Final answer:
Dietary fibers with high water-holding capacity, such as soluble fibers, are known to help normalize blood glucose levels, increase stool bulk, and reduce blood cholesterol levels, but they do not increase appetite. Instead, they can contribute to a feeling of satiety. The correct answer is option: a. normalize blood glucose levels.
Step-by-step explanation:
The question asks about the functions of dietary fibers, particularly those with high water-holding capacity that form gels. These functions include normalizing blood glucose levels, increasing stool weight and fecal volume, and reducing blood cholesterol levels. However, they do not include increasing appetite, which is the exception listed among the options.
Soluble fibers, which dissolve in water to form a gel-like substance, can lower blood cholesterol and glucose levels by slowing down digestion and absorption. This process can help in managing diabetes and cardiovascular health. On the other hand, insoluble fibers provide bulking and aid in regular bowel movements by absorbing water as they pass through the gastrointestinal tract.
Overall, fibers like cellulose, beta-glucan, and psyllium have various benefits for digestive health, but they are not linked to an increase in appetite; instead, they may contribute to a feeling of fullness which could lead to a reduction in appetite.