In this video, we're going to discuss the composition of the human microbiome. It turns out that in 2007, the Human Microbiome Project started. The Human Microbiome Project is really just a set of coordinated studies that are all designed to reveal the composition of the human microbiome. It also aims to study the relationships of the normal flora or the microbiome with various human hosts. One of the main goals of the Human Microbiome Project is to understand how changes in the microbiome throughout a person's lifetime can affect that person's health and disease. It's important to note that humans actually start to develop their microbiomes at birth, and it turns out that even the birthing method can affect the microbiome. Infants that experience a vaginal birth will be exposed to different microbes than infants that are born through a cesarean birth. Also, breast milk actually contains many beneficial microbes and carbohydrates that are really important for an infant's microbiome. The feeding method and the diet can also contribute to the microbiome.
Now in adults, there are many, many different factors that contribute to the microbiome changes that occur over a person's lifetime. Below in this image, we are showing you many of the different factors that can contribute to the microbiome. Interestingly, the microbiomes of obese adults actually differ from the microbiomes of lean adults. This goes to show that the microbiome can impact things such as obesity. Over time, it's important to note that a person's microbiome can change, and the person's microbiome changes as they are exposed to or encounter new microbes and new environments. A person's microbiome today may be different than their microbiome a year from now depending on their experiences and the microbes and environments they were exposed to.
Interestingly, researchers have begun to find a correlation between the microbiome composition and disease. It turns out that having an unhealthy microbiome can lead to a higher risk of disease. For example, intestinal dysbiosis, which refers to an imbalance of the microbiome, can actually lead to inflammatory bowel disease. By not having an appropriate intestinal microbiome, it could lead to an increased risk of inflammatory bowel disease. Taking a look at our image again, we can see many of the different factors that contribute to the microbiome. Again, humans acquire their microbiome at birth, and again the birthing method can affect the microbiome, the feeding method in terms of breast milk or formula, whether the baby goes to a daycare or a public school, or if they are homeschooled, they can be exposed to different microbes in different environments. Genetics can also play a part in the microbiome. Whether you have siblings can change the environment and again change the microbes that a person is exposed to. Different types of infections can also affect the microbiome and make changes in the microbiome. The diet that a person has throughout their lifetime, whether they are eating healthy foods or more fatty foods, will affect the type of microbiome that they have. Medications and vaccinations that a person may receive could affect their microbiome. The particular season, so in the summertime and the wintertime, a person's microbiome could change or differ, and habits such as smoking can also impact a person's microbiome, including secondhand smoking as well for infants.
All of these different factors can contribute to a person either having a healthy microbiome, a balanced microbiome that is appropriate, or it could lead to dysbiosis, which recall that dysbiosis once again is an imbalance in the microbiome. Notice here there is a lot more of this microbe and much less of this microbe, and that creates this imbalance, and the imbalance, this dysbiosis can lead to an increased risk of disease. For example, as said earlier, intestinal dysbiosis could lead to inflammatory bowel disease, and notice that this person here is not feeling well because their microbiome is not balanced. This concludes our brief lesson on microbiome composition, and we'll be able to get some practice applying these concepts as we move forward in our course and learn more about the microbiome as well. I'll see you all in our next video.