Gluten free diet is necessary when people have gluten intolerance as in

Celiac disease.

Celiac disease is diagnosed when people have the gene leading to Celiac disease and are unable to have gluten due to gastrointestinal symptoms like diarrhea. Celiac disease can lead to neuropathy and incoordination if not following a gluten free diet.

Often people choose to follow a gluten free diet since Gluten is considered to be an inflammatory product. There is no evidence that Gluten free diet will improve the course of your MS.