Hydrolysate of β-lactoglobulin by Lactobacillus delbrueckii subsp. bulgaricus CRL 656 suppresses the immunoreactivity of β-lactoglobulin as revealed by in vivo assays

MICAELA PESCUMA; ELVIRA M HÉBERT; GRACIELA FONT DE VALDEZ; LUCILA SAAVEDRA; FERNANDA MOZZI

INTERNATIONAL DAIRY JOURNAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 vol. 88 p. 71 - 78

0958-6946

Cow´s milk allergy affects mainly infants, especially those who cannot be breast fed due to the presence of β-lactoglobulin (BLG) in bovine milk. Lactobacillus delbrueckii subsp. bulgaricus CRL 656 can degrade BLG in its main epitopes and reduce IgE recognition in sera of allergic children. In this work, we aimed to study the in vivo immunomodulatory potential of BLG hydrolysates obtained by L. delbrueckii subsp. bulgaricus CRL 656 (H656) by using a murine model. BALB/c mice were gavaged with BLG, H656 or BioZate® and sensitized by BLG intraperitoneal injection. The effect of H656 was assayed by BLG-IgE response in sera, cytokine secretion in reactivated spleen cells, cytokine expression by real time PCR and intestine histology. Sera from mice gavaged with H656 showed lower (17.4 times) specific BLG-IgE values than that of allergic mice. Moreover, an increase in the secretion of IL-10, INFγ and IL-6 (58.3, 26.4 and 18.7%, respectively) and decrease in the IL-4 (59.2 %) concentration when allergic mice spleen cells were stimulated with H656 were observed as compared to those incubated with BLG. H656 was administered orally to evaluate its tolerogenic effect; a drastic reduction (97.7%) in IL-4 secretion together with an increase in the concentration of IL-10, IL-17A and IL-6 (62.6, 76.9 and 58.1 %, respectively) were noted when stimulating cells with BLG as comparing to the allergic group. In contrast, BioZate® oral administration had no effect on IL-4 secretion while an increase in the concentration of INFγ (52.4%) was observed respect to the allergic group. Real time PCR assay showed a higher expression of IL-4 (2.5-3.7 times) in the allergic mice, while when H656 or BioZate® was administrated the highest expression of IL-12 and IL-10 were detected (1.8-2.0-1.6-2.7 times, respectively). Furthermore, H656 immunization had a positive effect on intestinal mucosa. H656 had immunomodulating effect changing the normal allergic Th2 response towards a Th1 type. This hydrolysate could be added in infant foods to induce oral tolerance towards BLG in children with family history of food allergies.