Nutribliss Probiotics

human microbiome 5

Embracing Our Inner Ecosystem: The Critical Role of the Human Microbiome

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by

GM
in

Introduction

The human body is a complex ecosystem, hosting a staggering 38 trillion bacteria that make up about 50% of our cellular makeup. 1 This vast community of microorganisms, collectively known as the microbiome, plays a crucial role in our overall health, affecting everything from our immune system to our mental wellbeing. 1,2  This blog post explores the fascinating world of the human microbiome, debunking common misconceptions and highlighting the vital functions these microscopic inhabitants perform.

Understanding Your Microbiome

The microbiome consists of trillions of bacteria, viruses, fungi, and other microorganisms living in and on our bodies. 3,4 Far from being mere passengers, these organisms form a core part of our biological identity. The majority of these microbes reside in the gut, though many inhabit other areas such as the skin, mouth, and various mucosal surfaces. 5 Each site hosts a unique microbiome crucial to maintaining specific functions.

Seeding and Development

From birth, our bodies begin to accumulate microbes through contact with our mother, family members, and the environment. 6 This initial colonization sets the foundation for our immune system and teaches our bodies to differentiate between harmless and harmful entities. 7 By early childhood, our microbiome stabilizes, forming a complex network that remains with us throughout life.

Functions of the Microbiome

The activities of our microbiome are vast and vital:

  • Digestive Health: Our gut bacteria play a key role in digesting foods that our own enzymes cannot break down, like fiber. They produce short-chain fatty acids, crucial for nourishing gut cells and reducing inflammation. 8
  • Nutrient Synthesis: Beneficial bacteria synthesize essential nutrients such as B vitamins and vitamin K, which are crucial for various bodily functions. 9
  • Immune Regulation: The microbiome helps regulate our immune system, ensuring it reacts appropriately to pathogens without overreacting and causing inflammation.10
  • Protection Against Pathogens: By occupying space and resources, our microbiome prevents harmful pathogens from establishing a foothold in our bodies. 11

Gut Barrier Integrity

The gut barrier is a critical defense line, consisting of a single layer of cells that regulates what substances can enter the bloodstream from the gut. 12, 13 A healthy microbiome maintains the integrity of this barrier, preventing harmful substances from triggering immune responses that can lead to conditions like allergies and autoimmune diseases. 14 

Microbiome Health

A healthy microbiome is not about having specific microbes; rather, it’s about maintaining a balanced community that can effectively perform its necessary functions. 15 Factors like diet, exercise, sleep, and stress all influence the composition of our microbiome. 16 Daily choices can support or undermine the health of our microbiome, and by extension, our overall health.

Conclusion

Our understanding of the microbiome has transformed our view of what it means to be human. No longer do we see ourselves as isolated entities; we are superorganisms, our health inextricably linked to our microbial partners. 17,18 This shift in perspective is not just scientific but philosophical, influencing everything from medicine and hygiene to diet and lifestyle. As we continue to explore this inner universe, we may find that the key to health is not just about treating the human body but nurturing the myriad of life it hosts. 19,20

Citations

  1. Burokas, A., Arboleya, S., Moloney, R. D., Peterson, V. L., Murphy, K., Clarke, G., Stanton, C., Dinan, T., & Cryan, J. F. (2017). Targeting the Microbiota-Gut-Brain Axis: Prebiotics Have Anxiolytic and Antidepressant-like Effects and Reverse the Impact of Chronic Stress in Mice. Biological Psychiatry, 82(7), 472-487. 
  2. Mohajeri, M. H., Brummer, R., Rastall, R., Weersma, R., Harmsen, H., Faas, M., & Eggersdorfer, M. (2018). The role of the microbiome for human health: from basic science to clinical applications. European Journal of Nutrition, 57, 1-14. 
  3. Cryan, J., O’Riordan, K. J., Cowan, C., Sandhu, K., Bastiaanssen, T. F., Boehme, M., Codagnone, M., Cussotto, S., Fulling, C., Golubeva, A., Guzzetta, K. E., Jaggar, M., Long-Smith, C., Lyte, J., Martin, J. A., Molinero-Perez, A., Moloney, G., Morelli, E., Morillas, E., O’Connor, R., Cruz-Pereira, J. S., Peterson, V. L., Rea, K., Ritz, N., Sherwin, E., Spichak, S., Teichman, E. M., van de Wouw, M., Ventura-Silva, A., Wallace-Fitzsimons, S. E., Hyland, N., Clarke, G., & Dinan, T. (2019). The Microbiota-Gut-Brain Axis. Physiological Reviews, 99(4), 1877-2013. 
  4. Foster, J., Rinaman, L., & Cryan, J. (2017). Stress & the gut-brain axis: Regulation by the microbiome. Neurobiology of Stress, 7, 124-136. 
  5. Huang, T.-t., Lai, J., Du, Y.-l., Xu, Y., Ruan, L.-m., & Hu, S.-h. (2019). Current Understanding of Gut Microbiota in Mood Disorders: An Update of Human Studies. Frontiers in Genetics, 10. 
  6. van de Wouw, M., Schellekens, H., Dinan, T. G., & Cryan, J. F. (2017). Microbiota-Gut-Brain Axis: Modulator of Host Metabolism and Appetite. The Journal of Nutrition, 147(5), 727-745. 
  7. Butler, T., & Gibbs, J. (2020). Circadian Host-Microbiome Interactions in Immunity. Frontiers in Immunology, 11. 
  8. Gonçalves, P., Araújo, J. R., Di Santo, J. P. (2018). A Cross-Talk Between Microbiota-Derived Short-Chain Fatty Acids and the Host Mucosal Immune System Regulates Intestinal Homeostasis and Inflammatory Bowel Disease. Inflammatory Bowel Diseases, 24(3), 558-572. 
  9. Wijdeveld, M., Nieuwdorp, M., & IJzerman, R. (2020). The interaction between microbiome and host central nervous system: the gut-brain axis as a potential new therapeutic target in the treatment of obesity and cardiometabolic disease. Expert Opinion on Therapeutic Targets, 24, 639-653. 
  10. De la Fuente, M. (2021). The Role of the Microbiota-Gut-Brain Axis in the Health and Illness Condition: A Focus on Alzheimer’s Disease. Journal of Alzheimer’s Disease : JAD. 
  11. Suda, K., & Matsuda, K. (2022). How Microbes Affect Depression: Underlying Mechanisms via the Gut–Brain Axis and the Modulating Role of Probiotics. International Journal of Molecular Sciences, 23. 
  12. Galland, L. (2014). The gut microbiome and the brain. Journal of Medicinal Food, 17(12), 1261-1272. 
  13. Li, Y., Hao, Y., Fan, F., & Zhang, B. (2018). The Role of Microbiome in Insomnia, Circadian Disturbance, and Depression. Frontiers in Psychiatry, 9. 
  14. Petra, A. I., Panagiotidou, S., Hatziagelaki, E., Stewart, J. M., Conti, P., & Theoharides, T. (2015). Gut-Microbiota-Brain Axis and Its Effect on Neuropsychiatric Disorders With Suspected Immune Dysregulation. Clinical Therapeutics, 37(5), 984-995. 
  15. Generoso, J., Giridharan, V., Lee, J., Macedo, D., & Barichello, T. (2020). The role of the microbiota-gut-brain axis in neuropsychiatric disorders. Brazilian Journal of Psychiatry, 43, 293-305.
  16. Mullin, G., & Delzenne, N. (2014). The human gut microbiome and its role in obesity and the metabolic syndrome. 
  17. Banfi, D., Moro, E., Bosi, A., Bistoletti, M., Cerantola, S., Crema, F., Maggi, F., Giron, M., Giaroni, C., & Baj, A. (2021). Impact of Microbial Metabolites on Microbiota–Gut–Brain Axis in Inflammatory Bowel Disease. International Journal of Molecular Sciences, 22. 
  18. Wiley, N. C., Dinan, T., Ross, R., Stanton, C., Clarke, G., & Cryan, J. (2017). The microbiota-gut-brain axis as a key regulator of neural function and the stress response: Implications for human and animal health. Journal of Animal Science, 95(7), 3225-3246. 
  19. Bienenstock, J., Kunze, W., & Forsythe, P. (2015). Microbiota and the gut-brain axis. Nutrition Reviews, 73(Suppl 1), 28-31.
  20. Matenchuk, B. A., Mandhane, P., & Kozyrskyj, A. (2020). Sleep, circadian rhythm, and gut microbiota. Sleep Medicine Reviews, 53, 101340.