Bacteria are microorganisms that are generally known to be harmful to the body, as they are frequently the sources of infections and diseases.
However, there are types of live microorganisms called probiotics that benefit rather than harm the body.
Probiotics were first thought to benefit the human body by just improving the intestinal microbial balance; today, various medical conditions other than those involving the human digestive system can be treated or prevented by probiotics.
Probiotics started out with the idea of introducing bacteria from fermented milk into the human digestive system, with the premise that these bacteria would suppress the growth of harmful bacteria.
It was noted that certain Europeans, such as those from Bulgaria and Russia, who regularly drank fermented milk lived long and healthy lives.
The term probiotics was first introduced in 1953, and defined as “microbially derived factors that stimulate the growth of other organisms”.
The most common types of microorganisms used as probiotics are lactic acid bacteria (LAB) and bifidobacteria, certain yeasts and bacilli are also used. These microorganisms can lower the pH level of the intestines; at low pH levels, harmful bacteria are prevented from growing.
Research studies done since 1953 have shown that probiotics may help treat antibiotics-induced diarrhea, prevent and treat infections of the vagina and urinary tract, treat irritable bowel syndrome and shorten the duration of intestinal infections, prevent and treat pouchitis, or inflammation following colon surgery, prevent eczema in children, and reduce the chances of recurring bladder cancer.
Probiotics are also believed to improve general health and strengthen the immune system. However, the research done on the potential benefits of probiotics on human health has been very limited.
Moreover, the benefits shown by one particular strain of Lactobacillus or bifidobacteria may not be true for other strains.
Probiotics are considered and recommended as a safe treatment by the World Health Organization. However, studies have shown that there are situations where probiotics can be potentially harmful, such as in the case of critically ill patients.
For example, the death rate of patients with acute pancreatitis increased when fed with a cocktail of genetically modified probiotic bacteria.
Children were also found to become more sensitive to allergens when given probiotics in their first six months of life. People with lowered immune systems were also found to be adversely affected by probiotics; they became susceptible to lactobacillus septicemia, which is a potentially fatal disease.
Probiotics are available commercially in dairy products, primarily in yoghurt. Dairy foods can protect the bacteria as they travel through the human digestive tract by reducing the effect of stomach acid on the bacteria. The refrigeration of dairy products can also help keep the probiotic bacteria stable.
Probiotics can also be packaged as dried, concentrated cells in powder, capsule, or tablet form and available in various doses.