Prebiotics
See also :
Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial to health.As a functional food component, prebiotics, like probiotics, are conceptually intermediate between foods and drugs, and typically receive, depending on the jurisdiction, an intermediate level of regulatory scrutiny, in particular of the Health claims on food labels health claims made concerning them.
Typically, prebiotics are carbohydrates (such as oligosaccharides), but the definition may include non-carbohydrates. The most prevalent forms of prebiotics are nutritionally classed as soluble fiber. To some extent, many forms of dietary fiber exhibit some level of prebiotic effect.
Sources
Traditional dietary sources of prebiotics include soybean, inulin sources (such as Jerusalem artichoke, jicama, and Chicory root), raw oats, unrefined wheat, unrefined barley and Yacón. Some of the oligosaccharides that naturally occur in breast milk are believed to play an important role in the development of a healthy immune system in infants.
It is becoming more common to properly distinguish between prebiotic substances and the food that contains them. References to almonds, honey and other foods (most commonly in promotional materials from growers of those foods) as "a prebiotic" are not accurate. No plant or food is a prebiotic: Wheat, honey and many other foods contain prebiotics to a greater or lesser extent, ranging from fairly large portions (chicory root, Jerusalem artichoke) to only trace quantities (thousands of other plant-based foods). Referring to a food as "a prebiotic" is no more accurate than calling a food "a vitamin."
Top 10 Foods Containing Prebiotics
| Food | Prebiotic Fiber Content by Weight |
|---|---|
| Raw Chicory Root | 64.6% |
| Raw Jerusalem Artichoke | 31.5% |
| Raw Dandelion Greens | 24.3% |
| Raw Garlic | 17.5% |
| Raw Leek | 11.7% |
| Raw Onions | 8.6% |
| Cooked Onions | 5% |
| Raw Asparagus | 5% |
| Raw Wheat bran | 5% |
| Whole Wheat flour, Cooked | 4.8% |
| Raw Bananas | 1% |
While there is no broad consensus on an ideal daily serving of prebiotics, recommendations typically range from 4-8g for general digestive health support, to 15g or more for those with active digestive disorders.
A prebiotic has the following three characteristics: It’s a source of food for one or more strains of beneficial bacteria; It must remain undigested until it reaches the large bowel; and lastly, It modifies the colonic microbiota in such a way that contributes to the health and well-being of the host. (Source) Below are some prebiotics that meet these conditions:
- Galactooligosaccharide or GOS, the Stand-In Prebiotic : Mother’s milk is most likely the first prebiotic you’ve ever taken when you first stepped into this world. Besides being rich in lactose, human milk also contains non-digestible oligosaccharides which are favored by bifidobacteria and lactobacilli.More than just a source of food, studies found that babies who were given breast milk were fitter than those who were formula-fed. They suffered less colds and were less prone to allergic diseases. One of the reasons, researchers believed, is due to a richer gut microflora supported by the oligosaccharide content in mother’s milk. But if for some reasons you can’t breast feed your baby, all is not lost. While it’s still not possible to replicate breast milk, we can reproduce the prebiotic effects of human milk oligosaccharides using galacto-oligosaccharides (GOS) or other prebiotics. GOS are compounds produced through the enzymatic conversion of lactose from cow’s milk. Judging from the results of some studies, including this one, the gastrointestinal colonisation of infants that were given GOS-enriched formula was similar to babies who were given the real thing.
- Inulin : Inulins refer to a group of polysaccharides made up of fructose that can’t be digested by humans. It is found in many plants and fruits such as Jerusalem artichoke, chicory root, garlic, yacon, jicama, leek, onion, asparagus, burdock and banana, though the amount in most of them is believed to be too low to exert any significant positive effects.Among all the prebiotics, inulin is perhaps the most widely known and studied. In several in vitro and human studies, inulin appeared to have the most impact on the growth of bifidobacteria, multiplying their populations in as short as seven days of consumption. In some studies, populations of invasive microbes were also reduced (source).A dose of about five to eight grams of inulin per day should be enough to favorably change the composition of the gut microbiota. Over-consumption of inulin, however, could cause gas and bloating, especially among sensitive individuals. So it’s important to monitor your physiological responses to look out for symptoms of overdose. Due to its availability and potential health benefits, inulin has been increasingly added to supplements and foods as a sugar, fat or flour replacement, dietary fiber and of course, prebiotic.
- Lactulose, the Forgotten Prebiotic : If you’ve ever seen a doctor for constipation or hemorrhoid, you’re probably familiar with lactulose. It’s a thick, sweet syrupy liquid that helps to increase the water content and volume of the stools so that they become easier to pass. Unbeknown to many of us, lactulose is also a prebiotic. It contains a type of non-digestible sugar called galactofructose that boosts the growth of probiotic bacteria, which in turn helps to reduce the populations of pathogenic species (source). A dosage of 3 g per day for 2 weeks appears to be effective in bringing about a favorable change in the composition of gut microbiota according to a small study. Like inulin and GOS, lactulose also appears to improve the absorption of calcium and magnesium in a double-blind study involving 24 male volunteers.But before you start gulping down buckets of lactulose, do note that excessive intake of the synthetic sugar solution can cause bloating, abdominal pain and diarrhea, not to mention, bad gas.
- Pectin : a soluble fiber found in fruits and vegetables — is better known as a gelling agent in jams and jellies than as a prebiotic. But do you know that pectin actually packs a number of health-promoting benefits, including some gut-cleaning prebiotic goodness?In a study which appeared in BMC Microbiology, rats that ate a diet high in apple pectin had reduced levels of pathogenic bacteria but higher amounts of friendly bacteria than rodents that fed on whole apples, apple juice, puree or pomace. Kiwifruit pectin also displayed prebiotic potential in an in vitro study which found that the pectin helped Lactobacillus rhamnosus adhered better to intestinal cells than inulin, while reducing the adhesion of undesirable bacterium Salmonella typhimurium, the nasty microorganism behind a number of multistate outbreaks in the US. That may explain why pigs which were fed a diet containing freeze-dried kiwifruit or kiwifruit fiber had more beneficial bacteria and less harmful ones when compared to swine on the control diet in a separate research. But pectin is more than just a prebiotic. Researchers have long known that pectin can help to lower blood cholesterol levels, particularly very-low-density lipoprotein cholesterol (VLDL) particles which gets converted into low-density lipoprotein (‘bad’ cholesterol) in the blood. In 2010, a team of scientists from University of Illinois also suggested that citrus-based pectin is also capable of turning angry, inflammatory immune cells into anti-inflammatory, healing cells that speeds up recovery from infection.
- Millet acts as a prebiotic feeding microflora in your inner ecosystem.
See also
References
External links
- Food-Info.net on prebiotics and bifidogenic factors
- International Scientific Association for Probiotics and Prebiotics
- http://www.raysahelian.com/prebiotic.html
- http://www.sciencedaily.com/releases/2008/06/080627163121.htm
- http://www.sciencedaily.com/releases/2008/04/080401200444.htm
- http://www.prebiotic.ca/prebiotic_fibre.html
- http://www.dailymail.co.uk/health/article-400681/The-facts-prebiotics.html
- http://www.innvista.com/health/nutrition/biotics/prebiot.htm
- http://books.google.com/books?id=y2rvBwMy6HgC&printsec=frontcover#PPA43,M1
- http://books.google.com/books?id=XgF_VEDw-REC&printsec=frontcover
Medical Disclaimer
This information is not meant to be substituted for medical advice. Always consult a medical professional regarding any medical problems and before undertaking any treatment or dietary changes.
