Healing The Mind From Within

Gut health is deemed important for someone’s overall physical health, but it is also closely linked with psychological well-being. So how does the gut communicate with the mind? Our intestines are composed of countless microorganisms such as bacteria, viruses, fungi, and parasites. These microbes that make up the gut microbiome first come from vaginal delivery or breastfeeding, and later diets change the biome for the better or worse (Cleveland Clinic 2023). This relationship is symbiotic, meaning that the host, human, and the microbes benefit from each other through this interaction

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In addition to genetic predisposition, environmental factors, and stress levels, the gut microbiome is influenced by hormonal changes. These hormonal changes are frequent for women throughout their menstrual cycle, pregnancy, and menopause (Marano et al. 2023). Although previous research had generalized findings to women treating women’s hormones as stable, researchers are now trying to figure out the mechanisms behind major hormonal changes and how that influences mental health.

What functions does the gut microbiome serve?

The gut microbiome works with the digestive system to break down food, the immune system to distinguish and clear out pathogens, the endocrine system to secrete hormones, and also the nervous system through the gut-brain axis (Cleveland Clinic 2023). When the microbiome is balanced, it supports healthy functioning; when this balance is disrupted, a condition known as dysbiosis, it can contribute to inflammation. Dysbiosis is also related to obesity, asthma, diabetes, and other diseases affecting the gastrointestinal tract, cardiovascular and central nervous system.

Central to this network is the gut-brain axis where communication between the central nervous system and the microorganisms in the gut takes place. It acts as a highway between the central nervous system (CNS) and the enteric nervous system (ENS), which controls digestion. Although the ENS can act independently from the CNS, communication between them happens, for example, during a fight-or-flight response where digestion should be slowed down, or knowing when you are full to stop eating (Marano et al. 2023). 

How is the gut microbiome linked to psychological well-being?

The microorganisms in the intestines interact with nutrients such as prebiotics and probiotics in ways that can positively affect mental health. Prebiotics, with examples shown below, were found to reduce anxiety, depressive-like behavior, stress responsiveness, aid in neuron health and improve cognition (Generoso et al. 2021). These foods nourish the gut bacteria and increase diversity, which reduces overall inflammation that would otherwise reduce serotonin production. Bacteria in the gut also ferments these prebiotic fibers to produce fatty acids that signal the enteric system to calm down and act on the brain to improve mood. 

How is the gut microbiome linked to psychological well-being?

The microorganisms in the intestines interact with nutrients such as prebiotics and probiotics in ways that can positively affect mental health. Prebiotics, with examples shown below, were found to reduce anxiety, depressive-like behavior, stress responsiveness, aid in neuron health and improve cognition (Generoso et al. 2021). These foods nourish the gut bacteria and increase diversity, which reduces overall inflammation that would otherwise reduce serotonin production. Bacteria in the gut also ferments these prebiotic fibers to produce fatty acids that signal the enteric system to calm down and act on the brain to improve mood. 

References

Baker JM, Al-Nakkash L, Herbst-Kralovetz MM. Estrogen-gut microbiome axis: Physiological and clinical implications. Maturitas. 2017;103:45–53. doi: 10.1016/j.maturitas.2017.06.025.

Cleveland Clinic. (2023, August 18). Gut Microbiome. https://my.clevelandclinic.org/health/body/25201-gut-microbiome

Generoso, Jaqueline S et al. “The role of the microbiota-gut-brain axis in neuropsychiatric disorders.” Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999) vol. 43,3 (2021): 293- 305. doi:10.1590/1516-4446-2020-0987

Marano, Giuseppe et al. “Gut microbiota in women: The secret of psychological and physical well-being.” World journal of gastroenterology vol. 29,45 (2023): 5945-5952. doi:10.3748/wjg.v29.i45.5945

Mhanna, Amjad et al. “The correlation between gut microbiota and both neurotransmitters and mental disorders: A narrative review.” Medicine vol. 103,5 (2024): e37114. doi:10.1097/MD.0000000000037114

Roth, William et al. “Tryptophan Metabolism and Gut-Brain Homeostasis.” International journal of molecular sciences vol. 22,6 2973. 15 Mar. 2021, doi:10.3390/ijms22062973