Lower impact of vonoprazan–amoxicillin dual therapy on gut microbiota for Helicobacter pylori eradication

Background and Aim: Helicobacter pylori eradication can disrupt the gut microbiome. Here, we investigated the short-term impact of minimum antibiotic treatment—a 7-day vonoprazan and low-dose amoxicillin regimen (VA-dual therapy)—on gut microbiota and compared it with that of vonoprazan-based triple therapy (VAC-triple therapy). Methods: Fifty-nine patients with H. pylori infection were recruited (UMIN000034140) from March to May 2019 and randomly assigned to the VAC-triple therapy or VA-dual therapy groups, according to the first-line H. pylori treatment received. Fecal samples were collected before treatment initiation and 1 and 8 weeks after eradication therapy completion. The composition ratios of the bacterial taxa and the alpha and beta diversities were evaluated in both groups via polymerase chain reaction amplification of the V3–V4 region of the 16S rRNA gene and sequencing using the MiSeq system. Results: Nineteen patients were assigned to the VA-dual group and 24 to the VAC-triple group. Compared with baseline, the alpha diversity reduced significantly 1 and 8 weeks after VAC-triple therapy. However, for VA-dual therapy, the alpha diversities at 1 and 8 weeks after the treatment did not change significantly compared with those at baseline. Additionally, the beta diversity differed significantly between baseline and 1 and 8 weeks after VAC-triple therapy. VAC-triple therapy led to significant alteration in the relative abundance of Actinobacteria at the phylum level and Collinsella, Blautia, and Streptococcus at the genus level. Conclusions: Compared with VAC-triple therapy, VA-dual therapy induced minimal changes in the diversity and relative abundance of gut microbiota.