An oral health optimized diet reduces the load of potential cariogenic and periodontal bacterial species in the supragingival oral plaque: A randomized controlled pilot study

Abstract

This study aimed to investigate the effects of an oral health optimized diet on the composition of the supragingival oral plaque in a randomized controlled trial. Participants of the standard diet group (n = 5) had a diet high in processed carbohydrates and did not change their dietary behavior during the observation. The healthy diet group (n = 9) had to change the diet after 2 weeks from a diet high in processed carbohydrates to a diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, antioxidants and fiber for 4 weeks. Saliva and supragingival plaque samples were taken at the end of week two and eight of the observation period to investigate the composition of microbiota in saliva and supragingival plaque. Data were subjected to an exploratory analysis to identify significant differences. Statistically significant differences were only found in the healthy diet group between the baseline (week 2) and the final sample (week 8) for specific species in plaque and saliva samples. A reduction of the total counts of Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. was found in plaque samples of the healthy diet group. In saliva samples of the healthy diet group, the total counts of Actinomyces spp. and Capnocytophaga spp. decreased. A diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, and rich in fiber reduced Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. in the supragingival plaque.

Keywords: fatty acids; low-carb diet; nutrition; omega 3; oral microbiota; vitamins.

Conflict of interest statement

None declared.

© 2020 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Figures

FIGURE 1

Dietary pattern of both groups. The standard diet group followed a diet primarily based on carbohydrates. The healthy diet group changed their diet after 2 weeks to the health optimized diet for the following 6 weeks, in which the first 2 weeks were a transition period and a strict oral health optimized diet should be performed during the following 4 weeks

FIGURE 2

Boxplots of CFU counts, demonstrating the impact of diet on (a) dental plaque and (b) salivary microorganisms among 14 study probands after 2 weeks (baseline) and 8 weeks (final phase) following either a healthy‐ (n = 9) or a standard (n = 5) diet. Box plots represent the CFUs determined by selective agar plating, while horizontal lines indicate their median values. Undetectable values were ascribed to the lowest detection limit value of the assay to allow for log transformation. The CFUs are presented on a log10 scale per square centimeter (log10/ml). Error bars indicate from 5% to 95% percentile. The p‐values (t test) of the significantly different data (p ≤ .05) are marked on the graphs

FIGURE 3

Heatmap demonstrating the absolute distribution (in log10/ml) of different bacterial groups/species among 14 study probands after 2 weeks (baseline) and 8 weeks (final phase) following either a healthy‐ (n = 9) or a standard (n = 5) diet. The influence of diet on the dental plaque‐ and salivary microorganisms after two‐ and eight weeks is demonstrated on panels (a) and (b), respectively. Participant numbers for each treatment group are shown in columns and variables (bacterial groups, species, and genera) in rows. The colors as depicted on the color scale bars on the right vary to indicate data values change for the different samples; Plaque: low: 0–4, moderate: 4–8, high: 8–12; Saliva: low: 0–3, moderate: 3–6, high: 6–9