Artificial & Natural
Often, artificial ingredients are used to improve a product by making it one or more of the following: better tasting, safer, less expensive but deliver the same basic nutritional value with fewer calories. Artificial sweeteners (e.g. Sucralose, Acesulfame Potassium) are used in order to reduce total sugar content. All approved sweeteners and infinitesimal amounts of binders (as used in supplements) used in many products are perfectly amenable to the human digestive system and 100% safe for the general population (see FDA, ADA and Generally Regarded as Safe [GRAS] list for position on sweeteners, binders, etc). Additionally, artificial substitutes (e.g. sweeteners, colorings, flavorings, binders, etc.) are often safer than the "natural" counterpart because of common natural food allergies.
Notes on the use of "natural" in any statement
"Natural" can be very misleading, since natural ingredients, including flavorings, sweeteners or colorings, seldom come straight from nature and are extracted and processed in labs. Furthermore, there may be little to no difference between natural and an artificial ingredient/flavor, since they often contain the same key chemicals. The use of artificial flavorings/colorings saves plants from destruction and gives products a longer shelf life, which is important when sitting in your pantry or refrigerator. Additionally, and contrary to popular belief, natural flavorings/colorings are NO safer than artificial ones - some people may be even more likely to be allergic to them. And finally, to say you actually consumed natural vitamin such as C, you would have had to consume a food source- untouched - that contains the vitamin, such as a fruit or vegetable - thus it was directly from nature.
Sugar Alcohols
Sugars are considered short-chained carbohydrates (1-2 units) that yield 4 calories per gram. Sugar alcohols consist of a slightly different sugar molecule that does not stimulate an increase in blood glucose thus used in foods/fluids for diabetics. Sugar alcohols such as sorbitol, xylitol and mannitol are found naturally in many plants and fruits. They are now a common ingredient in sports nutrition bars or mixes because they improve taste, and help control blood sugar while sweetening the product with fewer calories (especially when combined with high intensity artificial sweeteners) since sugar alcohols only yield ~2-2.5 calories per gram. The lower calories effect is because not all of this type of sugar is absorbed, thus some passes through the digestive track which is the reason a very small percentage of users may get slight stomach/intestinal discomfort or a laxative effect. Sugar alcohols are perfectly safe and often a healthier alternative to conventional sugars/carbohydrates when consumed in the amounts found bars and mixes.