Oral microbial diversity in health: An ethnic comparative study

Udoh, Stephanie

Abstract

This work involved two key phases: an in-vitro study and a clinical trial (in-vivo) study. The in-vitro study compared the antimicrobial properties of an oral formulation containing 5% potassium nitrate and 0.24% sodium fluoride to 1% chlorohexidine using a flat-bed perfusion model. The in-vitro objectives were 1. SIFT-MS analysis of volatile organic compounds before and after treatment, 2. assessing biofilm bacterial load before and after treatment, 3. assessing antibacterial susceptibility and bacterial cell membrane permeability effects of the oral formulation. The clinical trial (in-vivo) phase explored ethnic-specific oral microbiota profiles within a healthy population, particularly focusing on Black African and White European ethnic groups. The in-vivo objectives included 1. comparing volatile organic compound levels in mouth air between the two ethnic groups, 2. analyzing the variation in tongue and subgingival plaque microbiota within low-risk individuals of both ethnicities, and 3. scrutinizing the differences in tongue and subgingival plaque microbiota between Black African individuals with low risk and high risk for developing type 2 diabetes.

The in-vitro study results showed that the 5% potassium nitrate and 0.24% sodium fluoride toothpaste demonstrated significant reductions in volatile organic compound levels (p < 0.01), diminished biofilm density (p < 0.01), and increased bacterial cell membrane damage (p < 0.001) when compared to the 1% chlorohexidine formulation within the flat-bed biofilm model. In the in-vivo study, notable similarities emerged in the oral microbiota of both ethnic groups, revealing comparable profiles in health across various analytical dimensions. While subtle variations were detected, factors such as diet, oral hygiene practices, and lifestyle choices likely influenced these differences. Additionally, the analysis spotlighted unique bacterial taxa, including Dialister species and Candidatus Nanosynbacter lyticus, highlighting distinctions between low and high-risk groups.

The study concludes that the tested oral formulation may present an effective alternative to Chlorhexidine. It reveals striking similarities in oral microbiota between White European and Black African individuals, with minor differences possibly influenced by diet and oral hygiene practices. Further research is vital to validate these findings, explore the formulation's clinical applications, and understand the implications of microbial variations for oral and systemic health in diverse racial groups.

• Thesis Type: Thesis
• Deposit Date: Oct 2, 2023
• Publicly Available Date: Mar 4, 2024
• Public URL: https://uwe-repository.worktribe.com/output/11148138
• Award Date: Mar 4, 2024