NANP Board Practice Exam

Fructooligosaccharides (FOS) are considered prebiotic carbohydrates primarily due to their unique ability to bypass degradation in the upper digestive tract. Instead of being broken down and absorbed in the small intestine, they travel to the large intestine intact. Here, these carbohydrates serve as a food source for beneficial gut bacteria, promoting their growth and activity. This process enhances gut health and contributes to the overall balance of the gut microbiome, which is a key characteristic of prebiotics.

In contrast to the other options, while immediate energy might be a characteristic of some dietary carbohydrates, prebiotics specifically work by supporting beneficial gut flora rather than providing energy. The absorption of carbohydrates into the bloodstream is not a feature of prebiotics; rather, prebiotics are intended to reach the large intestine where they can exert their beneficial effects. Thus, the primary reason fructooligosaccharides are classified as prebiotic carbohydrates is their ability to reach the large intestine undigested and to fuel the growth of beneficial microorganisms.