Efficacy of a curcumin extract (Curcugen™) on gastrointestinal symptoms and intestinal microbiota in adults with self-reported digestive complaints: a randomised, double-blind, placebo-controlled study

BMC Complement Med Ther. 2021 Jan 21;21(1):40. doi: 10.1186/s12906-021-03220-6.


Background: There is preliminary evidence to suggest curcumin can alleviate digestive symptoms in adults with self-reported digestive complaints and irritable bowel syndrome. However, in all these trials, curcumin was used as a component of a multi-herbal combination and there were consistent concerns associated with risk of bias in most studies. The goal of this study was to investigate the effects of a curcumin extract (Curcugen™) on gastrointestinal symptoms, mood, and overall quality of life in adults presenting with self-reported digestive complaints. Moreover, to determine the potential therapeutic mechanisms of action associated with curcumin, its effects on intestinal microbiota and small intestinal bowel overgrowth (SIBO) were examined.

Methods: In this 8-week, parallel-group, double-blind, randomised controlled trial, 79 adults with self-reported digestive complaints were recruited and randomised to receive either a placebo or 500 mg of the curcumin extract, Curcugen™. Outcome measures included the Gastrointestinal Symptom Rating Scale (GSRS), intestinal microbial profile (16S rRNA), Depression, Anxiety, and Stress Scale - 21 (DASS-21), Short Form-36 (SF-36), and SIBO breath test.

Results: Based on self-report data collected from 77 participants, curcumin was associated with a significantly greater reduction in the GSRS total score compared to the placebo. There was also a greater reduction in the DASS-21 anxiety score. No other significant between-group changes in self-report data were identified. An examination of changes in the intestinal microbial profile and SIBO test revealed curcumin had no significant effect on these parameters. Curcumin was well-tolerated with no significant adverse events.

Conclusions: The curcumin extract, Curcugen™, administered for 8 weeks at a dose of 500 mg once daily was associated with greater improvements in digestive complaints and anxiety levels in adults with self-reported digestive complaints. Compared to the placebo, there were no significant changes in intestinal microbiota or SIBO; however, further research using larger samples and testing methods that allow more detailed microbial analyses will be important. An investigation into other potential mechanisms associated with curcumin's gastrointestinal-relieving effects will also be important such as examining its influence on the intestinal barrier function, inflammation, neurotransmitter activity, and visceral sensitivity.

Trial registration: Australian New Zealand Clinical Trials Registry, Trial ID. ACTRN12619001236189 . Registered 6 September 2019.

Keywords: Curcumin; Gastrointestinal symptoms; IBS; Microbiota; Turmeric.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Affect / drug effects
  • Aged
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Curcumin / administration & dosage*
  • Digestion / drug effects
  • Double-Blind Method
  • Female
  • Gastrointestinal Microbiome / drug effects*
  • Gastrointestinal Tract / drug effects
  • Gastrointestinal Tract / physiopathology
  • Humans
  • Irritable Bowel Syndrome / drug therapy*
  • Irritable Bowel Syndrome / microbiology
  • Irritable Bowel Syndrome / physiopathology
  • Irritable Bowel Syndrome / psychology
  • Male
  • Middle Aged
  • Quality of Life
  • Self Report
  • Young Adult


  • Curcumin