Table 1 Characteristics of the participants and differences in the composition of gut microbiota between groups

Age (in years)

42.20 ± 15.05

43.45 ± 12.07

41.85 ± 14.15

42.19 ± 13.89

Female sex

13 (65.0%)

13 (65.0%)

13 (65.0%)

39 (65.0%)

Years of formal education**

 0–10

4 (20.0%)

13 (65.0%)

3 (15.0%)

20 (33.3%)

 > 10

16 (80.0%)

7 (35.0%)

17 (85.0%)

40 (66.7%)

Diabetes duration (in years)

16.20 ± 12.56

20.75 ± 13.09

–

–

 Body-Mass-Index (BMI)**

23.76 ± 2.65

27.15 ± 4.18

24.19 ± 2.72

25.03 ± 3.55

 Smoking (yes)*

2 (10.0%)

6 (30.0%)

1 (5.0%)

9 (15.0%)

Dietary habits

 No special diet

18 (90.0%)

14 (70.0%)

17 (85.0%)

49 (81.7%)

 Vegetarian

2 (10.0%)

2 (10.0%)

2 (10.0%)

6 (10.0%)

 Vegan

0 (0.0%)

0 (0.0%)

0 (0.0%)

0 (0.0%)

 Other diets

0 (0.0%)

4 (20.0%)

1 (5.0%)

5 (8.3%)

Contraceptives (yes)

4 (20.0%)

2 (10.0%)

4 (20.0%)

10 (16.7%)

 Further somatic diseases (yes)**

13 (65.0%)

18 (90.0%)

9 (40.0%)

40 (66.7%)

 Arterial hypertension

4 (20.0%)

4 (20.0%)

4 (20.0%)

12 (20.0%)

 Thyroid diseases**

8 (40.0%)

11 (55.0%)

2 (10.0%)

21 (35.0%)

 Hypercholesterolemia

4 (20.0%)

4 (20.0%)

0 (0.0%)

8 (13.3%)

High-sensitivity C-reactive protein

(hs-CRP (mg/dl))

1.59 ± 2.70

2.13 ± 2.66

2.28 ± 3.88

2.00 ± 3.11

Major depression (Mini-DIPS)

 Single episode

–

5 (25.0%)

–

–

 Recurrent episodes

–

15 (75.0%)

–

–

Severity of depression

(PHQ-9, range 0–27)***

6.05 ± 3.75

14.15 ± 3.54

1.80 ± 1.24

7.33 ± 5.98

TICS-SSCS (range 0–48)***

13.25 ± 9.78

27.80 ± 7.04

8.15 ± 4.66

16.40 ± 11.15

PAID sum score (range 0–100)***

20.55 ± 17.28

41.81 ± 15.31

–

–

 Number of species***

747.55 ± 44.30

737.75 ± 55.96

647.00 ± 83.21

711.85 ± 76.59

 Shannon index***

4.59 ± 0.20

4.61 ± 0.22

4.18 ± 0.45

4.47 ± 0.36

 ACE‡

807.17 ± 46.82

800.60 ± 59.09

711.60 ± 86.24

774.16 ± 77.90

 CHAO1*

788.59 ± 44.98

785.42 ± 61.22

702.20 ± 90.01

759.70 ± 77.49

 Phyla

  Firmicutes

   Numbers

   Relative abundance

41,950 ± 7755

0.39 ± 0.07

44,022 ± 9014

0.41 ± 0.08

37,190 ± 7583

0.34 ± 0.07

41,120 ± 8507

0.38 ± 0.08

  Bacteroidetes

   Numbers

   Relative abundance

56,430 ± 8806

0.52 ± 0.08

52,814 ± 8981

0.49 ± 0.08

59,305 ± 8434

0.55 ± 0.08

56,130 ± 9002

0.52 ± 0.08

  Actinobacteria

   Numbers

   Relative abundance

383 ± 345

0.0035 ± 0.0032

446 ± 220

0.0041 ± 0.0020

544 ± 294

0.0063 ± 0.0027

456 ± 293

0.0042 ± 0.0027

 Orders

  Lactobacillales

  Numbers

  Relative abundance

93 ± 58

9e-4 ± 5e-4

117 ± 139

1e-3 ± 1.2e-3

1023 ± 971

9e-3 ± 9e-3

401 ± 698

4e-3 ± 6e-3

 Families

  Veillonellaceae (Phylum Firmicutes)*

   Numbers

   Relative abundance

934 ± 569

0.006 ± 0.004

2647 ± 2228

0.02 ± 0.01

1770 ± 2487

0.01 ± 0.02

1784 ± 2039

0.01 ± 0.01

  Christensenellaceae (Phylum Firmicutes)***

   Numbers

   Relative abundance

2268 ± 940

0.01 ± 0.006

1935 ± 949

0.01 ± 0.006

834 ± 799

0.005 ± 0.005

1693 ± 1082

0.01 ± 0.007

  Lactobacillaceae (Phylum Firmicutes)***

   Numbers

   Relative abundance

19 ± 11

0.0001 ± 0.00007

55 ± 177

0.0003 ± 0.001

741 ± 721

0.005 ± 0.004

264 ± 531

0.001 ± 0.003

  Leuconostocaceae (Phylum Firmicutes)***

   Numbers

   Relative abundance

0.35 ± 1

0.000002 ± 0.000006

1,6 ± 3.7

0.00001 ± 0.00002

288 ± 493

0.002 ± 0.003

93 ± 306

0.0006 ± 0.002

  Succinivibrionaceae (Phylum Proteobacteria)***

   Numbers

   Relative abundance

1668 ± 3551

0.01 ± 0.02

3326 ± 5454

0.02 ± 0.03

75 ± 326

0.0005 ± 0.003

1717 ± 3960

0.01 ± 0.02

  Rhodospirillaceae (Phylum Proteobacteria)*

   Numbers

   Relative abundance

1995 ± 1585

0.01 ± 0.01

1998 ± 1494

0.01 ± 0.01

928 ± 1632

0.005 ± 0.007

1652 ± 1623

0.01 ± 0.01