How the Gut-Brain Connection Affects Your Mental Health Good + Good
redespite its somewhat charming nickname, the gut has become one of the sexiest areas of interest in medicine in recent years. While there is still a lot to learn, emerging science suggests a surprisingly significant gut-brain connection; it is increasingly apparent that the gastrointestinal system has a great influence on the way we feel, think and react.
ICYMI, your gastrointestinal system actually has its own “brain” known as Enteric nervous system (ENS) which communicates with the central nervous system (CNS) – of which the brain is a part –to influence mood, cognition and mental health, according to a study published in Integrative Medicine: Journal of a Clinician. The intestine and the noggin also communicate via hormones and the immune system.
All of the above are influenced by the gut microbiome, which may explain the growing body of research linking poor microbiome health to mood and cognitive disorders. Patients with various psychiatric disorders, including depression, bipolar disorder and schizophrenia, for example, have been shown have significantly different gut microbiomes than those without these conditions. And the deregulation of the gut microbiome has been bound at an increased risk of dementia, too.
Below, find more details on the science behind the gut-brain connection and the ways your microbiome appears to influence your mental well-being.
The Gut-Brain Connection: How Your Microbiome Influences Your Mood, Cognition, and More
The growing body of research linking the makeup of the microbiome to depression is compelling. Data published in the journal Natural microbiology in 2019, for example, found preliminary evidence linking low levels of certain gut bacteria (in particular, Coprococcus and Dialer) depression. People in the study who claimed to be in good mental health, on the other hand, had high levels of Coprococcus and another bug known as Fecalibacterium. A separate study published in the International Journal of Neuropsychopharmacology found lower levels of Bifidobacterium and Lactobacilli in people with depression, compared to those without.
The same researchers in the 2019 study also found that many forms of gut bacteria can produce mood-regulating / stimulating neurotransmitters (or their precursors) such as serotonin and dopamine. So if you are deficient in these specific bacteria, you are more likely to suffer from mood disorders, including depression, and to benefit from taking prebiotics and probiotics.
These same neurotransmitters influenced by the intestine, serotonin and dopamine, play a role in anxiety, too, and some research supports the idea that the makeup of the microbiome may impact symptoms of the disorder. For example, a study published in the journal General Psychiatry published in 2019 found that regulating gut health can help individuals manage anxiety. Research evaluated 21 different experiments to reach this conclusion and found that probiotic supplementation and dietary changes (including low FODMAP diets, addition of fermented foods, etc.) effectively reduced symptoms of anxiety. by regulating the intestinal microbiota.
Postpartum depression and anxiety
While the link between postpartum depression and microbiome makeup remains largely speculative at this point, it’s possible given that the microbiome undergoes significant changes during and after pregnancy – and scientists have already established a link between depression / anxiety and the general microbiome. Adding to the support of this theory, a study published in Frontiers in cellular and infectious microbiology specifically showed differences in the microbiomes of women who suffered from postpartum depression and those who did not.
Numerous animal studies have shown the link between stress and the gut microbiome. In a study of International Journal of Neuropsychopharmacology, germless mice, for example, exhibited elevated stress responses which were regulated by the introduction of probiotic species into their systems. This effect was repeated in later studies. And a 2018 study published in the journal Brain, behavior and immunity related injections of a particular bacterium, Mycobacterium empty, at reduced stress levels in rats. Promisingly, probiotics have also been shown to make humans more resistant to stress, according to a study published in the International Journal of Neuropsychopharmacology.
Attention deficit hyperactivity disorder (ADHD)
Western-style diets – high in sugar and saturated fat and low in fiber –are not so good for the microbiome, and research published in the International Journal of Neuropsychopharmacology has shown a link between these diets and ADHD rates. A reasonable conclusion, then, is that the microbiome may impact the symptoms and development of ADHD. Some research also supports this theory; in a clinical cohort, a change in the composition of the microbiome has been observed in adolescents and adults with ADHD. Another study found that children treated with probiotics had reduced levels of ADHD.
Sleep is intimately linked to mental health, and some studies have shown that supplementing with probiotics may improve your Zzzs. This could be in part because the gut microbes produce some form of melatonin along with other sleep regulating hormones such as serotonin, dopamine and gamma aminobutyric acid (GABA). On the other hand, researchers have also found that certain specific bacterial strains are correlated with poor sleep; However, it is not clear at this point whether poor sleep causes this specific gut composition, or if the reverse is true.
Cognition and memory
There is a growing body of scientific evidence that the gut also influences cognitive health. Memory and learning depend proper functioning of the hypothalamic-pituitary-adrenal axis (HPA axis), which refers to the interaction between the hypothalamus and pituitary gland just above the brainstem and the adrenal glands above the kidneys). The HPA axis is impacted by – what else? – the microbiome. Serotonin produced by the microbiota (or lack thereof) reappears here too, as it also plays a role in learning and memory. These are just two of the many links between cognition and the microbiome.
Strengthening this connection is research published in The frontiers of the neurosciences of aging showing that administration of microbiome-destroying antibiotics to mice caused cognitive impairment. Meanwhile, another study published in the International Journal of Neuropsychopharmacology showed that the administration of probiotics in a cohort of elderly humans improved their cognitive function. Both offer evidence for the effects gut microbes have on the way we (and mice) think.
While all of the above research is still in its infancy, it has exciting implications for some of the most delicate health issues we face today. After all, around one in four American adults suffer from a diagnosable mental disorder. As we await clarification and certainty on the myriad ways our gut microbiomes affect our brains and contribute to these issues, the best thing you can do for your health is support a healthy gastrointestinal ecosystem through proper nutrition. and exercise.
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