Study: Chronic Fatigue & Gut Bacteria

Kerry Beeson BSc (Nut. Med.) Nutritional Therapist

Have you ever wondered about the possible link between Chronic Fatigue Syndrome (CFS) and Irritable Bowel Syndrome (IBS)? The link between CFS and IBS is still not very clear, however, this new study assessed the connection between CFS, IBS and the association with gut bacteria. So we might just have some answers for you!

Chronic fatigue syndrome also known as Myalgic encephalomyelitis (ME), is a complex disease involving profound dysregulation of the central nervous system (CNS) and immune system. Researchers found, 30-90% people with CFS struggle with IBS type symptoms like abdominal discomfort, cramps, bloating, diarrhoea and constipation 1. In recent years the role of the gut microbiota in health conditions like CFS has been more widely recognised and examined.

woman in pain in bed
30-90% of chronic fatigue syndrome patients, suffer from IBS type symptoms as well

This study involved 100 participants split into 2 groups; 50 participants had CFS and the other 50 were healthy 2. 21 out of the 50 patients with CFS had IBS. Faecal samples for all the participants were analysed.

This study highlighted various types of gut bacteria were linked to chronic fatigue syndrome. They found the proportion of Faecalibacterium, Bacteroides, Roseburia, Alistipes, Clostridium, Dorea, Coprococcus, Ruminococcus and Coprobacillu varied between both groups of participants. The trend showed that these bacteria could be used as indicators to predict whether a patient had chronic fatigue syndrome.

Patients with chronic fatigue syndrome and IBS had a high level of a bacteria called Alistipes and a low level of Faecalibacterium compared to participants with CFS without IBS. However, even though participants that had CFS with IBS had more bacteria from the Bacteroides family, they had lower level of the Bacteroides vulgatus species.

They concluded that CFS is indeed associated with dysbiosis and the level of specific species could influence the aetiology of CFS as well as its severity. It would be interesting to see what else would be unveiled in future studies.

This substantiates that although our gut bacteria are tiny, they play a vital role in our health!

Check out the following blogs for further reading about this interesting topic:

Decreased bacterial diversity found in ME/CFS patients
Does a lack of sleep affect our gut bacteria?


  1. Live Science, 2017. Live Science. [Online]
  2. Available at: [Accessed 27 April 2017].
  3. Nagy-Szakal, D. et al., 2017. Fecal metagenomic profiles in subgroups of patients with myalgic encephalomyelitis/chronic fatigue syndrome. Microbiome, pp. 1-17.