The prebiotic effect of human milk oligosaccharides 3′- and 6′- sialyllactose on adhesion and biofilm formation by Clostridioides difficile - pilot study

Bacterial adhesion is the first stage of colonisation and biofilm formation by Clostridioides difficile. Cell wall proteins (Cwp) 84 and 66 play crucial roles in the pathophysiology of C difficile and may affect bacterial adhesion. Sialylated human milk oligosaccharides (HMOs) have potential to inhibit bacterial adhesion in vitro. The aim of this study was to investigate how 3'-sialyllactose (SL) and 6'-SL affect adhesion and C. difficile biofilm formation. Also, the influence of these substances on cwp84 and cwp66 genes expression by C. difficile was assessed. An adhesion assay was performed using three human colon cells in vitro, and biofilm formation was evaluated using crystal violet staining and confocal laser scanning microscopy. The effect of 3'-SL and 6'SL on cwp expression was measured using real time-PCR. Both tested HMOs decreased expression of the cwp84 gene, adhesion of C. difficile to human colon cells in vitro and biofilm formation. (C) 2021 The Authors. Published by Elsevier Masson SAS on behalf of Institut Pasteur.

Automated summary

This study investigated the effects of 3'-sialyllactose (SL) and 6'-SL on adhesion and biofilm formation of C. difficile. The results showed that both substances can inhibit the adhesion of C. difficile to human colon cells and reduce biofilm formation.