Heat map showing fold changes of small metabolic compounds in the three study groups, TB patients, healthy uninfected and latently infected individuals.

Fold changes are relative to the average abundance in the TST– group. Red indicates relative abundance higher than average in the TST– group; blue indicates relative abundance lower than average in the TST– group. Horizontal axis: samples belonging to the three study groups; vertical axis: top 50 compounds selected by variable importance in RF analysis, including compounds that could not be identified, but were strong predictors of sample status. Color bars above the heat map denote study groups: grey, TST–; green, TST+; red, TBactive. See also Figure S2.