ISSA Nutritionist Practice Exam 2025 - Complete Preparation Guide

A key characteristic of soluble fiber is that it dissolves in water. This property allows soluble fiber to form a gel-like substance when mixed with liquids, which plays a significant role in various physiological benefits. For example, soluble fiber can help to lower cholesterol levels by binding to bile acids and cholesterol in the intestines, promoting their excretion from the body. It also aids in regulating blood sugar levels by slowing down the absorption of sugars, providing a more gradual release of glucose into the bloodstream.

The other options do not accurately describe soluble fiber. Soluble fiber is not high in protein; it is primarily composed of carbohydrates. It does not contain gluten, as gluten is a specific type of protein found in wheat and related grains. Furthermore, soluble fiber is not digested in the stomach; rather, it is fermented by bacteria in the large intestine, contributing to gut health. Understanding these characteristics helps to appreciate the important role of soluble fiber in a balanced diet.