Preclinical and Limited Clinical Evidence for Spirulina in Ulcerative Colitis: A Systematic Review and Meta-analysis

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract. This study aimed to systematically review available animal and clinical studies on the effects of spirulina (Arthrospira platensis), a natural anti-inflammatory and antioxidant agent, on the condition of UC.

We conducted a systematic search in the PubMed, Scopus, Web of Science, and Embase databases for studies published from 1980 to April 2024. Experimental studies involving animal (mammalian) models or patients with UC were included. Pooled effect sizes were reported as mean differences (MD) or standardized mean differences (SMD) and 95% confidence intervals (CIs).

A total of 1,321 documents were identified through the systematic search. Following screening, 16 animal studies and 3 randomized controlled trials (RCTs), derived from one trial, were included. The beneficial effects of spirulina on body weight (MD=8.61, 95% CI=2.98 to 14.25, I²: 99.78%), clinical features (SMD=-2.39, 95% CI=-2.95 to -1.83, I²: 5.89%), colon length (MD=1.25, 95% CI=0.59 to 1.91, I²: 95.80%), oxidative stress, inflammatory markers, and gut microbiota in animal models of UC were reported. However, no effect of spirulina on disease activity was reported in the only RCT conducted. Nonetheless, improvements in quality of life, oxidative stress, sleep disturbances, stress scores, and anemia were noted.

Available animal studies suggest beneficial effects of spirulina on UC; however, the limited number of RCTs precludes definitive conclusions.