Significant differences in relative abundances of bacterial families composing the gastric mucosa-associated microbiota of 24 patients, who were stratified according to positive or negative H. pylori (HP) status (which was determined based on the results of conventional testing methods, as specified in the text) (A) and the presence or absence of treatment with proton pump inhibitor (PPI) drugs (B). (C) Comparison of family abundances among patient groups, which were defined according to both of the above-mentioned conditions. The middle line in the box plot represents the median value, and the box is drawn from 25% to 75% quartiles. Whiskers show minimum and maximum values, and the ends of the whiskers represent the nonoutlier range. An asterisk indicates a statistically significant difference after the P value of each comparison by t test analysis was corrected for multiple testing (FDR-adjusted Q = <0.05). In panel C, a nonsignificant (NS) differences (FDR-adjusted Q = >0.05) between each comparison is also indicated.