THE BLOG
06/17/2013 03:38 pm ET Updated Aug 17, 2013

Prebiotics and Probiotics: The Importance of Gut Health

You have about 10 trillion human cells in your body and around 100 trillion microbial cells (meaning microbes, otherwise known as bugs).

Doesn't that bug you? (Pun intended.)

Of course, not all bugs are made equal. In fact, some microbes are essential to the proper function of our guts; they help us to break down food, protect us against the bad bugs, and as it turns out could even help prevent obesity.

You've probably noticed advertisements promoting the added benefits of probiotics for digestive health in various foods and as supplements. The term probiotic was first coined by researchers Lilly and Stilwell in 1965 to describe substances secreted by one organism that stimulated the growth of another, beginning a new era for digestive health research. Industry data indicates that from July 2010 to July 2012, sales of probiotic foods and supplements has increased as much as 79 percent. Clearly, we have come a long way since 1965.

Interestingly, we are more familiar with the "opposite" of probiotics: antibiotics. Antibiotics are powerful medicines used to fight bacterial infections. If used properly, antibiotics save lives, but there is also an increasing concern about over-prescription and creating possible resistance in bacteria. So one question to ask today is whether overprescribing of antibiotics and antibiotics use in animals (and hence our food) has led to an increased interest in and need for probiotics. Our bugs are just not what they used to be. It may also be that pre- and probiotics are simply a hot topic in the mainstream media and health care journals.

Let's take a step back and examine what exactly are probiotics (and prebiotics). Prebiotics are the non-digestible carbohydrates that stimulate growth and activity of bacteria in our digestive systems. Prebiotics are found naturally in cruciferous vegetables such as broccoli, cabbage, cauliflower, kale, radish, asparagus, and whole grains.

Probiotics are mostly bacteria, which assist in the maintenance of the natural balance of microorganisms (microflora) in the intestines. Therefore, prebiotics feed the probiotics. An average human digestive tract has approximately 400 types of probiotic bacteria. These probiotic bacteria reduce the harmful bacteria, suggesting that probiotics can prevent infections in the digestive tract and reduce inflammation. Some medical professionals go as far as recommending probiotics for the common cold.

Lactobacillus acidophilus, which is found in yogurt, is the largest group of probiotic bacteria in the intestine. Other food sources of probiotics include sauerkraut, miso soup, sourdough bread, and pickles. And if those foods don't sound appetizing, supplements can be found almost everywhere vitamins are sold. Although most probiotics are bacterial in form, a yeast known as Saccharomyces boulardii (a type of baker's yeast) can also deliver health benefits if consumed live.

So why is there an increasing focus on adding probiotics to the diet, whether through foods or specific products? Poor digestive health places a burden not only on an individual but on the health care system. The National Commission on Digestive Disorders in the U.S. reported in 2009 that 60 to 70 million Americans are affected each year by digestive diseases at a cost that exceeds $100 billion in direct medical expenses. Each year, an additional 105 million visits are made to physicians related to digestive diseases. If pre- and pro-biotics can help us reduce even a portion of these costs, they are worth serious consideration.

Implications for the use of pre- and probiotics in the developing world for diarrheal diseases may be equally important. Diarrhea remains a primary cause of preventable deaths in children younger than age 5. A 2010 Cochrane review examined 63 trials of probiotics, which included 8,014 people with infectious diarrhea. Findings revealed that people who took probiotics were generally sick 25 hours less, without any adverse effects, and the risk of diarrhea lasting four or more days reduced by 59 percent.

On June 12, The Sackler Institute for Nutrition Science at the New York Academy of Sciences and The International Scientific Association for Probiotics and Prebiotics (ISAPP), held a conference entitled Probiotics, Prebiotics, and the Host Microbiome: The Science of Translation. The conference served as a neutral forum to critically examine the potential population-wide economic and public health benefits of translating current research into innovative functional foods and biotherapeutics for a broad spectrum of conditions including obesity, diabetes, inflammatory bowel disease, and undernutrition. The conference intended to present both the pros and cons of prebiotics and probiotics, identify gaps in knowledge and urgent research questions, and initiate debate among the scientific community to ensure evidence-based decision making.

All signs point to a growing public interest in the possible benefits of prebiotics and probiotics in digestive health and beyond. However, science has to lead the way to ensure sound evidence is the basis for introduction of interventions for public health and new products in the marketplace. Continued research, evaluation, and public health campaigns are necessary to disseminate accurate and unbiased information.

For more by Mandana Arabi, M.D., Ph.D, click here.

For more on personal health, click here.

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