The increase in consumer awareness of health, the rise of low-carb diets and the high-fiber focus that followed have all brought prebiotics into the limelight. Many ingredient suppliers are offering prebiotic ingredients that are high in fiber and relatively easy to incorporate into baked foods.
PRE VS. PRO
First, a lesson on the difference between prebiotics and probiotics. Prebiotics are nutrients that probiotic bacteria use as fuel sources. These include dietary fiber and carbohydrates that resist absorption in the upper small intestine, reaching the lower large intestine where most such bacteria thrive. Probiotics are cultures of bacteria living in the human gut that are healthful for normal intestinal function. Probiotics can prevent harmful bacteria from causing disease. Pro — O — are bacteria that Operate in the human gut. Pre — E — is what they Eat.
Prebiotics, such as inulin, short-chain fructo-oligosaccharides (FOS) and oligofructose help maintain a healthy level of probiotic bacteria in the gut by creating a hospitable atmosphere. Because they are versatile, prebiotic ingredients can be used in a variety of foods and formats.
Because it is more familiar to consumers, the most popular use is as a source of dietary fiber, according to the project leader at an ingredient supplier. Prebiotic fiber ferments in the lower digestive tract, where it is a primary food source for the microflora (probiotics) that live there. "For a fiber to be a true prebiotic, it should nourish only those microflora that are beneficial and not harmful or pathogenic bacteria," said the manager of scientific affairs for a company that produces natural prebiotic fiber.
Not all fibers are created equal. While insoluble fiber promotes regularity, prebiotic fiber has greater nutraceutical benefits. "Flourishing beneficial bacteria use prebiotic fiber as a food source and produce short-chain fatty acids (SCFAs), which are critical to colon structure and integrity, as a byproduct," a supplier noted. "The SCFAs also serve to build and enhance the immune structures in the colon that are crucial for good health.
Butyrate, one of the SFCAs produced, promotes the growth of bifidobacteria and is known to prevent tumor growth. "The more butyrate produced, the more beneficial to the body," noted the vice-president of application technology and technical services at one ingredient company. "Since non-fermentable fiber does not promote the growth of prebiotic microflora, the benefit to the immune system is lost unless prebiotic fiber is included in the diet."
The supplier pointed out that nourishing beneficial microflora results in numerous other health benefits that are not realized with regular fiber. Studies have shown that prebiotic fiber increases calcium absorption and increases soy isoflavone and magnesium absorption, making it invaluable when formulating for bone health, in addition to digestive health and immunity. (See Page 61 for more information on calcium fortification.)
Prebiotic properties of resistant starches and fiber in general make them a digestive aid. Fiber fosters satiety and promotes gastrointestinal health. Since constipation may affect up to 20% of people over age 65, FDA encourages the elderly to eat foods rich in dietary fiber because it acts as a prebiotic that normalizes and supports healthy bowel function.
Prebiotic ingredients available are numerous. One company produces a glucose polymer that is 90% prebiotic fiber. This ingredient can help make baked foods, cereals and nutrition bars sugar-free, lowglycemic and low-caloric. Inulin, a fiberlike ingredient widely recognized for its prebiotic qualities, can boost the body’s immune function and reduce cardiovascular health risks. Another producer of resistant starches said its products are used in foods for dietary fiber enhancement and caloric reduction and deliver 70 to 80% total dietary fiber with lower water holding capacity.Adding these fiber ingredients to baked foods not only increases the health benefits of the finished product, but also is easy to do because many of them are highly soluble, neutral tasting, non-gritty and white or colorless.