Bacteria are everywhere: in soil, dust, air, water and food. Recognizing their role in disease and taking measures to prevent and treat infections has saved many lives, but new hygiene standards are making our environment increasing sterile. We use pesticides to clean our soil, disinfectants to clean our homes, sanitizing sprays to clean the air, radiation and pasteurization to clean our food and antibacterial soap to clean our skin. Some experts believe this lack of exposure to normal bacteria in our environment has a negative effect on our health. Is it possible, or is cleaner really better?
Bacteria are not just part of our environment, they are part of us, too. Our bodies contain more bacterial cells than human cells, about ten times more. Scientists estimate that each person carries 500 to 1,000 species of bacteria, totaling one quadrillion (1,000,000,000,000,000) microbes. Bacteria that are expected to be present and do not usually cause disease are normal flora. Specific species vary with age, diet, culture, environment and anatomical location. Also appropriately referred to as “friendly” bacteria, normal flora play important roles in immunity and digestive health.
In the gastrointestinal tract, friendly flora help digest food, produce vitamins and aid the absorption of nutrients. They prevent colonization of potential pathogens, or “unfriendly” microbes, not only in the intestines, but also on the skin and in the mouth and vagina. Friendly bacteria keep unfriendly microorganisms under control by maintaining an acidic pH and producing substances that inhibit their ability to grow and reproduce. When the bacterial balance is disturbed, increasing populations of potentially harmful bacteria, viruses and fungi (such as the yeast Candida albicans) can cause symptoms that range from inflammation and infection to indigestion and diarrhea.
Dysbiosis, an imbalance of intestinal flora, may result from a change in environment, a new diet or the use of antibiotics. Although antibiotics are useful to treat dangerous infections, they often kill the protective bacteria along with the pathogenic species, causing common side effects like nausea, vomiting, diarrhea and vaginal yeast infections in women.
Bacteria play other important roles in immunity. They trigger the production of antibodies, which are proteins in the blood that alert the immune system to foreign substances. Low levels of antibodies produced in response to normal flora can cross-react with certain pathogenic microbes to prevent infection. Bacteria also stimulate the development of lymphatic tissue in the intestines, an extension of the immune system containing white blood cells that destroy foreign microorganisms and abnormal cells.
Bacteria can even impact allergies. When immune cells have not had sufficient exposure to microorganisms in the environment, they can overreact when they encounter foreign molecules. Hypersensitivity reactions aren’t limited to invading microbes and may also be triggered by harmless substances such as animal dander, pollen, mold spores and dust mites.
Some experts have noted that children in large families tend to have lower rates of allergic diseases, including hay fever, asthma and eczema. Older children can expose younger siblings to a wide array of bacteria that strengthen their developing immune systems.
Making Friends With Microbes
In general, cleaner is better only when it comes to individuals with compromised immune systems, who should always avoid unnecessary risk of infection. However, others can benefit from friendly bacteria and exposure can improve immunity and gastrointestinal function.
For healthy bacterial balance, avoid chemicals that kill normal flora, such as chlorine and antibiotics (unless infections are life-threatening). Antibiotics can be lifesaving medications, but they should only be used when absolutely necessary. Residues from antibiotics fed to animals can be ingested unintentionally, so choose organic foods, especially when it comes to animal products. Chlorine does reduce transmission of disease-causing microbes, but it also has a negative effect on the normal flora of the intestine and should be removed after it has served its purpose. Filter chlorine out of water used for drinking and showering, where it is inhaled with steam.
To increase exposure to friendly bacteria, spend time outside and play in the dirt. Gardening can provide benefits beyond bacteria, such as stress relief and fresh, seasonal, organic food. Avoid the use of pesticides, not just in the garden but on houseplants as well. When it comes to personal hygiene, antibacterial products are not necessary. Regular soap will kill unfriendly organisms, but excessive washing can remove protective skin oils as well as normal flora, increasing chances of irritation and infection. Friendly bacteria can also be supplemented. Look for products from reputable companies that have at least one billion colony-forming units (CFUs) per capsule, an expiration date and a lot number. Keep them in the refrigerator and take as directed by your doctor.