To investigate the clinical effects of probiotics in relieving chronic constipation in adults, and evaluate the improvement of symptoms in patients with constipation as well as their impacts on gastrointestinal function and gut microbiota.

Inclusion Criteria:

(1) Chinese adults aged 18-70 years who meet the Rome IV diagnostic criteria for chronic constipation (duration of at least 6 months, with less than three passing stools per week and/or Bristol Stool Scale types 1 and 2); (2) The patient rarely experiences diarrhea without using laxatives; (3) The criteria for irritable bowel syndrome were insufffcient ; (4) patients that could complete the study according to the requirements of the trial protocol; (5) participants (including male subjects) who have no family planning within 14 days prior to screening and voluntarily take effective contraceptive measures within 6 months after the end of the trial; (6) Patients capable of understanding the clinical study and willing to comply with the study requirements and procedures; (7) Subjects who have signed the informed consent form. Only those who meet all the above conditions can be selected for the study.

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Exclusion Criteria:

1. Use of probiotics, prebiotics, or antibiotics within two weeks prior to enrollment and throughout the intervention period;
2. Regular use of a high-fiber diet, as measured by the recommended food score (RFS);
3. Regular use of medications affecting bowel habits, such as irritable bowel syndrome, functional bloating, and functional diarrhea;
4. Currently have, or have had in the past 2 years, any gastrointestinal conditions such as: Crohn's disease, celiac disease, ulcerative colitis, malignant tumor of the colon;
5. Medical history of cardiovascular, liver, or renal diseases; alcoholics;
6. Hypersensitivity to probiotics or the ingredients used in this study;
7. Pregnancy or breastfeeding;
8. Participation in another clinical trial in the 3 months before enrollment. -