Published on June 14, 2016

What lies in your gut could be the answer to 'western diseases'

By Dr. Leana Guerin

Tuesday, June 14, 2016

We have long known that our bodies are colonized by microorganisms, but only recently are beginning to understand the central role they might play in our health and development of diseases.

The microbiome consists of bacteria, viruses, fungi and protozoa, although the main focus of attention has been on bacteria.


Dr. Leana Guerin is a board-certified
pathologist practicing at
Lawrence Clinical Laboratory at
Lawrence Memorial Hospital.
These organisms live on our skin and inside our bodies. The largest bulk of them are in our gut, especially the large intestine, where they make up a combined weight of about 3 pounds; the same weight as the human brain. They are so numerous that in our bodies, human cells are outnumbered 10 to 1.

One of the first roles of the microbiome that was understood was the layer of protection it provides from “bad bugs.” The classic example of this is the development of Clostridium difficile infection causing severe diarrhea after antibiotic exposure. The antibiotics kill the “good bacteria,” leaving the colon vulnerable to growth of C. difficile and subsequent production of a toxin that damages the colon.

The C. difficile infection can be treated with certain antibiotics, but sometimes they aren’t effective. In these cases, patients are often cured with a Gut Microbiota Transplant, a procedure where good bacteria are taken from the colon of a healthy donor and placed in the gut of the patient thus replenishing that person’s colon with beneficial bacteria.

Gut bacteria are involved in synthesizing and metabolizing important nutrients for us including vitamins and short chain fatty acids. They can also produce toxic compounds depending on the types of organisms that live in our gut and what we feed them. Additionally, the interaction of the bacteria in our gut with our immune system appears to play a critical role in the development of a healthy immune system.

When there is a shift from a healthy gut microbiome to an unhealthy one, it is called “dysbiosis.” Dysbiosis is being linked in more and more studies to a wide variety of conditions and diseases including obesity, type 1 and type 2 diabetes, liver diseases, cancer, heart disease, asthma, autoimmune diseases and neurologic diseases. It’s exciting to think the microbiome may be the common link to the development of all these “western diseases.”

You may be wondering how you ensure your microbiome is healthy. Unfortunately, this field of study is still too new to know what the optimal types and ratios of bacteria and other organisms are, although we do know some general guidelines.

Our diet not only provides our bodies with calories and nutrients but also feeds our bacteria. Typical “western” diets high in animal protein, fat, sugar and artificial sweeteners promote growth of less favorable bacteria at the expense of more favorable ones. Conversely, diets high in plant-based foods promote a healthier complement of gut bacteria.

Probiotics are another way we can encourage a healthy gut flora. Probiotic supplements and foods rich in probiotics, for example yogurt, kefir, fermented vegetables such as sauerkraut, apple cider vinegar, etc., can provide a continuous source of good bacteria to colonize your gut.

No doubt there will be many fascinating studies in this field in the coming years as we continue to learn how to best care for our gut flora and how it might help prevent and possibly even cure diseases.

— Dr. Leana Guerin is a board-certified pathologist practicing at Lawrence Clinical Laboratory at Lawrence Memorial Hospital, a major sponsor of WellCommons. She earned her medical degree at the University of Iowa where she completed fellowship training in surgical pathology with an emphasis on GI/liver pathology in 2010.

What lies in your gut could be the answer to 'western diseases'

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