Healthy Gut Microbiota, Brain, and Immunity
Did you know that a human body consists of approx. 30-40 trillion cells while hosting approx. 38 trillion bacterial cells?1 Did you know that probiotics can support anti-cancer and antidepressant therapies?2 In this blog post, let’s explore how gut bacteria can impact our mental and physical health and help overcome chronic disorders.
Bacteria residing in our gut are called “gut microbiota”. There are approximately 1,000 diverse species of bacteria and yeast living in harmony (symbiosis) with each other. Some friendly bacteria have names like Bifidobacterium or Lactobacillus, whereas an example of “bad bacteria” is Clostridium difficile.
The gut microbiota produces diverse molecules (metabolites) including serotonin and dopamine. These molecules can communicate with the brain via the autonomous nervous system. This network is known as “the gut-brain axis.”3 Gut microbiota regulates our mood and behavior, as well as strengthens our immune system to fight pathogens.4
Did you know that microbiota in infants can differ depending on the method of delivery (vaginal versus C-section)?5 The interactions between gut microbiota and the brain develop during the first three years of our life.6
“Alone we can do so little; together we can do so much.”
How does gut microbiota affect our health? Gut bacteria regulate diverse physiological functions in our body. When healthy symbiosis is disrupted, it leads to dysbiosis (dysregulation) of microbiota, as observed in people living with depression, anxiety, IBS, obesity, autism, Parkinson’s and Alzheimer diseases.7 Gut microbiota can also modulate pain.8
Exposure to chronic stress, antibiotics, or eating a Western diet of ultra-processed food can destroy healthy gut microbiota and lead to dysbiosis, neuroinflammation and development of diseases.9
Can we improve brain health and the immune system by taking care of our gut microbiota? Most of us are aware of health benefits of probiotics, which are live strains of bacteria and yeast. Examples of commonly used probiotics include yeast Saccharomyces cerevisiae (boulardii) and bacteria Lactobacillus acidophilus, or Bifidobacterium bifidus and bulgaricus.10
Did you know that Bifidobacteria probiotics can help fight cancer?11 Probiotics can reduce anxiety and improve sleep in people exposed to chronic stress, as well as support therapies for depression.12 Of equal health importance to probiotics are prebiotics which are food components (like dietary fibers or inulin) promoting growth of gut microbiota.13 Interestingly, prebiotics can also improve the immune functions.14
In conclusion, enjoying yogurt, kefir and other fermented foods (a source of probiotics) while consuming fruits and vegetables (a source of prebiotics, vitamins and micronutrients) is a wonderful expression of self-compassion and common sense to nurture our health and well-being.
Thank you, best wishes and stay well,
Greg
2. Clin Epigenetics 2015; Int J Mol Sci 2020; J Clin Med 2021
3. Brain Res 2018
4. Immunol Rev 2017; Trans Res 2017; Physiol Rev 2019
5. Microbiol Mol Biol Rev 2017
6. Clin Gastroentero Hepatol 2019
7. World J Gastroenterol 2017; J Neuroendocrinol 2019
8. Br J Anaesthesia 2019
9. Gut 2016; Front Microbiol 2018; Nutrients 2021
10. J Biomed Sci 2017
11. Front Microbiol 2020
12. Neurosci Biobehav Rev 2019; Nutrients 2019; J Clin Med 2021
13. J Biomed Sci 2019
14. Med Microbiol Immunol 2017
