Microbes make up large amount of the human body. They help to keep a human being healthy through the varying processes that they carry out. Microbes are an integral part of the human make-up, and these integral pieces may be in danger and thus causing danger for the health of their host’s body. Microbes are extremely diverse within differing people. Over time the microbes within a person can also change, during early development and with disease (Lozupone, 2012). Some people are trying to look at microbiomes through an ecological aspect, one such person is Catherine Lozupone. She worked on something called the American Gut project, which tried to discover the differences in microbes in the gut across populations, and what a ‘normal’ or healthy gut might look like (Pollan, 2013). When looking at microbes through an ecological aspect, it leads to the thought that everything relates to each other in some way, such as a physical environment might. When looked at this way it is possible to see how the lack or addition of certain elements (such as microbes) can lead to diseases within the environment (such as lungs).
A gut microbiome can be looked at like an environmental ecosystem. This is what Catherine Lozupone is doing at least. Both factors from the environment, such as where one lives, and the host itself can effect microbe diversity over a lifetime. It is possible that factors in infancy and as a child can lead to a susceptibility to immunological diseases such as atopic diseases and asthma (Lozupone, 2012). Atopic diseases are the result of a person having a genetic disposition to develop an allergic reaction, as well as higher levels of IgE*. IgE are antibodies found in lungs, skin and mucous membranes, and are associated with an overreaction to environmental antigens, basically allergic reactions (Dowshen, 2011).
It was previously thought that lungs were sterile. Now however, a team of scientists from Imperical College London discovered that every square centimeter of our lungs is home to 2,000 microbes. As stated above microbes vary between people, with development and disease. People who have diseases have vastly different microbes than those who do not, and those who do have disease tend to have a less diverse and healthy microbiome. This holds true with people who have asthma, they have a different microbes than those who have a healthy set of lungs (Zimmer, 2010). With the information taken from the Lozupone article that microbes in the lungs can come from the surrounding environment from when a person is younger.
The hygiene hypothesis also plays a role in this discussion. The hygiene hypothesis is something that questions if environmental surroundings, the microbes one has in childhood, and some infections in early diseases can possibly prevent atopic diseases in later stages of life. A study about exposure to foodborne and orofecal microbes versus airborne viruses was done in relation to atopy and allergic asthma. This study was done to try to discover if foodborne and orofecal microbes or airborne viruses are related to asthma or atopic diseases. This study was done with the hygiene hypothesis in mind in relation to what microbes one has, early infections and a person’s environment (Matricard, 2000).
Specifically this study looked at H. pylori, T gondii, and hepatitis A for oralfecal and foodborne causes. It discovered that they were inversely related to atopic diseases. Asthma was diagnosed in about 0.4% of participant members in this study, there were 245 participants. However, it was found that viruses transmitted through other routes, such as mumps, rubella, and chickenpox were not inversely related. Mumps, rubella, and chickenpox are highly infectious airborne viruses. Through this study it was shown that exposure to these diseases could have an effect on asthma and atopic diseases. According to the article, “…support the hypothesis that daily ingestion of traditionally processed food, not treated with antimicrobial preservatives and not subjected to hygienic procedures, may help to prevent atopy. A traditional or ‘unhygienic’ diet may act either by providing adequate daily microbial stimulation of the muscosal immune system …” This study shows that features of westernized life, such as a westernized diet, is related to atopic diseases and asthma (Matricard, 2000). This shows that what one is exposed to can help prevent atopic and asthmatic disease as far as viruses and environment (from which these diseases are found).
The study shows a relation between a person’s environment and the healthy, or non-healthy microbes they may have within their lungs, which may lead to asthma or atopic diseases. When looked at microbes in an ecological way, as an environment it leads to new questions, such as how can one substance relate to the decrease or increase of microbes within in one person. In relation to this blog post, there is a relation with everything shown. Microbes exist in the lungs, and there can be unhealthy or healthy amount of microbes. An unhealthy amount of microbes can lead to asthma or atopic diseases, and asthma and atopic diseases can come from the environment, or relate to previous viruses that a person has already had, such measles, mumps, or rubella. This in turn relates to the hygiene hypothesis. There is more to find out, but it is undeniable that by discovering microbes and the environment that they exist within and became of there is so much more to discover in relation to health.
References:
Dowshen, Steven, reviewed by. “Blood Test: Immunoglobulin E (IgE)” KidsHealth February 2011. Web
http://kidshealth.org/parent/system/medical/test_immunoglobulin_e.html#
Lozupone, Catherine A., et al. “Diversity, Stability and Resilience of the Human Gut Microbiota.” Nature 2012. Web.
http://www.nature.com/nature/journal/v489/n7415/full/nature11550.html
Matricard, Paolo M., et al. “Exposure to Foodborne and Orofecal Microbes versus Airborne Viruses in Relation to Atopy and Allergic Asthma: Epidemiological Study.” BMJ 12 February 2000. Web.
http://www.bmj.com/content/320/7232/412
Pollan, Michael. “Some of My Best Friends are Germs.” New York Times 15 May 2013. Web. Taken from ctools
Zimmer, Carl. “How Microbes Defend and Define Us.” New York Times 12 July 2010. Web.
Ecological and Evolutionary Medicine 
I thought the hygiene hypothesis was really interesting. I believe that it is at least partially true. I remember there was a part in the Pollan article which talked about how if a baby is born by C-section their gut microbiome is a lot less diverse than those of babies born the traditional way. According to what you say about the hygiene hypothesis, if someone has less microbiome diversity as a child, they are more likely to have asthma. My brother and I were both born through C-section and we both have asthma as well as allergic reactions to several different things. So I’m guessing this is because we didn’t acquire a lot of different types of microbiota when we were born. I was kind of confused when you said that microbiota diversity in the lungs affects asthma though. I remember reading somewhere a couple weeks ago that low gut microbiota diversity can increase risk of asthma, so I was wondering if asthma is influenced by both the gut and lung microbiota diversity?
I also found an article talking about how dogs can possibly help to protect kids from asthma. I think the way it works is kind of similar to how a baby acquires microbiota during birth (although it’s not nearly as effective as the birth way because you’re getting much less diversity this way). Apparently having a dog in the house can inoculate the gastrointestinal tract of babies, resulting in “a more mature immune response that is less sensitive to many allergens.” When they tested this on mice that had been given allergy triggers, the mice that were exposed to dust from homes with dogs had significantly fewer allergic responses compared to the mice that were exposed to dust from homes without dogs. It wasn’t mentioned in the article, but I think this might only work if the dog is around kids; I don’t think it will work if you get a dog later in life once you’re older. Again, I don’t know if this is true, but I’m saying this because we just got a dog two years ago and my brother’s allergies/asthma got worse around that time (he was 13 when we got our dog). Our dog mostly stays in my sister’s apartment now, but every time he comes home my brother starts coughing a lot. So I think our dog’s presence is actually worse for my brother’s asthma.
Here’s the link to the article: http://online.wsj.com/news/articles/SB10001424052702304173704579262664231190726
I found this post very interesting and one of the points that grabbed my attention the most was that before to long ago we didn’t know that the lungs had microbes on them at all, we thought they were a sterile part of our bodies. I was wondering how the university decided or why they wanted to look at the lungs for microbes. I found it odd that we didn’t have this information till a few years ago. Is that just because we assumed, so we didn’t look into it or was it because we didn’t have to correct tools or the advanced enough technology? A final question that I have is, are there other parts of our bodies we still think are sterile or have we determined if there are any?
I thought your post gave me some wonderful new insight into a key link between many topics we have discussed separately in class so far: our gut microbiomes & the hygiene hypothesis & environmental surroundings, to name some. The information you presented was often completely new to me; for example, I had no clue that scientists would initially think of the lungs as a sterile environment! This seems like an unrealistic expectation because if the gut isn’t totally pure, then how could they expect the lungs to be, since you presumably breathe pathogens in pretty regularly and could get new microbes introduced to that environment regularly?
I was happy that I could also take the lessons from your post on the topic of environmental influence and relate them to what I learned through researching for my Pollan post, which was on the rural vs. urban environment’s ability to influence the development of a person’s microbiome. I had never considered that rural vs. urban could also affect asthma and allergy tendencies not just through pollution levels but through altering the microbiome itself.