Using 16S rRNA Gene Sequencing Analysis Intestinal Microbiota in Constipation Patients

Characterization of Intestinal Microbiota in Constipation Patients: Using 16S rRNA Gene Sequencing Analysis

Constipation is a frequent, chronic gastroenterological problem that has many varied symptoms and thus has several clinical definitions. According to the Rome III criteria for chronic constipation, almost 16% of all adults are affected by chronic constipation worldwide, and it is more prevalent and symptomatic in women and elderly people. Slow transit constipation (STC) is the major category and is characterized by a decreased rate of colonic transit.

Recently, many researchers have focused on the relationship between intestinal microbiota and constipation and have demonstrated that intestinal microbiota contribute to the pathophysiology of functional gastrointestinal disorders.

Thus, there is a need for an improved understanding of gut microbiota composition in constipation patients and for the potential role played by the gut microbiota in the etiology of STC.To achieve this goal the investigators characterized and compared the intestinal microbiota among carefully selected patients with constipation that were clinically categorized based on Rome III criteria, and healthy controls using high throughput pyrosequencing of the 16S rRNA gene and a conservative approach to detect quantitative changes in the relative abundances of taxa.

Inclusion Criteria:

1. Chronic constipation according to Rome III criteria, defined as two or fewer spontaneous, complete bowel movements (SCBMs) per week for a minimum of 6 months;
2. Age > 18 years;
3. BMI: 18.5-25 kg/m2;
4. Slow colonic transit confirmed by colonic transit test (colonic transit time (CTT) > 48 hours);
5. Normal anorectal manometry, with no evidence of dyssynergia and confirmed ability to expel rectal balloon;
6. No radiographic evidence of functional (i.e. pelvic floor dyssynergia) or anatomical (i.e. significant rectocele and intussusception) impediment to the expulsion of the radio-opaque contrast;
7. Disease duration > 1 year;
8. Traditional treatment with dietary modification, laxatives (including osmotic and stimulant laxatives), and biofeedback tried over the past 6 months without success;

Exclusion Criteria:

1. Bowel constipation due to innate factor (i.e. megacolon) or secondary interventions (i.e. drugs, endocrine, metabolic, neurologic or psychologic disorders);
2. History or evidence of gastrointestinal diseases (i.e. obstruction, cancer, inflammatory bowel diseases) ;
3. Previous abdominal surgery, except cholecystectomy, appendicectomy, tubal ligation and cesarean section;
4. Previous proctological or perianal surgery;
5. A constipation condition meeting the Rome III criteria for IBS or functional abdominal pain syndrome;
6. Pregnant or breast-feeding women;
7. Infection with enteric pathogen;
8. Usage of probiotics, prebiotics and/or synbiotics within the last month;
9. Usage of antibiotics and/or PPIs within the last 3 months;
10. Smoking or alcohol addiction within the last 3 months;