Candida utilis and Chlorella vulgaris counteract intestinal inflammation in Atlantic salmon (Salmo salar L.)

PLoS One. 2013 Dec 27;8(12):e83213. doi: 10.1371/journal.pone.0083213. eCollection 2013.

Abstract

Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM) in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE). In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation. The dietary treatments consisted of a negative control based on fish meal (FM), a positive control based on 20% SBM, and four experimental diets combining 20% SBM with either one of the three yeasts Candida utilis (CU), Kluyveromyces marxianus (KM), Saccharomyces cerevisiae (SC) or the microalgae Chlorella vulgaris (CV). Histopathological examination of the distal intestine showed that all fish fed the SC or SBM diets developed characteristic signs of SBMIE, while those fed the FM, CV or CU diets showed a healthy intestine. Fish fed the KM diet showed intermediate signs of SBMIE. Corroborating results were obtained when measuring the relative length of PCNA positive cells in the crypts of the distal intestine. Gene set enrichment analysis revealed decreased expression of amino acid, fat and drug metabolism pathways as well as increased expression of the pathways for NOD-like receptor signalling and chemokine signalling in both the SC and SBM groups while CV and CU were similar to FM and KM was intermediate. Gene expression of antimicrobial peptides was reduced in the groups showing SBMIE. The characterisation of microbial communities using PCR-DGGE showed a relative increased abundance of Firmicutes bacteria in fish fed the SC or SBM diets. Overall, our results show that both CU and CV were highly effective to counteract SBMIE, while KM had less effect and SC had no functional effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / adverse effects
  • Animals
  • Aquaculture
  • Candida*
  • Chlorella vulgaris*
  • Fish Diseases / microbiology
  • Fish Diseases / therapy*
  • Intestinal Diseases / microbiology
  • Intestinal Diseases / pathology
  • Intestinal Diseases / veterinary*
  • Intestines / pathology
  • Kluyveromyces
  • Microbiota
  • Probiotics / therapeutic use
  • Saccharomyces cerevisiae
  • Salmo salar / microbiology*
  • Soy Foods / adverse effects

Associated data

  • GEO/GSE44978

Grants and funding

The research was financed by the Research Council of Norway (www.forskningsradet.no), grant no.417091. The yeast was provided by Borregaard ASA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.