Brain fog, lack of focus, or poor concentration can be frustrating. It can also be confusing if you’ve never had this problem before and it seemingly shows up out of nowhere. You may start to think that your brain is declining or maybe that you’ve even started showing signs of dementia or Alzheimer’s disease.

If you’ve ever found yourself sitting in front of the computer trying to get to work and you just can’t get started or you just can’t complete tasks that used to be no problem and you’re asking yourself, “Why can’t I concentrate anymore?” there could be a number of reasons or causes:

fatigue brain fog

  • ADHD
  • chronic fatigue syndrome
  • metabolic diseases
  • abusing alcohol or other substances
  • lack of sleep
  • your emotional state
  • stress
  • depression
  • vitamin deficiency
  • too much digital distraction

And maybe you resonate with a few of those. But what if was another possible root cause?


Gut-Brain Connection

gut-brain connection

While it isn’t accurate to say that all disease begins in the gut, it’s a great place to start.

It’s been well-established that our mood and psychological state affect our ability to concentrate. If you are experiencing stress, anxiety, or depression this will, of course, have an impact on our focus, attention span, and perhaps cause brain fog and forgetfulness.

However, a new area of research into the microbiome is finding that gut health often plays a major role in our mental health. About 90% of the bidirectional communication between the gut and the brain, actually originates in the gut. Meaning the gut is doing almost all of the talking. So it makes sense that healing our gut microbiome would have a positive effect on our mental health.

The gut and the brain communicate to each other in 3 different ways: Through the vagus nerve that runs from the brain to the intestines like an information highway, the neuroendocrine system consisting of signaling hormones and neurotransmitters, and the immune system response of inflammation.

Let’s look at each of these.

The Vagus Nerve

the vagus nerve

The vagus nerve is the longest nerve in the body. It connects your brain to many of your organs and it runs all the way down to your intestines. Information that runs along this nerve goes both ways, however, as mentioned before, most of it comes from the gut and goes to the brain.

Bad bacteria in the gut can create neurotoxins, such as ammonia and D-lactate, that travel via the vagus nerve into the central nervous system and can cause all kinds of issues like anxiety, irritability, insomnia, and confusion.

Your gut bacteria, good and bad, also can create neurotransmitters and hormones that have a direct impact on mood, causing symptoms like brain fog and low motivation. These signals are also communicated through the vagus nerve.


The neuroendocrine system includes the neuroendocrine cells, glands, neurotransmitters, and hormones, that regulate things like reproduction, metabolism, eating and drinking, blood pressure, and mood.

Your microbiome makes neurotransmitters like serotonin, dopamine, cortisol, glutamate histamine, GABA, and melatonin. These have a huge impact on your brain. Cortisol, glutamate, and histamine can contribute to anxiety but also a sense of alertness. They play their role in the fight/flight/freeze response. GABA and melatonin are calming neurotransmitters that promote relaxation and a good night’s sleep.

There are 3 neurotransmitters in particular that contribute to brain fog and lack of mental sharpness when their levels are too low:

You can ask your doctor about taking a neurotransmitter imbalance test if you think your brain fog is being caused by low levels of these chemicals. Meanwhile, eating a healthy diet with healthy fats and cutting out anxiety-causing foods can help. This will help support your digestive system and the growth of beneficial bacteria. Healing the gut is key!

If we have an imbalance in our gut microbiome, it may cause anxiety. But also if we’re stressed or anxious, it can lead to imbalances in gut bacteria. This can create a vicious cycle. Stress management through exercise, breathwork, therapy, and other mental health tools is important as well.

Immune System

When the immune system reacts to an infection or injury it creates inflammation which is a protective response necessary for healing.

gut health and immunity

Notice that when you’re sick you display what’s called “sickness behavior,” where you want to be alone, you need more rest, may have cognitive impairment, and a decreased appetite. All of this is slows us down so that our body can get to work healing the infection. But this is also very similar to depressive behavior. It’s also true that depression and anxiety have been associated with chronic inflammation in the brain and body.

Bad bacteria in the gut can release chemicals that increase inflammation. If we are in a chronic state of inflammation, such as in depression or a long-term illness, it can cause a lot of problems. This can lead to feeling foggy, tired, confused, and unmotivated.


Heal Your Gut

Healing your gut is a step in the right direction if you want to improve your concentration and get rid of your brain fog. Taking care of your body with proper diet and exercise and cutting out mood-disrupting foods, is a great start. You might also want to take a psychobiotic. These are probiotics that are clinically proven to ease depression and reduce anxiety and some are specifically great for improving memory. Some studies have even revealed that people on the autism spectrum have reduced numbers of good bacteria in their gut, showing that there may be a link.

Don’t underestimate the power of simple dietary changes in reducing brain fog and improving concentration.

Have you ever used probiotics and noticed any mental health benefits or changes in mood? Let me know in the comments!


*This post may contain affiliate links. Please see our affiliate disclosure. This site is not meant to be a substitute for medical advice, diagnosis, or treatment. Please see our medical disclaimer.