Mucosa-Associated Microbiota in the Gastrointestinal Tract of Healthy Japanese Subjects.

BACKGROUND

The importance of microbiota infiltrating the gut mucus layer has been reported in the pathogenesis of various gastrointestinal and systemic diseases. However, little is known about the mucosa-associated microbiota (MAM) in healthy subjects. The present study aimed to clarify the characteristics of the gastrointestinal MAM from the oral cavity to the rectum in healthy Japanese subjects.

METHODS

Seventeen healthy subjects were enrolled. In this study, 5 mucosa samples from the upper gut (intraoral, mid-esophagus, gastric corpus, gastric antrum, and duodenum) and 7 from the lower gut (ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum) were collected with a brush under endoscopic examination. MAM profiles of each sample were analyzed by 16S-rRNA V3-V4 gene sequences.

RESULTS

Collecting mucosa samples by brushing provided sufficient material for MAM profiling without causing adverse effects. The upper and lower gut MAM profiles differed significantly (p < 0.0001). In the upper and lower gut, the intra- and inter-individual MAM profiles were significantly different (p = 0.0008 and p < 0.0001 respectively).

CONCLUSIONS

The MAM profiles of the upper and lower gut were significantly different. The inter-individual differences in MAM were remarkable compared to the intra-individual differences.