Xylitol is a 5-carbon molecule that is similar to a monosaccharide (simple sugar molecule), except without a carboxyl functional group (carbon double-bonded to an oxygen, written C=O). It's classified as a polyalcohol. read more
Fructose looks much the same, only with different placements of the -OH and C=O groups. Sucrose is a disaccharide (two sugars joined by an oxygen) molecule made up of two glucose molecules. It's the only one of the sugars you mentioned that "contains" another sugar, although using the word "contain" is a bit misleading. read more
Sucrose, or ‘normal’ sugar, is made up of equal parts of fructose and glucose. So those with fructose malabsorption can often tolerate normal sugar when they cannot tolerate fruit or high fructose sweeteners such as honey, maple syrup or HFCS. But, sugar alcohols (sorbitol, mannitol, xylitol and all other sweeteners ending in ‘ol’) actually make fructose absorption more difficult, so they too can cause problems. read more
Dr. Peldyak uses visual aid chains to illustrate the many types of sugar chains, and why xylitol functions differently than fructose, glucose, dextrose, and other 6-carbon molecules. As a 5-carbon molecule, xylitol has a smooth surface with a lack of bonding sites. read more