Probiotics: The Good Bacteria
Written by Debra Kirchhof-Glazier
Bacteria are everywhere. Most people think of them as something to be avoided. However, not all bacteria are bad. In fact, some are absolutely essential for health.
About 90% of our 100 trillion cells consist of bacteria. Some of these reside in the small and large intestines, creating a diverse microflora. Many of these bacteria are beneficial and coexist in harmony with us. These good bacteria receive a place to live and in turn, provide us with health benefits.
The intestinal tract has a profound effect on our overall health. A properly functioning gastrointestinal system is essential not only for allowing us to absorb the nutrients we eat, but also for ridding our body of toxins and wastes and for enhancing immune function. In regard to the immune system, our intestines contain an extensive form of lymphatic tissue known as GALT (gut associated lymphatic tissue). About 40 to 50% of our immune cells during adulthood and 70% at birth come from GALT. A healthy intestine is key to overall good health, and a major factor in intestinal health is a proper balance between friendly and harmful bacteria.
There are over 400 different species of bacteria in our intestines. Harmful strains produce toxins and have been implicated in causing diseases like ulcerative colitis and inflammatory bowel disease. On the other hand, friendly strains provide several health benefits, including the production of fatty acids and vitamins that nourish intestinal cells and the activation of mechanisms that decrease inflammation and stimulate immune function. Lactobacillus and Bifidobacteria are the most common strains of beneficial intestinal bacteria. Lactobacillus is found in yogurt and fermented foods, such as the yogurt-like drink kefir and naturally prepared sauerkraut. These bacteria reside mostly in the small intestine and produce lactic acid, which helps with the absorption of minerals like calcium, copper, iron, magnesium and manganese. Some of the lactobacillus strains also produce antibiotics against streptococcus, staphylococcus, clostridium and yeasts. The bifidobacteria are among the most common friendly residents of the large intestine. They adhere to the walls of the colon and prevent harmful bacteria from gaining a foothold. They also secrete lactic acid and may play a role in reducing cholesterol.
Our medications and lifestyle can affect the balance of bacteria in our intestines. Antibiotics kill both good and bad bacteria and can pave the way for a shift in the balance, allowing harmful bacteria, yeast, and fungi to take up residence in favor of the beneficial bacteria. Antacids, which neutralize stomach juices that kill many harmful bacteria, can also shift the balance if they are used on a regular basis. Habitual use of laxatives slows the normal peristaltic movement of the colon, which allows harmful bacteria to remain longer and multiply. Oral contraceptives can make the intestinal tract less acidic, which encourages the growth of harmful bacteria and yeasts. Long-term stress slows peristalsis and decreases the production of digestive enzymes. This may explain why stress has been implicated in the development of irritable bowel syndrome, in increasing the symptoms of Crohn’s disease and ulcerative colitis, and increasing the likelihood of developing food allergies. Slower passage of undigested materials through the system keeps bacteria, including harmful ones, in the system longer and gives them a food source. And finally, modern methods of preparing and preserving foods have eliminated many of the good bacteria along with the bad. All of these factors can upset the healthy balance of bacteria in the system and result in the generalized condition known as dysbiosis.
Perhaps the most influential factor in triggering dysbiosis involves significant use of antibiotics. Physicians are becoming increasingly aware of the need to supplement their patients with probiotics after treatment with antibiotics. “Probiotics” is the term for dietary supplements that consist of friendly bacteria. Clinical applications of probiotics center around preventing and treating diarrhea arising from diverse causes. In addition, probiotics have been shown to be helpful as adjunctive therapies in the treatment of inflammatory bowel disease, irritable bowel syndrome, necrotizing enterocolitis, and stomach ulcers. Interestingly probiotics also have a significant effect in treating some allergic diseases, such as dermatitis, underscoring the importance of intestinal health for the entire body.
A dizzying array of probiotics is available in the market with dosages given in number of tablets or scoops of powder, often expressed in CFUs (colony forming units). The doses required to confer health benefits are in the range of one million to one billion CFUs per day. Some of these preparations include prebiotics, substances which enhance the action of beneficial bacteria by either serving as a food source or binding harmful strains so that the beneficial ones can predominate.
Probiotics are generally considered safe in healthy, immunocompetent people. There are, however, some isolated reports of serious infections arising from their use in patients with weak immune systems. In addition, studies on particular strains may not be applicable to all probiotic bacteria. It is best to consult with a doctor or clinical nutritionist before starting probiotic therapy.
In the meantime, it is prudent for most people to eat yogurt or take a probiotic supplement after antibiotic treatment. It is also a good idea to consume foods like buttermilk, natural sauerkraut, and yogurt on a regular basis and to stay regular to keep your intestine- and yourself- happy and healthy.
The Huntingdon Health and Wellness Association makes no medical claims or recommendations. Check with your doctor about your specific health care needs.