enhanced immune function and potentially mucosal protection. Intestinal microbiota analysis revealed Firmicutes as the most dominant phylum in all groups, followed by Actinobacteriota. Distinct bacterial community shifts were observed between the treatment groups, with a significant increase in the relative abundance of taxa such as Staphylococcus in yeast-supplemented diets and a significant decrease in Streptococcus and Weissella. Collectively, these findings suggest that the yeast additives, especially ABY, enhance gut health and immune function without compromising growth performance.
