Dieters often neglect the role that proper digestion plays in losing weight. Optimizing your digestive system can help improve nutrient absorption, prevent indigestion, and enhance the immune system. Popular digestive aids include probiotics, enzymes, and fiber supplements. Probiotics are friendly bacteria that inhabit your digestive tract and help to break down nutrients in food meals as well as defend against harmful bacteria. Digestive enzymes help break down proteins, fats and carbohydrates into smaller constituents so your body can efficiently use them. Fiber supplements help to control appetite, slow nutrient absorption, reduce glycemic load, eliminate bodily toxins and reduce constipation.