Asafoetida tastes like garlic but does not ferment - replace garlic with it and then try reintroducing. Try eating raw vegetables or pho style (where the veggies cook lightly in the broth after being served but not enough to become easily fermented and soluble). What you are aiming for is high insoluble fiber and limited soluble fiber - so you can still eat things high in insoluble fiber like banana, bok choy, green beans, nuts.