It may be an imbalance in your gut flora.
What is gut flora?
It is the group of microorganisms that live in your digestive tract. They include things like bacteria, fungi and protozoa. Bacteria, however, has the largest population, and are the most influential microorganisms in your gut. Most people have at least 300 different species of bacteria in their digestive tract.
Some are considered "good bacteria" while others are considered "bad bacteria." When the good and bad bacteria are in their proper balance in our guts, they perform essential health roles such as
- Synthesizing and excreting vitamins
- Prevent the spread of "bad organisms"
- Stimulate our immune system
- Metabolize drugs
- Produce gut-nourishing fatty acids
- Produce antibodies
- And help maintain a healthy gut lining
- Increase the risk of colon cancer
- Interfere with the absorption of nutrients
- Increase the risk of inflammatory bowel disease
- Increase the risk of irritable bowel disease
- And may even cause personality changes like paranoia, hostility and aggressive behavior.
Researchers at the University College Cork have discovered that mice fed a "good bacteria" or probiotic bacterium called Lactobacillus rhamnosus, which is common in yogurts and dairy products, can have a positive effect on mood. This probiotic in their guts tended to reduce levels of stress, anxiety and depression.
It is not totally understood how gut flora can influence chemical messengers in the brains of the tested mice. However, there is a direct communication path between our digestive tract and our brains via the vagus nerve.
To test whether or not the digestive tract of the test mice was communicating with the mice brains, the researchers severed the vagus nerve of the mice. After the nerve was severed, the probiotic no longer had an effect on the chemical signals in the mice brains.
This suggest that "good bacteria" in the guts of the mice were somehow having a positive effect in the brains of the mice.
More research is required to determine if "good bacteria" has the same positive effect on mood in humans.
How Do We Maintain A Healthy Gut Flora Balance?
The typical American diet of animal proteins and refined carbohydrates tend to cause an unhealthy imbalance in our digestive tract bacteria. On the other hand, a diet rich in vegetables, fruits, complex carbohydrates and less animal proteins helps create a healthy balance in our gut flora.
So, to maintain a healthy gut flora to improve your overall health and fitness and mood
- Eat a diet rich in vegetables, fruits and complex carbohydrates
- Eat less animal proteins
- Eat less sugar and corn fructose
- Eat more pre-biotic and probitoic rich foods like yogurt, dairy products, kefir and sauerkraut.
Discover Magazine: "From Guts To Brains - Eating probiotic Bacteria Changes Behavior in Mice"
Wikipedia: Gut Flora
Huffpost Healthy Living: "The Keys to Maintaining a Healthy Gut"
UCC: Probiotic Bacteria Lessens Depression