By Pat Anson, PNN Editor

A large new study has found high rates of fibromyalgia in patients with irritable bowel syndrome (IBS), adding to a growing body of evidence linking gut bacteria to chronic pain disorders. IBS patients were also more likely to have chronic fatigue syndrome (CFS).

The study, recently published in the journal Biomedicines, looked at more than 1.2 million IBS patients hospitalized in the U.S. over a three-year period. They found that the prevalence rate of fibromyalgia in the IBS patients was 10.7 percent, about five times higher than the fibromyalgia rate (1.4%) in the general adult population.

Fibromyalgia is a poorly understood condition characterized by widespread body pain, headaches, fatigue, insomnia and mood disorders; while IBS causes abdominal pain, cramps, bloating, gas and diarrhea. Gut bacteria has been associated with both IBS and fibromyalgia, but the exact mechanism of action remains unclear.

“This is yet another example where ailments in the gut are linked to ailments elsewhere in the body and mind,” said senior author Yezaz Ghouri, MD, an assistant professor of clinical medicine and gastroenterology at the University of Missouri School of Medicine. “As we continue to learn more about how gut health effects health elsewhere it is important that clinicians look for and manage somatic comorbidities in IBS patients.”

Fibromyalgia and CFS are known as “somatic” disorders because patients who have them often experience anxiety and depression – a tendency perhaps explained about the lack of effective treatments for their physical symptoms.

“Because IBS patients have higher prevalence of somatic comorbidities such as fibromyalgia and chronic fatigue syndrome, identifying and treating these disorders can improve their quality of life,” said lead researcher Zahid Ijaz Tarar, MD, a fellow in the division of gastroenterology and hepatology at the University of Missouri School of Medicine.

“Earlier identification of comorbidities is valuable to inform treatment strategies, including consulting other specialties such as rheumatology and psychiatry to improve the overall health outcomes in IBS patients.”

In addition to fibromyalgia, the research team found that hospitalized IBS patients were also significantly more likely to be white and female.  Less than one percent (0.42%) had a CFS diagnosis – a small percentage to be sure, but still higher than CFS rates in the general population (0.06%).

The high rates of fibromyalgia and CFS in IBS patients has led to speculation that poor diets or antibiotics may cause an imbalance of “bad” bacteria in the gastrointestinal system, allowing toxins to leak into the bloodstream and cause other health problems.

A recent study found that Klebsiella aerogenes, a bacterium that causes white blood cells to produce excess amounts of histamine, can trigger a painful immune system response.

Another study found that women with fibromyalgia have strikingly different types and amounts of bacteria than those without fibromyalgia. Faecalibacterium prausnitzii, a “good” bacterium that is normally abundant in the human gut, was found to be depleted in fibromyalgia patients. Other bacteria associated with IBS, CFS and interstitial cystitis were found to be abundant in fibromyalgia patients, but not in the healthy control group.