Impact of <i>Portulaca oleracea</i> L. extract in patients with irritable bowel syndrome

Background/Aims: Portulaca oleracea is known to have anti-inflammatory and immunoregulatory effects, and also showed positive effect on complete spontaneous bowel movement and bowel symptoms in patients with chronic constipation in a previous study. Thus, we aimed to investigate the impact of P. oleracea in patients with irritable bowel syndrome (IBS). Methods: Patients with IBS defined by ROME IV criteria were enrolled between July 2022 and April 2023. Patients were randomly assigned to P. oleracea or placebo group and took drugs for 8 weeks. Clinical data including gastrointestinal and IBS symptoms, laboratory tests including inflammatory and immunologic laboratory markers, and stool tests including fecal calprotectin and stool microbial analysis were evaluated at the baseline, week 4, and week 8. Results: A total of 108 patients were initially enrolled and 101 patients were finally included in the analysis. There was significant improvement during 8 weeks in P. oleracea group compared to placebo group in the aspect of gastrointestinal and IBS-related bowel symptoms (Gastrointestinal Symptom Rating Scale total score: from 44.1 to 31.7 vs. from 41.4 to 39.9; IBS-Symptom Severity Score total score: from 232.0 to 120.6 vs. from 202.7 to 178.2), especially in the aspect of abdominal pain. Interleukin-6 (IL-6) was significantly decreased during 8 weeks in P. oleracea group, although there was no significant difference between 2 groups. In addition, increase in IL-6 during study period was significantly associated with dysbiosis in stool microbial analysis. There was no significant adverse event. Conclusions: P. oleracea has positive impact in patients with IBS showing improvement of immunologic cytokine and stool microbiome.