Salivary microbiome with gastroesophageal reflux disease and treatment

Abstract

The effect of oral microbial composition on periodontal health and on systemic health has been, and is being established. The oral microbiome, in turn, can be altered by local and systemic diseases and conditions. Gastroesophageal reflux disease (GERD), has been associated with increased acidity in the oral cavity resulting in dental erosion, and controversially a reduced risk of periodontal disease. We hypothesized that presence of GERD was linked to a modified microbial profile in untreated GERD patients and that the use of proton pump inhibitor (PPI) drugs: potent disruptors of gut microbiome, in GERD patients might result in a salivary microbiome that is further distinct. Untreated GERD patients showed multiple differences in salivary microbiome as compared to healthy controls. Taxa found at lower levels related to the presence of GERD not treated by PPI included: Prevotella melaninogenica, Prevotella pallens, Leptotrichia, and Solobacterium moorei and thirteen others. In contrast, GERD patients chronically using PPI showed minimal differences in salivary taxa compared to healthy controls not using PPI.

Figure 1

Box plot of (a) Chao1 index of control, GERD patients not using PPI, and GERD patients using PPI. Comparison of the control to GERD patients not using PPI, p < 0.302, and the control comparison to GERD using PPI, p < 0.513; and (b) Shannon index in controls versus GERD patients not using PPI, p < 0.330 and versus GERD using PPI, p < 0.571. Principal coordinate analysis (PCoA) of saliva microbiome profiles of (c) all 3 groups; (d) negative controls versus GERD patient not using PPI; and (e) negative controls versus GERD patients using PPI reveal some differences in microbiota community structure in the GERD group not using PPI.

Figure 2

The bar plot reveals the 16 most common species and/or genus subgroups in saliva of the three groups studied (Control, without GERD and not using PPI, GERD, GERD patients not using PPI, and GERD + PPI, GERD patients using PPI) and allows comparison of relative taxa proportions.

Figure 3

Differentially abundant species in saliva of GERD patients not using PPI versus negative controls without GERD and not using PPI. Shown are the 17 taxa that showed changes in relative abundance at FDR < 0.05 in separate analyses V3 16S rDNA. Bars represent relative abundance in the two groups.