At the Magaziner Center, we specialize in identifying the underlying problems or deficiencies that may disrupt normal brain chemistry and cause resulting psychological effects. One such resulting psychological effect is depression. Depression of course is a chronic illness characterized by long periods of sadness, loss, anger or frustration that interfere with everyday life. While many patients we see have had a long history or “trial and error,” medications looking for optimal dosage, researchers are discovering what clinicians, such as we here at the Magaziner Center have empirical known. Probiotics can fight depression. A happy gut can make a happy brain.
“There is a growing recognition that a good diet can help people maintain mental and physical health, while a bad one will cause the disorder of body function, and even lead to several diseases.”
Similar observations were made in a May 2021 study. (1) The authors of this study wrote:
“There is a growing recognition that a good diet can help people maintain mental and physical health, while a bad one will cause the disorder of body function, and even lead to several diseases. A lot of attentions have been devoted to analyze every possible health-related factor in the daily diet, including food ingredients, additives, and cooking process.
With the support of high-throughput sequencing technology, there is accumulating evidence gradually clarifying that most of these factors are mainly through the interactions with gut microbiome to trigger downstream effects. The gut microbiome may be able to act as a very sensitive mirror in response to human daily diet.”
In the opening paragraph from a recent study (2) from University College Cork investigators explained :
“The brain-gut-microbiota axis has been put forward as a new paradigm in neuroscience, which may be of relevance to mental illness. The mechanisms of signal transmission in the brain-gut-microbiota axis are complex and involve bidirectional communications which enables gut microbes to communicate with the brain, and the brain to communicate with the microbes.”
Recent advances have shown that the gut microbiota (the collective name for the bacteria that lives in the digestive/intestinal tract) and its interaction with the brain, has an influence on behavior and mental health. A recent study in the The international journal of neuropsychopharmacology (3) acknowledged interaction that has attracted the attention of neuroscientists and psychiatrists as a potential therapy for various mental health disorders.
In April 2020, in the journal Molecular psychiatry,(4) researchers explained this communication further: “The gut microbiota are being called the human “second brain,” as they play a key role in the regulation of the central nervous system . Recent findings provide strong evidence for the presence of bidirectional communication networks between the gut microbiota and the central nervous system, and such crosstalk has been correlated with alterations in major depressive disorder and other psychiatric disorders.
This scoping review (study) found there is an evolving evidence of the involvement of the gut microbiota in the pathophysiology of neurocognitive and mental health disorders
These findings are not without their controversies. This is a new and emerging branch of investigation. This is eluded to in December 2020 paper (5) where the study authors offered this general overview:
“As individuals age, the prevalence of neurocognitive and mental health disorders increases. Current biomedical treatments do not completely address the management of these conditions. Despite new pharmacological therapy the challenges of managing these diseases remain. There is increasing evidence that the Gut Microbiome and microbial dysbiosis contribute to some of the more prevalent mental health and neurocognitive disorders, such as depression, anxiety, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), schizophrenia, bipolar disorder (BP), and dementia as well as the behavioral and psychological symptoms of dementia (BPSD) through the microbiota-gut-brain axis.
They continue:
“This scoping review (study) found there is an evolving evidence of the involvement of the gut microbiota in the pathophysiology of neurocognitive and mental health disorders.”
Simply, the brain and gut talk to each other. They have conversations about depression and other psychiatric disorders.
In a May 2017 publication in the journal Reviews in the neurosciences (6) speculated that the gut and brain talk about depression and other mental health disorders including bipolarism. The paper also speculated that major depressive disorder patients and bipolar disorder patients may benefit from probiotics. Here is what the research team wrote:
“Despite intensified research efforts to improve the treatment options and remission rates in mood disorders, no disease modifying treatment exists for these disorders. Accumulating evidence implicates the involvement of the gut microbiota in processes relevant to etiopathology (the origins of) of central nervous system-based disorders. . . The concept of psychobiotics, which is bacterial-based interventions with mental health benefit, is emerging in the field.”
The “moody microbiome.”
Citing this research was a March 2019 (7) study that examined the “moody microbiome.” Here doctors suggested that restoring the microbiome equilibrium in bacteria diversity and abundance might represent a novel strategy to prevent or treat mood symptoms and that results from recent clinical trials support for the beneficial effects of probiotics on alleviating depressive symptoms and increasing well-beings.
“When the gut is stressed, the gut may communicate bad thoughts to the brain that lead to psychiatric illnesses.”
In an earlier study (8) from the Ruđer Bošković Institute in Croatia, a leading institute for this microbiota research, doctors noted the proven existence of bidirectional communication between the brain and the gut. There is an increasing body of evidence which supports the hypothesis that cognitive and emotional processes are influenced through the brain-gut axis.
Dr. Brittany L. Mason, of the University of Texas Southwestern Medical Center wrote this in the journal Psychosomatics (9), about the gut and patients with anorexia nervosa and depression:
“Physical and mental health is dependent on the environment, and feeding (eating disorders) is a prime example of this environmental exchange. . . (Growing understanding shows) that gut bacteria regulate basic physiologic processes and are implicated in various disease states and contribute to regulation of mood. Responses to stress have effects on feeding behavior and mood and the regulation of the stress response by the gut microbiota could contribute to the dysfunction seen in patients with psychiatric illnesses.”
When the gut is stressed, the gut may communicate bad thoughts to the brain that lead to psychiatric illnesses.
Dr. Mason concludes: “Gut microbiota may contribute to dysfunction in psychiatric illnesses. New opportunities to modulate existing gut microbiota using probiotics could be novel targets for clinical interventions.” Probiotics may be the key for certain patients.
Doctors at Oxford University and their colleagues at other universities, released a study (10) titled: Psychobiotics and the Manipulation of Bacteria–Gut–Brain Signals.
Here is a summary of their fascinating findings on how the gut and brain talk to each other.
1.Gut bacteria produce a range of neurotransmitters through the metabolism of indigestible fibers. These include the following with a very simple and general explanation of its influence
dopamine (reward and pleasure)
noradrenalin (alertness and sexual arousal)
GABA Gamma-Aminobutyric acid (low levels linked to anxiety and issues of chronic pain)
serotonin (low levels implicated in depression)
acetylcholine (reward and arousal)
The gut produces the neurotransmitters, the neurotransmitters talk to the brain.
The gut talks to the brain through the metabolization of dietary fiber which produces short-chain fatty acids (SCFAs) – a communication link that may control inflammation related to depression
The gut talks to the brain through the metabolization of dietary fiber which produces short-chain fatty acids. These include acetate, butyrate, lactate, and propionate.
Short-chain fatty acids have been shown to reduce low-grade inflammation.
It is suggested that inflammation plays a role in depression.
Equally high fat diets have been shown to stimulate short-chain fatty acid acetate’s role in triggering the likelihood of obesity and inflammation.
3.The gut produces short-chain fatty acids, the short-chain fatty acids either reduce inflammation and has a positive effect on depression – such as on a high fiber diet – OR -short-chain fatty acids increases inflammation and its negative effects on depression – such as on a high fat diet.
Anti-inflammatory effect – regulation pro-inflammatory cytokine concentrations
It is suggested that pro-inflammatory cytokine concentrations (the inflammation that makes a disease worse) are capable of increasing the permeability of the blood–brain barrier permitting access to the potentially physically and mentally pathogenic entities.
In simplistic terms – the makers of bad thoughts because they can alter and lower levels of serotonin, dopamine, and glutamate (an amino acid involved in mental health). Strains of probiotics Bifidobacterium and Lactobacillus have been shown to help reduce the total quantity of pro-inflammatory cytokines, either directly or by increasing anti-inflammatory cytokines.
A study from October 2019 (11) demonstrates that the gut microbiota plays a crucial role in the maintenance of intestinal homeostasis (everything in balance). Additionally, it has been demonstrated that dysbiosis (microbial imbalance) is closely correlated with chronic intestinal inflammation, contributing to the development of chronic intestinal diseases, and also of brain pathologies, including neurodegenerative, neurodevelopmental, and psychiatric disorders. Further the importance of probiotics and prebiotics in targeting the microbiota-gut-brain axis in the context of some brain disorders are seen to be promising strategies for ameliorating brain disorders.
As these researchers point out, there are many complexities to this relationship between the gut and the brain and depression and other health factors. We acknowledge this in the articles below.
If you would like to explore more information, please contact our office so we can start a conversation with you.
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REFERENCES
1 Su Q, Liu Q. Factors affecting gut microbiome in daily diet. Frontiers in Nutrition. 2021;8.
2 Dinan TG, Cryan JF. Brain-gut-microbiota axis and mental health. Psychosomatic Medicine. 2017 Aug 11.
3 Foster JA, Lyte M, Meyer E, Cryan JF. Gut microbiota and brain function: An evolving field in neuroscience. Int J Neuropsychopharmacol. 2015 Oct 4. pii: pyv114. doi: 10.1093/ijnp/pyv114.
4 Yang Z, Li J, Gui X, Shi X, Bao Z, Han H, Li MD. Updated review of research on the gut microbiota and their relation to depression in animals and human beings. Molecular Psychiatry. 2020 Apr 24:1-4.
5 Halverson T, Alagiakrishnan K. Gut microbes in neurocognitive and mental health disorders. Annals of Medicine. 2020 Nov 16;52(8):423-43.
6 Rios AC, Maurya PK, Pedrini M, Zeni-Graiff M, Asevedo E, Mansur RB, Wieck A, Grassi-Oliveira R, McIntyre RS, Hayashi MA, Brietzke E. Microbiota abnormalities and the therapeutic potential of probiotics in the treatment of mood disorders. Reviews in the Neurosciences. 2017 May 8.
7 Kuo PH, Chung YC. Moody microbiome: challenges and chances. Journal of the Formosan Medical Association. 2019 Mar 1;118:S42-54.
8 Vlainić J, Šuran J, Vlainić T, Vukorep AL. Probiotics as an adjuvant therapy in major depressive disorder. Curr Neuropharmacol. 2016 May 26. [Epub ahead of print]
9 Mason BL. Feeding Systems and the Gut Microbiome: Gut-Brain Interactions with Relevance to Psychiatric Conditions. Psychosomatics. 2017 Jun 8.
10 Sarkar A, Lehto SM, Harty S, Dinan TG, Cryan JF, Burnet PWJ. Psychobiotics and the Manipulation of Bacteria–Gut–Brain Signals. Trends in Neurosciences. 2016;39(11):763-781. doi:10.1016/j.tins.2016.09.002.
11 Serra D, Almeida LM, Dinis TC. The impact of chronic intestinal inflammation on brain disorders: the microbiota-gut-brain Axis. Molecular neurobiology. 2019 Oct 1;56(10):6941-51.
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