Let’s say that you live in the 17th century and that you’re curious enough to take a poll of your neighbors to discovery that virtually every person has experienced the loss of a child or sibling. You’re also extremely diligent and thorough and so you sample enough people to realize that 60 of every 100 children do not survive past the age of 16. You then decide that something is desperately wrong with the childhood survival rates and so you visit your local physician/scientist for some answers.
The first expert explains that people die because of the person’s evil behavior. The next expert claims that there is irrefutable evidence that disease is caused by swamp vapors or foul odors from sewage. Unsatisfied, you consult the most prominent English physician of the time, William Harvey, and he explains that death is caused by something called miasmas, which is a fancy word for vapors created by planetary movements affecting the earth.
You’re still skeptical but since Louis Pasteur and Robert Koch have yet to discover that pathogenic germs cause infectious disease, you tentatively accept that miasmas must be the cause of disease and you cross your fingers and hope that the planets are aligned when your next child is born.
Now, fast forward to the present day and the idea of miasmas as the cause of disease seems ridiculous. Fortunately, we benefit from the knowledge acquired by many years of scientific advancement and the implementation of pathogen-fighting strategies (i.e., vaccination and antibiotics). As a result, childhood fatalities have significantly declined. We have improved childhood survival rates only because scientists, at one point, discovered the cause of infectious disease.
But what about present day illness? With all of our advanced technology and scientific knowhow, we still fall short of understanding the basic causes of some very significant diseases.
For instance, heart disease remains the leading cause of death in the United States and by performing a quick internet search you’ll find that heart disease is caused by high levels of cholesterol in the blood, high blood pressure, high levels of blood sugar, diabetes, blood vessel inflammation, etc. But, in many ways, these answers fall short and are unsatisfactory. For instance, let’s consider two of the most important “causes” of heart disease; high cholesterol and high blood pressure (i.e., hypertension)
The point is that someone may say that heart disease, the leading cause of death in the United States, is caused by high cholesterol, high blood pressure, high blood sugar, etc. but these are not root causes. Certainly, conditions such as high blood pressure contribute to heart disease and death, but what causes high blood pressure?
In the 17th century, people accepted that evil spirits or miasmas caused disease because they did not understand that pathogenic bacteria and viruses were to blame. Perhaps in a similar fashion, we accept that things like high stress and high blood pressure cause heart disease but there are underlying molecular and cellular factors at play and it is important to understand them so that real solutions can be implemented that prevents / cures heart disease.
Fortunately, progress is being made in understanding the root cause of one of the risk factors associated with heart disease, high blood pressure. In a recent publication, (http://physiolgenomics.physiology.org/content/49/2/96) researchers have found that the microorganisms residing in the intestines (i.e., gut microbiota) play a role in the development of high blood pressure in rats. The researchers claim that their findings “provide strong evidence that the gut microbiota has a causal role in the development of hypertension”. Furthermore, this work “supports a potential role for probiotics as treatment for hypertension”. In fact, a meta-analysis (http://hyper.ahajournals.org/content/early/2014/07/21/HYPERTENSIONAHA.114.03469) involving nine clinical trials has demonstrated that probiotic supplementation reduced systolic and diastolic blood pressure.
Perhaps this new discovery will spur further research into how changes in the gut microbiota increases high blood pressure. What bacterial strains promote hypertension? How do they interact with the body? What strains are most effective in controlling blood pressure and what therapies can be implemented to ensure optimal gut microbiota composition?
Since we know that balanced diets with plenty of fruits and vegetables that contain prebiotic fiber and environmental microbes promote gut microbiota diversity, and since we know now that gut microbiota composition plays a role in hypertension, this should provide further incentive to watch what we eat. It’s also important to consume high quality probiotic supplements on a daily basis with a diverse set of beneficial bacteria (http://www.libertybion.com/hero-probiotics).
When confronted with the cause of a disease, sometimes experts feel compelled to offer up explanations that remain unanswered by science. As an example, William Harvey used miasmas as a simple way to explain disease and death in the 17th century. The answers to these questions are difficult and take time. Now, armed with the knowledge that gut microbiota composition has a causal role in hypertension, science is one step closer to reducing the massive death toll caused by heart disease.