Could Black Mold Exposure Under My Friend S Home Be Causing Her Cyclical Vomiting Syndrome?

My best friend has been suffering from something similar to cyclical vomiting syndrome, in addition to other health issues, for about 5 years. She has seen GI, Neurology and MS physicians and they can t find a cause or help her get better. She very recently discovered that there is a lot of black mold underneath her home and in her air ducts. Could this be causing the vomiting? If so, what can she do?