Fecal microbiota differences in patients with thoracic cancer who receiving PPIs and/or antibiotics. (a) Heatmap of scaled relative abundances of oral-related bacteria detected in the gut of patients with thoracic cancer. Right box plot indicates comparing total relative abundance of the 29 genera of oral-related bacteria. A Mann-Whitney U test was used to assess statistical differences between indicated two groups. (b) Box plots comparing the relative abundance of the genera typically found in the oral microbiota (Granulicatella, Haemophilus, Actinomyces, Gemella, Rothia, Streptococcus, Atopobium, and Veillonella) are shown. A Mann-Whitney U test was used to assess statistical differences between indicated two groups (* p < .05, ** p < .01, *** p < .001, n.s. not significant). The number of samples in four groups; non-treatment (n = 26), antibiotic use (ATB; n = 19), PPI use (PPI; n = 22), concomitant use of antibiotics and PPIs (ATB+PPI; n = 13).