Is VSL#3 (probiotic supplement) effective for treating Irritable Bowel Syndrome (IBS) and bloating?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 8, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

VSL#3 is not specifically recommended for treating Irritable Bowel Syndrome (IBS) and bloating, as the evidence for its effectiveness is limited and inconsistent.

Key Points

  • The American Gastroenterological Association (AGA) suggests that probiotics may be beneficial for patients with pouchitis, but the evidence for IBS is very low quality and inconsistent 1.
  • The British Society of Gastroenterology guidelines suggest that probiotics, as a group, may be an effective treatment for global symptoms and abdominal pain in IBS, but it is not possible to recommend a specific species or strain 1.
  • A technical review found that the majority of evidence for probiotics in IBS comes from single trials with small sample sizes and variable quality, making it difficult to give specific recommendations 1.
  • Some studies suggest that probiotics can have a positive effect on symptoms of IBS, such as bloating and abdominal pain, but the evidence is not strong enough to support a specific recommendation for VSL#3 1.

Probiotics and IBS

  • Probiotics are live microorganisms that can confer a health benefit on the host, and some studies suggest that they can have a positive effect on symptoms of IBS.
  • However, the evidence for probiotics in IBS is limited by the large number of different strains and combinations of strains that have been studied, making it difficult to draw firm conclusions.
  • The AGA and British Society of Gastroenterology guidelines suggest that patients with IBS may want to try probiotics for up to 12 weeks to see if they experience any improvement in symptoms, but emphasize that the evidence is not strong enough to support a specific recommendation for any particular strain or combination of strains 1.

From the Research

Efficacy of VSL#3 in Treating IBS and Bloating

  • The efficacy of VSL#3 in treating Irritable Bowel Syndrome (IBS) and bloating has been investigated in several studies 2, 3, 4, 5, 6.
  • A systematic review and meta-analysis found that VSL#3 was associated with a trend toward improvement in overall response, but no clear evidence of effectiveness for IBS 2.
  • Another study found that Bifidobacterium bifidum, a component of VSL#3, reported the best results in treating IBS symptoms, with a dose of 1 × 10^9 CFU/day for 4 weeks 3.
  • A randomized, double-crossover clinical trial found that VSL#3 and a low-FODMAP diet were equally efficacious in managing IBS symptoms, with no significant difference in median reduction of IBS-SSS scores 4.
  • A double-blind, randomized placebo-controlled trial found that VSL#3 improved specific GSRS-IBS scores in diarrhea-predominant IBS subjects, but did not change the gut microbiota 5.
  • A randomized controlled trial found that VSL#3 reduced flatulence scores and retarded colonic transit in patients with IBS and bloating, but did not alter bowel function 6.

Mechanism of Action

  • The mechanism of action of VSL#3 in treating IBS and bloating is not fully understood, but it is thought to be related to its effects on the gut microbiota and colonic transit 2, 5, 6.
  • One study found that VSL#3 did not change the gut microbiota, suggesting that its mechanism of action may not be directly linked to the microbiota 5.

Dosage and Duration

  • The optimal dosage and duration of VSL#3 treatment for IBS and bloating are not established, but studies have used doses ranging from 1 × 10^9 CFU/day to 2 × 450 billion CFU/day for 4-8 weeks 3, 4, 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.