Fig. 3. Effects of BL-99 treatment on the fecal and serum metabolites in patients with functional dyspepsia.

a Changes in fecal metabolites from the baseline to the post-treatment period. Heatmap shows the changes in the mean relative abundance of metabolites from the baseline to the post-treatment period in samples within each group. For each species in each group, the significance levels of the comparisons between the changes in one group relative to the other three groups are calculated using the two-side Wilcoxon rank-sum test and denoted as follows: ns non-significant; *p < 0.05; **p < 0.01 (non-significant data in all comparisons are omitted). Boxplot showing the concentrations of short-chain fatty acids (SCFAs) in the fecal (b) and serum (c) samples at baseline and post-treatment period. Boxes represent the interquartile range between the first and third quartiles and the median (internal line). Whiskers denote the lowest and highest values within 1.5 times the range of the first and third quartiles, respectively. Dots represent outlier samples beyond the whiskers. p values are calculated using the two-side Wilcoxon rank-sum test. d The explained variations of fecal and serum SCFAs and clinical parameters by the gut microbiome at the post-treatment time point. Bar plots indicate the explained variation (effect size R²) of each metabolite or parameter. e Network view of gut species, fecal and serum SCFAs, and clinical parameters. Circles represent the SCFAs or clinical parameters, while the surrounding connected triangles represent the gut species that had the highest contributions to the SCFAs or parameters and were used in the random forest models. Patients in the placebo (n = 45), positive_control (n = 48), BL-99_low (n = 47), and BL-99_high (n = 45) groups were administered with maltodextrin (2 g/day), rabeprazole (10 mg/day), low-dose BL-99 (1 × 10¹⁰ CFU/day), and high-dose BL-99 (5 × 10¹⁰ CFU/day), respectively. Source data are provided as a Source Data file.