Changes in the gut microbiota correlate with changes in the expression of immune defence genes in patients suffering from multiple sclerosis (MS), a study published in Nature Communications reports.

It is not clear whether the changes play a role in, or, are a consequence of, MS disease progression.

Our intestine harbors many microorganisms and is an internal environment for a rich and diverse source of antigens. The gut mucosal immune system samples and processes these antigens continuously, generating specific immune responses.

Gut microbiome is, therefore, an important internal entity that influences immune functions and autoimmune diseases.

The gut microbiome has been implicated in numerous immune disorders, including MS, inflammatory bowel disease, type 1 diabetes, and rheumatoid arthritis. Changes in the abundances and types of gut microorganisms were found to be correlated with the development of these disorders.

The study

A previous study comparing 20 MS patients and 40 healthy participants found microbiota alterations in the patients with MS. In the current study, researchers sampled and analysed the gut microbiota of 60 MS patients and 43 healthy participants.

They found that microorganisms such as Methanobrevibacter (the main methane-producing microbe in the human gut) were more abundant in patients than in healthy participants.

These changes correlated with variations in the expression of immune response genes in blood immune cells, including genes involved in cell maturation and signaling pathways.

They also showed that in the patients, other microbiota alterations correlated with the use of immunosuppressive medication, suggesting that treatment with immunomodulatory therapy may normalize some of the MS-related changes in the microbiota.

More studies to determine whether these observed changes could be used as potential biomarkers for assessing MS disease progression are warrant. Methane in the breath may be used to screen for MS.

Further research with larger cohorts of patients and samples collected during disease progression is needed to test whether these gut microbiota alterations play a role in, or are a consequence of, changes in immune gene expression or the disease itself.

In addition, within a smaller group of patients, elevated levels of methane were found in the breath of patients compared to healthy participants, which is consistent with increased abundance of Methanobrevibacter in MS patients. More studies may confirm the use of methane in the breath to screen for MS.