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What are you doing to the microbes in your gut?



Lactobacillus casei, a microbe found in dairy products, the human intestine and mouth. Source: Flickr, user: ajc1

There are a hundred trillion cells in our body. You might think that most of the cells are human, but in fact, 90% of these cells are tiny microorganisms like bacteria that we can’t see with the naked eye! But where do these microbes come from, and what are they doing in our body?


Source: Wikimedia Commons, user: BruceBlaus

All mammals, including humans, are usually born free of bacteria and other microbes. However, shortly after birth, babies become colonized by microbes that come from their parents, the food they eat, and the environment. The colonization of our gut by microbes continues throughout our entire lifespan. The population of microbes in our gut tends to become more complex as we get older and start consuming solid food.

Now that we know a bit about how we obtain these microbes, how are they affecting us?

 Most of us reading this blog have “Westernized” or modern lifestyles, where we have access to clean water, processed food, modern medicine, and hygiene. This does not mean that our environment is completely sterile, but as it turns out, the gut microbe population is less diverse in people in Westernized populations compared to rural populations.

 So why is this important?

Lower diversity of microbes in our gut is associated with autoimmune diseases like Crohn’s disease and irritable bowel syndrome, as well as conditions like multiple sclerosis and autism. It may also explain why there is a higher prevalence of conditions like asthma and allergies in modern society.

 Watch the following video which showcases our interview with Dr. Laura Parfrey, a researcher in the Departments of Botany and Zoology at UBC, to find out more about how our lifestyle influences our gut, and more importantly, what we can do to make our gut microbes more diverse.

Source: own work

Dr. Parfrey recently found that the diversity of gut microbes differs between Westernized populations and rural populations. She specifically looked at eukaryotic microbes, which are essentially all the microbes that aren’t bacteria, and found that the Western population had a much less diverse set of microbes! This may help explain the increasing prevalence of autoimmune diseases and allergies in modern society. According to Dr. Parfrey, there is still a lot that we still don’t know about how microbes affect our health, and she explains further research questions and why she finds her research interesting, in the following podcast:

Source: own work

So, there are lots of microbes in our body, especially the gut, and they’re affecting our health more than we’ve thought previously! In order to keep our gut microbes healthy and diverse, people can avoid overemphasizing hygiene with their kids; and as for adults, people can incorporate more diverse sources of food into their diets, especially diverse sources of complex carbohydrates.


Discovery of the first natural antiviral

Penicillin was discovered as the first antibiotic by Alexander Fleming, who isolated it from fungus in 1928. This is considered to have been a huge breakthrough as its discovery led to the successful treatment of cases of bacterial disease, saving millions of lives, although its misuse has now made many types of bacteria resistant. However, natural antivirals have not previously been discovered, despite the prevalence of diseases caused by viruses including Ebola, HIV and influenza.

Japanese/Chinese honeysuckle. Source: Creative Commons

Japanese/Chinese honeysuckle.
Source: Wikimedia Commons

Earlier this year, researchers in China discovered what they call MIR2911, a product that prevents the reproduction of influenza A viruses (IAV). According to the researchers, the Japanese/Chinese herb honeysuckle has been used to treat the flu for thousands of years, and some studies (1, 2) show that it suppresses the reproduction of IAV. However, until now, the active compound responsible for this was unknown, as well as its mechanism of action.

Electron micrograph of IAV Source: Creative Commons

Electron micrograph of IAV
Source: Wikimedia Commons

The researchers found that MIR2911 acts against IAVs such as H1N1, H5N1, and H7N9, which have been responsible for the swine flu, avian flu, and Spanish flu pandemics respectively. MIR2911 suppresses IAV by binding directly to the influenza virus and inhibiting the expression of two genes that are vital in the replication of influenza viruses.

This is an important discovery as there has previously been no natural antivirals discovered, and this presents a novel therapeutic agent that can be used not only against influenza A, but potentially other viruses as well, due to its broad spectrum. The researchers say that their discovery is something akin to a “virological penicillin” that can be used and chemically modified, as has been done to penicillin, to produce drugs that can treat the flu. Hopefully, we will have learned from our use of penicillin in order to try to prevent widespread antiviral drug resistance.

The following video is about flu viruses and how they infect us:

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Source (user): maia86magnoly


Can a mother have different DNA than her children?

In 2002, Lydia Fairchild was told that she was not the mother of her children. Prior to this, she had applied for child support from the children’s father, and DNA tests were performed in order to verify that both parents were in fact, the children’s biological parents. Although the DNA of the children matched that of the father, a bizarre discovery was made: the children’s DNA did not match that of Fairchild. Instead, she became the subject of an investigation into possible welfare fraud, and was interrogated by Social Services about her identity and who the children’s real mother was. Could the DNA testing have been incorrect? Is it a possibility that a mother’s DNA doesn’t match that of her children?

A chimeric mouse (right) with pups (left). The patches of two differing fur colours represent two genetically distinct cell populations. Source: NIMH’s Transgenic Core Facility

In the same year, a study came out in the New England Journal of Medicine about another woman facing disputed maternity over her children. The researchers of the study found that the woman had chimerism, a rare condition in which an individual is composed of genetically distinct cells. In these cases, it was due to the fusion of two zygotes, each with its own DNA, resulting in offspring composed of two genetically distinct populations of cells. It was later found that Fairchild also had chimerism, and was able to keep custody of her children.

For more on chimerism and Lydia Fairchild’s case:

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Source: Amutanga on YouTube

In summary, chimerism can cause a mother to have different DNA than her children, and it is fascinating to consider that a person can have two distinct sets of DNA. Scientists have recently been able to make a chimeric sheep whose blood contained 15% human cells and 85% sheep cells, which has implications for the production of transplant organs. It is interesting to consider where the field of chimerism will take us, but of course, not without safety and ethical concerns.