Home TPN consumers are acutely aware of the risk of developing bloodstream or catheter-related infections.  Additionally, there has been recent national media attention, regarding the potential threat of food-borne illness from contaminated foods.  Therefore, it comes as a surprise to many, that there may be significant health benefits from the intentional ingestion of microorganisms.  Oral supplements containing bacteria or yeast, ingested for the purpose of promoting health, are referred to as probiotics.  In this initial  posting and in follow-up installments, we will examine the basis for using probiotics and issues regarding their use.     

The World Health Organization defines probiotics as “live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host.”   The host, in this case, is the person ingesting the probiotic.  The microorganisms used in probiotics consist of some of the same kinds of bacteria normally found in the human intestine and may also include some types of yeast. 

There are over 400 different species of bacteria known to reside in the normal human intestine.  Collectively, these resident intestinal bacteria are referred to as the intestinal microflora or more simply, for our discussion, the flora.  In total, it has been estimated that up to 100 trillion bacteria live in the normal healthy human intestine, accounting for up to 2 pounds of the body’s weight!  Ordinarily, the majority of these bacteria are thought to be beneficial, with a minor proportion of the flora having potential for detrimental affects on health.  The majority of intestinal bacteria are normally found in the colon.  In individuals with altered intestinal anatomy or function, the flora can be dramatically altered, both in composition and location within the bowel, compared to normal.  Antibiotic therapy, especially recurrent or chronic antibiotic treatment, can also result in an abnormal flora.  These alterations in the flora may result in an imbalance between “good” and “bad” bacteria or yeast.  This imbalance may impact health in a variety of ways.

While our knowledge of the intestinal ecosystem remains limited, there are several purposed mechanisms by which the intestinal flora may impart an influence on your health.  There are a growing number of studies aimed at identifying how and in what situations probiotics might be able to favorably influence an individual’s intestinal flora.  In upcoming discussion, we will explore current scientific thought regarding the use of probiotics, as well as practical considerations in selecting and using these products.