Probiotics: good for what's bugging you: an update of the latest research and trends in the probiotics arena.
The term probiotics is a combination of Greek and Latin words meaning, "for life." The scientific definition is slightly more defined: "live microorganisms administered in adequate amounts that confer a health effect on the host." More than 400 types of bacteria are thought to reside in and on the body. In healthy people, they outnumber human cells ten to one but just how they work is not yet understood. What is known is that they've been around longer than the hills--or mountains.
From Russia With Love: Roots of Natural Probiotics
The roots of probiotics can be traced back more than 2000 years to the Caucasus Mountains of Russia, where people live well past 100 years. Kefir, a cultured dairy drink credited with possessing an array of health benefits, was first discovered by nomadic shepherds who consumed the fresh milk that fermented in their leather sacks as they traveled.
Fast-forward several hundred years to the early 1900s, when Eli Metchnikoff, a Russian biologist who won the Nobel Prize for his work in immunology, argued that Bulgarian peasants lived long lives because they ate yogurt containing Lactobacillus bacteria. Using a scientific design to support his theory, his work suggested that Lactobacilli might counteract the putrefactive effects of gastrointestinal metabolism. Thus, the interest in probiotics was born.
Good For What Ails You
Probiotics available today can be found in products such as dairy foods, dietary supplements and drugs and the proposed benefits cover a wide range of ailments, including the prevention or treatment of antibiotic-induced diarrhea, acute-infectious diarrhea, travelers' diarrhea, colitis and vaginal infections. Other areas of research include suggested links between probiotic consumption and improved lactose digestion, the lowering of blood pressure and cholesterol, and the reduction of the risk for kidney stones.
A variety of reasons may contribute to the increased need to counteract intestinal enemies with an army of probiotic microbes. The overuse of antibiotics has engendered strains of deadly bacteria resistant to the drugs. There is newly-discovered evidence that allergies may be increasing because of society's overzealous desire to live in a germ-free environment--the abundant supply and use of antibacterial products designed to kill germs on and around us may actually be harming us in the long run. They may be preventing childhood exposure to microbes needed to train the immune system not to overreact during later exposure. Yet an age-old ingredient may be the secret to maintaining a healthy immune system: dairy.
Dairy: The Ideal Probiotic Delivery System
Dairy Management Inc.', (DMI), with funding from America's dairy farmers, is currently supporting several probiotic-based research projects at various universities across the U.S. Many of the projects are still in the preliminary stages. However by the year 2005, DMI plans to have completed a "functional genomic analysis" of probiotic organisms.
"In the U.S., foods containing beneficial probiotic bacteria are almost exclusively dairy products," said Mary Ellen Sanders, a consultant with Dairy and Food Culture Technologies and president of the International Scientific Association of Probiotics and Prebiotics, a newly formed scientific society. "Probiotic bacteria have a long history with dairy products. This is because some of the same bacteria that are associated with fermented dairy products also make their homes in different sites on the human body, including the mouth, the gastrointestinal tract and the vagina. Some of these microbes, therefore, play a dual role in transforming milk into a diverse array of fermented dairy products, meanwhile providing benefits to human health."
Dairy products provide a desirable probiotic delivery vehicle for several reasons. Traveling through the human digestive tract can be dangerous for some bacteria because of high acid levels in the stomach and high bile concentrations in the small intestine. Dairy products such as milk and yogurt help to buffer stomach acid and increase the chance that the bacteria will survive. Additionally, the healthful properties of probiotic bacteria blend with the healthful properties of milk products.
Yogurt is most widely known as the dairy product that contains "healthy bacteria." Approximately 80% of the yogurt manufactured in the U.S. contains Lactobacillus acidophilus added as a probiotic. The Bifidobacterium strain can also be found in dairy products as well. In addition to yogurt, probiotic bacteria have been added to certain types of milk, such as those labeled "Sweet Acidophilus Milk" and some cottage cheeses. Dannon recently introduced a cultured dairy supplement drink called Actimel, which contains a unique combination of beneficial live cultures, including Lactobacillus casei.
Researchers at the Southeast Dairy Foods Research Center (SDFRC), Raleigh, NC, are investigating a potential synergistic effect between components in dairy foods and probiotic cultures. "Dairy foods can be considered the ideal vehicle for reintroducing these beneficial bacteria to the human gastrointestinal system," said Todd Klaenhammer, PhD, director of the SDFRC and National Academy of Sciences member. "Some current evidence indicates that when probiotics are delivered through fermented dairy products, they are likely to show enhanced survival into the gut."
Trends: From Cavity Prevention to a Rotavirus Rescue
Probiotics are here to stay. There are identifiable trends in research looking at new uses for probiotics, such as the evaluation of expanding into other foods including sports bars, frozen yogurt and ice cream and creating blends of strains versus using individual ones. Researchers are also looking at treating non-gastrointestinal ailments with probiotic bacteria.
For example, researchers in Florida have developed a beneficial bacteria that may help prevent cavities. Although more than 100 kinds of bacteria reside in the mouth, the primary one, Streptococcus mutans, is thought to cause cavities by converting sugar from food into enamel-eating lactic acid. The researchers developed a way to knock out the bacterium's ability to make lactic acid. After screening hundreds of isolates from dental patients' mounts, a strain of Streptococcus mutans was found that behaves as a natural antibiotic against other strains. By combining this antibiotic in a novel strain of bacterium, a benign bug was created that could displace the bad bacteria in plaque. Studies suggest that one application, such as consumer ingestion as part of a dairy food, could ward off cavities for years.
Probiotic treatments could be natural alternatives to medications that combat common female health problems. For years, family doctors and OB-GYNs have been using probiotics to help prevent recurrence of urinary tract and vaginal infections. The good bacteria take up residence in the vagina and release hydrogen peroxide, which produces an environment hostile to yeast and other bacteria.
Preliminary studies also suggest that the Lactobacillus GG (LGG) strain, one of the most widely used probiotics, shows promise in treating Crohn's disease and irritable bowel syndrome (IBS), neither of which discriminates between men and women.
Children may also benefit from the use of probiotics. The treatment of milk-allergic toddlers with LGG seems to ameliorate both the extent and severity of allergic eczema. Recent studies from Finland have demonstrated a reduced incidence of milk allergy in toddlers given LGG during infancy. Swedish researchers have also reported that the rate of middle-ear infections in children prone to earaches was halved by an experimental nasal spray laced with alpha-streptococci--bacteria that normally inhabit the nasal passages and ear tubes.
The disorder most thoroughly studied in relation to probiotics is acute diarrhea in children. Lactobacillus rhamnosus GG, for example, has been shown to significantly reduce the duration of acute viral enteritis. Comparable findings have been demonstrated with Lactobacillus reuteri.
With the increase in antibiotic therapy for children also comes an increase in diarrhea-related symptoms. LGG has been shown to reduce the risk of antibiotic-associated diarrhea by approximately 75% in children in studies both in the U.S. and Finland.
Another intriguing area of probiotic research is the use of these microbes for immune regulation. It appears that at least some probiotics may be capable of both down-regulating the allergic response, while enhancing immune response against potential pathogens. For example, LGG has been shown to increase the antibody response to rotavirus infection and rotairus vaccine.
Examining the Next Steps in Realizing Probiotics
In order to achieve the benefits expected by the consumer and manufacturing communities, there are some areas that need to be addressed. One of these areas is probiotic stability. One of the keys to successful long-term marketing of any probiotic is the organism's ability to survive until the time of consumption in levels that have been shown to be effective. Currently, probiotic selection is based on the ability to survive manufacturing conditions, as well as storage and distribution times and temperatures. Researchers at the University of California at Davis are developing a technique to enhance survival of bifidobacteria in dairy foods by entrapping them in a calcium alginate gel.
Another challenge will be developing a regulatory framework. Currently, regulators are searching for ways to define some standards for the many products that are marketed as probiotics.
In addition to the two common probiotic strains--Lactobacillus and Bifidobacterium--there is a small number of bacterial strains that emerging research suggests may be beneficial for several conditions, including diarrhea prevention and intestinal well-being, stomach ulcers, immunity, surgical care and women's urogenital health. Several clinical studies have resulted in the following preliminary findings:
* Combination products, such as those containing L. acidophilus (LA-5), L. bulgaricus (LBY-27), B. lactis (BB-12) and S. thermophilus were shown to reduce episodes of traveler's diarrhea compared to placebo.
* L. rhamnousus GG S. boulardii, a combination of Lactobacillus spp and Bifidobacterium, may significantly lower the incidence of therapy-induced diarrhea and flavor-perception disturbance in H. pylori-positive patients who are neither causing nor exhibiting symptoms of disease.
* In a randomized, double-blind placebo-controlled trial, feeding L. rhamnosus GG to 132 pregnant women and their newborns for six months following birth resulted in significant reduction in the occurrence of atopic dermatitis.
* There is evidence that strains such as L. rhamnosus GR-1 and L. fermentum RC 14 can colonize the vagina and confer health benefits to the host, including reduced risk of colonization and infection by bladder and vaginal bacteria and yeast.
* In 2002, four papers indicated that probiotic Lactobacilli may have a major impact on surgical patient care. Three studies using L. plantarum 299 showed significant reduction in infection rates in abdominal, pancreatic and transplant surgery patients at high risk of morbidity and mortality.
Consumers are Catching on
There's no doubt that the probiotic buzz is circulating. The market for probiotics is expected to grow close to 10% annually for the next five to 10 years. Represented mainly by probiotic yogurts/drinks and dietary supplements, the current market value is estimated to be between $1.2-1.8 billion in sales, with projected revenues to reach $3.5 billion by 2007. Key influencers in the expansion of the probiotic market include physicians, pharmacists and other professional healthcare providers, as well as manufacturers and their marketing strategists.
"The future of probiotics holds much promise," said Dr. Sanders. "However the data supporting their use is still emerging and has limitations."
Some key areas for research include defining biomarkers useful for assessing the impact of probiotics on human health; following up on preliminary studies with confirmatory studies; establishing mechanisms of action; developing dose-response studies; defining the active principle in probiotic products (viable cells, fermentation end-products, cell wall components, etc.); validating in vitro assays; and epidemiologically studying probiotic effects, possibly in populations with significant penetration of probiotic use.
Genomics may also play a key role in the future of probiotic research. "The genomes of five probiotic Lactobacillus and Bifidbacterium strains are already sequenced, and genome sequences of 12 additional probiotic strains are on the way," said Dr. Klaenhammer. "With such extensive genomic data, we plan on designing chips with which to pinpoint genes critical for colonizing, interacting with, and functioning in human tissues, such as the gut and vagina, and to knock out specific bacterial genes to evaluate their roles in these host-related interactions. The field is now positioned to do the right microbiology and the right clinical trials."
From the Caucasus Mountains in Russia to the dairy cases of today's supermarkets, probiotics have proven to be a viable asset to human health and survival. Realizing the full potential of probiotics will take a long time, but the case for ongoing research and consistent consumer education is as strong as it has ever been.
This article in a nutshell:
* The origin of probiotics
* Health benefits
* Dairy as delivery
* Probiotic trends
* Examining the next steps in realizing probiotics
* Efficacious strains
* Consumers are catching on
About the author: Amy Skovsende is director--Technology Marketing for Dairy. Management, Inc. (DMI), Rosemont, IL. DMI is the domestic and international planning and management organization that builds demand for U.S.-produced dairy products on behalf of America's dairy farmers. Ms. Skovsende can be reached at 800-248-8829; E-mail: email@example.com; Website: www.extraordinarydairy.com.
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|Date:||Sep 1, 2003|
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