We are all familiar with the term ‘probiotics’ – those ‘good’ bacteria that keep the bad bacteria in our gut at bay. Now there is a new buzzword doing the health rounds – ‘prebiotics’. Prebiotics are fast gaining interest and respect as a broadening field of research reveals how they have always played a crucial role in the maintenance of our health. Read on to find out how pre- and probiotics together create an intestinal symbiosis that benefits us, the host.
WHAT’S THE DIFFERENCE?
Probiotics and prebiotics are two different things although probiotics are dependent on the latter for optimum functioning. Probiotics are live microorganisms (bacteria), and prebiotics are a form of dietary fibre and indigestible carbohydrate that ‘feed’ or nurture probiotics so that these beneficial bacteria can perform at their best to keep us healthy.
When the prebiotics and the probiotics combine, as in fermented dairy products such as unsweetened yoghurt, a symbiotic effect is created because the foods contain both the live bacteria and the fuel they require to thrive.
NATURAL COMPONENTS AND NATURAL SOURCES
- Oligosaccharides (indigestible carbohydrates which have three to ten simple sugars linked together) are prebiotics found in thousands of different plant species including the more familiar: chicory root, Jerusalem artichokes, onions, leeks, garlic, legumes, wheat, asparagus, jicama, tomatoes and bananas.
- Inulin is a prebiotic found in as many as 36 000 plants, including: chicory root (from which most commercial inulin is extracted), burdock root, dandelion root, onions, garlic, asparagus, leeks, Jerusalem artichokes, raw apple cider vinegar and mother’s milk.
- Fructooligosaccharides (FOS), a subgroup of inulin, is also a prebiotic and can be added to dairy foods and baked goods.
- Studies are starting to show that lactose (found in dairy products) may be considered a prebiotic.
More than 400 strains of bacteria inhabit the gastrointestinal tract (GI). Many of these are the ‘friendly’ or ‘normal’ micro flora that protect the host from the disease-causing bacteria (and sometimes viruses and fungi) known as ‘pathogens’. The two most beneficial gut micro flora are listed below.
Lactobacillus bacteria are the most common naturally-occurring probiotic in the small intestine. They are found in:
- Mainly yoghurt and kefir (a Turkish type of yoghurt)
- Miso, a fermented soybean paste
- Tempeh (a product originally from Indonesia made from fermenting whole soybeans)
- Unpasteurised sauerkraut
- Some buttermilks, sour creams and cheeses
Bifidobacteria is the most common bacterial species in the colon although some are found in the lower part of the small intestine. Food sources include:
- Fermented dairy products such as yoghurt and kefir
- Fermented teas such as kombucha
- Unpasteurised sauerkraut
Fiona Hunter, British freelance nutritionist, says: ‘Eating foods containing prebiotics or taking prebiotic supplements is good insurance if you are generally healthy. They will help to stimulate the “good” bacteria in your gut and maintain it and your immune system at a healthy level.’2
As research continues to highlight the benefits of prebiotics, food producers are including inulin, oligosaccharides and FOS in their cereals, flavoured waters, breads and cereal bars. In addition to this, prebiotic supplements are becoming more readily available to the consumer.
Probiotic supplements come in various forms including liquids, mouth sprays, chew tablets, powders, capsules, straws, oil-based options and even suppositories. There are a large variety of trusted products available over the counter, which are safe for adults and children alike, and which cater for specific health needs. Consult your health practitioner if you need guidance.
Many probiotic capsules, tablets and powders contain ‘freeze-dried’ bacteria. Freeze-drying is a dehydration process used to preserve perishable material and put it into an easy-to- transport form.
Can one take too many probiotics? According to Mark Timon, who holds a master’s degree in biology from the University of Bridgeport in Connecticut and is author of The Complete Dictionary of Health and Nutrition, the answer is no: ‘The major components of fecal material are sloughed off cells of the intestinal lining (which replaces itself every 7 days) plus expelled probiotic bacteria…. Studies… confirmed that a higher intake of probiotic bacteria results in a higher excretion of probiotics in fecal material. No deleterious effects were noted, but marked benefits were received by those using probiotic supplements.’3
Stress, our deteriorating modernday diet, bad lifestyle choices, and the overuse of an- tibiotics all lead to the decrease of the good bacteria we need in our intestine to remain healthy. Remember, the root of all illness lies in the gut, so the maintenance of the good, well-nourished microflora in the small and large intestines through the symbiosis of prebiotics and probiotics is essential.
What can prebiotics do for you?
Prebiotics offer a health benefit based on the concept of ‘prebiotic effects’. In other words the growth and quality of the good bacteria in our gut is stimulated by the consumption of certain prebiotic-rich foods and dietary supplements. These beneficial changes in the composition, and number, of the good bacteria in the gut, in turn, lead to increased health in the human host.
Ongoing research and studies reveal that prebiotics:
■ Reduce the risk and severity of GI infection and inflammation, including diarrhoea, inflammatory bowel disease, ulcerative colitis, and bowel function disorders, including irritable bowel syndrome.
- Increase the bioavailability and uptake of minerals.
- Reduce the risk of obesity by promoting satiety and weight loss.
- Moderate cholesterol and triglyceride levels: both indicators of heart disease.
- Inulin can reduce atherosclerosis (hardening of the arteries) by 30%.
- Improve the immune system.
- Treat Irritable Bowel Syndrome and Crohn’s Disease.
- May be of use in the treatment of cancer, osteoporosis and diabetes.
What can probiotics do for you?
When there are more bad bacteria than good in the digestive tract, a state of ‘dysbiosis’ occurs and disease-causing pathogens take hold. Supplementation with probiotics will reinstate symbiosis. Many probiotics have the same delivery mechanism and some have unique ways of fighting off pathogens.
- Produce anti-microbial sub- stances such as hydrogen- peroxide that attach to path- ogens and destroy them.
- Produce lactase to aid the digestion of lactose.
- Help to maintain the barrier between undigested food and the blood stream by keeping the lining of the gut healthy and intact.
- Compete with pathogens for nutrients.
- Some work together to benefit the host and some work individually, as seen below:
Irritable bowel syndrome (IBS)
IBS is probably the most common complaint when it comes to digestive disorders, but a combination of Lactobacillus bacteria can bring relief by creating a hostile environment for the bad bugs that cause IBS. Bifidobacterium infantis and Lactobacillus plantarum are also beneficial in their ability to reduce inflammation in the lining of the intestinal tract.6
Diarrhoea is often associated with IBS. Lacto-bacilli and Bifidobacteria have the ability to absorb bile acids thereby reducing the fluids and mucus in the colon that may contribute to ordinary, antiobiotic-induced and IBS-related diarrhoea. Antibiotics kill off the good as well as the bad bacteria.
Ulcerative colitis occurs only in the colon or rectum, where ulcers form. The condition often results in diarrhoea. Research6 has shown that a probiotic combination prevents the onset of acute colitis.
Research suggests that probiotics help keep mucosal surfaces intact, encourage antibody responses, thereby boosting immunity, and increase white blood cell production.3
Pathogens are at their most destructive when they are able to adhere to the intestinal lining (mucosa) where they are then able to multiply. Probiotics prevent pathogen adhesion by dislodging pathogens that have already taken up residence on the GI and by lining the walls of the intestine themselves so that harmful bacteria cannot ‘take root’ there.
Studies reveal that probiotics may also be beneficial in fighting respiratory infections, in- fluenza, herpes and even HIV/AIDS.3
Bifidobacteria lower the risk of colon cancer. Probiotics also metabolise prebiotic fibres from fruits and berries into equol, butyratre, and ellagic acid which also offer protection against cancer.3
Diabetes and heart health
Probiotics play an important role in digestion and consequently in diet-related illnesses. Lactobacillus helveticus, for example, helps break down protein and sugars, but also is extremely adept at breaking down dietary cholesterol.
As probiotics aid digestion, there is a more efficient nutrient uptake resulting in a feeling of ‘being full’ which, in turn, leads to better appetite control and subsequent weight loss.
Furthermore, studies have shown that probiotic yoghurt containing Lactobacillus acidophilus and Bifidobacterium lactis improved total cholesterol and LDL-C concentrations in type 2 diabetic people, and may reduce cardiovascular disease risk factors.8
Last, but certainly not least, probiotics manufacture vitamins, especially B vitamins, including vitamin B6, that detoxify chemicals and metabolise hormones.
As modern research continues to unfold, the importance of pre- and probiotics becomes more evident. By attaining and maintaining that delicate balance of the right bacteria in the gut, we can rest assured that we will benefit from their varied delivery mechanisms to both prevent and man- age certain diseases
- Can J Gastroenterol. 2004 Mar;18(3):163-7 Redefining lactose as a conditional prebiotic. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=Pu Med&list_uids=15054489&dopt=Abstract
- Mark Timon health and nutrition education site: http://marktimon. com/2012/10/22/sesprobiotics/
- Brownawell AM, et al. Prebiotics and the health benefits of fiber: current regulatory status, future research, and goals. J Nutr 2012 May; 142(5): 962-74. Epub 2012 Mar 28. http://www.ncbi.nlm.nih.gov/pubmed/22457389
- http://bodyecology.com/articles/prebiotics_essential_to_heart_health.php#. UMD266DuiZQ
- Fedorak R. Probiotics in the Management of Ulcerative Colitis. Gastroenterol Hepatol (N Y). 2010 November; 6(11): 688-90.
- Fuller R. Probiotics in human medicine. Gut 1991; 32: 439–42. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1379087/pdf/gut00585-0117. pdf
- Ejtahed HS, et al. Effect of probiotic yogurt containing Lactobacillus acidophilus and Bifidobacterium lactis on lipid profile in individuals with type 2 diabetes mellitus. J Dairy Sci. 2011 Jul; 94(7): 3288-94.
- http://www.genoscope.cns.fr/spip/-Propionibacterium-freudenreichii,340-. html
- http://www.bodyecology.com/articles/prebiotics_essential_to_heart_health. php#.ULNo-ZHuiZT