Bacteria need not always cause harm to the human body. Out of the thousands of species of bacteria that reside in the body, certain strains are actually beneficial to the host. The term 'probiotics' is used with reference to the strains of friendly bacteria that help maintain the balance of microbial flora in the gastrointestinal tract. On the other hand, 'pathogens' refer to disease-causing microbes. Though probiotics mainly comprise strains of bacteria, a strain of yeast called Saccharomyces boulardii is also referred to as a probiotic. Lactobacillus acidophilus, Bifidobacterium longum, Streptococcus thermophilus, Enterococcus faecium, and Leuconostoc mesenteroides are some of the strains of bacteria that are placed in the category of probiotics. More than 50 species belonging to the Lactobacillus genus are a part of the intestinal microbial flora. Lactobacillus acidophilus is one of the species that is commonly used in the form of supplements. Imbalance of the Intestinal Microflora Prolonged use of antibiotics, stress, alcohol abuse, poor dietary habits, or illnesses can disrupt the microbial balance of the gastrointestinal tract, thereby putting a person at a risk of developing infections. Such an imbalance can be corrected by following a diet that is rich in probiotics, or by taking probiotic supplements that contain live beneficial bacteria. It is believed that consumption of prebiotics may also increase the activity of the lactic acid bacteria and the bifidobacteria. The term 'prebiotic' refers to a specialized, non-digestible food ingredient or a nutrient that may promote the growth of friendly bacteria. Garlic, onion, asparagus, rye, whole wheat, barley, and chicory root are some of the examples of prebiotics. Mechanism of Action The antimicrobial activity of probiotic supplements is believed to be due to the production of bacteriocins, which are substances that are produced by the beneficial bacteria to inhibit the growth of other bacterial strains. Certain strains of the Lactobacilus acidophilus produce bacteriocins such as acidophilin and lactocin. CH5 is another bacteriocin that is produced by this bacterium. It is believed that CH5 may help inhibit the growth of Salmonella typhimurium and Campylobacter jejuni. In the event of an imbalance of the gut microflora, the use of probiotics may help restore the balance through the process of colonization resistance and the production of organic acids. Probiotic Supplementation The natural balance of intestinal microflora can be improved by probiotic supplementation. Probiotics are available in the form of tablets, liquids, powders, and capsules. Single, dual, or multi-species formula are readily available in the market. While the single species Lactobacilus acidophilus formula is very commonly used, a dual or a multi-species formula that contains two or more strains of beneficial bacteria can also be used. If you are planning to buy a supplement, do check the number of live cells that a single dose contains. It would be best to opt for a supplement with the number of active cells ranging from 1-10 billion in a capsule or a serving. The supplements with a higher live cell count are likely to be more effective. Look for capsules that have a coating that prevents bacteria from being destroyed in the acidic environment of the stomach. Make sure that you follow the manufacturer's guidelines regarding the storage of these supplements. Health Benefits ► Acidophilus is an acid-loving milk bacterium that helps in the production of lactase enzymes, thereby facilitating the digestion of lactose. It is believed that the use of this supplement may increase tolerance to milk products in those who are lactose intolerant. It may also improve the process of absorption of nutrients by the body. ► It is believed that the use of acidophilus may prove beneficial for treating diarrhea that is induced by the use of antibiotics. ► Lactobacillus acidophilus also inhibits the growth of a fungus called Candida albicans in the vagina, thereby lowering the incidence of yeast infections in women. ► Probiotic supplementation also helps improve digestive health. It may prove beneficial in alleviating the symptoms associated with constipation and indigestion. ► Intake of probiotics can help strengthen the immune system, thereby lowering the risk of many ailments. If you are planning to buy probiotic supplements, make sure that you buy the ones that have been manufactured and marketed by reputed brands. The use of these supplements may sometimes cause gas and bloating. Some people may develop an allergic reaction. It would therefore be best to consult a medical practitioner before taking these supplements. Do inform your doctor about any other drug that you may be taking. This is to prevent adverse drug interactions. If you don't wish to take these supplements, you can include yogurt, cottage cheese, fermented products, or other dietary sources of acidophilus in your diet. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.