My dog has ate xylose, google makes me think it is the same as xylitol which is very toxic but the rang the vets and they didn’t seem interested…
AFAIK, xylose is the sugar form (reasonably safe) and xylitol is the alcohol form (and toxic to dogs).
This article on xylose in dog food may ease your mind. https://www.researchgate.net/publication/337186238_Beynen_AC_2019_Xylose_in_petfood
Hope your dog is ok.