Friendly Bacteria

—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, 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.

Antibiotic effects

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.

Antiviral 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 herpesvirus.

Anticancer effects

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.

Other benefits

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 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 of cells;

• help maintain healthy cholesterol and triglyceride levels; and

• break down and rebuild hormones.

Lactobacilli

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.

Lactobacillus plantarum

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 membranes.

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

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 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.

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)