Obesity, Fatty Liver and Colon Cancer: Are You Growing Gut Friends or Foes?

In the publication, “The Influence of the Gut Microbiome on Obesity, Metabolic Syndrome and Gastrointestinal Disease,” found in the 6th volume of the Journal, Clinical and Translational Gastroenterology (2015), authors Parekh, P. et al. review the role of the GI tract microbes in human diseases. This is a summary and interpretation of their findings.

With almost 1,000 different species (not individuals, species) of bacteria living in the human gastrointestinal (GI) tract, there is a lot going on in there! Our gut can be a GI “battlefield” full of friends who help us by breaking down toxins, feeding us nutrients, and producing energy for our bodies, or a field full of enemies breaking through holes in our intestines, killing off the good guys and taking over.
Most of us know that obesity is when you have excess body fat. Sometimes, when we have excess body fat, especially in the abdomen, we can also have Metabolic Syndrome. Did you know that the Journal of the American Medical Association (JAMA) states that almost 35% of American adults live with Metabolic Syndrome? What does Metabolic Syndrome mean? Metabolic syndrome is when you have a disorder of energy storage. This often results in a larger waist line, high blood pressure, excess fats in the blood (cholesterol, triglycerides) and insulin resistance (as seen in Diabetes Type II). These factors can lead to heart problems and even death. Why are we talking about this in an article about gut bacteria? Well, researchers are now learning a lot more about how gut bacteria affect food energy storage and insulin resistance.

Certain bacteria in your gut, called Methanogens, break down sugars in your food into products called short-chain fatty acids (SCFAs). These SCFAs are energy for the host (that’s you)! Pretty neat, huh? SCFAs have also been found to be protective against diet-linked obesity and insulin resistance.

sBacteria that produce them are considered the “good guys.”  What happens when we kill off our “good guys” through the use of antibiotics? Scientists say there appears to be a link between early antibiotic use and the development of childhood obesity. Although, more studies are needed and this is just one factor, while diet and exercise also play a role.
There have been some interesting studies done on this so far, and I’m sure many more will come. In one study, Probiotics were used to treat obesity in a mouse model. Probiotic bacteria fed to the mice, including Bifidobacterium animalis, Lactobacillus rhamnosus, and L. paracasei were shown to slow weight gain and improve the balance of glucose sugar and insulin. More studies are needed, however, since this area of Probiotic research is relatively new.
Taking it to the next step, there is something called a fecal microbiota transplant (FMT) where feces from a donor is implanted into the GI tract of a recipient. This method includes the entire community of bacteria and not just a few species. Since bacteria love to communicate, this may be the key to a successful gut re-population. Researchers found that when feces samples from obese mice were donated to average-sized germ-free mice, the average-sized mice became obese. This was also seen in a case where a human FMT recipient suddenly started putting on a good amount of weight after receiving a stool sample from an overweight donor.
In an interesting FMT study, 18 men with Metabolic Syndrome participated. Nine of the men had a sample of their own stool self-implanted and the other nine men had a sample of stool implanted from a lean donor. Crazy enough, the nine men who received the lean stool donation saw a great reduction in their triglyceride levels and increased insulin sensitivity post-FMT. In the future, this method may show promise for those affected by Metabolic Syndrome.
All this is interesting, but, what if you’re not overweight? What if your digestive issues are a bit different? There’s a microbe for that too! Studies on Irritable Bowel Syndrome, Crohn’s and chronic acid-reflux patients are now finding links between certain bacterial species specifically found in the guts of people who suffer from each of these disorders that are not present in gut-healthy individuals.

We can now link changes in the gut microbe community with non-alcoholic fatty liver disease (NAFLD). This is when more than 5-10% of the liver’s weight is due to fat, and it is not the result of alcohol. In people with NAFLD, they have found lower levels of the good bacteria, Ruminococcacae and higher levels of E. coli. People with NAFLD and certain related liver issues have been found to have “leaky gut” where there are holes or breaks in the intestinal wall. This allows bacteria and bacterial products to move through, into the bloodstream where they come into contact with our immune cells. This results in inflammation. If the leaks are not repaired, the inflammation doesn’t stop (without turning off the immune system). Of note, one study did show that a certain probiotic was able to improve fatty liver and even lead to weight loss.
We know that certain bacterial species are helpful. These “good guys” break down our food, remove toxins, release nutrients and energy into our body and help our immune system develop. Other strains of bacteria have been found to be pro-inflammatory and pro-carcinogenic (cancer-causing) and even work to damage your DNA by breaking the double-strands. Damaged DNA can ultimately lead to tumor growth, as in some cases of colon cancer. It is important to learn how to eat healthy so that you can “grow” more of the good bacteria than these bad bacteria.  You don’t want to wait until cancer is detected. If you suspect that you may already have colon cancer, please educate yourself and make an appointment to get imaging done along with some lab work. There are options for recovery and hope is not lost!
If you are interested in reading more, this article is based on the following publication:
Parekh, P., Balart, L., and Johnson, D. (2015). The Influence of the Gut Microbiome on Obesity, Metabolic Syndrome and Gastrointestinal Disease. Clinical and Translational Gastroenterology. 6 (e91). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816244/