Constipation is a heterogeneous and multifactorial disease, influenced by a number of different genetic and environmental factors. By applying the standard two-stage GWAS strategy to design and carry out a metagenome-wide association study (MGWAS) to find the relationship between gut microbiota and constipation, to identify disease-associated metagenomic markers.

This study is a two-stage case-control metagenome-wide association study (MGWAS) based on deep next-generation shotgun sequencing of DNA extracted from the stool samples from a total of 50 Chinese constipation patients and healthy controls.

Inclusion Criteria:

1. Chronic constipation according to Rome III criteria;
2. Age ≥ 18 years;
3. BMI: 18.5-25kg/m2;

Exclusion Criteria:

1. Bowel constipation due to innate factor (e.g. megacolon) or secondary interventions (e.g. drugs, endocrine, metabolic, neurologic or psychologic disorders);
2. History or evidence of gastrointestinal diseases (e.g. cancer, inflammatory bowel diseases);
3. Previous abdominal surgery, except cholecystectomy, appendicectomy, tubal ligation and cesarean section;
4. Previous proctological or perianal surgery;
5. Rectal prolapse and/or grade 3-4 internal hemorrhoids according to AGA classification;
6. A constipation condition meeting the Rome III criteria for IBS or functional abdominal pain syndrome;
7. Pregnant or breast-feeding women;
8. Infection with enteric pathogen;
9. Usage of probiotics, prebiotics, antibiotics or PPIs within the last month;
10. Smoking or alcohol addiction within the last 3 months;
11. Uncontrolled hepatic, renal, cardiovascular, respiratory or psychiatric disease;
12. Disease or therapy with drugs (e.g. antidepressants, opioid narcotic analgesics, anticholinergics, calcium antagonists, nitrates, antimuscarinics) that, in the opinion of the investigator, could affect intestinal transit and microbiota.

50 faecal samples were obtained from constipation patients and 50 faecal samples were obtained from healthy volunteers