The Gut-Brain Axis in IBS and Bloating - An Overview of the Science and Solutions
Irritable Bowel Syndrome (IBS) affects between 5% and 10% of people worldwide, with women experiencing it more frequently than men. While IBS is often described as a functional gut disorder—meaning symptoms occur without visible damage—it’s increasingly understood as a condition shaped by complex interactions between the gut, brain, immune system, and microbiome. Based on the current Rome IV criteria, IBS is defined by chronic recurrent abdominal pain associated with altered bowel habits without detectable organic disease. Classification based on symptoms includes IBS with diarrhoea (IBS-D), IBS with constipation (IBS-C), and IBS with mixed bowel patterns (IBS-M).
This article explores how the gut-brain axis influences IBS and bloating, and highlights evidence-based strategies to support digestive and emotional wellbeing.
🧠 What Is the Gut-Brain Axis?
The gut-brain axis is a two-way communication system between your digestive tract and your brain. It helps regulate digestion, mood, and immune responses. In IBS, this system can become disrupted, leading to persistent symptoms.
Key Players in Gut-Brain Communication
-
Enteric Nervous System (ENS): Often called the “second brain,” the ENS communicates with the central nervous system via the vagus nerve. In IBS, this connection can become hypersensitive, increasing pain perception and disrupting bowel movements.
-
Serotonin Signalling: About 90% of serotonin is produced in the gut. It helps regulate motility and pain. Imbalances in serotonin are linked to IBS subtypes—especially diarrhoea-predominant (IBS-D) and constipation-predominant (IBS-C).
-
Gut Microbiota: Your gut microbes produce short-chain fatty acids (SCFAs), neurotransmitters, and other compounds that influence brain function and immune responses. In IBS, microbial imbalances (dysbiosis) can lead to inflammation, increased gut permeability, and altered mood.
Natural Remedies That Support the Gut-Brain Axis
Targeted herbs and supplements can help restore balance and relieve IBS symptoms. Here are some of the more researched options:
🍃 Peppermint Oil
Peppermint oil is a well-established natural remedy for IBS. Its active compound, L-menthol, relaxes intestinal muscles by blocking calcium channels—helping reduce cramping and bloating. A 2014 meta-analysis found peppermint oil significantly more effective than placebo in relieving global IBS symptoms.
🧫 Probiotics
Probiotics are beneficial bacteria that help restore microbial balance. Certain strains and combinations have been shown to reduce bloating, abdominal pain, and improve overall IBS symptoms. Multi-strain, high-colony-forming units (CFU) may offer greater benefits providing a higher concentration of active, live microorganisms, but it’s best to consult a professional for personalised guidance. Talk to Rebecca Traylen, Head of Nutrition at Probio7, the 1:1 consultation is free.
Lifestyle and Diet: Foundational Support for IBS
Supplements work best when paired with lifestyle changes that support digestive health and reduce stress.
Low FODMAP Diet
This clinically validated dietary approach reduces fermentable carbohydrates that can trigger bloating and discomfort. It’s effective for many people with IBS but should only be followed short-term under professional supervision to avoid depleting beneficial gut bacteria.
Physical Activity
Regular movement improves gut motility and reduces stress. Activities like walking, yoga, or swimming 3–5 times per week can help regulate digestion and ease bloating.
Final Thoughts
The gut-brain axis offers a powerful lens for understanding IBS and bloating. By combining dietary strategies like the low FODMAP diet with targeted probiotics, herbal remedies like peppermint oil, and lifestyle changes, individuals can find meaningful relief.
As research continues to evolve, integrative approaches that support the gut-brain connection are paving the way for more personalised and effective care.
References
-
Mayer, E. A., Ryu, H. J., & Bhatt, R. R. (2023). The neurobiology of irritable bowel syndrome. Molecular psychiatry, 28(4), 1451–1465. https://doi.org/10.1038/s41380-023-01972-w
-
Rome IV Criteria. Available at https://theromefoundation.org/rome-iv/rome-iv-criteria/ Accessed August 2025
-
Stoyanova M, Gledacheva V, Nikolova S. Gut–Brain–Microbiota Axis in Irritable Bowel Syndrome: A Narrative Review of Pathophysiology and Current Approaches. Applied Sciences. 2025; 15(12):6441. https://doi.org/10.3390/app15126441
-
Khlevner, J., Park, Y., & Margolis, K. G. (2018). Brain-Gut Axis: Clinical Implications. Gastroenterology clinics of North America, 47(4), 727–739. https://doi.org/10.1016/j.gtc.2018.07.002
-
Crowell M. D. (2004). Role of serotonin in the pathophysiology of the irritable bowel syndrome. British journal of pharmacology, 141(8), 1285–1293. https://doi.org/10.1038/sj.bjp.0705762
-
Raskov, H., Burcharth, J., Pommergaard, H. C., & Rosenberg, J. (2016). Irritable bowel syndrome, the microbiota and the gut-brain axis. Gut microbes, 7(5), 365–383. https://doi.org/10.1080/19490976.2016.1218585
-
Khanna, R., MacDonald, J. K., & Levesque, B. G. (2014). Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis. Journal of clinical gastroenterology, 48(6), 505–512. https://doi.org/10.1097/MCG.0b013e3182a88357
-
Zhang, T., Zhang, C., Zhang, J., Sun, F., & Duan, L. (2022). Efficacy of Probiotics for Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis. Frontiers in cellular and infection microbiology, 12, 859967. https://doi.org/10.3389/fcimb.2022.859967
