Can studying gut microbiomes help brain disorders and mood disorders?
The relationship between the gut and the brain has now been scientifically proven to be a valid and working one. The Gut-Brain axis does exist, and it does affect our daily lives more than we know. In a controversial claim, the bacteria found in our guts may influence the way the brain works and therefore affect our moods.
The claim is based on a study in which a germ-free sterile mice, never exposed to bacteria, were found to be releasing twice the stress hormone when stimulated compared to normal mice. This inspired the theory that there is such a thing as psychobiotics or a group of microbes capable of exerting influence over the moods of people.
How is it possible that microorganisms from the gut can work its magic all the way to the brain? One theory suggests it does this through the stimulation of the Vagus nerve. The Vagus nerve acts as a sort of information superhighway between the brain and the gut. Another theory is related to how gut microbiomes breakdown food into chemicals that affect the whole body or even how tiny DNAs from the microorganism alter nerve function.
Scientists even discovered that transferring fecal matter between people not only rebalances gut microbiomes but also transfers behavior. In depressed patients who underwent a fecal transplant, their symptoms of anhedonia, or the lack of pleasure from things, virtually vanished after the procedure.
Another potential application of the study of gut microbiome is in the field of treating the brain disorder Parkinson’s disease. When fecal matter from Parkinson patients was placed inside the gut of mice, their brain symptoms became much worse.
With these pieces of evidence, researchers are hopeful that the future of medicine will rely heavily upon studies in the realm of gut-brain axis.
Are antibiotics more harmful when given earlier in life?
If you were asked whether babies and germs should be mixed, you would probably answer by reflex with a resounding no. These two life forms are not exactly meant to go hand and hand, at least in a traditional sense. Yet, this exact concept is what the book “Let Them Eat Dirt: Saving Your Child from an Oversanitized World” is trying to challenge. Written by doctors Brett Finlay and Marie-Claire Arrieta, this book takes a controversial stand against the over sanitation of the baby’s environment.
Until recently, it has been the norm that a baby’s environment should be as clean as possible. To quote the book, the belief was “the only good microbe is a dead one.” It is undeniable that we are now here today because of the milestones in medicine that aimed to control microbes which include vaccines, sterilization, pasteurization of food, and antibiotics, but with today’s emerging slew of autoimmune diseases, it has become clearer that this old time tested strategy might not work anymore.
In the book, the authors cite the phenomenon in which countries that have a tendency to over sanitize have significantly higher rates of non-infectious diseases like asthma, diabetes, and autoimmune conditions. While those who are located in environments that have a richer microbial profile tend to report lower numbers of these diseases.
To support this position, the authors pointed out an article published by Dr. David Strachan almost 25 years earlier. In the article, Dr.Strachan states that the absence of exposure to bacteria in early childhood contributed to the development of allergies, and that without bacterial exposure, our immune system will not fully mature. These propositions would later become known as the hygiene hypothesis.
With the recent emergence of studies supporting the hygiene hypothesis, the authors of the book enumerated the possible culprits in hindering the development of the immune system.
One culprit is the misuse of antibiotics. It is stressed in the book that antibiotics are truly lifesavers. In the past, 90 percent of children would eventually die due to bacterial meningitis, but now a full recovery is the standard. Sadly, the world is experiencing a trend in antibiotic overuse. It has been estimated that between 2000 and 2010, the use of antibiotics has increased by 36 percent worldwide. Even more alarming is that the use increases during flu season where the drugs are virtually useless because influenza is caused by viruses which do not respond to antibiotics. The true harm is not that it is useless but the damage it causes to the normal flora.
Even if we use antibiotics properly for the correct indications, there is still the problem of antibiotics used in our food. Antibiotics are widely used as supplements given to livestock which increase the meat yield. This practice has been banned in Europe but is still in action here in the United States. Parallel to the growth induced in animals, antibiotics seem to have a similar effect in children. According to the CDC, the states with the highest rates of antibiotic usage also have higher rates associated with obesity.
At first, this was just a matter of statistics but after recreating the observation in the lab, the concern is definitely valid. When mice with sterile guts were given bacteria from obese mice, the test subjects became obese too. This further supports the notion that bacterial composition affects weight gain.
The effect does not end with weight alone. It would appear even allergies are deeply rooted in the way bacterial flora is set up. In a study published in the British Medical Journal, it was shown that antibiotic exposure during early life was associated with an increased likelihood of developing asthma in the future, but remarkably, antibiotics given later in life did not produce the same effect. This brings into light that timing is also an important factor to consider when talking about antibiotics. One thing remains clear: modifying the bacteria in our body has a greater impact than we first thought.
The importance of antibiotics in our survival over the past hundreds of years cannot be stated enough. What books like these are urging is not to discredit antibiotics but to revolutionize the way we look act microbes. Over the past decades, it seems like the focus of making antibiotics is to increase its strength not to mention the profitability through its widespread use. What the authors of Let Them Eat Dirt are wisely asking us is to be respectful of our body’s natural defenses and to harness its full potential through the judicious use of medications.
Let Them Eat Dirt: Saving Your Child from an Oversanitized World
Blaser Explores Link Between Obesity, Antibiotic Use