One Bug You Want On Your Side

Our guts are teeming with billions of bacteria essential to our gastrointestinal health and our ability to ward off chronic disease. When these bacteria work in our favor, we don’t give them a second thought. But when our natural balance is off, many of us question the role that these bacteria play and how we can restore them.

Probiotics—also known as friendly bacteria—help keep our gastrointestinal (GI) tract running smoothly. They help us digest food, absorb nutrients and keep harmful organisms from taking over, says Dr. Melinda Ring, medical director of Northwestern Integrative Medicine in Chicago. “It is important to have enough healthy bacteria; they crowd out other potentially harmful organisms and help keep them from proliferating.”

These healthy bacteria also help stimulate the immune system to prevent colds and flu as well as help treat inflammation in conditions like inflammatory bowel disease and eczema. Even those with lactose intolerance find that they can tolerate more lactose in their diet if they have enough good bacteria in their gut.

Diet or Supplement?

“Our GI tract has trillions of microflora that are an arsenal of immune defense,” says Victoria Shanta Retelny, RD, LD, a Chicago-based food and nutrition expert and author of The Essential Guide to Healthy Healing Foods (Alpha Books/Penguin). “Use food as a first line of defense on a daily basis because you never know when foreign invaders, like a virus or bacteria, will enter your system.”

Look for live, active cultures in fermented dairy products such as yogurt, kefir, miso, tempeh, kim chi (Korean fermented cabbage), sauerkraut and fermented cheese products. The bacteria you’ll most commonly find in foods include lactobacillus or bifidobacterium species, a type of yeast called Saccharomyces cerevisiae (boulardii) and a yogurt starter culture called S. thermophilis.

The types and amounts of live active cultures vary among products. Check food labels to determine which strains of bacteria are in a product. Find out how much is alive when you’re eating the product, because live active cultures can dissipate on the store shelf. Contact the manufacturer or review its website to find this information, says Retelny.

But if you have symptoms associated with irritable bowel syndrome, such as loose stools; have recently had any type of GI infection; or have recently taken a course of antibiotics, it’s a good idea to take a probiotic supplement until symptoms improve, Retelny says. Supplements typically contain strains like enterococcus, bacillus and escherichia.

Different strains of bacteria help with different problems. Popular over-the-counter products, like Florastor and Culturelle, can be used for antibiotic-associated diarrhea, inflammatory bowel conditions and irregularity. Activia (think Jamie Lee Curtis) contains Bifidus regularis, which can help speed emptying of the gut when irregularity
is the problem.

You can also consume foods that help create more friendly gut bacteria. These prebiotics—sugars that feed healthy bacteria in the gut—are found in foods like onions, garlic, shallots, honey, wheat bran, bananas, artichokes and leeks, says Retelny.

Chronic Disease

Not only will probiotics help you ward off digestive troubles as simple as diarrhea and irregularity, but there’s evidence that imbalances in gut bacteria are linked to chronic conditions.

Researchers at Rush University Medical Center are studying how the GI tract plays a role in a variety of illnesses. One study involves characterizing the changes in the intestinal bacteria in HIV-positive patients, says Dr. Ece Mutlu, a gastroenterologist and director of the Inflammatory Bowel Disease Program
at Rush.

Even when the HIV virus is controlled, the disease can still progress in patients with HIV. “Our goal is to see whether HIV patients harbor different bacteria compared to controls and whether bacterial differences could help explain the immune activation in HIV,” says Mutlu.

Mutlu is also studying the role of stress in people with IBD. “We’ve already learned that if you can control stressin people with IBD, their symptoms improve,” she says. “We’re looking into why some people benefit from stress controls and others don’t.”

Other studies at Rush are exploring whether there are early bacterial changes in the intestines of people who develop Parkinson’s disease. Symptoms, such as constipation, may appear years before a diagnosis of Parkinson’s and could be a clue to changes in the gut that occur before those in the brain, says Mutlu.

Gut health has also been linked with obesity. Researchers have found that people who are obese may harbor gut bacteria that more efficiently extract calories from food, compared to the bacteria from someone who is lean. The extra calories add up and contribute to weight gain.

“The question has been asked whether it is the bacteria that extract more calories, or the diet of an obese person that changes the bacteria, or both that contribute to obesity,” says Mutlu. “It seems that diet profoundly affects the intestinal microbes. However, we haven’t learned how to manipulate the microbes to find an impact on a particular disease yet.”

Researchers also know that intestinal bacteria play a role in the development of autoimmune diseases like colitis and allergies and asthma. The gut flora trains the immune system to respond properly to foreign substances. But if there’s too little exposure to bacteria in childhood, the immune system doesn’t develop properly, and the person becomes more susceptible to allergies and asthma, known as the hygiene hypothesis.

This idea explains the link between bacterial exposure and dramatic increases in autoimmune and inflammatory diseases over the past 50 years.

“If we can change some of the bacteria, we may be able to affect the development of these types of illnesses and perhaps put a stop to their increase over the last few decades,” says Mutlu.

For many people, taking probiotics on a regular basis is a good idea, says Ring. “There’s very little risk if you have a normal, intact immune system. Our bodies are exposed to so many environmental toxins, organisms and medications that can negatively impact the normal gut milieu. Taking probiotics to keep the gut in balance is one of the core things we can do to maintain health.”

Published in Chicago Health Summer/Fall 2013