Probiotics Our Friendly Bacteria
An estimated 10 quadrillion bacteria make their home in the average digestive system. Fortunately, less than one percent of the 400 different species found in the intestine are potentially harmful. The majority of intestinal flora are friendly bacteria, otherwise known as probiotics. These probiotic bacteria support good health by limiting the growth of harmful bacteria, promoting good digestion and increasing resistance to infection.*1
Probiotic bacteria are completely non-toxic. In fact, friendly bacteria have been used safely and effectively for more than 8,000 years, proving their value to human health.*2 Most often, probiotics have been consumed as part of cultured foods, such as acidophilus milk, yogurt, soy tempeh, and idli (cultured wheat). The friendly bacteria in these foods, specifically Lactobacillus acidophilus, L. bulgaricus, and Bifidobacterium bifidum, multiply in the warm, moist environment of the human body by feeding on the carbohydrates and protein in the digestive tract, then establish colonies along the intestinal wall. Beneficial Roles of Probiotics
Lactobacillus acidophilus and other friendly bacteria play many important roles in maintaining good health.* According to experts, regular consumption of probiotics is the best way to maintain healthy intestinal flora.*3, 4 Lactobacilli species do not survive very long in the colon, so bacteria colonies need to be routinely replenished.*
Healthy digestion:
In addition to producing numerous vitamins, probiotics support healthy digestion.* Part of the reason fermented foods are healthful is that some of the proteins, fats and carbohydrates are partially digested by the bacteria, which increases overall digestibility and nutritional value of the food.*5, 6
Lactose intolerant individuals may gain even more benefits from probiotics. Lactobacilli bacteria ferment as much as half of the lactose in milk—the part of milk that results in the symptoms of bloating, cramps and gas in lactose intolerant individuals—by converting it to lactic acid. Consequently, people with lactose intolerance report fewer digestive problems with cultured dairy foods compared to fresh milk.*5, 7
The nutritional profile of foods is improved after being cultured with probiotics. Levels of several B vitamins, including vitamins B1, B2, B6 and B12, niacin, folic acid and pantothenic acid are higher in fermented foods, such as yogurt, cheese, kefir and buttermilk.*5 Fermentation also boosts the digestibility of soy foods.*8
Inhibiting bacterial growth:
Probiotics act as natural antibiotics, slowing the growth of harmful bacteria.*5, 6 These friendly bacteria produce substances, including lactic acid, acetic acid, benzoic acid, hydrogen peroxide and natural antibiotics, which limit the reproduction of certain disease-causing bacteria.*9
Another way that probiotic bacteria maintain a healthy digestive tract is by competing with harmful bacteria in the intestine. When the intestine is full of large colonies of beneficial bacteria, disease-causing bacteria are simply not able to multiply into harmful numbers because there are no available attachment sites on the intestinal wall.* This is one of the ways L. acidophilus inhibits the growth of Candida albicans, coliform (e. coli) bacteria and salmonella.*3, 4, 10, 11
Diarrhea can have many causes, but it always has the same result for the bacteria living in the intestine—it flushes them out, leaving the body vulnerable to the growth of opportunistic bacteria. It is important to replenish the body with probiotics during and after a bout of diarrhea.* Probiotic bacteria can also help keep the colon healthy when traveling.*4
Lactobacilli are one of the primary bacteria found in normal vaginal flora, and their presence is believed to inhibit the overgrowth of harmful bacteria, such as Candida. Lactobacillus acidophilus cultures are a popular folk remedy for vaginal health.*4, 10
Recolonization After Antibiotic Use:
Antibiotics, given to treat bacterial infections, ironically can contribute to unhealthy bacteria growth. Antibiotics destroy bacteria, the good along with the bad, leaving the intestine without its normal, healthful flora. In this compromised state, disease-causing bacteria can multiply unchecked by friendly bacteria.*12 When ingested during and following antibiotic usage, L. acidophilus rapidly restores normal flora, shortening the time that undesirable organisms remain in the gut.*3, 12 Bifidobacterium bifidum can also help normalize the intestinal flora after using antibiotics.*10