Probiotics are microbes believed to present some health advantages to the host organism. According Guarner and Schaafsma (1998, p.327), probiotics can be defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host”. The most common are lactobacillus and bifidobacteria although some yeast species belong to this category. These microbes are ingested along with fermented foods where they are introduced as dynamic live cultures. Such foods include yogurt and nutritional complements as well as soy yogurt among others.
‘Probiotic bacterial cultures’ are included in human foods with an aim of increasing the number of normal flora in human alimentary canal which may be threatened by a number of factors including treatment with antibiotics. However, there is no proof that probiotics can entirely replace normal flora when it’s completely eliminated by adverse factors. Nevertheless, probiotics may play the roles of normal microbes. There are suppositions that these microbes are of medicinal importance to consumers. However, studies on the perceived benefits are not at an advanced stage and thus, some of the claims remain unsubstantiated (Sanders, 1999).
According to Dairy Council of California (2000, p.1), several research undertakings have revealed that probiotics are helpful in management of several kinds of diarrhea such as “antibiotic-associated diarrhea in adults, travelers’ diarrhea, and diarrheal diseases in young children caused by rotaviruses”. Here, most of the studies are focused on Lactobacillus casei, Bifidobacterium lactis and Lactobacillus GG. Treatment of diarrhea with these microbes should be augmented with rehydration so as to replace the lost body fluids and electrolytes.
Further studies have indicated that probiotics such as Lactobacillus bulgaricus and Streptococcus thermophilus have the ability to treat lactose intolerance in individuals suffering from the condition. These strains work by synthesizing lactic acid from lactose thus intolerant individuals can put up with higher amounts of lactose in the body. As such, probiotics may help to control this condition which affects seventy percent of the world population (Dairy Council of California, 2000).
Besides, there is a proof that probiotic bacteria can stop or holdup the onset of cancer in potential victims. This is attributed to the fact that some gut microbes that produce carcinogens can be ameliorated by probiotic microbes thus limiting the rate of tumor formation. The bacteria involved here are lactobacillus species as well as Bifidobacterium while Lactobacillus casei checks the recurrence of cancer in the urinary system. However, this argument is highly disputed by various scientists and there are calls to carryout further research using internationally recognized cancer markers (Brady, Gallaher and Busta, 2000). Thus, it is hard to make authoritative judgments regarding the effectiveness of probiotics in cancer management.
It is also argued that probiotic bacteria help to control allergies (usually those associated with milk) through enhancing mucosal barrier activity. Thus, these microbes may help to prevent the condition that is continually on the rise in the western countries. Other researchers argue that probiotics help to lower the levels of cholesterol circulating in blood. It is said that these microbes synthesize bile in the alimentary canal thus blocking it from re-absorption. Some studies have shown that these bacteria reduce low density lipid levels in individuals with normal amounts of cholesterol (Brady, Gallaher and Busta, 2000). However, more research is needed in individuals with exaggerated levels of cholesterol. A closely related observation is that probiotics help to control cardiovascular ailments such as hypertension and “ischemic heart syndromes” through the action of ACE inhibitor formed in the fermentation process (Dairy Council of California, 2000). They also enhance food bio-availability and digestibility thus supporting the host nutritionally. It is also said that probiotics help to control constipation although more evidence is required.
Moreover, some researchers claim that probiotic bacteria boost the “specific and non-specific immune response” through stimulation of macrophages, escalating the amount of cytokines, enhancing “natural killer cell activity” and escalating the levels of immunoglobulin (Sanders, 1999, p.69). These activities protect the body from various diseases including inflammations. They also protect an individual from ailments resulting from sexual intercourse and nearly all vaginal and urinary tract infections resulting from bowel microbes. However, more research is required to verify these claims.
Probiotics have great potential in controlling various clinical conditions. More studies will help to recognize and classify the available species of probiotic bacteria and determine their correct dosage. At the moment, full potential of probiotics is not yet explored as scientific inquiries are at early stages.
References
Brady, L., Gallaher, D., and Busta, F., 2000. The role of probiotic cultures in the prevention of colon cancer. Journal of Nutrition, 1(30), p.410.
Dairy Council of California., 2000. Probiotics – Friendly Bacteria with a Host of Benefits. Web.
Guarner, F. and Schaafsma, G. J., 1998. Probiotics. International Journal of Food Microbiology, 39 (1), p. 237.
Sanders, M. E., 1999. Probiotics. Food Technology, 53(11), p.67-77.