Although it is not widely understood, studies have repeatedly shown that a healthy gut reinforces a positive outlook and behavior, while depression and a variety of behavioral problems have been linked to an imbalance or lack of gut bacteria.
A recent animal study, for example, published in the journal Neurogastroenterology & Motility, found that mice who were lacking gut bacteria actually behaved differently from mice with healthy gut bacteria by engaging in what was referred to as "high-risk behavior." This altered behavior was accompanied by neurochemical changes in the mouse brain. According to the researchers, microbiota (gut flora) plays a role in the communication between your gut and your brain, and:
"Acquisition of intestinal microbiota in the immediate postnatal period has a defining impact on the development and function of the gastrointestinal, immune, neuroendocrine and metabolic systems. For example, the presence of gut microbiotaregulates the set point for hypothalamic-pituitary-adrenal (HPA) axis activity."
Therefore, this finding coincides with the theory that your gut flora may be a factor which contributes to the specific foods you should eat to stay healthy, but it also helps explain how your diet and gut flora can impact your mental health - for better or worse.
Remember, your diet is largely responsible for your gut health, and when you feed your body the fuel it's designed for, your gut flora will be able to maintain optimal balance, which then supports optimal physical and mental health.
Did you know that your brain and gut are actually created out of the same type of tissue?
During fetal development, one part turns into your central nervous system while the other develops into your enteric nervous system. These two systems are connected via the vagus nerve; the tenth cranial nerve that runs from your brain stem down to your abdomen. This is what connects your two brains together.
This is why your intestinal health can have such a profound influence on your mental health, and vice versa. For an interesting and well-written layman's explanation of the gut/brain connection, read through Sandra Blakeslee's 1996 New York Times article Complex and Hidden Brain in Gut Makes Stomachaches and Butterflies.
A fact that I found most interesting is that certain neurotransmitters, such as serotonin, can also be found in your gut. In fact, the greatest concentration of serotonin, which is involved in mood control, depression and aggression, is found in your intestines - not your brain! Your bowels also contain some 100 million neurons—more than in either your spinal cord or your peripheral nervous system.
An excellent article by Adam Hadhazy, published in Scientific American, explains the intrinsic connection between your gut and your psychological well-being.
"The system is way too complicated to have evolved only to make sure things move out of your colon," says Emeran Mayer, professor of physiology, psychiatry and biobehavioral sciences at the David Geffen School of Medicine at the University of California, Los Angeles (U.C.L.A.). For example, scientists were shocked to learn that about 90 percent of the fibers in the primary visceral nerve, the vagus, carry information from the gut to the brain and not the other way around…
Doesn't it make perfect sense to nourish your gut flora in order to achieve optimal serotonin function? Doing so will clearly have a profound impact on your mood, psychological health, and behavior!
How to Optimize the Bacteria in Your Gut
Fortunately, optimizing your gut flora (the balance between "good" and "bad" bacteria in your gut) is relatively easy.
First, the MOST important step is to avoid consuming sugar and processed foods. The sugars actually serve as fuel for the growth of pathogenic anaerobic bacteria, fungi and yeast, and competitively inhibit your good bacteria, tending to crowd them out of their appropriate niche. These pathogenic bacteria, fungi and yeast then produce metabolic waste products that will cause your health to deteriorate.
When you eat a healthy diet that is low in sugars and processed foods, it automatically causes the beneficial bacteria in your gut to flourish. This is one of the many reasons why I highly recommend beginning to reduce sugars and most grains from your diet, with the intention and plan of eventually eleminating them completely.
Even with a low-sugar diet, there are other factors that influence your microflora. Therefore, you should also strive to avoid some of the factors that destroy healthy bacteria, such as:
- Chlorinated water
- Antibacterial soap
- Agricultural chemicals
- Lassi (an Indian yoghurt drink, traditionally enjoyed before dinner)
- Fermented milk, such as water or milk kefir
- Various pickled fermentations of cabbage, turnips, eggplant, cucumbers, onions, squash and carrots
- Natto (fermented soy)
However, if you simply do not like any of these types of fermented foods, your next best option is to use a high quality probiotic supplement.
I've used many different brands over the past 10 years or so and there are many good ones out there. I also spent a long time researching all of them and have found one that is science and evidence-based and is effective called NutraMetrix NutriClean Probiotics. If digestion after eating a meal is a problem, I would suggest NutraMetrix Digestive Enzymes with Probiotics. This product is helpful because it provides the essential enzymes to facilitate healthy breakdown and absorption of the foods you eat leading. The enzymes prevent symptoms such as stomach upset, constipation, diarrhea, acid reflux, and heart burn. Click on the links to learn more about these beneficial supplements for your health.
Questions? Contact me anytime - I'm more than happy to help!
Alissa Robertson, MS, RD