Table 3 The variability of the metabolites in faecal samples of healthy subjects collected over three consecutive days expressed as measured with coefficient of variation and the inter-class correlation coefficient.

Positive features

(total n = 4517)

Intra-individual

Subject 1

39.1 ± 30.5

40.1 ± 4.44

47.4

49.1 ± 6.80

Subject 2

46.3 ± 37.0

41.6

Subject 3

38.8 ± 32.8

52.2

Subject 4

44.1 ± 32.2

41.0

Subject 5

40.0 ± 35.1

51.3

Subject 6

36.1 ± 29.4

53.0

Subject 7

42.5 ± 31.3

42.9

Subject 8

33.4 ± 29.4

60.9

Subject 9

45.7 ± 35.5

43.8

Subject 10

35.4 ± 30.5

56.5

Inter-individual

Timepoint 1

79.3 ± 51.9

76.9 ± 2.18

17.3

18.0 ± 1.13

Timepoint 2

76.2 ± 48.6

17.4

Timepoint 3

75.1 ± 51.9

19.3

Intra-class correlation coefficient

% of features

Good or excellent test-retest reliability (ICCs 0.75-1.0)

15.2

Moderate test-retest reliability (ICCs 0.50–0.75)

37.0

Poor test-retest reliability (ICCs < 0.50)

47.8

Negative features

(total n = 1154)

Variability

Mean CV% of detected features ± SD

Mean CV% of features ± SD

% of features with < 30 CV%

Mean % of features with < 30 CV% ± SD

Intra-individual

Subject 1

40.9 ± 30.1

41.7 ± 5.43

43.3

47.6 ± 7.64

Subject 2

49.1 ± 38.0

42.9

Subject 3

37.0 ± 30.4

53.5

Subject 4

44.3 ± 30.6

39.5

Subject 5

47.9 ± 38.6

43.2

Subject 6

39.3 ± 29.9

49.9

Subject 7

46.2 ± 34.9

40.9

Subject 8

32.3 ± 28.2

62.7

Subject 9

43.1 ± 31.8

43.6

Subject 10

36.5 ± 31.7

56.0

Inter-individual

Timepoint 1

90.9 ± 56.7

89.0 ± 3.52

8.67

8.43 ± 1.91

Timepoint 2

91.1 ± 55.3

6.41

Timepoint 3

84.9 ± 55.1

10.2

Intra-class correlation coefficient

% of features

Good or excellent test-retest reliability (ICCs 0.75-1.0)

24.1

Moderate test-retest reliability (ICCs 0.50–0.75)

37.3

Poor test-retest reliability (ICCs < 0.50)

38.7