Hellobee

I’m a scientist involved in the human microbiome project, which studies how changes in the normal bacteria present on our bodies impact human health and disease. Today I’m sharing a general overview as well as a personal look at the bacteria in my gut.

The Human Microbiome

Our bodies are covered with bacteria. Luckily, most bacteria are not harmful, and many of them actually play a role in keeping us healthy. Together, we call these communities of bacteria the human microbiome.

You can think of each body site as a distinct community that requires a different set of bacterial species, similar to how plant communities vary depending on climate zones, altitude or soil types. Interestingly, not only do these bacterial communities differ across body site, they also differ across individuals. That means the bacteria on your body is probably very different from your neighbors. There are so many factors that shape what bacteria are on your body, including what you eat, where you live, your personal hygiene, etc. Even differences in your genes can influence bacterial populations, affecting things like the acidity of the digestive tract, or the robustness of an immune response.

Beginning at birth

For the most part, a baby acquires its microbiome at birth, and delivery mode can have a major impact. Vaginally born infants’ skin will have bacterial species very similar to the species found in their mother’s vagina. Whereas C-section born infants have bacterial species similar to those found on their mother’s skin. The differences between these two groups can last for many months, and some studies suggest C-section delivered children appear to have a higher risk for asthma, obesity and other metabolic diseases later in life. However, the underlying cause for these differences is not clear.

Being in this field of research, I stressed about delivery mode when I was pregnant with M. But Mr. Ice Cream reminded me (several times throughout pregnancy) that even if I had a C-section it didn’t automatically mean I was setting M up for poor health.

When bacteria go amok

Even though many bacteria contribute to our health, subtle imbalances in the bacterial communities can also lead to adverse health outcomes. Acne, for example, is an annoying, although not particularly dangerous, skin condition. At the root of acne is an imbalance between acne-causing bacteria and healthy bacteria. Of course, the relationship between adverse health outcomes and the microbiome is more complex. Consider obesity, a highly heritable condition, that is also clearly influenced by sedentary lifestyle and poor eating habits. Several studies have demonstrated that thin people and obese people have different bacterial communities in their guts[7]. And when obese people lose weight, their bacterial communities change accordingly. Understanding the bacterial communities that contributes to leaner body mass may offer new ways to treat obesity in the future.

A peek into my gut

Using a commercially available kit from uBiome, I had the bacteria in my gut sequenced. Here are a few of the highlights including a list of the top bacteria found in my sample. Interestingly, I had a higher percentage of Akkermansia compared to the average participant in the uBiome database. Recently, [Akkermansia has been shown to prevent weight gain and inflammation][8]. My gut microbiome was also shown to be dominated by Bacteroidetes, which is correlated with weight loss and lower body weight. It will be interesting to see if the percentage of Akkermansia and dominance of Bacteroidetes stays constant as I get older or if I will see a decrease over time. My dad and Mr. Ice Cream just submitted samples to be sequenced, so it will be interesting to see how their data compares to mine.

The top bacteria found in my gut.

I have a higher percentage of the bacteria Akkermansia

Greater microbiome diversity is associated with health, but varies among individuals. When compared to samples of the same type in the uBiome database, my gut sample was 76% more diverse than all other gut samples. In addition, uBiome offers tips on how to improve your gut diversity including the use of probiotics and eating certain foods.

My gut bacteria (red bar) is diverse.

Are we are TOO clean?

If you are like me, you probably hover above public toilets, wipe down grocery cart handles, press elevator buttons with your knuckles and disinfect all your kids’ toys. In fact, it’s crazy how we go out of our ways to obsessively avoid germs, despite an increasing awareness that some bacteria are actually beneficial. The “hygiene hypothesis” says that a lack of exposure to bacteria early in life is a major factor involved in the development of allergic reactions and immune-related disorders. And while it’s true that our lives are undeniably better since the discovery of antibiotics, we can’t deny that diseases such as allergies, inflammatory bowel syndrome, asthma, diabetes and obesity are on the rise. Given that our microbiome is important in maintaining a healthy state, the increased use of antibiotics combined with the reduced exposure to bacteria might be related to the increase in diseases of the immune system and obesity. Obviously, we should still support vaccinations and we should still treat infections with antibiotics, but we should also embrace that many bacteria are important for our health.

What’s in YOUR gut?

If you want to get your microbiome sequenced, use this code to get 15% off your first uBiome kit (think Christmas/Hanukah gift for the science geek in your life!). Images from this post are from the ubiome participant interface.