Abstract
Background
This follow‐up study evaluated microbiome changes in periodontal recall patients after consuming a nitrate‐rich diet that led to a marked decrease of gingival inflammation.
Methods
Subgingival microbial samples of 37 patients suffering from gingival inflammation with reduced periodontium were taken before professional mechanical plaque removal (baseline) and subsequently after 2 weeks of regularly consuming a lettuce juice beverage (day 14) containing a daily dosage of 200 mg of nitrate (test group, n = 18) or being void of nitrate (placebo group, n = 19). Three hundred base pairs paired‐end sequencing of the V3‒V4 hypervariable region of the 16S rDNA was performed.
Results
At baseline, there were no significant differences about the bacterial diversity parameters between the groups (Mann‐Whitney U test). After intervention in the test group, Rothia and Neisseria, including species reducing nitrate, increased significantly (negative binomial regression model). Alpha diversity decreased significantly from 115.69 ± 24.30 to 96.42 ± 24.82 aRSVs/sample (P = 0.04, Wilcoxon signed‐rank test), accompanied by a significant change in beta diversity (P < 0.001, PERMANOVA). In the control group, however, no genus changed significantly, and alpha‐, as well as beta‐diversity did not change significantly.
Conclusions
The decrease of gingival inflammation in periodontal recall patients induced by a nitrate‐rich diet is accompanied by significant compositional changes within the subgingival microbiome.