Laparoscopic cholecystectomy (LC) is widely used in the gallbladder stone, gallbladder polyp, gallbladder cancer and other diseases. Some of the patients would develop diarrhea after surgery, and studies have reported an increased risk of colorectal cancer after LC. The aim of the present study was to examine the effects of LC on the gut microbiota.

Inclusion Criteria:

1. Gallbladder polyps diameter mm >10;
2. The history of the symptoms of patients with gallbladder stones, there was no history of acute attack in the past month;
3. Age <70 years old;
4. No serious systemic diseases such as diabetes, hypertension, heart disease, lung disease and so on/American anesthesia Association (ASA) grade I or II;
5. BMI<30;
6. Families have better care and observation, and away from the hospital within 1 hours; patients and their families understand the process of ambulatory surgery (24 hours) and the pros and cons.

Exclusion Criteria:

1. Less than 18 years old;
2. With previous gastric surgery ;
3. Major systemic diseases ;
4. Pregnancy or lactation;
5. The use of antibiotics or yogurt within 2 months before the study.