Immunomodulatory effect of short-term supplementation with Bacillus toyonensis BCT-7112T and Saccharomyces boulardii CNCM I-745 in sheep vaccinated with Clostridium chauvoei.

The bacterium Clostridium chauvoei is the causative agent of blackleg in livestock, and vaccination is the most effective means of prevention. The aim of this study was to assess the effect of short-term supplementation with Bacillus toyonensis and Saccharomyces boulardii on the immune response to a C. chauvoei vaccine in sheep. Sheep were vaccinated subcutaneously on day 0 and received a booster dose on day 21, with 2 mL of a commercial vaccine formulated with inactivated C. chauvoei bacterin adsorbed on aluminum hydroxide. Probiotics were orally administered B. toyonensis (3 × 108 cfu) and S. boulardii (3 × 108 cfu) over five days prior to the first and second doses of the vaccine. Sheep supplemented with B. toyonensis and S. boulardii showed significantly higher specific IgG, IgG1, and IgG2 titers (P<0.05), with approximately 24- and 14-fold increases in total IgG levels, respectively, than the nonsupplemented group. Peripheral blood mononuclear cells from the supplemented group had increased mRNA transcription levels of the IFN-γ, IL2, and Bcl6 genes. These results demonstrate an adjuvant effect of short-term supplementation with B. toyonensis and S. boulardii on the immune response against the C. chauvoei vaccine in sheep.

Saccharomyces boulardii attenuates inflammatory response induced by Clostridium perfringens via TLR4/TLR15-MyD8 pathway in HD11 avian macrophages.

Macrophages are professional phagocytic cells that play a critical role in initiating immune responses by presenting antigen and phagocytic clearance. The macrophages can be targeted for immunomodulation by beneficial microbes, such as probiotics. The aim of this study is to investigate the protective effect of Saccharomyces boulardii against Clostridium perfringens infection in avian macrophage cell line HD11. In this study, HD11 macrophages were prestimulated with S. boulardii for 6 h and then infected with C. perfringens for 3 h. Results showed that S. boulardii enhanced phagocytosis and bactericidal capacity against C. perfringens by HD11 cells. The S. boulardii effectively promoted the mRNA expression of CD80, CD83, and CD197 cell-surface molecules in C. perfringens-infected HD11 cells. Moreover, we found that prestimulation with S. boulardii reduced the mRNA expression of CD40, toll-like receptor [TLR] 4, and TLR15 induced by C. perfringens and thereby downregulated the mRNA expression of myeloid differentiation primary response 88, TNF receptor associated factor 6, nuclear factor kappa-B p65 subunit, and c-Jun N-terminal kinase genes in HD11 cells. The upregulation of cytokines (interleukin [IL]-6, tumor necrosis factor alpha, and IL-10) and inducible nitric oxide synthase mRNA expression in C. perfringens-infected HD11 cells were noticeably inhibited by S. boulardii pretreatment. Conclusively, these results might provide a new insight into the role of S. boulardii in regulating avian immune defense against C. perfringens invasion and immune escape.

O probiótico Saccharomyces boulardii modula a resposta de IgG2a em camundongos expostos aos antígenos de Leishmania infantum / Probiotic Saccharomyces boulardii modulates IgG2a response in mice exposed to Leishmania infantum antigens

O objetivo do presente estudo foiavaliar os efeitos do probiótico Saccharomyces boulardii na modulação da resposta imune humoral de animais expostos a antígenos de Leishmania infantum. Para isso, 16 camundongos BALB/c foram imunizados com antígeno particulado de Leishmania infantum e divididos em dois grupos experimentais, um composto por animais suplementados e outro por animais não suplementados com o probiótico. Amostras de sangue dos animais foram colhidas semanalmente durante o período experimental e submetidas ao Ensaio da Imunoabsorbância Ligado à Enzima indireto para avaliação dos títulos de IgG totais e o perfil dos isotipos de IgG produzidos (IgG1 e IgG2a). A suplementação com o probiótico não exacerbou a produção de IgG total em comparação ao grupo controle, não havendo diferenças significativas entre os dois grupos. Porém, as soroconversões de IgG2a foram mais elevadas no grupo suplementado, no qual registrou-se um aumento de 1,46 vezes no final do experimento. Assim,a suplementação com S. boulardii foi capaz de modular a resposta de IgG2a/IgG1 nos animais expostos aos antígenos de Leishmania infantum.

The aim of the present study was to evaluate the effects of the Saccharomyces boulardii probiotic on the modulation of humoral immune response in animals exposed to Leishmania infantum antigens. For this, 16 BALB/c mice were immunized with Leishmania infantum particulate antigen and divided into two experimental groups, one consisting of supplemented animals and the other not probiotic supplemented animals. Blood samples from the animals were taken weekly during the experimental period and subjected to the Indirect Enzyme-Linked Immunosorbance Assay for evaluation of total IgG titers and the profile of the produced IgG isotypes (IgG1 and IgG2a). Probiotic supplementation did not exacerbate total IgG production compared to the control group, with no significant differences between the two groups. However, IgG2a seroconversions were higher in the supplemented group, which showed a 1.46-fold increase at the end of the experiment. Thus, supplementation with S. boulardii was able to modulate the IgG2a/IgG1 response in animals exposed to Leishmania infantum antigens.