Which of the following statements is true of xylitol?

Xylitol is indeed a five-carbon (not "five chain") sugar alcohol that is commonly derived from birch trees and other plants. It is a type of sugar substitute that is known for its dental benefits. One of its primary advantages is its non-cariogenic nature, meaning it does not contribute to tooth decay.

The reason this statement is accurate lies in the structure of xylitol. Unlike traditional sugars, xylitol cannot be fermented by the bacteria that cause tooth decay, such as Streptococcus mutans. This characteristic is a result of its unique chemical structure, making it more beneficial for oral health. It also helps in maintaining a neutral pH in the mouth, which is critical for reducing the risk of caries.

In contrast, the other statements about xylitol contain inaccuracies. For example, xylitol does not allow sucrose to bind with cariogenic bacteria; instead, it competes with other sugars for uptake by these bacteria. Furthermore, it actually promotes salivary flow and does not decrease oral pH, which is advantageous for remineralizing teeth. Lastly, xylitol is not fermented by mutans streptococci, which differentiates it from sucrose and other fermentable carbohydrates that are