When we speak of preventing and stopping disease, the immune
system first comes to mind. The skin acts as a barrier to unwanted pathogens (bacteria, viruses, and fungi that cause health problems), and if they breech this first wall, the immune system attacks. What many of us don’t know is that the immune system is not always our first defense. Instead, bacteria—yes, bacteria—are.
The home guard in the digestive tract are what we call "friendly" bacteria. These are bacteria that fight off the bad bacteria—such as E. coli—and keep our intestinal tracts "in balance." When friendly bacteria are not at appropriate levels, and when unfriendly bacteria dominate, health problems can result. These include gas, bloating, intestinal toxicity, constipation, and malabsorption of nutrients.
These friendly bacteria—which are often known as
"probiotics" when in supplement form—have a number of health benefits.
We all know what antibiotic activity is: the ability to hunt down
and kill harmful bacteria. We also realize that pharmaceutical antibiotics do have a
downside—they kill all our bacteria, including our good bacteria, and have side
effects. And, of course, the increasingly common problem of antibiotic-resistant
bacteria—bacteria that cannot be killed by our arsenal of antibiotics—is due to
our overuse and overdependence on antibiotics.
Many types of friendly bacteria produce their own
antibiotics—although "replacement-biotics" might be a better word. That is
because friendly bacteria produce substances that inhibit or "scare" the bad
bacteria, preventing them from forming colonies that eventually cause problems. Natural
antibiotics produced by friendly bacteria do not have any uncomfortable side effects.
Viruses are another pathogen of which we are all aware. The common cold is a viral infection, as is human immunodeficiency virus (HIV). However, viruses are much harder to treat and destroy than bacteria. To date, there is no class of drugs known to destroy viruses completely,
although there are antiviral agents that prevent against the virus initially doing damage.
Some friendly bacteria have antiviral effects—they help prevent a viral foothold from becoming a serious threat. Although the exact mechanism by
which these bacteria do this is not known, there have been a number of laboratory tests
that indicate that certain strains produce hydrogen peroxide, which functions as a virus
killer. In her book Probiotics, Nature’s Internal Healers, Natasha
Trenev documents several studies in which friendly bacteria were used to inhibit the
By now, most of us realize that diet can be a risk factor for cancer—a diet high in animal fat and fried foods may contribute to a number of types
of cancer. One of the reasons for this may be because cancer-causing substances are
produced in the body from the nitrates used in the curing of luncheon meats. Friendly
bacteria have the ability to neutralize nitrates.
In 1987, Fernandes, et al., (FEMS Microbiology Reviews 46)
listed ways that friendly bacteria may destroy cancer:
1) Some species of friendly bacteria eliminate potentially
cancer-causing substances before they "turn" cancer-causing.
2) Some strains have the ability to alter enzymes that turn a potentially carcinogenic agent into a carcinogenic agent.
3) Some strains have the ability to suppress some tumor activity.
|"Postulated health advantages associated with probiotic intake"
1) Alleviation of symptoms of lactose malabsorption
2) Increase in natural resistance to infectious diseases of the intestinal tract
3) Suppression of cancer
4) Reduction in serum cholesterol concentrations
5) Improved digestion
6) Stimulation of gastrointestinal immunity."
—The American Journal of Clinical Nutrition,
In addition to these three benefits, friendly bacteria also have the ability to
- manufacture vitamins B1, B2, B3, B5, B6, B12, A, and K, and
essential fatty acids;
- aid in the digestive process by helping digest lactose (milk
sugar) and protein;
- clean the intestinal tract, purify the colon, and promote regular
- increase the number of immune system cells;
- create lactic acid, which balances intestinal pH;
- protect us from environmental toxins such as pesticides and
pollutants, reduce toxic waste at the cellular level, and stimulate the repair mechanism
- help maintain healthy cholesterol and triglyceride levels; and
- break down and rebuild hormones.
Lactobacilli are one of the most important types of friendly
bacteria found in the digestive tract. These bacteria get their name (lacto) because they
are able to turn milk sugar into lactic acid. They play a key role in producing fermented
milk, yogurt, and cheeses.
The "father" of lactobacilli could well be Elie
Metchnikoff, who, in 1908, noted that people in Bulgaria lived longer than those in other
countries, despite the fact that Bulgaria was considered "underdeveloped." His
investigation of this led him to diet, yogurt, and lactobacilli. His work was the first to
prove that lactobacilli could transform milk sugar into lactic acid. Metchnikoff also
hypothesized that this acidity would provide a hostile environment for unfriendly
bacteria. This was later proved correct.
Lactobacilli are able to "balance" unfriendly bacteria because when they produce lactic acid, they alter the intestinal environment, making it
unsuitable for unfriendly bacteria. In other words, lactobacilli don’t destroy the
unfriendly bacteria; they destroy their home, forcing them to leave.
Lactobacilli have other benefits. They may help normalize
cholesterol levels, and certain strains may antagonize Candida albicans. There is
indirect evidence that lactobacilli may help relieve anxiety and depression. This is
because the amino acid tryptophan serves as an antidepressant, and lactobacilli release
this amino acid.
Although other Lactobacillus species are better
known—in particular acidophilus—there are other powerful strains. One of
these is L. plantarum, which is the predominating Lactobacillus species on
both the oral and intestinal human mucosa. According to many researchers, for lactobacilli
to perform at optimal levels, they must be present in high numbers on the mucous
One strain of the L. plantarum species has been tested
clinically for its effect on irritable bowel syndrome (IBS). In both studies, subjects
showed a decrease in IBS symptoms and reduced pain. (Niedzielin, et al., in manuscript;
Nobaek, S., et al., in manuscript)
Lactobacillus salivarius is another Lactobacillus
species. L. salivarius is a new culture, requiring a special culturing process,
and, after years of research, is just now becoming available. It flourishes in the small
L. salivarius is classified as a facultative bacterium,
which means that it can survive and grow in both anaerobic (without oxygen) and aerobic
(with oxygen) environments, although its main effects take place in anaerobic conditions.
This is a decided advantage over the well-known Lactobacillus acidophilus, which
has little or no growth in an aerobic environment.
One unique benefit of L. salivarius is its ability to help
break down undigested protein and disengage the toxins produced by protein putrefactions.
Another benefit is its rapid reproduction—it doubles its population every 20 minutes.
Other than the obvious health advantages, this rapid growth is also an economic advantage:
you do not have to take so much.
Food for the friendly bacteria
Bacteria need nourishment.
They get this from our diet, especially fiber.
However, there are "special" foods which friendly bacteria find particularly
One of these is fructooligosaccharides, or FOS. FOS are sugars
linked together in such a way that they cannot be digested. Instead, FOS pass through the
stomach to the small intestine and colon where they are consumed by our friendly bacteria.
Feeding friendly bacteria is not all that FOS do for us. FOS can
- reduce the growth of unfriendly bacteria
- maintain regular bowel movements
- maintain cholesterol and triglyceride levels, and
- maintain healthy blood sugar levels
FOS should not be seen as a replacement for friendly bacteria.
They are meant to amplify the benefits of friendly bacteria, not replace them.