Table 1 Baseline characteristics of study patients

Sex (female: male)

15:9

14:11

0.644

Age (years)

41.8 ± 12.3

47.5 ± 13.9

0.131

Body mass index (kg/m²)

23.5 ± 2.5

24.2 ± 3.4

0.441

Marital status (single or divorced: married)

3:21

4:21

1.000

Place of residence (suburban area: urban area)

16:8

21:4

0.158

Drinking water (tap water: well water)

364:6

365:5

0.761

Style of dining (dining at home: dining out)

20:4

22:3

0.953

Education status (Junior high school and below: high school: college or more)

9:8:7

10:10:5

0.745

Smoking (yes: no)

21:3

19:6

0.503

Drinking (yes: no)

23:1

21:4

0.370

Digestive Symptoms

18(75.0%)

15(60.0%)

0.263

 Abdominal pain

10(41.7%)

6(24.0%)

0.187

 Heartburn

1(4.2%)

2(8.0%)

1.000

 Acid reflux

7(29.2%)

3(12.0%)

0.256

 Abdominal distension

5(20.8%)

6(24.0%)

0.791

 Belching

3(12.5%)

2(8.0%)

0.962

Endoscopy diagnosis

 Superficial gastritis

8(33.3%)

8(32.0%)

0.921

 Erosive/Hemorrhagic gastritis

16(66.7%)

14(56.0%)

0.444

 Atrophic gastritis/Intestinal metaplasia

3(12.5%)

4(16.0%)

1.000

 Gastric polyp

1(4.2%)

3(12.0%)

0.632

Family history of gastric carcinoma

2(8.3%)

0(0.0%)

0.452

 Chronic disease history

3(12.5%)

3(12.0%)

1.000

 Hypertension

1(4.2%)

1(4.0%)

1.000

 Diabetes mellitus

2(8.3%)

0(0.0%)

0.452

 Hyperlipidemia

1(4.2%)

2(8.0%)

1.000

Long-term medication history

2(8.3%)

1(4.0%)

0.971

 Antihypertensive drugs

1(4.2%)

1(4.0%)

1.000

 Hypoglycemic agents

1(4.2%)

0(0.0%)

0.984

History of antibiotics use in two years

13(54.2%)

11(44.0%)

0.670

 Penicillin

12(50.0%)

8(32.0%)

0.200

 Cephalosporin

9(37.5%)

6(24.0%)

0.305

 Ofloxacin

3(12.5%)

0(0.0%)

0.632

 Metronidazole/ tinidazole

1(4.2%)

1(4.0%)

1.000