Beneficial bacteria play a major role in keeping us healthy. A recent study that examined the gut flora of elderly people found that the greater the variation in their intestinal bacteria, the better their overall health. They were less frail and performed better on cognitive tests. Dr. Ilseung Cho, gastroenterologist at the NYU Medical Centerís School of Medicine says, "What we're only now beginning to realize is that there's very close interaction between the bacteria within GI tract and human health and disease."
Beneficial bacteria are not only important for proper digestion, they are a key element in our bodyís ability to synthesize vitamins so they can be used by the body, particularly vitamin K and the B-vitamins. They boost the immune system and some studies have found that they may reduce the risk of cancer.
Species of bacteria living in the human gut number between 300 and 1000, although it is believed that 99% of our gut bacteria comes from only 30 or 40 different species. There are tenfold more microorganisms in our intestines than there are cells in our body, which number approximately 10 trillion. The term for these beneficial gut bacteria is "probiotics," (from the Latin "pro" and the Greek "biota," meaning "for life").
A Short History of Probiotics
Dr. Elie Metchnikoff, a Russian scientist and professor at the Pasteur Institute in Paris at the turn of the 20th century, was the first to discover the benefits of probiotics. He had observed that Russian peasants living in the steppes lived life spans that were unusually long. He also noted that their diet contained large amounts of milk fermented with lactic acid bacteria and hypothesized that their longevity was due to this diet. Metchnikoff found that his own health greatly benefitted when he began to eat milk fermented with what he called "Bulgarian Bacillus." Fellow doctors in Paris began to follow his example and began prescribing fermented milk to their patients, and the first probiotics as medicine were born.
How Probiotics Keep Us Healthy
The probiotics most commonly used today are Lactobacillus and Bifidobacteria, which can be obtained either through food or in probiotic supplements. They can aid in balancing the microflora of the intestines after taking antibiotics or to help in recovery from an illness. The problem with excessive antibiotic use is that they not only destroy the bacteria that cause disease, they remove the beneficial bacteria as well, which lets opportunistic organisms such as the yeast Candida to gain a foothold. Candida normally grows harmlessly in the digestive tract, however, if a lack of good bacteria allows it to grow unchecked, it can transform itself into candidiasis (thrush), a fungus that causes damage to the intestines and can lead to many different health problems, such as tiredness, fuzzy thinking, asthma and psoriasis. The use of probiotics, particularly after a course of antibiotics, can help to keep the harmful microbes in check.
Although the colon hosts the largest concentration of probiotics in the body, they also reside in other areas of the body, providing support to the immune system. As much as 80% of our bodyís immune response depends on the presence of probiotics, which promote cytokine, macrophage and T-cell production. Probiotics can also create natural antibiotics in response to pathogens that may have become resistant to standard antibiotics. Not only that, but if the targeted pathogen develops a resistance to the antibiotic produced by the probiotic, the probiotic can modify the antibiotic to create one that is better at fighting the pathogen, an ability that standard antibiotics do not have.
A number of studies have found that probiotics are hostile to cancer by stimulating cancer-fighting chemical production in the body, which shrinks tumors and promotes the death of cancer cells. They also aid in the immune systemís defense against viruses, including herpes, flus, colds, ulcers and rotavirus. A study that was done on 2- to 5-year-old Indian children who were prescribed either probiotics or a placebo for six months found that those children who took the probiotics had fewer incidents of diarrhea, fever, cold and flu than those who took the placebo.
Where You Can Find Probiotics
If you are interested in including some probiotics in your diet, they can naturally be found in a variety of fermented foods such as kefir, yogurt, miso, kimchee, sauerkraut and kombucha. The label should state that the product contains "live active cultures" that help to ensure you are getting the probiotics you are looking for. Otherwise, most health food stores carry probiotics as supplements, often in the refrigerated section. Supplements with the greatest variety of Bifidobacterium and Lactobacillus are best.