You may not like to think of yourself as a walking petri dish, but in fact, your gut is home to a steamy brew of more than 500 different species of bacteria. Most of these bacteria are friendly, and play a crucial role in keeping you healthy. When they’re in balance, the bacteria happily digest food, make vitamins and fend off harmful microorganisms.
But a number of factors can upset the bacterial balance in your colon. Chief among these is taking antibiotics, which wipe out the good bacteria along with the bad. Other causes include stress, exposure to a food-borne pathogen, a chronically poor diet, or a bout of diarrhea. The resulting imbalance can cause digestive problems, yeast and urinary tract infections, weakened immunity, and possibly allergies.
You can restore balance to your system by taking probiotics, friendly live bacteria found in supplements and cultured foods such as yogurt, kefir (a sort of liquid yogurt), some cheeses, sauerkraut, miso soup and kombucha tea.
Probiotic supplements and foods contain many of the same species of bacteria already found in the colon, and are therefore considered very safe to take on a daily basis. However, please consult your doctor before embarking on a supplement regime, especially if you are trying to treat a specific problem.
How They Work. Probiotics protect you, in part, by creating an environment that is inhospitable to harmful organisms. Lactobacillus and Bifidobacterium, for example, produce lactic acid, which discourages invaders by raising the acidity of the colon.
Probiotics also stimulate immunity in the colon, increasing antibody activity and the ability of white blood cells to attack harmful microbes. Some probiotic strains are known to target and destroy specific pathogens, including those that can cause enteritis, colitis, and stomach and intestinal ulcers.
Probiotics occupy space on the intestinal wall and help crowd out harmful organisms. They also strengthen the barrier function of the intestinal wall, which helps prevent ‘leaky gut syndrome,’ a condition that can lead to food allergies. In fact, a study of children with food allergies found that probiotics decreased symptoms of their eczema.
Health Claims. Probiotics have proven beneficial for a wide range of digestive problems, from the not-so-serious (but annoying) bloating, gas and constipation, to the more serious IBS (Irritable Bowel Syndrome) and IBD (Inflammatory Bowel Disease), including Crohn’s disease.
The Bifidobacterium and Lactobacillus bacteria produce lactase, an enzyme that digests lactose and can ease symptoms of lactose intolerance.
If you need to take antibiotics, supplementing with probiotics during and after your prescription can prevent diarrhea associated with taking the drugs and also recolonize your colon with friendly bacteria.
‘You might take antibiotics for a respiratory infection,’ explains Bill Griffin, owner of New Moon Natural Foods, ‘but end up with a digestive problem. After antibiotics, the organisms don’t necessarily grow back in balance, especially if you were out of balance when you got sick.’
Take Candida yeast, for example. Normally found in small amounts in the colon, Candida is unaffected by antibiotics and can flourish after friendly bacteria are wiped out. The resulting overgrowth of yeast can cause digestive problems, skin and mouth infections, and vaginal infections. Many women find that probiotics not only help prevent yeast infections, but inhibit vaginosis and urinary tract infections, as well.
Probiotics have also been successful in treating infectious diarrhea and traveler’s diarrhea. Ample levels of friendly bacteria can even help remove cholesterol from the body.
Choosing a Product. For general maintenance of health, cultured foods like yogurt are a good choice. But if you need a ‘loading’ dose after an illness or taking antibiotics, you may want to take supplements, which usually contain higher concentrations of bacteria. Here are some hints for choosing a probiotic product:
• Live bacteria are measured in CFU, or Colony Forming Units. There are no official recommended doses for probiotics, but a daily dose of one billion CFUs or greater is generally considered beneficial. (That may sound like a ridiculously huge number, but it’s small compared to the 10 trillion microorganisms that currently live in your gut.) Colony Forming Units should, as the name suggests, grow and multiply once inside the colon.
• Many products list the kinds of bacteria, but not the CFUs. If CFUs are listed, they generally refer to the number of viable bacteria at the time of manufacture. This value can drop significantly by the time you purchase a product. When buying yogurt, look for the Live Active Culture (LAC) seal, indicating that, at manufacture, the product contained at least 100 million CFUs per gram. When buying supplements, ask your health food store to recommend reputable brands, or consult Consumer Reports or the independent ConsumerLab.com.
• Buy all probiotic products well before their expiration date, and store as directed.
• Avoid yogurt products that are high in sugar (including high fructose corn syrup) and artificial colors and flavors. Sugar feeds yeast, which may already be proliferating if you have taken antibiotics or tend to eat a high-sugar diet.
• Each strain of probiotic acts differently in the body – one may attach well to the intestinal wall, while another may fight a particular microbe. To cover your bases, buy products that contain a combination of bacteria. Two of the more common kinds are Lactobacillus and Bifidobacterium. You may see the species name abbreviated, as in L. acidophilus, or B. lactis.
• Enteric-coated supplements are designed to survive stomach acid and make it through to the colon. Bill Griffin suggests taking enteric-coated supplements on an empty stomach so the probiotic passes through quickly and spends minimum time in stomach acid. An alternate recommendation is to take probiotics with food to dilute the digestive acids. However, this exposes the probiotic to stomach acid for a longer period of time, possibly decreasing its chance of survival.
