Skip to main content


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.

Research Insights

SupplementHealth OutcomeEffect TypeEffect Size
Lactobacillus delbrueckiiIncreased PMN Cell Phagocytic CapacityBeneficial
Lactobacillus delbrueckii VPro 315Enhanced Natural Killer Cell Tumoricidal ActivityBeneficial
Lactobacillus delbrueckii VPro 315Increased PMN Cell Phagocytic CapacityBeneficial
Lactobacillus lactis LLa61Increased PMN Cell Phagocytic CapacityBeneficial
Lactobacillus lactis LLa61Reduced Myeloperoxidase LevelsNeutral

Pillser helps you make informed health decisions by providing comprehensive, unbiased information about supplements. This includes detailed research on supplement ingredients, their benefits, potential risks, and their overall efficacy. You can contribute by sharing your feedback and suggestions.

Send us an email at