Bacteria in the gut may hold key to many diseases

What if there was a pill that could restore the natural balance of bacteria in your gut and treat not only digestive ailments but other diseases as well?

Medical researchers are just beginning to scratch the surface of this science, explains Dr. Ilseung Cho, assistant professor of medicine and associate program director of the division of gastroenterology at the NYU Langone Medical Center in New York City.

Cho researches the hundreds of species of bacteria in our intestinal tracts, part of the trillions of microorganisms in our bodies known as the "microbiome."

He previously sat down with CBS News chief medical correspondent Dr. Jon LaPook to discuss how this ecosystem of good and bad bacteria in our bellies may contribute to obesity. Antibiotics that fight bacterial infections, for example, have been linked to weight gain and increased body fat, apparently by upsetting the normal interaction between the bacteria in our guts and the food we eat. For example, research suggests antibiotic use may lead to some foods being more thoroughly digested and absorbed, leading to weight gain.

Research has linked the microbiome not only to gastrointestinal illnesses like colon cancer, inflammatory bowel disease and celiac disease, but also to ailments outside of the digestive system, such as heart disease and rheumatoid arthritis.

That's because the microbiome plays a major role in the body's immune system.

"The...digestive system is one of the most important immune system organs in the body," explains Cho. If the natural balance of bacteria in the gut is disrupted, it might trigger an inflammatory cascade of immune system reactions in the body, which can result in symptoms like the painful swelling of the joints in rheumatoid arthritis.

Celiac disease is a classic example of the interaction between the immune system and the gut, according to LaPook, who is also a practicing gastroenterologist at NYU Langone Medical Center. In people with celiac disease, the wheat protein gluten is recognized by the immune system as an invader which triggers an inflammatory reaction. That can cause many problems throughout the body including abdominal pain, diarrhea and weight loss, as well as neurological issues like brain fog or migraines. It can also cause infertility, short stature, and malabsorption of nutrients that leads to conditions such as osteoporosis.

Another medical condition that illustrates the consequences of upsetting the normal gastrointestinal microbiome is the serious -- sometimes deadly -- bacterial infection Clostridium difficile, or C. diff. Sometimes people treated with antibiotics develop a C. diff infection after receiving medical care. Symptoms include diarrhea, fever, loss of appetite, nausea and abdominal pain, and about 14,000 Americans die from C. diff each year.

Other antibiotics may treat the infection, but they don't always work. That's when a fecal transplant comes in, which is essentially what it sounds like: A healthy donor's stool is transplanted into the gut of a person with the infection in order to restore the natural balance of bacteria.

Studies suggest the procedure is more than 90 percent effective in treating C. diff cases, but the difficulty of administering it via colonoscopy -- not to mention the "ick" factor, notes LaPook -- don't always make this a readily available option.

That's led Canadian researchers to develop an alternative -- a medication dubbed the "poop pill," which contains healthy bacteria in capsule form. The researchers took a relative's donor stool and processed it in a lab to extract the bacteria before packing it in a triple-coated gel capsule that won't digest until it reaches the intestines. Patients down between 24 and 34 pills in one session to try to restore the balance of bacteria.

Researchers tried this method on 27 people and cured them all of C. diff.

In the future, Cho says scientists hope to identify and isolate "keystone" bacteria that play the most important roles in keeping the gut's balance on track. That could be the key to treating a variety of diseases.

"By re-establishing some of those key players, you may be able to switch someone from diseased to healthy," said Cho.

Watch the video above with Dr. Cho and Dr. LaPook to find out more about the microbiome and its impact on your health.

The Human Microbiome Project has more information on ongoing studies.

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