Inhibitory Inhibitory effects of Lactobacillus rhamnosus and Lactobacillus casei on Candida biofilm of denture surface

Objective: Candida albicans biofilm is associated with denture-related stomatitis and oral candidiasis of elderly. Probiotics are beneficial bacteria and have antibacterial activity against pathogenic bacteria. The purpose of this study was to investigate the antifungal activity of various probiotics against C. albicans and the inhibitory effects of probiotics on Candida biofilm on the denture surface. Design: The spent culture media of various probiotics were investigated the antifungal efficacy against C. albicans. Candida biofilm was formed on a denture base resin and was then treated with Lactobacillus rhamnosus and Lactobacillus casei. Also, the biofilms of L rhamnosus and L. casei were formed and were sequentially treated with C. albicans. Colony-forming units of C albicans on the denture surface were counted after spreading on agar plate. The denture base resin was treated with the spent culture media for 30 days, after which the denture surface roughness was analyzed with an atomic force microscope. Results: L. rhamnosus and L casei exhibited stronger antifungal activity than other probiotics. The spent culture medium of L. rhamnosus and L. casei exhibited the antifungal activity against blastoconidia and biofilm of C albicans. L rhamnosus and L casei showed the antifungal activity against Candida biofilm, and the biofilm of L rhamnosus and L. casei inhibited formation of Candida biofilm on denture surface. Neither of the probiotics affected the surface roughness of the denture base resin. Conclusions: L rhamnosus and L. casei may be the ideal probiotics for the prevention and treatment of denture-related stomatitis. (C) 2017 Elsevier Ltd. All rights reserved.