Your Gut Might Know Best Why You Feel Depressed4 years ago | Nutrition
By Joy Stephenson-Laws, JD, Founder
Depression is one of the most common mental disorders in the United States, and it has been in the news a lot lately. The recent deaths of Kate Spade and Anthony Bourdain, along with countless others, from depression are examples - very sad and upsetting!
Our brains, which contain about 100 billion cells, are affected by depression. Nerve cells called neurons are responsible for how you take in the outside world (sensory input) and send motor commands to your muscles. Neurons are basically the electrical signal carriers in the brain.
But what if those bugs that live in your gut are also sending signals to your brain?
There are trillions of microbes that live in your gut (sometimes referred to as the “gut microbiome”), and reportedly they too may play an important role in how your brain functions. The types of microbes in your gut are greatly influenced by what you eat.
And now, a recent study discusses how through signaling to the brain gut microbes may contribute to depression and anxiety.
"What this study says is that many things in your diet might affect the way your brain functions, but one of those things is the way diet changes the gut bacteria or microbes. Your diet isn't always necessarily just making your blood sugar higher or lower; it's also changing a lot of signals coming from gut microbes and these signals make it all the way to the brain," said one of the doctors describing the research in this report.
The study compared obese mice on a high-fat diet to mice on a regular diet. The mice on the high-fat diet showed significantly more signs of anxiety, depression and obsessive behavior. Interestingly, when mice on the high-fat diet were given antibiotics which altered their gut microbiome, their conditions were either reversed or improved.
To further investigate the issues, researchers transferred gut bacteria from the experimental mice to mice who did not have bacteria of their own (germ-free mice). The germ-free mice who received bacteria from the mice who were fed a high-fat diet (but not given antibiotics) showed increased levels of anxiety and obsessive behavior. Meanwhile, germ-free mice who received bacteria from the high-fat diet mice who DID receive antibiotics did not show signs of behavior disorders.
Now, back to the brain.
Researchers looked for clues in two areas of the brain: the hypothalamus (helps control whole body metabolism) and the nucleus accumbens (important in mood and behavior).
"We demonstrated that, just like other tissues of the body, these areas of the brain become insulin resistant in mice on high-fat diets," said one doctor.
“And this response to the high fat is partly, and in some cases almost completely, reversed by putting the animals by antibiotics. Again, the response is transferable when you transfer the gut microbiome from mice on a high-fat diet to germ-free mice. So, the insulin resistance in the brain is mediated at least in part by factors coming from the microbiome."
The next goal for researchers is to identify the specific types of bacteria involved in these processes as well as the molecules that these bacteria produce.
According to the report, the “...eventual goal is to find drugs or supplements that can help to achieve healthier metabolic profiles in the brain.”
What does this mean for you?
This does NOT mean that antibiotics are the solution to having a high-fat diet. You should follow a healthy diet with plenty of fruits, vegetables and some healthy fat. Research has shown that this is one of the most effective ways to reduce your chances of developing depression and other types of disease.
The study just suggests that antibiotics altered gut bacteria which in turn changed signals affecting mood to the brain in mice. We need further tests on humans. However, this study provides some evidence that gut bacteria may have some influence on your mood.
"Going forward, we want to get a more sophisticated understanding about which bacteria contribute to insulin resistance in the brain and in other tissues. If we could modify those bacteria, either by putting in more beneficial bacteria or reducing the number of harmful bacteria, that might be a way to see improved behavior."
How can you be proactive?!
One way to determine whether your gut bacteria is balanced is to take a gut bacteria test. And if you are out of balance, you can work with a competent healthcare professional to change your diet or find quality nutritional supplements to take.
Certain foods like sauerkraut, kimchi, yogurt and kombucha are sources of good bacteria that may have a positive impact on your gut and mental health. And don’t forget you also need prebiotics.
Be mindful of any medications you are taking, both prescription and over-the-counter, as these may negatively affect your population of good bacteria in your gut.
Clearly, when we eat we are not just feeding our guts, but we are also feeding our minds (our brains).
Enjoy your healthy life!
The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, attorneys, nutritionists, nurses and certified fitness instructors. This team also includes the members of the pH Medical Advisory Board, which constantly monitors all pH programs, products and services. To learn more about the pH Medical Advisory Board, click here.