By: Pooja Sarkar
PROBIOTICS: – In modern times we have turned to the use of supplements of beneficial bacteria, known as probiotics. The word probiotic, a Greek word, meaning “for life.” Probiotics are live microorganisms that when administered in adequate amounts confer a health benefit on the host (UNFAO/WHO 2001).Probiotics are now becoming more widely used, usually in the forms of foods or supplements. Probiotics are frequently recommended by physicians.
Worldwide, a diverse array of probiotic products is on the market. Yogurt is perhaps the most common probiotic-carrying food, but the market has expanded beyond yogurt. Cheese, fermented and unfermented milks, juices, smoothies, cereal, nutrition bars, and infant/toddler formula all are food vehicles for probiotic delivery. In addition to being sold as foods, probiotics are sold as dietary supplements, medical foods, and drugs (although there are no probiotics currently sold as drugs in the United States). Often these products are composed of concentrated, dried microbes packaged into capsules, tablets, or sachets.
CHARACTERISTICS OF PROBIOTICS:
- It should be nonpathogenic, nontoxic, and free of significant adverse side effects.
- It must retain stability during the intended shelf life of the product.
- It contains an adequate number of viable cells to confer the health benefit.
- It should be compatible with product format to maintain desired sensory properties.
- It should be labeled in a truthful and informative manner to the consumer.
Alleged health effects of probiotics:-
- Relieve effects, promote recovery from diarrhea (rotavirus, travelers’ and antibiotic-induced)
- Produce lactase, alleviate symptoms of lactose intolerance and malabsorption
- Relieve constipation
- Treat colitis
- Reduction of Helicobacter pylori infection
- Relieve irritable bo
- wel syndrome
Immune system effects
- Stimulate humoral and cellular immunity
- Inhibit pathogen growth and translocation
- Stimulate gastrointestinal immunity
- Reduce chance of infection from common pathogens (Salmonella, Shigella)
- Reduce risk of certain cancers (colon, bladder)
- Detoxify carcinogens
- Suppress tumors
- Reduce cholesterol and plasma triglycerides
- Reduce blood pressure in hypertensives
- Reduce allergic symptoms
- Synthesize nutrients (folic acid, niacin, riboflavin, vitamins B6 & B12)
- Increase nutrient bioavailability
- Improve urogenital health
- Optimize effects of vaccines (e.g. rotavirus vaccine, typhoid fever vaccine)
[According to the, a conference that was cofunded by the National Center for Complementary and Alternative Medicine (NCCAM) and convened by the American Society for Microbiology in November,2005.]
Key genera and species of microbes studied and used as probiotics:-
L. acidophilus L. plantarum
L. rhamnosus L. fermentum
PREBIOTICS: Prebiotics may be defined as non-digestible or low-digestible food ingredients that benefit the host organism by selectively stimulating the growth or activity of one or a limited number of probiotic bacteria in the colon to improve host health.
The fermentation of prebiotics produces short-chain fatty acids, namely acetate, butyrate and propionate, which are not digested or poorly digested in the small intestine and stimulate the probiotic bacteria administered to humans. Complex carbohydrates pass through the small intestine to the lower gut where they become available for some colonic bacteria but are not utilized by the majority of the bacteria present in the colon. Their presence reduces colonic pH, which inhibits growth and activity of pathogens.
PREBIOTICS COMMONLY USED IN HUMAN NUTRITION:
- Galactooligosaccharides (GOS)
- Fructooligosaccharides (FOS)
- Inulin and its hydrolysates
- Sugar alcohols (such as lactitol, sorbitol and maltitol).
Some prebiotics occur naturally in foods such as leek, asparagus, chicory, Jerusalem artichoke, garlic, artichoke, onion, wheat and oat, as well as soybean. Now a days, many prebiotic compounds are added to many foods including yogurts, cereals, breads, biscuits, milk desserts, nutrition bars, ice-creams, spreads, drinks, water, infant formula, as well as to some animal foods.
CHARACTERISTICS FOR PREBIOTICS:
- It should be resistant to the degradation by stomach acid, mammalian enzymes or to hydrolysis.
- The intestinal microbes should be capable of performing fermentation (breakdown, metabolism) of the prebiotic.
- There should be selective stimulation of the growth and/or activity of positive microorganisms in the gut by the prebiotics.
- Good prebiotics are stable under heat and when dried, and can be stored at room temperature for months. The product should be free of any danger to human and animal health.
- All the products are generic and the information on the label must not mislead the user.
In practice, combined mixtures of probiotics and prebiotics are often used because their synergic effects are conferred onto food products. The term synbiotic has been proposed for such combinations. A synbiotic has been defined as “a mixture of prebiotics and probiotics that beneficially affects the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract, by selectively stimulating the growth and activating the metabolism of one or a limited number of health promoting bacteria, and thus improving host welfare”.
WHO BENEFITS MOST FROM PROBIOTICS:- The people who benefit most from probiotics are those who are most susceptible to infections, those who have disorders involving diarrhea, those people taking antibiotics, and pregnant and nursing mothers, and people undergoing radiation treatments of the pelvis or abdomen. These people will see the greatest difference in their health by using probiotics regularly.
SIDE EFFECTS AND RISKS:-
- Probiotics’ safety has not been thoroughly studied scientifically, however. More information is especially needed on how safe they are for children, young, elderly people, and people with compromised immune systems.
- An important problem with the use of probiotics is the maintenance of viability to produce beneficial effects to the consumer.
- The probiotics need to survive in several environments including processing treatments, storage conditions and human body conditions. The ability to live through the stressful acidic conditions and bile solutions in human body vary among the strains of probiotic bacteria.
- Probiotic products taken by mouth as a dietary supplement are manufactured and regulated as foods, not as drugs, so care must be taken.
FUTURE RESEARCH IN THE PROBIOTICS AREA:-
· The future research in the field of probiotics may be related to determine the physiological role, mechanisms of action, and extent of influence of probiotics on human health using human feeding studies.
· Validating the biomarkers used for assessing probiotic function.
- Assess effects of probiotics on populations and activity of gut microbes. The application of gene based methods holds much promise in this field.
- Determine the role of probiotics as part of a whole food compared to isolated component.
- Conduct research to improve product formats, consumer acceptance, stability, and efficacy of probiotic-containing products.