Effects of Spirulina (Arthrospira) platensis supplementation on intestinal permeability, antioxidant and inflammatory markers, quality of life and disease severity in patients with constipated-predominant irritable bowel syndrome: a randomized double-blind, placebo-controlled trial

Abstract

Background Irritable bowel syndrome (IBS) is a chronic, functional gastrointestinal disorder (FGID) which is characterized by chronic pain related to defecation and alteration in GI motility. Recent findings indicated that intestinal barrier dysfunction, hyperpermeability, oxidative stress, and inflammation play a role in IBS pathogenesis. Considering the antioxidant properties of Spirulina (Arthrospira) platensis (SP), this study aimed to investigate the effect of SP supplementation on Quality of life (QoL), disease severity, antioxidant capacity, oxidative stress index and intestinal permeability in constipation-dominant IBS (IBS-C) patients. Methods This study was a parallel randomized, double-blind, placebo-controlled clinical trial involving 60 IBS-C patients aged 18-50 years. The patients were given either 1 g SP (two capsules/day; each capsule contained 500 mg of SP) or placebo for 12 weeks. IBS-QoL, IBS-Severity system score (IBS-SSS), plasma total antioxidant capacity (TAC), malondialdehyde (MDA), and zonulin levels were measured at baseline and the end of the intervention. Univariate comparison and intention-to-treat (ITT) were used for analysis. Results SP supplementation compared to placebo resulted in a significant increase in QoL score (7.05 +/- 2.02 vs. - 1.57 +/- 2.49; p = 0.008), TAC (145.27 +/- 30.77 vs. -54.90 +/- 45.72; p < 0.001) and decrease in IBS-SSS (-32.17 +/- 8.96 vs. 1.07 +/- 8.49; p = 0.002), MDA level (- 11.61 +/- 2.57 vs. - 2.00 +/- 2.24; p < 0.001) and zonulin level (- 0.22 +/- 0.05 vs. 0.12 +/- 0.07; p = 0.001). These results remained significant after adjusting for baseline values. Conclusions SP supplementation demonstrated a promising effect in the management of IBS. However, larger trials with a dose-dependent approach in IBS-C and other subtypes of IBS are warranted.