Many people with ME/CFS also experience digestive disorders such as irritable bowel syndrome. Therefore, of interest is a review study – published on the 1st March 2024, which aimed to enhance understanding of the role that the gut microbiome – the trillions of microbes, including bacteria, viruses, and fungi which inhabit the gut, may play in ME/CFS.
The research team identified 11 published studies that considered the gut microbiome of people with ME/CFS compared with healthy controls.
In the 11 studies, there were a total of 1,033 participants; 480 healthy controls, and 553 with ME/CFS – notably, the studies used a combination of different diagnostic criteria for ME (International Consensus Criteria), ME/CFS (Canadian consensus criteria), and CFS (Fukuda criteria) which do not all require the same symptoms to be present for a diagnosis.
Despite the differences in criteria used, the authors considered the findings of the 11 studies together, and observed that compared with healthy controls, those with ME/CFS had:
- Significantly different types of microbes within the gut.
- Approximately a 34% decrease in gut microbial diversity – the number of different species.
While the findings from this review may indicate involvement of the gut microbiome in ME/CFS, the authors acknowledge some limitations:
- The lack of consideration of potential differences in the gut microbiome between males and females with ME/CFS.
- All included studies focused on gut bacteria- the gut microbiome also includes other micro-organisms such as fungi, viruses, and protozoa.
ME Research UK notes that more research is needed to consider the gut microbiome of people diagnosed with ME/CFS using criteria which are comparable, and require the presence of post exertional malaise. Further research should also explore the role of other gut microorganisms in ME/CFS, such as that currently being undertaken by Professor Simon Carding at the Quadram Institute – funded by ME Research UK, specifically investigating viruses in the gut.
