Gut Microbiome: Studying the links between people, bacteria, and MS

October 25, 2013

Our bodies are made of billions of cells. However, the cells in our bodies are far outnumbered by the bacteria that cover our skin and inhabit our gut. These bacteria are now increasingly recognized to have an important role in maintaining our health. For example, skin bacteria help protect us from more dangerous bacteria that could invade us. Gut bacteria help digest our food. There are suggestions that changes in these bacteria, particularly those in the gut, might play a role in several diseases. For example, there are differences in the types of bacteria in the guts of obese people compared to those of normal weight and changing these bacteria can alter obesity, at least in mice.

At a recent presentation at the ECTRIMS meeting, the gut microbiome (the numbers and types of bacteria that inhabit the gut) was discussed. There is evidence from animal models of MS that the gut microbiome might have an influence on the immune system and the ability of the immune system to attack the brain. This evidence is now being extended to human studies. The first step is to try to determine which bacteria inhabit the gut of healthy people compared to that of people with various diseases including MS. This is a very difficult task because many of the bacteria that inhabit our gut cannot be grown in the laboratory. Recent advances in DNA sequencing are now being harnessed to help identify these bacteria. With this technique, bacteria do not need to be grown in the laboratory in order to identify them. Rather, the genes in these bacteria can be sequenced and used to identify which organisms are present. This technique has now been used to detect many new species of bacteria that had previously been unknown. Several studies are now being conducted around the world aimed at determining differences in the bacteria of healthy people and those with diseases, including MS.

As this research progresses, the gut bacteria of many people will need to be studied to determine which bacteria differ between normal people and patients with disease. These differences will then need to be further studied to identify which might contribute to causing a disease rather than which might be the result of the disease. Finally, studies will then need to be conducted to see whether altering these bacteria might have an effect on the disease. These studies are in their earliest phases, but it is exciting to think about the interaction between people, bacteria and diseases. This will be an important field to follow in the coming years, with the potential to alter the way we look at many diseases and the treatment of these, including MS.