We don't usually think of bacteria as a good thing, but in the right places and amounts, strains of beneficial bacteria called probiotics, and the prebiotics that feed them, are valuable to our health.
Under normal circumstances, friendly bacteria live in our digestive tract in a healthy balance. Within the colon there are over 500 bacterial species, making up about 95% of cells in the body. The good bacteria (microflora) in our gastrointestinal tract play a significant role in our health. These good bacteria break down vitamins and also ferment fibres and carbohydrates that are not digested in the upper GI tract to create 10% of our daily energy. They also help the body fight infection and disease by acting as an effective barrier; allowing nutrients to be absorbed, and keeping out toxins and pathogens (foreign bacteria or viruses). However, factors like poor diet, or medications including birth control pills, antibiotics and corticosteroids, can upset this balance and lead to a host of difficulties.
WHAT ARE PROBIOTICS AND PREBIOTICS?
Probiotics are cultures containing live microorganisms (good bacteria) which, when taken in adequate amounts, results in a health benefit on the host. Probiotic microorganisms can be found in both supplement form and as components of foods and beverages. Certain yogurts and other cultured dairy products contain such helpful bacteria, particularly specific strains of Bifidobacteria and Lactobacilli. Not all bacteria present in fermented milk products or yogurt have a probiotic effect. For this reason, in order to consider a Lactobacillus or Bifidobacterium a probiotic, the specific strains selected must exert a clinically established health benefit.
Prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth of one or a limited number of bacterial species in the colon, such as Bifidobacteria and Lactobacilli, which have the potential to improve host health. Prebiotics are, simply speaking, the “food” for beneficial bacteria. Prebiotics are found in whole grains, bananas, onions, garlic, honey and artichokes.
Probiotic bacteria taken together with prebiotics that support their growth are called “synbiotics.” Both work together in a synergistic way more efficiently promoting the probiotics’ benefits. Fermented dairy products, such as yogurt and kefir, are considered synbiotic because they contain live bacteria and the fuel they need to thrive.
ACTIONS OF PROBIOTICS AND PREBIOTICS:
Consumption of probiotics, particularly certain species of Bifidobacteria and Lactobacilli, can help balance the flora, increasing the number of helpful bacteria, and inhibiting the growth of harmful bacteria, in the intestine. Consumption of probiotics can also modify the gut immune response and improve its barrier function. More recently, probiotics have also been shown to modulate the activity of the immune system, helping to control or reduce the development of certain allergies. There’s encouraging evidence that probiotics may help:
* Treat diarrhoea, especially following treatment with certain antibiotics
* Prevent and treat vaginal yeast infections and urinary tract infections
* Treat irritable bowel syndrome
* Reduce bladder cancer recurrence
* Speed treatment of certain intestinal infections
* Prevent and treat eczema in children
* Prevent or reduce the severity of colds and flu
The principal characteristic and effect of prebiotics in the diet is to promote the growth and proliferation of beneficial bacteria in the intestinal tract, and thus, enhance the effect of probiotic bacteria. Prebiotics have also been shown to increase the absorption of certain minerals, such as calcium and magnesium. Prebiotics may also help inhibit the growth of lesions, such as adenomas and carcinomas in the gut, and thus reduce the risk factors involved in colorectal diseases.
SUPPLEMENT FORMS OF PREBIOTICS AND PROBIOTICS:
THE VERDICT ON PREBIOTICS AND PROBIOTICS:
Prebiotics and probiotics produce a favourable potential impact on the balance of the body’s microflora, and thus directly or indirectly in their enhancement of the function of the gut and systemic immune system. Although benefits vary, depending on the type and amount of a prebiotic or probiotic consumed, daily consumption of foods containing these functional components is beneficial. In addition, effects of probiotics are strain-specific and must be demonstrated through appropriate clinical trials.