Ranking of emulsifiers/thickeners and other problematic additives?

Our son’s doctor is letting us try any research-based non-medication intervention we want before trying a new med since inflammation has gone down to borderline and he has been off steroids for quite a while. Calprotectin was never higher than 150ish. No official Crohn’s diagnosis, but there was mild inflammation at terminal ileum and illeal…
Ranking of emulsifiers/thickeners and other problematic additives?