Xylitol vs Maltodextrin: which is worse?

What is Xylitol?

Xylitol is a five-carbon sugar alcohol (pentitol) naturally found in birch wood, corn cobs, fruits, and vegetables. It has the same sweetness as sucrose but provides 40% fewer calories and does not raise blood glucose or insulin levels. Most commercial xylitol is produced from xylose derived from corn cob or hardwood hemicellulose hydrolysis.

What is Maltodextrin?

Maltodextrin is a polysaccharide derived by partial hydrolysis of starch — most commonly corn starch in the US, but also wheat, potato, or rice starch. It is a white powder with a mild, slightly sweet taste and is highly soluble. Despite being classified as a carbohydrate, maltodextrin has a high glycemic index (GI of 85–105), often higher than table sugar.

Documented risks

Xylitol: Xylitol is safe for humans at normal consumption levels. Like other sugar alcohols, it can cause osmotic diarrhea and gastrointestinal upset at doses above 40–70 g/day. Critically, xylitol is highly toxic to dogs — even small amounts (0.1 g/kg body weight) can cause severe hypoglycemia and hepatic failure in canines, as documented in multiple veterinary case reports. The FDA and ASPCA have both issued warnings about xylitol pet toxicity. For humans, it is well-tolerated and has dental benefits.

Maltodextrin: Maltodextrin's very high glycemic index (GI 85–105) means it causes rapid blood glucose spikes, potentially problematic for people with diabetes or insulin resistance. A 2012 study in PLoS ONE (Bhatt et al.) found that maltodextrin suppressed beneficial gut bacteria (like Lactobacillus) and increased Escherichia coli biofilm formation associated with Crohn's disease. A 2022 study in Nutrients noted maltodextrin's potential to disrupt gut microbiome composition at typical dietary intakes. Regulatory agencies have not restricted its use, but nutrition researchers increasingly flag it as a low-quality carbohydrate.