Connecting Gut Bacteria, and the Brain
People used to think, as long as you weren’t a cannibal, what you ate was not as important as your personality. However, it turns out that your personality and what you eat are connected.2,3,5,7
Scientists found that transplanting fecal bacteria from timid mice to aggressive mice and vice versa affected the levels of the neurochemical, brain-derived neurotrophic factor (BDNF).1 The transplant increased BDNF levels in the timid mice making them adventuresome, and decreased levels in the adventuresome mice making them timid. How many people get kicked to the curb because they are too bold, or not bold enough?
BDNF is linked to anxiety.8-12 Anxiety comes from the perception of threat, whereas fear comes from actual threat.13,14 Regrettably, the old mammal brain, whose mantra is, “survive now, ask questions later,” cannot distinguish between perceived and actual threat. Thus, if you believe there is a lion at the door, in terms of the brain chemistry involved in fight-or-flight and stress regulation, then there is lion at the door. 15
The problem with anxiety, and especially persistent anxiety, is that it overworks your stress regulatory processes. This causes your body’s protective mechanisms to go from helping you to hurting you.16 It is like wearing your car’s brakes down until the pads are gone and your brakes become a liability, not an asset. In addition when you are anxious you think and act in unflattering ways. People often become agitated, acerbic, curt, or distracted. None of these things are on the date fun dial. Also, people with eating disorders are more likely to eat poorly when overly stressed. When you overeat, or make poor food choices you often become disappointed. This can be followed by depression. So there is a potential for a rapidly occurring downward synergy between your moods, global state of mind, self-agency, and behavior. The collateral damage of this synergy makes people less loveable.
Does the animal research translate to humans?
While “this is huge,” as my Godson would say, the research is embryonic, and although people can be rats sometimes, we are not mice. So, does the animal research really translate to humans? Emeran Mayer MD, PhD, the pioneer of brain-gut interaction research, who has approached the animal research cautiously, says, “Some of the findings from the animal studies can be extrapolated to humans.”
Dr. Mayer, a neuroscientist and gastroenterologist, and Director of the Oppenheimer Family Center for the Neurobiology of Stress at UCLA was the first to establish a solid connection between the brain and the gut. Mayer’s team studied 23 healthy women for a month.17 They gave 12 of them fermented milk twice a day, containing 5 different strains of healthy bacteria. The remaining 11 women drank milk without the probiotics. Mayer scanned the women’s brains before and after the treatment, while showing them emotionally evocative pictures of faces. According to the brain responses, the women who received the probiotic treatment perceived negative emotions as less threatening. Perception is the key that unlocks the door to human behavior.
Connecting the Dots
We know that nine tenths of the cells in our bodies are bacteria as opposed to human cells. We know that we have a mutualistic relationship with the bacteria in our gut.18 We know that the bacteria in our gut behaves very much like warring street gangs only concerned with serving their interest.19,20 We know that these selfish bacteria affect the choices of foods that we eat.21,22 We also know that they are very vulnerable to our choices, i.e., certain food choices sustain certain bacteria while killing off others.23 We know that some bacteria is compatible with our best interest, whereas some in not.22,24-27 We now know that bacteria influence our brain function by altering neurochemicals in our brains that affect our behavior.3,28-30 However, we have just begun to articulate the operational mechanisms and dynamics. Some think it has to do with bacterial waste getting into the bloodstream and conceivably into the brain and changes the neurochemistry underlying our moods.31,32 Others think that gut bacteria travel along the vagus nerve, which is like a freeway from the gut to the brain. I suspect it is tremendously complex, and involves cellular binding status of receptors on the gut cell surfaces, and the incitation of intracellular processes and those consequences on informational substances like hormones etc. Science is concerned with many things, regrettably (or fortunately), what I suspect is not one of them.
However, all scientists share this concern: probiotic intervention, like the use of antidepressants is a difficult enterprise at best. Yes, there are conceivable benefits in some cases but understanding
the particulars is like teaching a feral cat to sit. It can be accomplished, but getting there is going to be arduous and ugly.
In the interim, register with the American Gut Project and find out what type of gut bacteria you have. Observe how your body, brain, and gut bacteria respond to the foods you eat and various probiotics. Become a good consumer of the facts. Drink the kombucha, not the Kool-Aid when it comes to this. In terms of eating your way to love, start by loving yourself with what you eat. And as always, remain fabulous and phenomenal.
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