VSL#3® May Reduce Abdominal Pain and Bloating in Ulcerative Colitis Remission with IBS-like Symptoms: An Exploratory Randomized, Double-Blind Placebo-Controlled Trial

Background: Irritable bowel syndrome (IBS)-like symptoms are common in patients with ulcerative colitis (UC) in sustained clinical and endoscopic remission and are associated with impaired quality of life. Evidence for targeted treatments in this setting remains limited. Objective: To evaluate the efficacy of the multistrain probiotic VSL#3® in patients with UC in stable remission and IBS-like symptoms. Methods: In this randomized, double-blind, explorative, placebo-controlled trial, adults with UC in stable remission for ≥6 months and Rome IV C1 or C4 symptoms received VSL#3® 450 billion colony-forming units or placebo twice daily for 8 weeks. The primary endpoint was symptom relief at week 8 assessed by the 5-point Subject’s Global Assessment of Relief scale. Secondary endpoints included Irritable Bowel Syndrome Symptom Severity Scale scores (IBS-SSS), bowel habits, biochemical remission assessed through fecal calprotectin, IBS-QoL, and IBDQ. Results: Fifty-five patients were randomized. The primary endpoint did not differ significantly between groups. Between-group differences in IBS-SSS total score were not statistically significant at week 8; however, numerically greater and directionally consistent reductions in symptom severity and abdominal pain were observed with VSL#3® across visits, persisting at follow-up. In exploratory subgroup analyses, restricted to patients with higher abdominal pain and bloating scores at baseline, significant intragroup improvements in abdominal pain and bloating were observed with VSL#3® but not with placebo. Quality of life improvements were numerically greater and more sustained with VSL#3®. Conclusions: Within the limitations of the small sample size, these results show a signal of benefit in the quality of life of UC patients with IBS-like symptoms and suggest a potential complementary role for VSL#3® in symptom-oriented management, particularly for abdominal pain and bloating. Larger, adequately powered randomized trials are warranted to confirm these exploratory findings.