Preliminary study of the oral mycobiome of children with and without dental caries

Abstract

Children’s oral health is in a dire state, with dental decay (caries) being one of the most common chronic diseases. While the role of bacteria in the oral microbiome and dental caries is established, the contribution of fungi is relatively unknown. We assessed the oral mycobiome in childhood (n = 17), to determine if the composition of fungi varies between children with and without caries. Oral mycobiome composition was assessed by using Illumina MiSeq to sequence the ITS2 region, which was amplified from dental plaque. This revealed that the oral mycobiome in the investigated children contained 46 fungal species. Candida albicans was the most abundant species and was ubiquitous in all samples, indicating this species may not be involved in caries development as previously suggested. While the overall diversity of fungi was similar, independent of caries status (p > 0.05), we found caries influenced the abundance of specific fungi. Children without caries had a significantly higher abundance of 17 species compared to children with caries, which had three enriched species (p < 0.001). While the differentially abundant species between health and caries may be specific to an Australian population, our findings indicate the mycobiome plays a role in oral health.

Supragingival mycobiome and inter-kingdom interactions in dental caries

“…hardly 0.0001%), which is even lower than that found in saliva (0.06%) [26]. Nevertheless, mycobiome analysis revealed the presence of a complex fungal community, consistent with previous reports [6][7][8]. Several core taxa identified in this study are in common with those studies, including Candida, Malassezia, Cryptococcus, Cladosporium, and Saccharomyces, supporting the presence of an endogenous oral mycobiome.…”

“…In the current study, C. albicans showed a strong association with dental caries and was almost exclusively identified in children with advanced caries. In contrast, Fechney et al (2019) found no such association and detected C. albicans in all samples from healthy as well as caries subjects. This contradiction may be explained, at least in part, by differences in the selection and grouping of the study subjects between the two studies.…”

“…The 2019 study used sequencing of the Internal Transcribed Spacer 2 (ITS2) to analyze supragingival plaque samples from seventeen 7 to 10-year-old Australian children. It identified 46 fungal species, 17 of which were more abundant in children without caries and 3 in children with caries; surprisingly, Candida was not among the caries-associated taxa [8].…”

Candida biome of severe early childhood caries (S-ECC) and its cariogenic virulence traits

“…The oral mycobiome and the prevalence of it predominate constituent Candida, in childhood caries has been sparsely studied. In a recent preliminary study of 15 Australian children, Fechney et al concluded that their oral mycobiome comprised at least 46 fungal species [14]. Further, they noted that the diversity of fungi was similar irrespective of the caries status of this small pediatric cohort, and caries influenced the abundance of specific fungi.…”

“…It is generally recognized that the mutans-group streptococci are the prime movers of the caries process due to their acidogenic and aciduric nature [10]. However, several studies have now shown that the aciduric oral yeasts, mainly belonging to Candida species, frequently co-inhabit these lesions with mutansstreptococci, and significantly contribute to the caries process [11][12][13][14]. There is also a substantial body of data to indicate cross-kingdom synergistic, interactions between this fungus and cariogenic CONTACT Lakshman Perera Samaranayake lsamaranayake@sharjah.ac.ae M28-125, College of Dental Medicine, University of Sharjah, Sharjah 27272, UAE bacteria within such polymicrobial-biofilm habitats [15,16] making the eukaryote a candidate caries pathogen.…”