Fibromyalgia and Irritable Bowel Syndrome: Understanding the Gut-Brain Connection

Fibromyalgia and Irritable Bowel Syndrome: Understanding the Gut-Brain Connection

Published on Thursday, February 29, 2024 by Keydella Fuller

Understanding the Intricate Relationship Between Fibromyalgia and IBS

Fibromyalgia (FM) and Irritable Bowel Syndrome (IBS) are both complex, life-altering conditions without an apparent causative factor, often coexisting in the same person. The key to understanding and improving these two conditions lies in the awareness of the gut-brain connection. You can read more on fibromyalgia here. In this article, we will explore how FM and IBS symptoms overlap and if the gut microbiome may play a role in both conditions. 

How are FM and IBS Linked?

IBS and FM have a higher prevalence in women with overlapping symptoms such as anxiety, depression, insomnia, brain fog, and possible immune dysfunction. Stress has been found to worsen both conditions, and up to 70% of FM patients may also be diagnosed with IBS. A potential explanation for this link and an area of growing interest is the gut microbiome's role in both conditions. 

How is the Brain Involved?

The gut-brain connection is complex and links, well, you guessed it, the gut, aka gastrointestinal (GI) tract, and the brain’s central nervous system (CNS). The GI tract is home to many nerves that send signals from the gut to the brain. These signals affect our moods, emotions, cognition, and energy levels, in addition to ensuring the GI tract functions appropriately in the digestion of food and absorbing nutrients. 

The signals are sent by the trillions of bacteria that live in our gut, the gut microbiome. Research has found that the gut microbiome and the wastes it produces influence inflammation, our stress response, emotional behavior, pain receptors, and neurotransmitters like serotonin, dopamine, and others. Thus, disruptions in the gut microbiome can lead to increased anxiety, depression, and a weakened immune system, all common occurrences in patients with FM and IBS. . 

The brain also impacts the gut. Have you ever experienced anxiety and then suddenly had to use the bathroom? That's because the brain and its neurotransmitters affect gut motility and permeability, known as the gut-brain axis.

Support The Gut To Support The Brain

Whenever I work with a new client with GI or brain/mood symptoms, as is common in FM, I start by addressing the guts foundation. Leaky gut can contribute to imbalances in the gut microbiome and contribute to symptoms. You can read more about leaky gut here.

Research has found that supplementing with specific probiotic strains such as Lactobacillus, Enterococcus, and Bifidobacterium bifidum has been shown to reduce IBS severity. For FM, Lactobacillus casei and Bifidobacterium infantis may help with cognitive impairment. Testing for small intestinal bacterial overgrowth, or SIBO, is also recommended, as it is significantly associated with FM.

The Trio: Sleep, Stress and Nutrition

These three key areas also impact the gut-brain connection and thus are likely why it may improve FM and IBS symptoms: adequate sleep, lower inflammation, stress, and better nutrition selection. Poor sleep can flare symptoms, worsen pain and fatigue associated with FM, and worsen GI symptoms in IBS. Good sleep hygiene, including maintaining a regular sleep schedule, creating a comfortable sleep environment, and exercising regularly, has been shown to help improve sleep.

Stress and how we manage it can worsen FM and IBS symptoms. Find an effective and sustainable way to reduce your stress. You may like singing or dancing, reading a book, or doing gentle exercise, yoga, or breath work. Find what works for you and practice it daily. 

Nutrition is key. For IBS, a Low FODMAP diet may help symptoms, and for FM, an anti-inflammatory diet with good-quality fruits, vegetables, proteins, and healthy fats may be beneficial. While nourishing the body, identify if any food sensitivities or intolerance contribute to symptoms. Common triggers for FM could be gluten intolerance.

In Conclusion

FM and IBS have some overlapping symptoms, such as anxiety, depression, pain, and gastrointestinal symptoms like bloating or diarrhea. Supporting gut health through diet, sleep, stress management, and supporting the gut-brain connection can positively impact both conditions. Probiotic supplements may also be beneficial. Before starting any new supplement regimen, consult with your healthcare provider or find a functional medicine practitioner to support you on your journey to health optimization. 


  1. Chang, L. (n.d.). The Association of Irritable Bowel Syndrome and fibromyalgia. The Association of Irritable Bowel Syndrome and Fibromyalgia. 
  2. Erdrich, S., Hawrelak, J. A., Myers, S. P., & Harnett, J. E. (2020). Determining the association between fibromyalgia, the gut microbiome and its biomarkers: A systematic review. BMC musculoskeletal disorders, 21(1), 181. 
  3. Fibromyalgia and Sleep: Sleep Disturbances & Coping. (2023, December 22). Sleep Foundation. Retrieved January 20, 2024, from 
  4. Garofalo, C., Cristiani, C. M., Ilari, S., Passacatini, L. C., Malafoglia, V., Viglietto, G., Maiuolo, J., Oppedisano, F., Palma, E., Tomino, C., Raffaeli, W., Mollace, V., & Muscoli, C. (2023). Fibromyalgia and Irritable Bowel Syndrome Interaction: A Possible Role for Gut Microbiota and Gut-Brain Axis. Biomedicines, 11(6), 1701. 
  5. Kadayifci, F., Bradley, M., Onat, A., Shi, H., & Zheng, S. (2022). Review of nutritional approaches to fibromyalgia. Nutrition Reviews, 80. 

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