FWIW, the long term result (post this article) was to recommend that no such thickeners be administered to anyone under 12 months of age (it was not only neonates who suffered). This was was an observational response pending any actual study of the cause (whether manufacturing or inherent to the source material)
I’m not aware of any subsequent study but the result is not unreasonable.
Also the current recommendation is to consult the doctor if the child is under 12 years old, but doctors still continue to prescribe thickeners based on xanthan gum or any other gums.
I’m not aware of any subsequent study but the result is not unreasonable.