The oral mucosal microbiome in children with Crohn’s disease exhibits reduced biodiversity compared to healthy children, revealed by 16s profiling

Abstract

The oral microbiome was examined in a cohort of treatment naïve children diagnosed with Crohn’s disease (n=27, CD) or ulcerative colitis (n=6, UC). A cohort of 28 children were grouped as a healthy control (HC) group. Bacterial DNA was extracted from tongue and buccal swabs and the V1-V2 region of the 16s gene was amplified and sequenced using the MiSeq. Sequences were analysed with the Mothur pipeline.Reduced biodiversity of the tongue was indicated by differences in the inverse Simpson’s index for both sites (CD tongue=9.39; HC=12.87). Analysis of species richness by rarefaction showed a significant reduction in species richness in CD tongue samples compared to HC tongue samples. Analysis of community structure and membership using AMOVA showed that the populations on HC and CD tongues were significantly different (P <0.001). LEfSe analysis identified 20 OTUs that were significantly enriched on the tongues of healthy children including H. parainfluenzae, N. flavescens, F. periodonticum, Streptococcus sp., Porphyromonas sp., Actinomyces sp. Children with Crohn’s have an altered microflora that may contribute to their oral health problems. These data could potentially be used to diagnose a patients overall gastrointestinal health.

Ulcerative Colitis Seems to Imply Oral Microbiome Dysbiosis

“…As expected, we found an important interindividual variability between the salivary microbial profiles of the participants of the study. However, our results indicated a decrease in alpha diversity indices in UC patients, in agreement with the observations of Zhang et al during the active phase of CD, and the results of Docktor et al and Elmaghrawy et al in pediatric cohorts [2,13,15]. In the same line, Lucas López et al described a decrease in alpha diversity indices in the gut microbiome of UC patients [3], so it can be hypothesized that UC could be associated with a loss of both gut and oral bacterial diversity.…”

“…This general inflammatory state associated with the IBD condition could affect the oral mucosa and lead to an oral dysbiosis that could contribute to the worsening of the inflammatory state and play a crucial role in the oral manifestations of these patients [5]. However, only a few studies have focused on analyzing changes in the oral microbiome of IBD patientsmost of them performed in the CD phenotype [9][10][11][12][13][14][15]. Regarding UC, most of the data come from pediatric populations or animal models [2,3,[16][17][18], and only one study has focused on the analysis of the oral microbiome of a specific UC cohort, performed in a murine model of colitis [16].…”