Over the past century, human advances in infectious disease research and public health have led to a significant drop in mortality rates around the world. Today, the biggest threat to human health comes from noncommunicable diseases such as cardiovascular disease, cancer and respiratory diseases , a disease that is not transmitted directly from one person to another.
However, in a recent article in the leading academic journal Science, scientists have come up with a new view that many of the most commonly associated diseases, such as obesity, diabetes, cardiovascular disease, can also be transmitted from person to person through microbes. The evidence provided by these scientists suggests that the various bacteria, fungi and viruses that live with us in the human gut may be an important factor in the social spread of noncommunicable diseases.
“If we can prove our hypothesis correct, it will completely rewrite the textbooks of public health,” said Brett Finlay, a professor of microbiology at the University of British Columbia and lead author of the paper. “
Professor Finlay and colleagues from the Canadian Advanced Research Institute (CIFAR) Human and Microbiome programme are very concerned about the gut flora. In our gut, there are at least thousands of different kinds of bacteria that help us digest food, produce nutrients such as vitamins, and train our immune systems. How the microbes in the gut look and structure, are often affected by what we eat, where we live, and how we interact with our surroundings. In Professor Finlay’s view, far-fn relatives are not as good as their immediate neighbors, and are also established in the similarity of the gut microbiome.
The researchers cite several pieces of evidence to support the link between intestinal flora and noncommunicable diseases. Specifically, one, including inflammatory bowel disease, cardiovascular disease, often found that the diseased individual has characteristic intestinal flora disorders. Moreover, the separation of intestinal bacteria from people with noncommunicable diseases such as inflammatory bowel disease and type 2 diabetes, or individual mice, and transfer of fecal transplants to animal models can cause symptoms in otherwise healthy animals. The researchers believe the evidence can be found in correspondence with the Koch principle used to test pathogenic microorganisms for infectious diseases.
Imbalanced gut microbiome can spread to other individuals, which can lead to the spread of noncommunicable diseases (Image Source: Supplied
The article stresses that “obesity is a major risk factor for many noncommunicable diseases” and that there is growing evidence that “microbes are an important factor in obesity”. The study authors cite some examples to illustrate the relationship. For example, a 30-year study tracked more than 12,000 people and found that if you had an obese friend, you were 57 percent more likely to get fat yourself.
Another study of U.S. military families showed that their body mass index (BMI) also increased in areas with higher rates of obesity;
For type 2 diabetes, which is particularly affected by obesity, data show that within one year of a couple diagnosed with type 2 diabetes, the spouse is also prone to a trend of type 2 diabetes, which can last for more than three years.
“Putting these facts together shows that many traditionally non-communicable diseases are also likely to be contagious. Professor Finlay said.
These are often thought to be the result of similar “environmental factors” such as diet and lifestyle, but the researchers note that “shared” intestinal flora is likely to be a contributing factor.
However, scientists also make it clear that the theory requires more scientific evidence to clarify the mechanismbehind. The study authors hope their observations will stimulate further discussion and research, including determining the effects of environmental factors on the flora, identifying who is in the microbiome that causes disease and can spread, and whether the bacteria that can be protected also have “contagion” effects.
Given that gut flora can play a role in a variety of health conditions, we may share more than food, knowledge, and emotions with close friends and family. For the health of yourself and those around you, it may be time to take care of your little partners in your gut.