The average adult has two to four pounds of bacteria in the digestive tract. The vast majority of these organisms, about 85%, are beneficial. The remaining 15% are potentially harmful, but they won't make you sick as long as they're outnumbered by the good guys.

Any change in this microbial balance, known as dysbiosis, can lead to a host of digestive problems, such as diarrhea, bloating and constipation. If the harmful organisms continue to multiply, they can contribute to more serious diseases, including inflammatory bowel disease and even cancer.

It doesn't take much to disturb the balance. Here are the main risks and bow to combat them…

Supplements for Gut Health

If you experience any type of digestive discomfort-heartburn, constipation, diarrhea, bloating—more than once or twice a month, you could benefit from daily supplements.

Probiotics can help counteract the effects of modern life (antibiotics, chemicals in food and water, etc.). They also can help ease discomfort from diarrhea and inflammatory diseases such as IBS.

Look for a product that contains a combination of live organisms-it will replenish a range of beneficial organisms in the intestine. I recommend brands such as Pharmax, Metagenics and Enzymatic Therapy, which produce high-quality supplements. Follow the dosing instructions on the label.

Also, broad-spectrum digestive enzymes are particularly helpful for adults age 50 and older, who tend to produce low levels of digestive enzymes and often have difficulty with digestion.

The same companies that produce probiotics manufacture high-quality digestive enzymes. Follow the label instructions.


The ability of antibiotics to kill bacteria also is their downside. They can save you from infection, but they can wipe out beneficial organisms at the same time.

Researchers have found that a single course of antibiotic therapy can disrupt the balance of some intestinal bacteria for years. Many antibiotic patients get yeast infections-Candida, the organism that causes them, flourishes when beneficial organisms are killed by antibiotics. The use of powerful, broad-spectrum antibiotics (such as Cleocin) has resulted in an increase in infections with C. difficile, a dangerous organism that thrives when the body's natural balance is disturbed.

What to do: Tell your doctor that you would rather not take an antibiotic unless you really need it. It's estimated that up to half of antibiotic prescriptions are unnecessary. For example, millions of Americans every year are given antibiotics for colds, sinus infections and sore throats-illnesses that usually are viral, not bacterial.

If you do need an antibiotic, ask your doctor if you can take a narrow-spectrum agent, such as penicillin. Narrow-spectrum antibiotics kill fewer beneficial organisms than broad-spectrum antibiotics such as Cipro.

Also helpful: Take a probiotic supplement (see box) while using antibiotics and keep taking it for about a week afterward. Take the supplement about four or five hours after taking the antibiotic. Otherwise, the antibiotic will kill the beneficial organisms in the probiotic supplement. You may want to continue to take a probiotic daily. (See page 169 for more information on antibiotics and digestive disorders.)

Poor Diet

The foods that most Americans eat every day are chemically processed, low in fiber and high in fat and sugar. They're among the main causes of bacterial overgrowth, the proliferation of harmful intestinal bacteria.

Many chronic digestive problems-gas, diarrhea, constipation-are thought to be caused by bacterial overgrowth.

What to do: Probiotics can help, but you also will need to cut down on the processed foods in your diet. Better yet, try to eliminate them completely. Be particularly wary of refined carbohydrates such as white bread, pasta, candy, pastries, cookies and chips, which are rapidly digested by your gut, causing a spike in blood sugar.

Emotional Stress

We all get "butterflies when we're anxious. For reasons that still aren't clear, stress-related signals from the brain travel to the intestine, causing an upset stomach and other symptoms. The worse the stress, the more intense the symptoms.

Example: Patients with irritable bowel syndrome (IBS) tend to have higher stress levels than those without it. Also, when animals in laboratory studies are stressed, they have a 20% to 25% reduction in a particular "good" organism in the intestines and a corresponding increase in one that's harmful.

What to do: Schedule time every day for something that helps you unwind. Some people enjoy a half-hour of yoga, doing a hobby or working in the garden.

Air Travel and IBD Don't Mix

Air travel may cause inflammatory bowel disease (BD) symptoms to flare. Airline cabins are pressurized to 8,000 feet-which means that plane passengers get about 25% less oxygen than people at sea level. The lower oxygen level can cause the body to produce higher levels of molecules that activate inflammatory pathways, resulting in a recurrence of IBD symptoms.

Exercise is ideal because it decreases levels of stress hormones while increasing endorphins, brain chemicals that impart a feeling of well-being.


Sooner or later, just about everyone who travels will suffer from sudden diarrhea that usually is attributed to bad water or unsanitary conditions.

Fact: It can be caused by the mere act of traveling, Travel disrupts your circadian rhythm—physical, mental and behavioral changes driven by the 24-hour biological clock that regulates sleep and wakefulness. You probably don't sleep well before a're rushing around getting ready...and you may suffer from jet lag after you arrive at your destination.

The nerves, hormones and blood vessels that regulate the intestines are very sensitive to circadian changes. It's common for travelers to experience dysbiosis, along with the digestive problems that accompany it, even with no foreign organism present.

What to do: Take care of your digestive health before you leave for your trip. Try to get enough sleep. Go for long walks. Keep your stress level to a minimum. Avoid drinking alcohol (it causes dehydration and disrupts your circadian rhythm—and avoid alcohol on the plane as well.

Also important: Fortify your system with a healthy breakfast, such as oatmeal, on the day you leave. Pack healthy snacks, such as high-protein bran bars, so you don't have to eat the food served in airports or on the plane. Nutritious meals will help maintain the optimal bacterial balance.

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