title: Dietary administration of Lactobacillus delbrüeckii and Bacillus subtilis, single or combined, on gilthead seabream cellular innate immune responses.
abstract: The effects of oral administration of Lactobacillus delbrüeckii ssp. lactis and Bacillus subtilis, single or combined, on gilthead seabream cellular innate immune responses were investigated. Fish were fed four different diets: control (non-supplemented); or diet supplemented with 10(7) cfu g(-1)L. delbrüeckii ssp. lactis; 10(7) cfu g(-1)B. subtilis; or with 0.5x10(7) cfu g(-1)L. delbrüeckii ssp. lactis and 0.5x10(7) cfu g(-1)B. subtilis. This feeding regime lasted for 3 weeks, and all experimental groups were then fed the control commercial diet for another week. Six fish were sampled at weeks 1, 2, 3 and 4. Head-kidney leucocytes were isolated and the main cellular innate immune parameters (leucocyte peroxidase content, phagocytosis, respiratory burst activity and cytotoxicity) were evaluated. Leucocyte peroxidase content was lower in all groups at week 3 but the levels tended to recover during the last week of the experiment. Respiratory burst activity was not affected at any time of the experiment in any of the experimental groups. However, phagocytic activity increased after 2 weeks of feeding the single bacteria-supplemented diets, whereas the combination of the two caused an increment which persisted for as long as the bacteria were being administered. Cytotoxic activity was also significantly increased after 3 weeks of feeding the mixture of the two bacteria. After 1 week back on the control diet, the parameters in the experimental groups had recovered or even dropped below those recorded in the control group, suggesting that the bacteria did not persist in the seabream gut.
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Salinas
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuesta
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Esteban
authors.forename: José
authors.initials: J
authors.lastname: Meseguer
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001412:Bacillus subtilis / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic; D007111:Immunity, Cellular / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D007778:Lactobacillus / Q000276:immunology*; D007962:Leukocytes / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D016897:Respiratory Burst / Q000276:immunology; D021541:Sea Bream / Q000276:immunology* / Q000382:microbiology
chemical_list: D009195:Peroxidase