psyllium
polydextrose
It may cause problems to sensitive individuals.
Caution
May cause symptoms in more sensitive people. Track your own reaction.
Polydextrose is a synthetic fiber that is not histamine-containing in and of itself. However, in some people with histamine intolerance, it may cause digestive problems that can be mistakenly interpreted as a reaction to histamine.
Safer alternatives
Suitable
Ascorbic acid (vit. C synthetic)
baking soda
Generally considered safe for most individuals with histamine intolerance.