The potential impact of delivery mode and breastfeeding on oral Candida species carriage in a population of young adults.

OBJECTIVES: In early life, children are exposed to microorganisms from maternal and environmental sources, which influence the development of their microbiome throughout life. Several studies have demonstrated the influence of the delivery mode and breastfeeding on the oral microbiome of children, mostly regarding bacterial colonization. However, their influence on the oral fungal carriage is still underexplored. This study aimed to assess the association of the delivery and feeding mode with the oral carriage of yeasts in adulthood.

METHOD AND MATERIALS: Fungal oral carriage was evaluated by collecting unstimulated saliva in 185 healthy dental students (mean age of 21.51±1.55 years old; 81.6% females). Yeast identification was performed by culture in ChromAgar Candida medium and sequencing of the 18S genes and ITS regions for determination of the species. Demographic and clinical data of each participant was recorded through questionnaires and oral examinations were performed in a subgroup of participants (n=49).

RESULTS: Candida species were isolated in 37.5% of all participants. The prevalence of yeasts in the oral cavity was significantly higher in those who were born by vaginal delivery compared to those born by caesarean-section (p=0.035), whereas no statistically significant differences were observed regarding breastfeeding (p=0.398). Low salivary flow rate and frequency of dental visits also were associated with oral yeast carriage (p<0.05).

CONCLUSION: Our study suggests a possible impact of the type of delivery on fungal colonization, which is sustained throughout life due to oral health-related factors.