Transcriptome analysis of the Clostridioides difficile response to a specific lactobacilli probiotic formulation: explanations for its mechanisms of action

Abstract

Aims: Clostridioides difficile infections (CDI) are a major cause of morbidity and mortality in hospitalized patients. A probiotic formulation (Bio- K+) comprised of Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacti. rhamnosus CLR2 strains have been shown to reduce the incidence of CDI and antibiotic-associated diarrhea (AAD). This research aims to therefore elucidate the mechanism of action of the three probiotic strained against C. difficile R20291, independently of the acidification of the environment. Methods and Results: Antitoxin activity was evaluated using ELISA method and the expression of C. difficile genes was evaluated using transcriptomic analysis in co-culture assays conducted in a bioreactor allowing precise control of the pH. The fermentation results demonstrated a decrease for toxin A and many genes directly related to C. difficile virulence were underexpressed in the co-cultures. Conclusions: The lactobacilli tested could have a role in the motility, the quorum sensing (QS), the survival of the spores, and the germination potential of the spores, which are essential elements for the virulence of C. difficile.