Peppermint oil (PO) products have been promoted for irritable bowel syndrome (IBS) for quite a long time. When I have recommended PO as a possible treatment, I frequently say that “I guarantee that it will….give you fresh breath. It might help your stomach symptoms.”
A recent randomized, double-blind “PERSUADE” study (Zsa Zsa R. M. Weerts et al Gastroenterol 2020; 158: 123-36) shows that PO likely has some efficacy for stomach symptoms in IBS. This trial enrolled 189 patients & 178 completed study (mean age, 34 years, 78% female) from the Netherlands. Subjects were divided in three groups -instructed to take the study capsule 3/day for 8 weeks:
- 182 mg small-intestinal release PO-SI
- 182 mg ileocolonic release PO-IC
The primary endpoint was at least a 30% decrease in the weekly average of worst daily abdominal pain
- The primary endpoint did NOT differ significantly between the three groups: PO-SI with 46.8%, PO-IC with 41.3%, and Placebo with 34.4% response.
- The PO-SI but not PO-IC was associated in secondary improvements compared to placebo in abdominal pain (P=.06), discomfort (P=.02), and IBS severity (P=.02).
- Adverse events were mild with PO, but more common than placebo. Adverse events included heartburn, belching, and headache.
- The authors calculate that the number needed to treat with PO-SI would be 8 which is higher than recent ACG monograph which suggested an NNT of 4 (Am J Gastroenterol 2018; 113: 1-18). Even an NNT of 8 compares favorably with other treatments: linaclotide 6, plecanatide 10, and eluxadoline 12.5.
- the studied population was mainly young adult, predominantly white and female; thus the findings may not be generalized to other groups
- the peppermint smell could have undermined blinding despite presentation in capsule form
- relatively short duration study
The associated editorial by BD Cash (pgs 36-37) notes that PO medicinal use began in 1753 by Carl Linnaeus. PO is thought to work via smooth muscle calcium channel antagonism. The findings of working in the small intestine and not ileocolonic release could “spur additional therapeutic development.”
My take (borrowed in part from editorial): “These results reaffirm that PO can improve viscerosensory symptoms of IBS …and is well-tolerated… [It is] clearly not a gangbuster as a monotherapy.” While the findings show modest effect, the findings are supported by a “robust” study as this is the first randomized, double-blind placebo-controlled clinical trial of PO.
Related blog posts:
- Irritable Bowel Syndrome (part 1) (2017) –Mechanism, Pathophysiology, Definitions
- Irritable Bowel Syndrome (part 2) (2017) -Treatments
- Evidence-Based IBS Treatment Recommendations from ACG
- Mechanisms of irritable bowel syndrome | gutsandgrowth
- Psychological Treatments for IBS
- Balanced summary of probiotics & Microbiome effects on brain
- Don’t Skip this Article -Rome IV Summary | gutsandgrowth
- How Effective are the Treatments for Functional … – gutsandgrowth
- Cognitive Behavioral Therapy for RAP in childhood GutsandGrowth
- amplified pain syndromes | gutsandgrowth
- Anxiety and Functional Abdominal Pain | gutsandgrowth
- Brave New World: Psychotropic Manipulation & Pediatric ..
- Change the Name: “Functional” is Lousy | gutsandgrowt
- What NOT to say with functional pain | gutsandgrowth
- Acupuncture for irritable bowel syndrome
- Ondansetron for Irritable Bowel with Diarrhea?
- What to make of FODMAPs
- FODMAPs Advice From Harvard
- An Unexpected Twist for “Gluten Sensitivity” | gutsandgrowth
- Low Quality Evidence for Dietary Therapy in IBS
- Why Eliminating Gluten May Help Irritable Bowel Syndrome
Also, fidaxomicin has received FDA approval for pediatric use for C diff infections: