Did you know that within your gut, you have roughly 100 trillion bacteria, more than the number of cells in your body, belonging to about 1,000 species?

Psychobiotics Directly Impact Psychological Well-being

Scientists have recently discovered that some of these species, called psychobiotics, directly impact our mood. They maintain the normal functioning of our brains and nervous systems by producing and modulating critical neurotransmitters such as dopamine, serotonin, noradrenaline and GABA. They also synthesize certain essential nutrients such as folic acid, niacin, vitamin B12, and vitamin K2. Psychobiotics have thus been shown to have a positive effect on mental health conditions like anxiety and depression, and may have an impact on many more psychiatric conditions.   In this way, psychobiotics play a vital role in maintaining our psychological well-being.   Psychobiotics are friendly, ie probiotic, bacteria that have lived in the human gut for thousands of years and are essential to our emotional stability. Like all probiotics, they are symbiotic, meaning that they benefit us in return for the benefits that we provide (including nutrition and a cozy home).  One could say that they are like little doctors, as they seem to respond to our unique makeup, upregulating or downregulating the production of numerous compounds essential to human wellbeing.

A Brief History of Psychobiotics

Psychobiotics were first discovered around 2012 by two microbiologists, Drs. Ted Dinan and John Cryan, at University College Cork, Ireland. Both scientists have conducted extensive studies on the “gut-brain axis,” which refers to the profound links between the human gut microbiome, ie the bacteria in our gut, and the human brain.  Since then, there has been an accelerating amount of research into psychobiotics with some major recent discoveries. We now know that psychobiotic bacteria influence our mood through many pathways, and especially the vagus nerve, an enormous nerve that links the digestive system with the nervous system.

The Psychobiotic “Superstrains”

Some major psychobiotics include: Lactobacillus rhamnosus, which is believed to reduce anxiety by changing the expression of GABA receptors Bifidobacterium longum, which produces BDNF, now recognized to play a major role in neuroplasticity, relieves depression and anxiety in doing so, and by reducing the steroid hormone cortisol. Lactobacillus plantarum, which is used to reduce anxiety by boosting serotonin and dopamine and lowering cortisol. Bifidobacterium breve, which reduces anxiety, but the synthesis of it declines with age. Intriguingly, Breve, along with Bifidobacterium Longum, seems to slow down MCI or mild cognitive impairment, and could slow down the progression of Alzheimer’s disease itself.

Taking Care of your Internal Garden

To benefit from psychobiotics, you can incorporate them into your diet through nutrition. Eating foods such as certain yogurts or fermented vegetable products can be beneficial to what we call “gut flora” which could indeed be compared to a garden existing in our digestive tracts. We need to take care of our internal gardens. That is one of the best ways we can keep the “weeds,” ie opportunistic bacteria, in control. Some examples of fermented foods high in psychobiotics, as well as probiotics in general, include sauerkraut, kefir, kimchi, cottage cheese, buttermilk. In addition to fermented foods, taking probiotic supplements on top of fermented foods can also be advantageous. 

Grandma was Right. Eat your Veggies! Prebiotics and Psychobiotics

Prebiotics are also important for benefiting from psychobiotics. Prebiotics are substances that act as food for beneficial microorganisms, encouraging their growth. Eating a diet rich in prebiotic fibers such as onions, leeks, cabbage, apples, bananas, and oats can improve gut health and mental well-being. That could be a major reason why diets high in fiber, such as the Mediterranean diet, are known to improve mood and wellbeing in general. Aside from the fact that the peoples of the Mediterranean eat many fermented foods! Regrettably UPF’s, or Ultra Processed Foods, which are commonly sold in the modern world, are not fermented, and nor do they include fresh, fiber rich vegetables or fruit that psychobiotic bacteria feed upon, and this could be a key reason why depression and anxiety are on the rise. I hope this introduction has excited you about the potential of psychobiotics to mitigate depression and anxiety with few side effects!