Lupus: Can Gut Microbes Make a Difference?
Systemic lupus erythematous (SLE) results from a mistaken response of the body’s immune system against healthy tissue affecting several organs such as skin, kidneys and brain. The underlying causes of SLE remain unknown although several evidences point towards an important role of gut microbes, also known as gut microbiota. Researchers at Virginia Tech have recently discussed the contribution of diet and gut microbes to SLE occurrence and pathogenesis in a publication entitled “SLE: Another Autoimmune Disorder influenced by Microbes and Diet?” published in the journal Frontiers in Immunology.
The human gut harbors trillions of microorganisms essential to maintaining tissue homeostasis and health. Disruption of its normal flora is associated with several autoimmune diseases, including SLE. The authors of this review performed several laboratory studies using animal models to address the role of microbiota in SLE, finding that SLE induces a clear change in animals’ gut microbes, namely, a depletion of lactic acid bacteria Lactobacilli, and increase of Clostridial species. Importantly, dietary treatments that improved symptoms in animal models reverted the gut flora to normal. “Our work shows the potential benefits of modulating gut microbiota, especially by increasing the level of Lactobacilli, in the treatment of lupus. Lactobacilli can be introduced as probiotics, which are known to be beneficial to the host when administered in adequate amounts,” the authors suggested.
In humans, external factors such as antibiotics and diet modulate the gut microbiota with a potential impact in lupus. Antibiotics are known to trigger lupus flares in patients, which can be in part through removal of certain gut commensals thereby facilitating lupus progression. In fact, African Americans, who are more likely to develop lupus, have used antibiotics much more frequently than people in West African countries. Dietary components can also influence SLE by changing the composition and function of gut microbiota. For example, vitamin D, vitamin A, and omega-3 polyunsaturated fatty acids, have been found to modulate lupus onset or flares.
Overall, modulation of gut microbiota is very important to control flares in patients and future therapies may take these evidences into account. “Further studies are necessary to determine whether the modulation of diet — likely to be less expensive and safer than immunosuppressive drugs — can be effective at establishing a healthy balance between the host and symbiotic microbiota in the gut of SLE patients. If so, diet modulation might become a cost-effective approach for the management of SLE,” the authors concluded.