Gut Microbes Failure To Communicate Linked To Disease
September 17, 2013

Going With Your Gut: Intestinal Microbes Linked To Health Issues

Brett Smith for - Your Universe Online

A new research review from Oregon State University has suggested that intestinal microbes play a big role as the immune system in keeping a person healthy.

Review researchers said health issues such as autoimmune disease or clinical depression can sometimes be traced to immune dysfunction that starts with a “failure to communicate” in the human digestive tract. They theorized that future healthcare may be guided by the personalized assay of an individual’s “microbiome” to see what prebiotics or probiotics might help fight off disease.

“Asked about their immune system, most people might think of white blood cells, lymph glands or vaccines,” said study author Natalia Shulzhenko, an assistant professor and physician in the OSU Department of Biomedical Sciences. “They would be surprised that’s not where most of the action is. Our intestines contain more immune cells than the entire rest of our body."

“The human gut plays a huge role in immune function,” Shulzhenko said. “This is little appreciated by people who think its only role is digestion. The combined number of genes in the microbiota genome is 150 times larger than the person in which they reside. They do help us digest food, but they do a lot more than that.”

Shulzhenko said that microbes in the gut are in a constant conversation with the body and a disruption in the “crosstalk” could facilitate disease.

“In a healthy person, these microbes in the gut stimulate the immune system as needed, and it in turn talks back,” the OSU scientist explained. “There’s an increasing disruption of these microbes from modern lifestyle, diet, overuse of antibiotics and other issues. With that disruption, the conversation is breaking down.”

In the new review, which was published in the journal Clinical Reviews in Allergy and Immunology, the research team looked at how microbe dysfunction can result in malabsorption and diarrhea, which affects millions of children around the world and is often not resolved simply through better nutrition. Conversely, a high-fat diet may condition gut microbes to prefer these foods, leading to more fat absorption and weight gain.

Shulzhenko noted that there is currently an explosion of research surrounding intestinal microbes being facilitated by genomic sequencing advances. This research is allowing scientists to understand and appreciate some of this conversation between the body and gut microbes, Shulzhenko said.

The results of the review covered a range of diseases, including celiac disease and inflammatory bowel disease. Some studies in the report even found a connection to depression, late-onset autism, allergies, asthma and cancer.

Learning about these interactions is a first step to addressing them, Shulzhenko said. Once researchers establish a better model of what healthy microbiota in the gut looks like, they could be able to personalize therapies to restore any balance that may have been disrupted. The study researchers also predicted the development of new types of probiotics to mitigate the impact of antibiotics on gut microbes, when such drugs are used.

The study researchers emphasized that some lessons in health care may need to be unlearned as we begin to consider the role of gut microbes – such as the love of antimicrobial cleansers and the idea that using an antibiotic is always a good choice.