Ex Vivo Analysis of the Effect of Endoscopic Premedications on the Microbiota Profile in Gastric Juice.

BACKGROUND AND AIM

Dimethicone (GAS), lidocaine (XYL), and protease (PRO) are commonly used as premedications during esophagogastroduodenoscopy (EGD). However, the effects of these drugs on the gastric microbiota remain unexplored. Therefore, we aimed to investigate the effects of these premedications on gastric juice collected from patients undergoing EGD.

METHODS

Gastric juice was endoscopically aspirated from six patients and divided into six aliquots for in vitro analysis. The samples were mixed with premedications in corresponding treatment sets: GAS, XYL, PRO, MIX (a mixture of GAS, XYL, and PRO), and control (CTL1 and 2; no medication treatment). After extraction of microbial DNA from the treated samples, the 16S rRNA amplicon sequence was analyzed to determine the microbiota profile in terms of (1) the amount of genomic DNA (gDNA), (2) α-diversity indices, Shannon index, number of observed operational taxonomic units (OTUs), and Chao1 index, (3) weighted and unweighted UniFrac distances, and (4) the relative abundance of phyla and genera.

RESULTS

The total amount of extracted gDNA did not significantly differ between the six groups. The α-diversity indices did not significantly differ between treatment groups. Although GAS, PRO, and MIX differed significantly from the technical replicates in the weighted UniFrac distance ( = 0.03 all), no significant difference was observed in the unweighted UniFrac distance. However, significant differences were observed in the relative abundance of several bacterial microbiota at the phylum and genus levels.

CONCLUSIONS

Premedications affect the microbiota profile of specific phylum- and genus-level bacterial groups. University Hospital Medical Information Network Clinical Trials Registry: UMIN-CTR 000040192 and UMIN-CTR 000051289.