Table 3 Univariate and multivariate linear regression analyses of the pre-treatment Shannon diversity index and clinical characteristics in the total population (N = 28)

All patients

28

3.5 ± 0.7

Sex

Male

14

3.9 ± 0.6

ref

Female

14

3.2 ± 0.6

-0.6 (-1.1, -0.2)

0.01

-0.8 (-1.6, 0.1)

0.08

BMI

Normal/underweight

16

3.5 ± 0.7

ref

Overweight/obese

12

3.5 ± 0.7

-0.1 (-0.5, 0.5)

0.96

0.5 (-0.3, 1.2)

0.24

Smoking status

Never-smoker

20

3.5 ± 0.7

ref

Ever-smoker

8

3.7 ± 0.7

0.3 (-0.3, 0.9)

0.33

-0.8 (-2.0, 0.4)

0.20

Antibiotics

Yes

3

4.0 ± 0.6

0.5 (-0.3, 1.3)

0.23

0.8 (-0.2, 1.7)

0.11

No

25

3.5 ± 0.7

ref

PPIs

Yes

5

3.5 ± 0.8

-0.007 (-0.7, 0.7)

0.98

-0.6 (-1.4, 0.3)

0.19

No

23

3.5 ± 0.7

ref

Laxatives

Yes

8

3.7 ± 0.5

0.2 (-0.4, 0.8)

0.51

-0.2 (-0.9, 0.5)

0.62

No

20

3.5 ± 0.7

ref

Prebiotics/Prebiotics

Yes

8

3.4 ± 0.8

-0.2 (-0.8, 0.4)

0.54

0.0 (-0.7, 0.6)

0.90

No

20

3.6 ± 0.6

ref

Supplement

Yes

4

3.4 ± 1.0

-0.1 (-0.9, 0.6)

0.70

No

24

3.6 ± 0.6

ref

Lung/pleural metastasis

Yes

17

3.5 ± 0.6

-0.2 (-0.7, 0.4)

0.54

No

11

3.6 ± 0.7

ref

Brain metastasis

Yes

5

3.3 ± 0.8

-0.3 (-1.0, 0.4)

0.36

No

23

3.6 ± 0.6

ref

Albumin

< 3.2 g/dL

12

3.4 ± 0.6

ref

≥ 3.2 g/dL

16

3.6 ± 0.7

0.2 (-0.4, 0.7)

0.50

Cohort

EGFR-WT

13

3.3 ± 0.7

ref

EGFR-mutant

15

3.8 ± 0.6

0.5 (0.1, 1.0)

0.03

0.6 (0.0, 1.2)

0.05