Dr. Jose U. Scher, a current Arthritis Foundation-funded investigator, has been looking at the relationship between bacteria and inflammatory diseases for more than 10 years. Dr. Scher’s current Arthritis Foundation funded project, “Pan-Microbiome in At-Risk Subjects and New-Onset Rheumatoid Arthritis (RA),” looks at the relationship of bacteria (or “microbiome” in the mouth, lungs, and intestines) and the development of RA.
“Different areas of the body have different populations of microbes,” Dr. Scher explained. “What is important is the diversity, or different types and numbers of bacteria. When we look at the bacteria found in the mouth, lungs, and gut of healthy individuals and compare them to those found in new RA patients who have not been treated yet, we see differences. The diversity of bacteria in each area changes in the RA patient. Certain bacteria may disappear and others may increase in numbers. In a healthy individual, there is a balance in the diversity of bacteria. It makes us question whether certain bacteria are triggering the body to produce an immune response.”
Dr. Scher began his work in immunology, looking at potential triggering factors for autoimmune diseases, specifically microbiomes and triggering effects. “We are asking: can you modify the microbiome in order to treat or prevent autoimmunity?” he explained. “Pharmaceutical companies are looking for the cocktail of microbes that can help patients. But what if it is not the microbes themselves, but the metabolites (chemicals) they produce that is important? Are some of the metabolites produced by certain bacteria beneficial? These are questions that need to be answered before we can come up with a safe and effective therapy.”
In a paper published in the November 2016 issue of BioMed Central Microbiome, Dr. Scher looked at the relationship in types and numbers of bacteria in the lungs and the possible development of RA. The study looked at lung fluids collected from untreated early-stage RA patients, healthy patients, and patients with lung sarcoidosis (an inflammatory disease that affects mostly the lungs). The study found that there were fewer types and amounts of bacteria found in the lungs of RA patients when compared to the lungs of healthy patients. The types and amounts of bacteria found in the lungs of the untreated early-stage RA patients were similar to those found in the sarcoidosis patients. The conclusion was that the bacteria in the lungs may drive the development of RA in some cases.
Dr. Scher also presented the results from a different study looking at the relationship between methotrexate, bacteria, and RA at the November 2016 ACR annual meeting. The results of that study showed that some bacteria respond more positively to methotrexate than others. “This offers the potential for a personalized medicine approach,” Dr. Scher explained. “By testing which bacteria are present in the gut, we can predict who will respond best to methotrexate. This could save some patients a lot of time and money if they knew they would be less likely to respond to that type of treatment.”
While Dr. Scher is optimistic about the future of microbiome research, he also cautions people. “There are a lot of steps between the development of a concept, research, and finding a true therapy. It takes time. I am thankful to the Arthritis Foundation for allowing us to be their partners in doing this important research.”
Dr. Scher is a rheumatologist at New York University Langone Medical Center.