Advisor(s)
Ping Zhang
Committee Member(s)
Amjad Javed
Janice Jackson
Jessica Scoffield
School
School of Dentistry
Document Type
Thesis
Department (new version)
Dentistry
Date of Award
9-9-2024
Abstract
Purpose: Probiotic Lactobacillus species are shown to have beneficial effects against early childhood caries (ECC). On the other hand, the wide use of probiotic Lactobacillus spp. in dairy foods is believed to underline the global increase in ECC prevalence. Candida albicans has been frequently detected in children with ECC and has shown cariogenic potential in animal models of dental caries. The objective of this study was to determine the interactions between lactobacilli and C. albicans in growth competition, biofilm formation and acid production. Methods: Growth competition between C. albicans SC5314 and probiotic L. rhamnosus GG or caries-associated L. rhamnosus M72-26 were assessed on Lactobacillus de Man, Rogosa and Sharpe (MRS) agar and Todd Hewitt-Yeast (THY) agar. Biofilm formation was evaluated by culturing lactobacilli and C. albicans together or in separate transwell chambers to only allow metabolite exchange. Acid production by lactobacilli and C. albicans single- and dual-species biofilms at different time intervals was analyzed using Orion pH meter. Results: L. rhamnosus GG and L. rhamnosus M72 inhibited the growth of C. albicans on MRS agar but not on THY agar when lactobacilli were grown 24 hours earlier. L. rhamnosus GG resulted in more biofilm formation than C. albicans in THY medium. However, in MRS medium, C. albicans resulted in significantly higher biofilm formation. L. rhamnosus M72 + C. albicans dual-species culture resulted in lesser biofilm than C. albicans mono-species culture in MRS and THY medium with or without physical contact. L. rhamnosus GG + C. albicans dual-species culture showed significantly lesser biofilm formation than C. albicans mono-species culture in MRS medium, while the dual-species resulted in more biofilm than mono-species C. albicans in THY medium. These results were significant only when organisms were in physical contact with each other. The lactobacilli and C. albicans dual-species biofilm showed similar levels of acid production as lactobacilli single-species biofilm, but the levels were significantly higher than C. albicans single-species biofilm. Conclusions: Probiotic lactobacilli may prevent ECC development by inhibiting the growth and biofilm formation of C. albicans only under favorable condition. It may, in fact, accelerate ECC progression by increasing acid production.
ProQuest ID
Recommended Citation
Menon, Leena Unnikrishnan, "Effects of Probiotic Lactobacilli on Candida albicans: Implications for Early Childhood Caries" (2024). All ETDs from UAB. 7565.
https://digitalcommons.library.uab.edu/etd-collection/7565
