this is just my opinion but avoidance diets don't address the underlying problems ie nutritional imbalances that give ms-ers GI issues.
IMHO, and that's all it is, you don't need to avoid gluten if your zinc status is optimal. in MS patients that is usually not the case.
your serum zinc level should be close to 18.2 - 18.4 umol/L based on a study of almost 1200 healthy controls. there are more studies to support a healthy zinc level in the high teens.
if yours is low teens like many ms-ers, or in the single digits like mine was at first test, then sure, avoid gluten. but that doesn't fix the reason you should avoid it in the first place.
i used to suffer when i ate bread. then i discovered and corrected my zinc deficiency. now bread and other gluteny products do not bother me.
legumes are the same deal, take a lot of zinc to digest.
whether you're talking gluten or legumes it's all about the phytic acid. a study:
Nutrition Research Volume 9, Issue 1, January 1989, Pages 127-132
Effect of soybean fiber and phytate on serum zinc response1
MSKim Cranwella and PhDMichael Liebman, a
Changes in serum zinc levels after oral zinc administration was used as an index of zinc absorption. Ten adult males received a single dose of zinc gluconate on 5 separate occasions, either alone (control) or with 1 of 4 aifferent soybean treatments. The soybean treatments consisted of a high-fiber, high-phytate treatment (ground soybeans); a high-fiber, low-phytate treatment (dephytinized ground soybeans); a low-fiber, high-phytate treatment (tofu); and a low-fiber, low-phytate treatment (dephytinized tofu). The dephytinized soybean treatments yielded significantly higher postingestive serum zinc values than did the non-dephytinized treatments whereas no differences were observed between the high- and low-fiber treatments. These data suggested zinc absorption is more inhibited by soy phytate than by soy fiber.
so, you can eat high phytate foods but your zinc intake also has to be high or you start seeing the negatives of low zinc manifested in the various ways experienced by ms patients.