Impact of Probiotic Intervention on Lymphocyte Activity in Mice Challenged with Pea Albumins (Pisum sativum L.)

Background: Probiotics are microorganisms with proven health benefits in humans. However, the mechanisms underlying the direct effects of these compounds on immune cells remain unclear. This study aimed to examine the effects of probiotics on immunity in mice exposed to allergenic dietary proteins, specifically pea albumin (PA). We hypothesized that probiotics would alter lymphocyte activity, leading to measurable differences in the immune response to these proteins. Methods: The relationship between probiotic intervention and the adaptive immune response to PA was tested in Balb/c and C57BL/6 mice to account for strain differences. ELISA and flow cytometry were used to determine specific immunoglobulin titers, lymphocyte profile, including CD4+/CD8+ ratio, and cytokine release. Results: We observed higher levels of pea albumin-specific immunoglobulins in the serum and fecal extracts of Balb/c mice than in those of C57BL/6 mice. Probiotic intervention significantly impacted serum and fecal IgA levels (p < 0.05). We found that probiotic intervention generally increased the percentage of CD4+, CD4+ CD25+, and CD8+ T cells in the Peyer’s patches, mesenteric lymph nodes, spleen, and head and neck lymph nodes of Balb/c mice, which was not observed in C57BL/6 mice. In ex vivo cultures, lymphocytes from probiotic-treated Balb/c mice responded to PA stimulation by significantly altering the levels of secreted cytokines (p < 0.05). The Balb/c and C57BL/6 mice, administrated probiotic preparation and PA, presented differences in the SCFA profiles (p < 0.05). Conclusions: the multivalent probiotic preparation significantly modulated humoral and cellular immune responses against PA in Balb/c mice. This suggests that it may be an important tool for the targeted modulation of the immune response to dietary proteins.