Microbiome - Important Health Consequences Later in Life

Babies Have a Microbial Window of Opportunity

Rhonda W.

Article Summary

The article is an excerpt from a book called Let Them Eat Dirt: Saving Your Child from an Oversanitized World by B. Brett Finlay, PhD and Marie-Claire Arrieta, PhD.  The premise of this section of the book is that microbiome in infants can have important health consequences later in life.   There have been many advances in the human environment in the last 100 years.  The advances include things like chlorinated water, antibiotics, antivirals, vaccinations, and many others that make humans healthier.  Statistics like 100 years ago 75 million people died from H1N1 influenza in a two year span to now days where dying from H1N1 is rare.  These advances focus on getting rid of microbes and helping humans live longer. 

Infectious diseases have declined because of antibiotics, vaccines, and sterilization.  Some of the surgeries that are now performed wouldn’t be possible without antibiotics and sterilization. However, according to the research conducted by the authors non-infectious diseases have increased rapidly over the years; diseases such as diabetes, obesity, and asthma. Diabetes, obesity, and asthma are only a few of the non-infectious diseases that have become increasingly common in developed countries.  Genes are a cause of these types of diseases and disorders but the increase in these can’t be explained by just genes since they haven’t changed much over the years. 

Dr. David Strachan published an article about twenty-five years ago claiming that the lack of exposure to bacteria and parasites during childhood could cause an increase in allergy cases because the lack of bacteria and parasites prevents the immune system from developing properly.  His concept was named “hygiene hypothesis”.  There is a large amount of solid evidence supporting his proposal, however, it was unclear what factors lead to the lack of microbial exposure.  Personal cleanliness could be one of those factors but the authors of the book point out that the bigger impact to the lack of microbial exposure is antibiotics.

Antibiotics are common in treating ailments and are overused.  Studies show that the use of antibiotics increase during the flu season but antibiotics aren’t designed to treat viruses, they are designed to combat bacteria.  Antibiotics are also used in feeding livestock to help fatten them up to produce more meat per animal.  There is correlation between children overusing antibiotics and their weight.   Scientists at the Centers for Disease Control conducted a study that showed that states in the US with higher antibiotic use also have higher rates of obesity. Since the study was only correlational it didn’t prove that antibiotics cause obesity.  Microbiologist were skeptical that bacteria or lack of bacteria could cause obesity.  Experiments on mice and other experiments show convincing data that bacteria early in life can help determine weight later in life. 

Asthma has been a focus of experiments to see if the presence or lack of bacteria can impact the likelihood of a child developing asthma.  The University of British Columbia conducted studies on mice. The results showed that there is a critical window of time early in life when antibiotics could have an impact on the development of asthma.  The authors of the book conducted the study in humans by taking samples from feces of babies and comparing those that were at risk and those that weren’t at risk. Their research also points to a critical window of time where the microbial changes in the intestine could have long term immune consequences.  From both studies it seems that change in the intestinal bacteria can have an impact on the lungs.

During their research Finlay and Arrieta found that the differences in bacteria weren’t limited to the type of bacteria but also included the bacterial compounds.  One of the compounds in the gut is known as acetate and many of the bacterial compounds were detected in the urine of the babies so another point of proof that bacterial metabolites go everywhere in the body.  Their lab is still trying to figure out how the four bacteria (nicknamed FLVR) impact the immune system and lead to asthma. With this information there is a possibility of having preventative therapy for human asthma. 

What I Learned and Why the Article was Interesting

There are many scientific studies to read and replicate that can impact society.  While browsing through the articles listed at Scientific American I tried to pick an article that was published in the last couple of months and was current on information and research.   The book Let Them Eat Dirt was published September 20, 2016 and is considered a best seller already.   The purpose of the book is to give parents the latest cutting-edge scientific research about the human microbiome. This information can help parents raise their children.  

Many things made the article interesting.  One was the authors made it easy for the everyday person to read and understand that article.   Both authors have PhDs but used terms in their book to make the scientific research and information understandable for parents.  Another thing that is interesting about the article is the overview of the medical advances and how they have impacted society in a positive way but also a negative way.   The authors do a great job of explaining how humans rarely die from a microbial infection but now non-infectious diseases are more prevalent.

I find it interesting that we have known about microbes that cause infectious diseases for two hundred years and have battled them to keep people from dying but there is strong evidence that suggests early exposure to these microbes is beneficial.  This makes the title Let Them Eat Dirt appropriate since now days many parents don’t want their kids to get dirty and don’t seem to let them do things like play in the dirt.  This information is also helpful since technology has also changed the life style of children.  I remember as a kid I played outside until it was dark, rode bikes, got dirty, ate snacks without washing my hands, and drank out of the hose when I was thirsty.  Now many kids stay inside, play on smart phones and tablets, and drink bottled or filtered water.   Of course this is observation and could be a point of study. 

Learning that a bacteria from the gut could have an impact on the immune system and impact the healthiness of the lungs and other parts of the body is interesting. Another thing I learned is that sometimes a cure or a solution can cause another problem so a breakthrough can be for better or worse.  The authors mentioned they are still trying to figure out more information in regards to the four bacteria and their impact on asthma. It will be interesting to find out what more studies provide but it would also be interesting to find out what other areas bacteria can impact besides the lungs and the development of the immune system.  

For more details about their study the article can be found at: http://www.scientificamerican.com/article/babies-have-a-microbial-window-of-opportunity-excerpt/