Principal Investigator changed his job

This randomized study evaluates the effectiveness of the a probiotic formula, compared with the antibiotic rifaximin, in the treatment of Small Intestinal Bacterial Overgrowth (SIBO) in Irritable Bowel Syndrome (IBS) patients.

Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disease in which recurrent abdominal pain is associated with defecation or a change in bowel habits. Disordered bowel habits are typically present (ie, constipation, diarrhea, or a mix of constipation and diarrhea), as are symptoms of abdominal bloating/distention.

IBS pathophysiology is multifactorial and may include alterations of the gut microbiota, food intolerances and Small Intestinal Bacterial Overgrowth (SIBO). However, SIBO is a distinct entity than IBS, as patients can present SIBO without IBS. SIBO is diagnosed based on objective tests (breath test or microbial culture of duodenal aspirate) while IBS is a functional syndrome, diagnosed on symptoms (Rome-IV criteria).

A probiotic formula composed of strains Pediococcus acidilactici CECT 7483 and Lactobacillus plantarum CECT 7484 and CECT 7485 was previously shown to improve quality of life in patients with IBS.

Rifaximin is a a non-absorbable antibiotic commonly used for the treatment of SIBO.

Inclusion Criteria:

• Patients diagnosed with IBS according to Rome IV criteria (Lacy et al. Gastroenterology 2016) and with SIBO according to North American Consensus (Rezaie et al., Am J Gastroenterol. 2017), providing Informed Consent.

Patients taking set doses of Proton Pump Inhibitors (PPIs) or antispasmodics can be included.

Exclusion Criteria:

• Use of antibiotics in the 4 weeks before study initiation.
• Use of probiotics in the 2 weeks before study initiation.
• Use of loperamide or other prokinetics in the week before study initiation.
• Use of Plantago ovata, lactulose or other laxans in the week before study initiation.
• Use of antidepressants.
• Suspicion or confirmed diagnose of coeliac disease, inflammatory bowel disease (IBD), symptomatic diverticulosis/diverticulitis, or endometriosis.
• Previous intestinal surgery, except appendectomy and herniorrhaphy.
• Short bowel syndrome or pancreatitis.
• Concomitant treatment with immunosuppressors, oncologic disease, severe cardiovascular disease, positive for HIV, hepatitis B virus (HBV) or hepatitis C virus (HCV).
• Other conditions that can interfere with the effect of probiotic.
• Pregnant or lactating women.