Can You Diagnose Fibromyalgia Through A Stool Test?

“Wow, I heard that now there is a test of the bacteria in your poop that can diagnose fibromyalgia!”

That was in a recent Facebook post from a person who has been suffering from fibromyalgia and got excited by a blog she had seen.  It linked to a report about a report about some research, and said there was a new way to diagnose fibromyalgia. (The problem was, that yes, it was a report about a report).

Here’s Why It’s Dangerous To Read Headlines….

The truth that got distorted came from a research study published in 2019 showing distinct differences in intestinal bacterial composition and metabolism in women with fibromyalgia, compared to women without fibro. 

But we have to think carefully to understand what that means for people with fibromyalgia. Unfortunately, we can’t diagnose fibromyalgia with a stool test.

Sometimes writers with good intention distort the meaning of research because they don’t understand how to interpret the data.  Or perhaps they want to get attention and don’t care so much about the truth.  So they write compelling but misleading headlines.   So if you don’t have a science background, it can be really hard to know what’s real and what’s distorted info-mercial. 

Perhaps I can give clarity to this article…

What Did The Research Really Prove?

The title of the article was “Altered microbiome composition in individuals with fibromyalgia”[1] in the journal Pain. June 2019.  It’s a great study, and very important to the scientific understanding of fibromyalgia.

“Microbiome” is the name of the overall ecosystem of microbes (bacteria, yeast, and viruses) that live in your body. In the past 10-20 years there has been an explosion of research demonstrating how vast and important is the microbiome. The part of the microbiome that gets the most attention is the microbiome in the gut–the intestinal microbiome. That’s what this research studied.

It’s the first time that it has been proven that people with fibromyalgia have different bacteria in their poop. And these bacteria are associated with differences in metabolism and important immune-modulating compounds in the blood of the subjects.  These metabolic changes could be related to the symptoms of fibromyalgia. 

It also showed that those differences correlated with the severity of fibromyalgia symptoms. Important difficult things like pain intensity, fatigue, sleep disturbance, and cognitive impairment.

Those are the basic research findings.  It’s really important and good news, as I will discuss later in this article.  But it doesn’t add up to diagnosing fibro.

Does This Mean You Can Diagnose Fibromyalgia in My Poop? 

Even the authors of this study say easy-to-misinterpret things like “furthermore, these results suggest that the composition of the microbiome could be indicative of the diagnosis of FM.” So to someone who really wants an objective test for fibro, they might think, “oh yeah, here it is, I’ve been walking around with an invisible illness and now we can get a definitive diagnosis!”.

Not so fast.

The authors said, “could be indicative”.  That’s research-speak for “we have no firm conclusions, but I want to say something optimistic about the meaning of this research”.

The research compared people with fibromyalgia to healthy people. It tells us that something substantial and important is different about the biome of people with fibro compared to healthy people.   And together with a ton more research, this kind of test may be used to diagnose fibromyalgia,  and yield effective treatments for fibromyalgia that even conventional MD’s will be willing to discuss. 

It also adds credence to the notion that there are actual physiological abnormalities in fibromyalgia, and its not “just all in your head”.  We have plenty of evidence of real physiologic changes in fibromyalgia.  But some boneheads are still stuck in the past and think it’s all psychological. 

But the research didn’t distinguish fibromyalgia from other painful conditions that might have similar symptoms with fibromyalgia. 

It’s kind of like showing that people with pneumonia have elevated white blood cell count.  OK, so I know there is an infection.  But an elevated white count doesn’t help distinguish pneumonia from other things with elevated white blood cell count, like soft tissue infection, or kidney infection. 

In the same way, these research findings don’t distinguish fibromyalgia from neuropathy, arthritis, chronic myofascial pain, or other conditions that cause chronic pain and may well have changes in the biome.

What’s The Good News In This Study? 

The good news is that the research lends support to our understanding of fibromyalgia, and the way that many pro-active doctors and patients already treat and heal from fibromyalgia. 

Alterations in the biome can be associated with a number of other physiologic changes, leading to inflammation, oxidative stress, mitochondrial dysfunction, and the symptoms of fibromyalgia.  Many people with fibromyalgia will get significantly better when they do functional and lifestyle steps to correct dysbiosis and the intestinal permeability[2] that often accompanies it[3].  That kind of treatment rests on the assumption that dysbiosis is part of the problem in fibromyalgia.  Now we have evidence to support that assumption.  That’s good news!

How Does This Study Help Us Understand and Treat Fibromyalgia? 

This study provides evidence for one piece of the complex puzzle that is fibromyalgia.

Lets unpack the assumptions and principles that underlie this ‘functional and lifestyle’ approach to treating fibromyalgia.  The past few decades have seen development of a few lines of research that support the approach, even if it’s not yet accepted by mainstream doctors.  Research has shown that:

  • Many chronic illnesses are associated with characteristic changes in the intestinal biome. 
  • Changes in the biome are often associated with increased intestinal permeability.  Also known as “leaky gut syndrome”, intestinal permeability was a joke to conventional docs when I was in training.  Recent years have shown that it is a real phenomena[4][5] and is associated with chronic illnesses affecting many bodily systems.
  • Intestinal permeability is associated with various compounds that inappropriately leak out of the intestine and into the blood circulation.  That includes bacterial cell wall components like lipopolysaccharide (LPS), Hydrogen sulfide, undigested food particles, and bacteria themselves.  These can all cause activation of the immune system and ‘sterile inflammation’[6].
  • Sterile inflammation is increasingly being understood to underlie many of our chronic illnesses including chronic pain[7] and fibromyalgia[8].
  • Sterile inflammation can lead to activation of brain immune cells called “glial cells”.  Glial activation has been shown in people with fibromyalgia.  They are likely part of what drives central sensitization (so that everything hurts), brain fog and other neurological symptoms[9].
  • Changes in intestinal barrier function and consequent systemic inflammation can have synergy with chronic stress and autonomic dysfunction, environmental toxins, and other variables.  The resulting vicious cycles shift the physiology over the course of months or years, and then the symptoms show up.

As you can see, it’s a pretty complex picture.  This research demonstrates that people with fibro have dysbiosis.  And that fits with these other abnormalities that can cause the characteristic symptoms.  Hopefully further research will complete the picture so that more doctors see the multifactorial nature of fibromyalgia and other chronic diseases.

My Life Is a Wreck from Fibro.  What Can I Do Now?

We can see how fibromyalgia is a multisystem dysfunction.  How does it get started?  Various genetic and early-life experiences can set the stage.  Later in life, various events can ‘pull the trigger’ and start or accelerate one or more of these vicious cycles.  And certain physiologic changes and lifestyle habits can perpetuate the process.

Based on those principles, there is an often-effective path of fibromyalgia treatment.   It’s for people who are suffering and don’t want to wait 20-40 years until we have a rock solid mechanistic picture and therapies that are proven in randomized controlled trials.  They want to take reasonable, safe, and rational action based on the best currently available evidence.  Does that sound like you?

Many of my colleagues and I accommodate that desire.  Rather than just treating the symptoms with sleep medications or nerve-pain medications like Lyrica or Cymbalta, we take a multifactorial approach to address the dysfunctions described above. (Of course, sometimes symptomatic treatment with medications is appropriate.  Each case is different.) 

We evaluate various antecedents, triggers, and perpetuating factors that can contribute to the physiologic changes and symptoms of fibromyalgia.   We look at fibromyalgia as a complex systems process that develops over time, like water flowing downstream.   Treatment involves addressing those physiologic changes directly, going ‘upstream’ as far as possible toward the actual roots of the physiologic dysfunction.

For instance, recommendations commonly include:

  • Eliminating foods that can stimulate the intestinal immune system and contribute to intestinal permeability.
  • Consuming foods and supplements that support healthy biome and intestinal barrier, and reduce oxidative stress and inflammation. 
  • Taking nutrients that support mitochondrial function and neuromuscular function.
  • The use LDN (low dose naltrexone).  It is a prescription medication which reduces inflammatory chemicals and causes the body to strengthen its own pain blocking endorphins and enkephalins[10]. 
  • I also use PEA, which is a natural product that works through cannabinoid receptors and other mechanisms to reduce activation of inflammatory cells that contribute to pain[11].
  • Nutritional or pharmacologic treatment to treat subclinical thyroid or adrenal dysfunction.
  • Mind-Body training, which can normalize the stress system, reduce pain, enhance sleep, and improve energy[12].
  • Use botanical or other natural compounds that can normalize stress hormone function and help sleep naturally.

Summing up, the new data about biome changes in fibromyalgia support the role of dysbiosis and intestinal permeability in fibromyalgia.  It doesn’t yet help us diagnose fibromyalgia.   More research is needed to definitively understand these issues.  In the meantime, evidence from small clinical trials, basic science, and much anecdotal evidence support a multifactorial approach to correcting underlying physiologic issues, and improve symptoms and quality of life in fibromyalgia.

I’ll be discussing this approach to “heal the gut and reduce inflammation”, as well as other aspects of fibromyalgia management in future blog posts.  You can sign up to get notification of future posts by clicking here.


[1] “Altered Microbiome Composition in Individuals with Fibromyalgia:” PAIN 160, no. 11 (November 2019): 2589–2602. https://doi.org/10.1097/j.pain.0000000000001640.

[2] “Altered Intestinal Permeability in Patients with Primary Fibromyalgia and in Patients with Complex Regional Pain Syndrome.” https://doi.org/10.1093/rheumatology/ken140.

[3] “An Insight into the Gastrointestinal Component of Fibromyalgia: Clinical Manifestations and Potential Underlying Mechanisms.” https://doi.org/10.1007/s00296-014-3109-9.

[4] Intestinal permeability – a new target for disease prevention and therapy. https://doi.org/10.1186/s12876-014-0189-7

[5] Intestinal Permeability and Its Regulation by Zonulin: Diagnostic and Therapeutic Implications. https://doi.org/10.1016/j.cgh.2012.08.012

[6] Increased serum IgA and IgM against LPS of enterobacteria in chronic fatigue syndrome (CFS): Indication for the involvement of gram-negative enterobacteria in the etiology of CFS and for the presence of an increased gut–intestinal permeability. https://doi.org/10.1016/j.jad.2006.08.021

[7] Cytokines, Inflammation, and Pain: https://doi.org/10.1097/AIA.0b013e318034194e

[8] Neuroinflammation and Central Sensitization in Chronic and Widespread Pain. https://doi.org/10.1097/ALN.0000000000002130

[9] Mast cells, glia and neuroinflammation: partners in crime? https://doi.org/10.1111/imm.12170

[10] Reduced Pro-Inflammatory Cytokines after Eight Weeks of Low-Dose Naltrexone for Fibromyalgia. Biomedicines 5, 16. https://doi.org/10.3390/biomedicines5020016

[11] Palmitoylethanolamide in Fibromyalgia: Results from Prospective and Retrospective Observational Studies. Pain Ther 4, 169–178. https://doi.org/10.1007/s40122-015-0038-6

[12]  Mind-Body Medicine: State of the Science, Implications for Practice. https://doi.org/10.3122/jabfm.16.2.131

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