Researchers studying lupus, an autoimmune disease that strikes mostly women of childbearing age, are zeroing in on the gut.
You might think of germs as the enemy, but actually it’s more complicated. Your gut is home to potentially thousands of different species of bacteria of different kinds, which together we call the human microbiome. They help us break down food and protect us from infection. Think of yourself as a big ecosystem, full of life. In fact, the bacterial ecosystem in humans and other mammals is one of the most complex ecosystems on the planet. The same bacteria live elsewhere in the body, but the gut contains the biggest population.
Your microbiome isn’t exactly like your neighbor’s or sister’s. Hormones make a difference. For example, although men can get lupus too, sex hormones may change the gut in ways that explain why lupus is more common in women. How you live affects your microbiome. There may be many subtle effects of environment we don’t yet know about. We do know that diet and medications, especially antibiotics, change your ecosystem. In general, healthier people have a more diverse collection of bacteria.
Researchers have begun to analyze the microbiome as a player in the immune system. Is it possible that we need some germs to fight off others? To see the process from the very beginning, researchers may work with mice bred in labs to be germ-free. These mice do develop differently in ways that would impair immunity, research suggests.
Scientists also see the microbiome as an especially promising area of research for autoimmune problems, when the immune system creates symptoms even though no identifiable infection is present. It makes sense to suspect gut microbes in conditions involving the digestive system. But animal research suggests that the human microbiome may play a role in conditions that wouldn’t have an obvious connection to digestion, including type 1 diabetes, rheumatoid arthritis, and lupus.
That’s why Gregg Silverman, MD, and his team at New York University are surveying the microbiome in over a 100 lupus patients, using cutting-edge DNA sequencing technology to identify all the bacteria in their guts. If the sequence reveals a tell-tale pattern, perhaps a new unknown bacterium, doctors could one day have tests predicting who is most at risk for lupus, and find ways to prevent the disease or treat it earlier.
The bacteria may, for example, trigger the body to produce interferons, a group of proteins named for their ability to interfere with viruses. That would help explain why people with lupus develop fevers and feel exhausted, as they might with a virus like the flu.
Symptoms of lupus usually start in the teen years into the thirties. Besides fatigue and unexplained fevers, early signs of lupus include thinning, ragged body hair caused by inflammation of the skin and scalp; painful swollen joints; and gastrointestinal troubles. The butterfly rash across the cheeks and nose is a clear sign; however, only about half of lupus patients develop it.
Women of color are two to three times more likely to develop lupus than caucasians, although it’s not clear how the gut may be involved.
Some people with lupus develop antiphospholipid syndrome: their immune system mistakenly attacks proteins in the blood and causes clots. Manipulating gut bacteria may prevent the dangerous disorder.
While the research is underway, what can we do now to fight or prevent conditions possibly tied to our gut bacteria? Infants are born germ-free but quickly collect bacteria. Children born by C-section seem to miss out on needed bacteria in the mother’s vagina, so one simple step may be to apply vaginal fluid to the baby’s skin.
Fiber feeds the bacteria you want to favor and helps keeps your microbiome diverse. Load up on greens, and other vegetables. Garlic, onions, and asparagus all contain a key fiber called inulin. If you already have a digestive problem, you may need to choose your vegetables carefully or eat them cooked. Whole grains may be helpful but again, not for everyone. However, it’s a safe bet that you shouldn’t gorge on the “whites” — sugar, flour, potatoes — which have become so big a part of the American diet.
July 27, 2016
Christopher Nystuen, MD, MBA