But at the very least, the findings point toward a new understanding of human health and disease. Say Lora Hooper, an immunologistand the university of Texas southwestern medical center in dalas who was not involved in the work with multiple sclerosis, neurobiologist are at loss to explain why the disease progresses so erratically, so the idea that changes in the body's microbes may alter the blood-brain barrier to make the brain more vulnerable to damagelis appealing Petterson notes.