Answer: Polyglycitol syrup is just a blend of other non-keto sweeteners, so it is also not keto friendly.
Polyglycitol syrup is a type of hydogenated starch hydrolysate (HSH) syrup. It's a mix of maltitol and sorbitol, both of which are non-keto sweeteners.
Polyglycitol syrup has a glycemic index of 39, meaning that it will spike your blood sugar and interfere with ketosis.
Safety is a concern with any artificial sweetener. There's fierce debate over the safety of many sugar substitutes. Eliminating sugar is great, but nobody wants a replacement that's going to cause health complications.
A 2009 review by the European Food Safety Authority found no significant safety concerns with Polyglycitol syrup.
The European Food Safety Authority found that as little as 1 g of polyglycitol syrup can cause gastrointestinal distress. Large quantities can have a laxative effect, so make sure you have easy access to a bathroom if you decide to eat a ton of candy with polyglycitol syrup.