This is a new, and so far unreplicated study. I did a bit of a research dive on xylitol as I use xylitol gum when I can't brush (and toothpaste with xylitol when I can - but that's not swallowed) as it's toxic to streptococcus mutans.

I was concerned about effects on my microbiome. Turns out it's associated with positive population changes in the microbiome (including increased akkermansia, which correlates with positive health outcomes).

The study you reference is behind a paywall. I'd like to read it, particularly the methods section but haven't ponied up the $$ for a one-time read. Fortunately, most researchers *do* belong to organizations that give them access, so we'll see the (to me surprising) connection between ingested xylitol and serum levels either replicated - or not within a year or so (short term study, not sure how may subjects would be needed for a decent p value but probably under 50).

That said, insulin spikes aren't good for us and anything that tastes sweet can cause a 'cephalic' insulin response.