WEDNESDAY, Sept. 13, 2017 -- Certain types of bacteria in the gut may play a role in the progression of multiple sclerosis, according to researchers working with mice. The research, the study authors believe, could lead to new ways to treat multiple sclerosis, or MS, an autoimmune neurodegenerative disease that affects about 2.5 million people worldwide. "The [gut] microbiome is very malleable," study senior author Sergio Baranzini said. "You could relatively easily change it in an adult who has MS or is susceptible -- something you cannot do with their genetics. This is not a magical approach, but it is hopeful." MS occurs when the immune system attacks the insulation, or myelin, around nerve