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?
Sources: http://www.sciencemag.org/news/2016/01/your-poor-diet-might-hurt-your-grandchildren-s-guts
http://www.sciencedirect.com/science/article/pii/S1550413114003118
Image source: http://edbites.com/2013/01/gut-feelings-eds-and-the-microbiome/
Posted by Jordan Milone (3)
I think it is extremely interesting that scientists have found a correlation between obesity and a low fiber diet. I wonder if this has more to do with the quality of the food obese people (and all people with a poor diet) eat in general, as opposed to it being just low in fiber. Like all correlational studies, it is possible that the correlation is the result of a third variable; I would be interested to see further studies that evaluate whether low fiber diet leads to the diseases mentioned. Really interesting read, I don't think Americans pay enough attention to eating balanced, high fiber diets and maintaining their gut microbiota, which could be due to the lack of education about it. It is certainly not a topic I have learned all that much about.
ReplyDeletePosted by Jenna Lansbury
It is quite possible that there is a third variable involved. I'm sure it's not always just as simple as eating more fiber in some cases. The article that I got this information from didn't have a link to the studies showing the correlation between low gut diversity and obesity so I was unable to read very much into it. But I agree, I think there is a huge lack of education about the importance of a healthy diet, not just for the sake of maintaining a healthy weight, but because it effects so many other important biological functions in the body that have greater long-term effects.
DeletePosted by Jordan Milone (3)
I had no idea that fiber and diversity of the microbiome were connected. This was a very beneficial article, I do not think that many people realize how important eating enough fiber is for their health. It was interesting to see the variation between how much fiber we should be getting and what Americans are actually consuming. It would be interesting to see more studies performed on microbiomes and fiber. I will definitely be eating more fiber!
ReplyDeletePosted by Leah DeLorenzo
I've always been interested in the connection between health and the microbiome but I had no idea that it was connected to fiber intake. I think a good diet is a great preventative for many illnesses and diseases, and this article gives a great scientific explanation as to why. I know probiotics are a good way to help boost the microbiome but I’m curious if it they can be a substitute for sufficient fiber intake.
ReplyDeletePosted by Hannah Jordan (2)
While probiotics can be effective depending on the potency and strain, many of them have a hard time making it past the acidity of the stomach. If you can find a probiotic that can make it into your intestinal tract, I'm sure it can't hurt! Fiber is really more of a fuel for the microbiota in your large intestine that keeps them healthy and alive, so I'm not sure if probiotic supplements could be taken as a substitute for a high fiber diet. You could possibly get higher microbiome diversity but the key is to keep it healthy with a healthy high-fiber diet.
DeletePosted by Jordan Milone (3)