Probiotics, Prebiotics, Fiber And Cholesterol

What are probiotics and their benefits?

1. Probiotics are microbial foods or supplements that prevent or reduce the colonization of pathogenic flora and reestablish normal gut flora.
2. The microbial strains that prove to be the most beneficial are Lactobacillus and Bifidobacterium.
3. There are several clinical applications for probiotics which include treatment of antibiotic-associated diarrhea, urinary tract infections, and Candida vaginitis, reduction in Clostridium difficile, the management of hepatic encephalopathy, and the reduction in serum cholesterol levels.
4. Potential benefits may also include management of inflammatory bowel disease and the prevention of cancer.
5. Food sources of probiotics consist of dairy products with live microorganisms such as yogurt and culture-added milks.
6. Other forms of probiotics are capsules, tablets, and powders but the amount of viable bacteria is often lower than what the label claims.

What are prebiotics, their functions and benefits?

1. Prebiotics are nondigestible food ingredients that stimulate the growth or activity of specific bacteria in the colon.
2. The major prebiotics are transgalactosylated disaccharides, fructooligosaccharides (FOSs), xylooligosaccharides, and soybean oligosaccharides.
3. The most well-known prebiotic is FOS. FOSs resist enzyme hydrolysis by the small intestine and arrive in the colon completely intact. While in the colon bacteria ferment them, producing energy, short chain fatty acids, and various gases. Fermentation allows an increased production of Bifidobacterium, which proves to be beneficial to the health of the host. Increased levels of Bifidobacterium have shown to increase calcium absorption and decrease the growth of potential pathogens.
4. Foods with a high FOS content include chicory, onions, and bananas. In addition, FOSs have been added to beverages and dietary supplements (e.g., they appear as inulin or FOS on the ingredient list on food labels).

What is dietary fiber and what are its benefits?

1. Fiber refers to carbohydrates and related substances in the diet that are not digestible; therefore, it is not classified as a nutrient.
2. Fiber does perform several physiological functions in the gastrointestinal (GI) system. The primary properties of fiber in the gut seem to be (a) its hydrophilic capacity, which increases stool bulk and decreases transit time, (b) its ability to bind other dietary substances, so that changes in the fiber in the gut seem to be its hydrophilic capacity, which increases stool bulk and decreases transit time, and (c) its ability to bind other dietary substances, so that changes in the fiber content of the diet will alter absorption and bioavailability of both nutrients and toxins.
3. The physiological consequences have been shown to affect the control of diabetes mellitus, disorders of lipid metabolism, and obesity. Fiber content of the diet may also affect the incidence of some cancers. Another positive aspect of fiber ingestion is fiber fermentation. All fibers, except lignin, can be fermented by the gut bacteria and produce components known as short-chain fatty acids (SCFAs).
4. The three most common fatty acids produced are propionate, acetate, and butyrate. Each of these provides energy to the colonocytes, but only butyrate has trophic effects on the colonocytes. The more soluble the fiber (pectins, gums, mucilages), the greater is the SCFA production.

What is cholesterol and its role in human body?

1. Cholesterol is a member of the sterol group of organic compounds. It is derived from fats and can be synthesized endogenously in quantities sufficient to meet metabolic demand.
2. Cholesterol is an integral part of cell structures and a precursor of some hormones and vitamin D.
3. Cholesterol is present in some foods and is absorbed during the process of digestion. Dietary sources of cholesterol may be associated with the development of atherosclerosis.