References:
https://www.ncbi.nlm.nih.gov/pubmed/28271513 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070655/
For me, cutting gluten and fried foods out of my diet entirely minimized my stomach woes. The gluten thing came about after I was tested for antibodies when my son was diagnosed with type 1 diabetes. So, lucky, not lucky I guess.
You could also conceivably make your own pills, which at least in my experience nobody will question: https://www.amazon.com/Cap-M-Quik-Tamper-Capsule-Filling-Mac... (I don't make my own pills, but I've carried around a variety of pills that look like they were made that way.) But for baking soda that's probably a little elaborate, plus I don't know what happens if you take baking soda that way rather than in water.
I've done keto and it worked for me, could have been the elimination of gluten in retrospect. Haven't tried the probiotics.