Stability of the infant gut microbiota. (A to C) Individual plots depicting the stability of the gut microbiome over time for three children (see figure S9 for plots for all children). All sample pairs from the same child were compared using the Jaccard index and plotted as a function of their age. Child identifiers are colored as Abx− (green, A), low Bacteroides (blue, B), or Abx+ (red, C). (D) Median of stability was calculated for all consecutive samples and plotted for Abx+ and Abx− children. Box boundaries are the 25th and 75th percentiles, and the median is highlighted. P = 3.3 × 10−5, KS-test. Inset shows the estimated variance of measurements for each group (mean + standard error). The median values for subjects presented in panels (A) and (C) are shown as green and red stars, respectively.