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Immune enhancement in rainbow trout (Oncorhynchus mykiss) by potential probiotic bacteria (Lactobacillus rhamnosus).

  • 2003-11
  • Fish & Shellfish Immunology 15(5)
    • Sami Nikoskelainen
    • A. Ouwehand
    • G. Bylund
    • S. Salminen
    • E. Lilius


The present study assessed the immune enhancement of fish by a lactic acid bacterium (LAB) Lactobacillus rhamnosus (ATCC 53103). The bacterium was administered orally at five different doses 7.9 x 10(4) (LAB4), 2.1 x 10(6) (LAB6), 2.8 x 10(8) (LAB8), 1.9 x 10(10) (LAB10) and 9.7 x 10(10) (LAB11) CFU/g feed to rainbow trout for two weeks and the feed was changed to un-supplemented diet. From the onset of feeding supplemented diets at 1, 2, 3 and 4 weeks, blood and mucus samples were taken. During the LAB feeding period L. rhamnosus persisted in the fish intestine and in the tank water in high numbers. However, L. rhamnosus disappeared from the intestine, skin mucus and tank water within one week after the change to the non-supplemented feed. In comparison to untreated control fish, respiratory burst activity of blood cells was raised significantly in the LAB4 treated group on week 2. Serum-mediated killing of Escherichia coli was increased significantly in group LAB6 on week 2. Serum immunoglobulin levels were significantly raised only in LAB8 group on week 1 and in LAB4 and LAB8 at the end of the trial. The results show that rainbow trout immune parameters were enhanced by using probiotic bacteria.

Research Insights

SupplementHealth OutcomeEffect TypeEffect Size
Lactobacillus rhamnosus R0011Elevated Serum Immunoglobulin LevelsBeneficial
Lactobacillus rhamnosus R0011Enhanced Serum-Mediated E. coli KillingBeneficial
Lactobacillus rhamnosus R0011Increased Respiratory Burst ActivityBeneficial
Lactobacillus rhamnosus SD-5217Elevated Serum Immunoglobulin LevelsBeneficial
Lactobacillus rhamnosus SD-5217Improved Immune FunctionBeneficial
Lactobacillus rhamnosus SD-5217Improved Serum-Mediated Pathogen KillingBeneficial
Lactobacillus rhamnosus SD-5217Increased Respiratory Burst ActivityBeneficial

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