Fig. 6: Reanalysis of existing longitudinal gut microbiome studies with GMWI2.

a Changes in GMWI2 in patients with irritable bowel syndrome observed six months (6-mo) after undergoing fecal microbiota transplantation. Only subjects experiencing symptom relief (“Effect” group) displayed a significant increase in GMWI2 (P = 0.039, one-sided Wilcoxon signed-rank test). n, number of FMT donor samples (17 total samples from two healthy donors) or number of FMT recipients. b GMWI2 scores for dietary groups (EEN, Vegan, and Omnivore) at baseline and at the first 5–6 days of dietary intervention. The EEN group showed significant changes in GMWI2, with values significantly decreased by day 2 and thereafter (P < 0.05, two-sided Wilcoxon signed-rank test). No significant change in GMWI2 was observed for the Omnivore and Vegan groups compared to baseline. n, number of unique individuals who each provided a stool sample per time point. c GMWI2, Shannon Index, and species richness before and after antibiotic intervention. Despite recovery in Shannon Index and species richness at day 42 and day 180, respectively, GMWI2 remained significantly lower compared to day 0, suggesting incomplete gut microbiome recovery even after ~6 months (P < 0.05, two-sided Wilcoxon signed-rank test). n, number of unique individuals who each provided a stool sample per time point. d GMWI2 of gut microbial communities after 24-h in vitro fecal fermentation with five different prebiotic oligosaccharides. The experiment was conducted in triplicates for each study group. The height of the bars represents the mean GMWI2 (numbers inside the solid bars), and error bars indicate the standard deviation from the mean. Points represent individual triplicate samples. Different small letters above the bars denote groups with significant differences in GMWI2 as determined by Tukey’s HSD test (P < 0.05). Control groups: NS0, no substrate addition at 0 h; NS24, no substrate for 24 h. Prebiotic groups: FS24 fructooligosaccharide, IN24 inulin, GS24 galactooligosaccharide, XS24 xylooligosaccharide, FL24 2’-fucosyllactose. Standard box-and-whisker plots (i.e., center line, median; box limits, upper and lower quartiles; whiskers, 1.5× interquartile range; points, individual GMWI2 scores or α-diversity values) are used to depict groups of numerical data in (a–c).