How The Bacteria In Our Gut Influence Our Minds

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Can’t focus? Feeling anxious or depressed? Easily stressed? It turns out the common phrases, “butterflies in the stomach” and “having a gut feeling,” have scientific truths. Researchers have discovered complex bidirectional communication between the brain and the gut. Some scientific sources have even gone as far as referring to the gut as the “second stomach” – and rightfully so. Read on for more on the intriguing relationship between mental health and gut microbes.

How Do Bacteria Alter the Brain?

You’ve probably heard that the brain is the most complex object in the known universe. So how does a bunch of bacteria in your gastrointestinal system influence such a sophisticated and powerful organ?

The intricate link between the digestive system and the brain is facilitated by the vagus nerve. This cranial nerve is part of the gut-brain axis that extends from the brainstem to gut, via lungs, esophagus, and heart. Interestingly, up to 90% of the vagus nerve is exclusive to the gut-brain communication network. So where do the bacteria come into play?

Your gut bacteria break down your dietary intake into short-chain fatty acids that enter the bloodstream. In turn, the blood releases hormones and neuroactive compounds that stimulate the brain, affecting various functions. According to a study [1] published in the Journal of mSystems, gut microbes can even influence gene expression through microRNAs.

The Impact Of Imbalance In Gut Bacteria

According to an article appearing in the Harvard School of Public Health [2], there are trillions of microorganisms or microbes in the human body, with the gut claiming the biggest share. This complex network of microbiota consists of both harmful (pathogenic) and helpful (symbiotic) microbes. Although these two categories typically coexist peacefully, the balance can be disturbed by anti-biotics, certain diets, and infectious diseases.

Dysbiosis or an imbalance of harmful and healthy gut bacteria is linked to a host of neurological health issues ranging from stress, depression, anxiety, autism to neurodegenerative diseases such as Parkinson’s or Alzheimer’s. For a better understanding of the importance of the gut-brain connection, consider the following research studies:

• According to a study [3] published in the Journal of Psychology, “germ-free” mice produced up to 2 times the amount of stress hormone in comparison to a “normal mice” that were in contact with microbes.

• In another study [4], researchers concluded that their findings supported a connection between Autism Spectrum Disorders and the gut microbiome’s influence on the brain. They went on to support the idea of probiotic treatment to address pathogenic bacteria in the GI and improve autism behavioral symptoms.

What are the implications of the elaborate gut-brain connection? In the words of Hippocrates, “All disease (including mental disorders) begins in the gut.” This suggests that medical experts could leverage the power of microbes and a healthy gut to treat or prevent neuropsychiatric and neurological disorders.