Immunomodulating potential of supplementation with probiotics: a dose–response study in healthy young adults

Abstract

Certain probiotic microorganisms have been found beneficial in the treatment of immune-related diseases and may also affect immune function in healthy people. Intervention studies of probiotics in healthy humans are urgently required. Here, the immunomodulating potential of Bifidobacterium animalis ssp. lactis (BB-12) and Lactobacillus paracasei ssp. paracasei (CRL-431) was studied in a double-blind placebo-controlled parallel dose-response trial (n=71) based on five randomly assigned groups of young healthy adults supplemented for 3 weeks with 0, 10(8), 10(9), 10(10) and 10(11) CFU day(-1), respectively, of a mixture of BB-12 and CRL-431. No statistically significant dose-dependent effect was found for phagocytic activity in blood leukocytes, fecal immunoglobulin A (IgA) concentrations or production of interferon-gamma and interleukin-10 in blood cells. When evaluating data according to the amount of viable BB-12 recovered from faeces, the interferon-gamma production in blood cells was significantly reduced. In conclusion, no solid effect on the immune function of young healthy adults supplemented with even high doses of B. animalis ssp. lactis BB-12 and L. paracasei ssp. paracasei CRL-431 was demonstrated in this study.

Probiotics and immunity

“…169,171 In contrast, supplementation of volunteers with L. fermentum ECET5716 for 2 weeks before and 2 weeks after vaccination with an inactivated trivalent infl uenza vaccine increased serum IL-12 levels before vaccination, and enhanced vaccine-induced elevations in serum TNF-α. 172 It also induced signifi cantly higher levels of specifi c IgA, but not IgG or IgM, compared with the placebo group.…”

“…paracasei CRL-431) did not enhance phagocytosis at any of the four doses tested. 169 The effect size is frequently small and of questionable clinical relevance, although subjects with low innate immune responses may benefi t signifi cantly. 160,161,166 Of note, even though several small studies indicated that L. casei Shirota supplementation could increase NK cell and phagocytic activity, one of the probiotic supplementation studies with the highest methodological quality did not.…”

“…166 It might be advisable to determine whether a probiotic has any effect and whether it retains this effect when used in combination with another probiotic before proceeding with a dose-response study that ultimately shows that a probiotic combination has no effect at four different doses. 169 Another potential explanation for the differential effectiveness of probiotics in animals and humans might be that the composition of the intestinal microfl ora is likely to vary to a much greater extent between individual humans than between individual mice that are kept in the same environment and fed the same diet. Since in vitro studies suggest considerable interactions between different commensal and probiotic strains, 30,31 human responses to probiotic treatment might differ depending on the composition of the individual's endogenous fl ora.…”

Probiotic intervention has strain-specific anti-inflammatory effects in healthy adults

“…The immunomodulatory effects of probiotics have mostly been studied in certain disease conditions, such as allergies [2] and inflammatory diseases [3,4] , though the general, healthy population mostly consumes probiotics. The immunomodulatory effects of probiotics in healthy populations have not been fully established and only a few randomized, double blind, placebo-controlled studies have addressed this question [5][6][7][8][9] . Also, there are few studies where the effects of different…”

Dose–response study of probiotic bacteria Bifidobacterium animalis subsp lactis BB-12 and Lactobacillus paracasei subsp paracasei CRL-341 in healthy young adults

“…Furthermore, the recovery of BB-12 and CRL-431 from fecal samples was determined. The effects on various immune parameters were also studied and are to be published elsewhere (Christensen et al, 2006).…”