Psyllium. This fiber is considered one of the best types of fiber due to extensive research supporting its effectiveness. It is suggested to help lower cholesterol, manage blood glucose levels, and acts as a stool softener. Additionally, it may aid in managing certain irritable bowel syndrome symptoms and may support weight management.Psyllium. This fiber is considered one of the best types of fiber due to extensive research supporting its effectiveness. It is suggested to help lower cholesterol, manage blood glucose levels, and acts as a stool softener. Additionally, it may aid in managing certain irritable bowel syndrome symptoms and may support weight management.