What is the microbiome? What does a healthy microbiome look like? These questions can be difficult to answer. To us Americans, a relatively healthy microbiome might still be dysbiotic, or imbalanced. The microbiome consists of trillions of microbes living in a human's large intestine.Our gut microbiota has huge impacts on our health including protection from pathogens and development of immune response. The microbiota can be effected quickly and easily by factors such as antibiotics and diet. The microbes depend on high-fiber intake to be healthy and to work at maximum capacity in our intestines. Unfortunately for us, the average American fiber intake is significantly less than what it should be. The recommended amount of daily fiber is between 25 – 30 grams for females and males between 18-50 years of age, and even this is low compared to the diets of some other countries. For example, rural Africans eat about 60-140 grams of fiber per day. Despite our recommended amount of daily fiber, the average daily intake is only 15 grams for Americans. It’s no surprise that America has a poor food system. Our diets consist mostly of processed and refined foods, which consequently, do not contain much fiber. Most of the fiber in our diets should come from plants, legumes or animal fiber, of which we do not eat enough of.
Why is a healthy microbiome so important? A study done around the beginning of 2016 on rodents fed a low-fiber diet showed that diversity of microbes declines with each subsequent generation. To ensure the experiment was accurate, the rats were fed the feces of an American to give them the microbiota of a human. The rats were fed a diet of pellets that had 30% less fiber than the control food which was considered high-fiber. The results were shocking. Tests showed that 60% of microbes lost at least half of their population in the microbiome on this low-fiber diet. The offspring of these mice had even less microbes since the parents were unable to pass what little microbes they had onto their offspring during birth or through their feces. The fourth-generation offspring had 1/4th of the microbe diversity of the original generation.
So, what are the consequences of a low diversity microbiome? Researchers found that some consequences could be obesity and inflammatory bowel disease. While it’s not a definite cause, researchers have reason to believe that obesity and microbiome diversity could be connected because they found that obese people have a lower diversity microbiome than the compared leaner people. In other microbiota enumeration studies, there have been implications that low diversity in microbiota are related to metabolic syndrome and cancer, as well as inflammatory bowel syndrome, once again. As mentioned above, rural Africans eat 3-7 times more fiber than Americans. As a result, they have greater stool mass, their intestinal transit time was twice as fast and they didn’t show signs of diseases such as diabetes, heart disease and colorectal cancer. The moral of the story is: eat more fiber! Diet is so important for our current selves and our future generations. As biology majors, don't we know that the goal is to produce healthy offspring?
Image source: http://edbites.com/2013/01/gut-feelings-eds-and-the-microbiome/
Posted by Jordan Milone (3)