By Dr. Phillip Goglia
According to lead author Dr. Kirsten Tillisch:
"Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut. Our study shows that the gut–brain connection is a two-way street... 'When we consider the implications of this work, the old sayings 'you are what you eat' and 'gut feelings' take on new meaning.'"
The implications are particularly significant in our current era of rampant depression and emotional "malaise." And as stated in the featured article, the drug treatments available today are no better than they were 50 years ago. Clearly, we need a new approach, and diet is an obvious place to start.
Previous studies have confirmed that what you eat can alter the composition of your gut flora. Specifically, eating a high-vegetable, fiber-based diet produces a profoundly different composition of microbiota than a more typical Western diet high in carbs and processed fats.
The featured research tells us that the composition of your gut flora not only affects your physical health, but also has a significant impact on your brain function and mental state. Previous research has also shown that certain probiotics can help alleviate anxiety:
• The Journal of Neurogastroenterology and Motility5 reported the probiotic known as Bifidobacterium longum NCC3001 normalized anxiety-like behavior in mice with infectious colitis by modulating the vagal pathways within the gut-brain.
• Other research found that the probiotic Lactobacillus rhamnosus had a marked effect on GABA levels—an inhibitory neurotransmitter that is significantly involved in regulating many physiological and psychological processes—in certain brain regions and lowered the stress-induced hormone corticosterone, resulting in reduced anxiety- and depression-related behavior. It is likely other lactobacillus species also provide this benefit, but this was the only one that was tested.
It's important to realize that you have neurons both in your brain and your gut -- including neurons that produce neurotransmitters like serotonin. In fact, the greatest concentration of serotonin, which is involved in mood control, depression and aggression, is found in your intestines, not your brain! Perhaps this is one reason why antidepressants, which raise serotonin levels in your brain, are often ineffective in treating depression, whereas proper dietary changes often help.