Probiotics - Friendly Bacteria

Probiotic microorganisms are “Gram positive anaerobic bacteria and are included primarily in two genera, Lactobacillus and Bifidobacterium”. (WHO, 2001, pg7). They naturally occur in the human intestine (but not in new-borns). A example of a probiotic supplement is “inner health plus”, which contains the microorganisms Lactobacillus acidophilus and Bifidobacterium lactis and the prebiotic “colostrum powder” to sustain the organisms.

Currently in vitro tests are use to examine the ability of probiotics to function in humans. However , the available tests are inadequate to accurately “predict the functionality of probiotic microorganisms in the intestine”. (WHO, 2001, pg7)

Newborns have no bacteria in their gastrointestinal system. The modes of transmission for digestive microbes are primarily the diet. Microbes are present in uncooked fruits, vegetables, and dairy products. The first colonization of microbes in a newborn’s intestine are from breast milk. Website [3]. It is debated that the most important digestive microbes are lactic acid microbes (Lactobacillus). Microbes are labelled as friendly because they assist digestion, particularly of lactose. “Bacteria such as Lactobacillus…species have been used extensively in food processing throughout human history, and ingestion of foods containing live bacteria, dead bacteria, and metabolites of these microorganisms has taken place for a long time” (Norio Ishibashi and Shoji Yamazaki ,2001, page 1)

The pathogenicity of these microbes to the host have rarely been accounted for. If probiotics were found to be pathogenic and this “unfriendly” they would not be used in probiotic supplements. However, probiotic bacteria have been isolated from infected lesions. Lactic acid bacteria and bifidobacteria have been isolated from endocarditis, bacteremia, and bloodstream and local infections, which naturally occur in human intestines and thus are used in probiotics. “A generalised explanation of how lactobacillus and bifidobactirum have been found in infections is that they are the result of “oppotunistic infections”. (Norio Ishibashi and Shoji Yamazaki 2001, page 2). It is difficult to prove the pathogenicity of probiotic bacteria, because anaerobes are generally considered to not be pathogenic. (Norio Ishibashi and Shoji Yamazaki 2001, page 3) showed a proposed invasion mechanism for probiotic bacteria, where they travel through the mucosal barrier of the intestine and by translocation through the mesenteric lymph nodes or the