Table 1: IBS symptom scores, the relative proportion of the components of the fecal microbiota, and the diversity indexes in the four parts of the trial. Results are given as mean (SD).

VariablesRun-in period1st treatment periodWashout period2nd treatment period

IBS symptom score (range 0–15)
 Active treatment 1st period6.17 (1.07)6.18 (1.83)6.58 (2.55)5.14 (2.12)
 Placebo treatment 1st period6.26 (2.20)5.61 (1.31)5.80 (2.61)6.77 (1.85)
Bacteroides
 Active treatment 1st period0.07 (0.05)0.07 (0.06)0.07 (0.07)0.12 (0.10)
 Placebo treatment 1st period0.19 (0.17)0.21 (0.16)0.16 (0.12)0.14 (0.10)
Faecalibacterium
 Active treatment 1st period0.54 (0.23)0.53 (0.21)0.47 (0.26)0.46 (0.26)
 Placebo treatment 1st period0.44 (0.23)0.56 (0.21)0.54 (0.15)0.61 (0.25)
Lachnospiraceae
 Active treatment 1st period0.38 (0.22)0.40 (0.17)0.46 (0.23)0.42 (0.24)
 Placebo treatment 1st period0.37 (0.21)0.23 (0.14)0.30 (0.16)0.26 (0.18)
“Common” Simpson’s D
 Active treatment 1st period0.46 (0.09)0.48 (0.10)0.46 (0.13)0.48 (0.11)
 Placebo treatment 1st period0.52 (0.20)0.51 (0.23)0.54 (0.12)0.46 (0.18)
“Alternative” Simpson’s D
 Active treatment 1st period321 (382)59 (19)67 (21)28 (10)
 Placebo treatment 1st period921353389
“Alternative” Shannon’s H
 Active treatment 1st period6.42 (0.80)5.86 (0.03)5.73 (0.27)5.47 (0.36)
 Placebo treatment 1st period6.096.425.796.12