Insights Into the Mechanisms of <em>Lactobacillus acidophilus</em> Activity Against <em>Entamoeba histolytica</em> by Using Thiol-Redox-Proteomics

Abstract

Amoebiasis is an intestinal disease transmitted by the protist parasite, Entamoeba histolytica, following the ingestion of contaminated food and water. In the colon, E. histolytica can phagocytose bacteria that are the main components of the microbial flora. Most infected individuals are asymptomatic but for unknown reasons, the parasite can become virulent and invasive, causes amebic dysentery, and migrates to the liver, where they cause hepatocellular damage. For the last few decades, it has become evident that E. histolytica virulence is directly linked to its interaction with the gut microbiota. Lactobacillus acidophilus is a common inhabitant of healthy human gut and a probiotic that present antimicrobial activity against many pathogenic bacteria, fungi and parasites. The purpose of this study was to examine the mechanisms behind the innate amebicide activity of L.acidophilus. We found that this activity is mediated by hydrogen peroxide (H2O2) produced by L. acidophilus. Redox proteomics shows that L. acidophilus triggers the oxidation of many essential amebic enzymes like pyruvate:ferredoxin oxidoreductase, the lectin Gal/GalNAc and cysteine proteases (CPs). Further, trophozoites of E.histolytica cultivated with L.acidophilus show reduced binding to mammalian cells. These results support L.acidophilus as a prophylactic candidate against amoebiasis.