The coining of the word probiotic has ambiguous beginnings, but the widely accepted definition of today--"live, microorganisms, that when administered in adequate amounts, confer a health benefit on the host"--has been established by the World Health Organization (WHO) and the Food and Agricultural Organization of the United Nations (FAO) in their 2002 joint guideline report for "The Evaluation of Probiotics in Food." While the inherent intestinal manifestations of these bacteria assist with bowel movements, and vitamin production and absorption, the conferred benefits associated with supplementation can affect nearly every system of the body.
Diarrhea
There are three major families of probiotics including Lactobacillus, Bifidobacteria, and the yeast, Sacchromyces boulardii. The probiotics inherent to the human gut maintain homeostasis by consistently keeping the levels of bad, disease-causing bacteria low. According to the National Center for Complementary and Alternative Medicine (NCCAM), disruption of this sensitive balancing act can develop into illness. Imbalances may occur secondary to prolonged or chronic use of antibiotics, which kill both good and bad bacteria; as well as invasion by "unfriendly" bacteria, yeast, fungi and parasites. According to the article "Clinical Applications of Probiotic Agents," published in the American Journal of Clinical Nutrition, different strains of probiotics prove effective in the prevention and treatment of diarrhea caused by Clostridium difficile, traveler's diarrhea, antibiotic-associated diarrhea, as well as preventing diarrheal diseases in children.
Eczema
In the "Introduction to Probiotics" article, NCCAM discusses current interests in probiotic research, namely the intimate relationship between the gut and the immune system. Interests lie in how oral probiotic administration can influence systemic immune regulation. In early childhood, the immune system becomes primed to recognizing self versus non-self. The 2006 review article, written by S. Parvez, et al. and published in the Journal of Microbiology, suggests that the introduction of milk proteins can cause a developing immune system to become hypersensitive and lead to reactive states of atopic dermatitis, or eczema. According to the "Clinical Applications of Probiotic Agents" article, "intestinal microflora can contribute to the processing of food antigens in the gut and probiotics could modify the structure of potential antigens and reduce their immunogenicity." Some lactobacillus strains effectively moderate the allergic response and relieve eczematous states.
Lactose Intolerance
Fermentation is an ancient process used to preserve foods that would have otherwise spoiled. Probiotics initiate the fermenting process; turning milk into yogurt and cabbage into sauerkraut. The fermentation of milk produces the intermediate, lactic acid. Parvez, et al. states that the "lactic acid of the yogurt alleviates the symptoms of lactose intolerance in lactase-deficient individuals."
Vaginal/Urinary Tract Infections
A 2003 article, discussing the "Potential Uses of Probiotics in Clinical Practice" detailed how oral supplementation of lactobacilli leads to the transfer of friendly bacteria from the rectum into the vaginal and urinary tracts. Urinary tract infections in women are most commonly due to the colonic bacterium known as E-coli, while vaginal infections generally result from microorganisms that become dominant under opportunistic environments. Parvez, et al. suggests that lactobacilli, whether ingested orally or vaginally inserted, inhibit disease-causing, bacterial and yeast growth by producing an unfavorably, acidic environment.
Other Uses
The beneficial use of probiotics have also been investigated for the treatment of inflammatory bowel disease, the prevention of bowel cancer, and both treatment and prevention of H-pylori infections, the number one cause of peptic ulcers. The mechanisms by which probiotics act on these conditions is further elucidated in the article "Potential Uses of Probiotics in Clinical Practice."
References
- American Journal of Clinical Nutrition: "Clinical Applications of Probiotic Agents"
- Clinical Microbiology Reviews: Potential Uses of Probiotics in Clinical Practice
- Journal of Applied Microbiology: "Probiotics and their Fermented Food Products are Beneficial for Health"
- National Center for Complementary and Alternative Medicine: An Introduction to Probiotics
- WHO/FAO: Guidelines for the Evaluation of Probiotics in Food
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