Comparison of dysenteric and non-dysenteric stool. (A) Genus-level comparison of dysenteric and non-dysenteric diarrheal stool (top) stratified by age; (bottom) stratified by country. (B) Proportional abundance boxplots of Prevotella, Lactobacillus, and Streptococcus in dysenteric and non-dysenteric diarrheal stools by age category. The upper whisker extends from the 75th percentile to the highest value that is within 1.5 * IQR of the hinge, where IQR is the inter-quartile range, or distance between the first and third quartiles. The lower whisker extends from the hinge to the lowest value within 1.5 * IQR of the hinge. Data beyond the end of the whiskers are outliers and are not plotted. Asterisks above the whisker indicate a statistically significant difference (by t-test) between dysenteric and non-dysenteric stools placed in the panel with the more abundant mean. A single asterisk indicates P <0.05; double asterisks indicate P <0.01. Prevotella is significantly associated with non-dysenteric cases overall (P = 0.0003) and in age groups 0 to 6 months (P = 0.01), 12 to 17 months (P = 0.03), and 24 to 59 months (P = 0.001). Lactobacillus is significantly associated with non-dysenteric cases overall (P = 0.0002) and in children 6 to 11 months (0.02) and 12 to 17 months (P = 0.003), while the genus Streptococcus is associated with dysentery overall (P = 0.007), particularly in children aged 12 to 17 months (P = 0.01).