—Your first line of defense?
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,
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
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
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 herpesvirus.
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
1) Some species of friendly bacteria
eliminate potentially cancer-causing substances before they "turn"
2) Some strains have the ability to alter
enzymes that turn a potentially carcinogenic agent into a
3) Some strains have the ability to
suppress some tumor activity.
advantages associated with probiotic intake"
1) Alleviation of symptoms of
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, May
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 bowel movements;
increase the number of immune system
create lactic acid, which balances
protect us from environmental toxins
such as pesticides and pollutants, reduce toxic waste at the
cellular level, and stimulate the repair mechanism of cells;
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
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)
L. Plantarum may also compete for
"intestinal space" with unfriendly bacteria—and win. In an animal
study, one group of rats was colonized with Escherichia coli and
another group with the same E. coli strain together with a strain of
L. plantarum. Rats given L. plantarum in addition to E. coli showed
lower counts of E. coli in the small intestine and caecum (where the
large intestine begins) one week after colonization compared with
the group colonized with E. coli alone. The authors note that "the
results indicate that L. plantarum colonization competes with E.
coli for intestinal colonization and can influence intestinal and
systemic immunity." (Herías, M.V., et al. Clin Exp Immunol 116, no.
2 (May 1999): 283-90)
L. Plantarum appears to have other
beneficial properties as well. One study notes that it not only
helps preserve nutrients such as omega-3 fatty acids, but also
increase their content. L. plantarum has also demonstrated the
ability to reduce and eliminate potentially pathogenic
microorganisms both in vitro and in vivo. (Benmark, S. Nutrition 14,
nos. 7-8 (July 1998): 585-94)
Finally, one strain of Lactobacilli—L.
plantarum variant OM—has the unique ability to "liquefy gelatin."
Gelatin is used to determine if a product can break down protein
into usable nutrients (amino acids). Thus, L. plantarum variant OM
rapidly digests protein.
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 intestine.
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
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.
L. salivarius may be useful to help prevent
and fight Helicobacter pylori, which is now acknowledged to be a
leading cause of ulcers. In one study, L. salivarius (but not L.
casei or L. acidophilus) was able to produce a high amount of lactic
acid and completely inhibit the growth of H. pylori in a mixed
culture. The authors of this study conclude that "L. salivarius was
found to be a potentially effective probiotic against H. pylori." (Aiba
Y., et al. Am J Gastroenterol 93, no. 11 (November 1998): 2097-101;
Kabir, A.M. Gut 41, no. 1 (July 1997): 49-55)
Food for the
Bacteria need nourishment. They
get this from our diet, especially fiber. However, there
are "special" foods which friendly bacteria find
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
Feeding friendly bacteria is not
all that FOS do for us. FOS can also
reduce the growth of
maintain regular bowel
maintain cholesterol and
triglyceride levels, and
maintain healthy blood sugar
FOS should not be seen as a
replacement for friendly bacteria. They are meant to
amplify the benefits of friendly bacteria, not replace
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