Lactococcus lactis Administration Modulates IgE and IL-4 Production and Promotes Enterobacteria Growth in the Gut from Ethanol-Intake Mice

Background: It is well known that alcohol can trigger inflammatory effects in the gastrointestinal tract (GIT), interfering with mucosal homeostasis. Objectives: This study evaluated the effectiveness of Lactococcus lactis treatment in controlling the increase in molecular biomarkers related to allergic inflammation and the effect on the diversity and abundance of the Enterobacteriaceae family in the GIT after high-dose acute administration of ethanol. Methods: Mice received ethanol or saline solution by gavage for four consecutive days, and 24 h after the last administration, the animals were given L. lactis or M17 broth orally ad libitum for two consecutive days. The animals were subsequently sacrificed and dissected. Results: L. lactis treatment was able to restore basal levels of secretory immunoglobulin A in the gastric mucosa, serum total immunoglobulin E, interleukin (IL)-4 production in gastric and intestinal tissues, and IL-10 levels in gastric tissue. L. lactis treatment encouraged the diversification of the Enterobacteriaceae population, particularly the commensal species, in the GIT. Conclusion: This research opens a field of studies regarding the modulatory effect of L. lactis on immunological and microbial changes induced after alcohol intake.