Avaliação experimental dos efeitos moduladores do tratamento oral com Lactococcus lactis sobre a inflamação alérgica e alteração da microbiota intestinal desencadeados pela ingestão aguda de álcool

Abstract

The alcohol can trigger inflammatory effects in the gastrointestinal tract interfering with mucosal homeostasis and inducing an inflammatory response of allergic type, having high serum immunoglobulin (Ig) E levels and increased levels of interleukin (IL)-4 gastric mucosa. Several studies have shown that excessive alcohol consumption alters the composition of intestinal microbiota in rodents and humans, disrupting the microbiota homeostasis. The aim of this study was to evaluate the modulatory effects of oral treatment with Lactococcus lactis on allergic inflammation and altered intestinal microbiota triggered by acute alcohol intake in mice. For four consecutive days, intragastric administration of 0.2 mL of 50% ethanol per animal or saline solution, and twenty-four hours after the last administration, the animals were given in bottles, Lactococcus lactis, M17 broth or water only for two consecutive days. The completion of the second day of ad libitum treatment, the animals were sacrificed, and made collections of blood, stomach and small intestine, to immunological and histological analysis, and collection of the stomach, small intestine and large intestine (colon), for microbiological analysis. Regarding immunological, morphological and functional analyzes, treatment with Lactococcus lactis was able to restore basal levels of secretory IgA in the gastric mucosa, serum total IgE, IL-4 production in gastric and intestinal mucosa and IL-10 levels in the gastric mucosa. Moreover, Lactococcus lactis reduced hepatic degeneration caused by ethanol, IL-10 levels in the intestinal mucosa, and increased IFN-g levels in the gastric mucosa. The microbiological analysis, ingestion of ethanol by animals strongly detached Enterobacteriaceae from the stomach mucosa and small intestine and reduced presumptive lactic acid bacteria and presumptive L. lactis populations in the GIT. L. lactis treatment encouraged the diversification of Enterobacteriaceae population, particularly the commensal species, in the GIT. This study opens perspectives for the therapeutic use of Lactococcus lactis in the treatment of allergic inflammatory processes triggered by acute ingestion of alcohol and biotherapeutic modulation of the intestinal microbiota with this LAB appears to be a promising strategy to reduce alcohol-induced injuries.