There is a biological reason that people can share in the human experience of: “butterflies in the stomach”, “nervous diarrhea” before a special event, feeling nauseous or vomiting upon seeing or hearing traumatic news or even having your saliva and digestive secretions released just by thinking of food. This is because the brain and gut are physiologically connected. Emotions can cause physiological changes in the gut and digestive disturbances can cause an array of mental health issues.
Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) in humans are two conditions that exemplify the consequences of a faulty gut–brain communication.1,2
The involvement of the gut microbiota in the pathophysiology of IBS has been shown repeatedly, as symptoms of IBS develop after the disruption of the gut bacteria or ‘microbiome’ due to acute bouts of gastroenteritis 3,4 or following the use of antibiotics.5
In addition, gastrointestinal dysfunction such as bowel diseases are frequently accompanied by comorbid psychiatric conditions.6,7
How the gut and brain are connected:
There is no denying that the gut and the brain have a very complex and multidirectional network of communication.8 It has been repeatedly shown in studies that bidirectional communication exists between the brain and the gut and involves neural, hormonal, immunological pathways 9 and microbiota influences.10,11,12
In embryological development the cells that form the gastrointestinal nervous system, the Enteric nervous system (ENS), originate from the neural crest cells.2 The same grouping of neural crest cells will give rise to much of the cells that predominate the peripheral nervous system.13 The ENS, is often called the second brain, because of its neuronal connection that is connected with the Autonomic Nervous System (ANS) to communicate with the central nervous system (CNS).2
These neural crest cells will migrate to the vagal level 13, which will give rise to the vagus nerve.
The vagus nerve, or cranial nerve X, is controlled by the parasympathetic nervous system which will increase digestive secretions and peristalsis when food is tasted.14
Stressful events will affect the sympathetic nervous system to decrease digestive secretions and peristalsis and stimulate vasoconstriction in the mucosa, which would decrease overall digestion and chronically lead to pathologies.14,15
Different neurotransmitters or molecules produced by intestinal microbes such as nitrous oxide (NO), GABA will act upon the ENS. This in turn causes a cascade of second messengers such as serotonin and acetylcholine to be released causing the brain to be signalled and leading to different behaviours in food intake, stress and anxiety.16
With approximately 70% of the body’s immune system residing in the gut, it is no wonder that the quality and quantity of the microorganisms that reside there influence the immune system and communication with the brain.10 The microbiota communicate with the CNS through neural, endocrine and immune pathways.10
Much of the current research in the gut-brain axis focuses on the crucial role that the microbiota in the human body have to play on the proper development and maturation of a normal functioning brain and stress response.9
In studies of germ free mice it was observed that brain development was abnormal when the gut microbiome was missing.14,19,20 It seems to influence the inflammatory reactions within the brain by modulating the activation of microglial cells, affecting myelination and neurogenesis in adult brains.14,8 And would affect the regulation of of the stress response (e.g.,hypothalamic-pituitary-adrenal axis, HPA).10
When mice were given probiotics strains, neuronal development changes and psychotropic effects occurred signalling that microorganisms can alter brain chemistry.21 Which sheds light on possible treatments for patients with anxiety, depression and stress related symptoms.9,17,18
Even transplanting microorganism through fecal microorganisms transplantation (FMT) showed a changed level in anxiety between mice subjects.9,12,22,23
The following lab tests are important to consider when working with patients experiencing anxiety, depression, stress and/or digestive concerns in order to get a clearer picture of the presenting concerns as well as to have objective references as to which monitor treatment:
High-sensitivity C-reactive protein (hsCRP)
C-reactive protein (CRP) is a substance produced by the liver. It increases in the presence of inflammation in the body, and a high level of CRP in the blood is a marker of systemic inflammation that can be associated with anxiety and depression as well as digestive concerns.14
|Vitamin D – 25(OH) is an easy blood test that can assess your baseline level. In many cases, low levels of vitamin D are found in patients with depression, schizophrenia 27 and also can modulate the gut bacteria.24 The level can be tested at anytime for patients whether supplementing with vitamin D or not. But to keep in mind that testing levels in patients residing in Canada, March and April will represent lower levels and testing in August or September will reflect higher levels. Once a change in dose is made it best to test 4 to 6 weeks after to see bodily response.|
Thyroid panel Treatment Methods:
A complete thyroid panel should measure Thyroid Stimulating Hormone (TSH), Free Triiodothyroine (fT3), Free Serum Thyroxine (fT4), Reverse T3 (rT3), and Thyroid Antibodies. This will ensure a clear idea of the functioning of the thyroid as hyperthyroid or hypothyroid can exert anxiety and depressive states and will direct treatment in addition to addressing potential digestive concerns.
|An adrenal panel will reflect how the body is handling stress currently. High levels of stress can change the release patterns of cortisol, that allow very high levels of cortisol to circulate for longer periods of time, and it’s subsequent decrease in production so patient’s may feel tired and wired, experiencing anxiety, sleep disturbances and feeling like they cannot cope with the stressors.|
Hair cortisol is an objective measure of how the body is handling chronic stress (over 1 month) rather than an acute measure of cortisol.25,26
Recent data on the importance of gut bacteria show that specific strains can affect the development and functioning of different neuronal populations. For example, Lactobacillus helveticus R0052 affects the functioning of CNS neurons in the hippocampus and amygdala, Lactococcus lactis subspecies cremoris H61 modulates the activity of the auditory brain stem neurons and Lactobacillus reuteri (DSM 17938) is implicated in the function of visceral nociceptive neurons of the gut.14 This diverse specificity of microorganisms that interact with specific neuronal connections suggests great potential for probiotics to help target certain health issues and more research is needed in this area.
In the meantime in clinical practice, adding probiotics should be a mainstay in any naturopathic protocol. With the research on the proper development and management of a healthy nervous system, digestive system and positive psychotropic effects to manage mood and anxiety. It is likely that at one point or another in a patient’ lifetime, probiotics would be a relatively safe and cost effective treatment to undergo and an excellent preventative health measure.
It would even be suggested that during pregnancy and infancy, probiotics would improve the mother’s microbiota, likely decrease the use for antibiotics during pregnancy, allowing healthful colonization to the infant if vaginally delivered. And supplementing with probiotics during childhood would allow the proper development of the gut and brain health to prevent mood disorders and help create successful stress management regulation throughout childhood and adolescence.
It is hard to say which strains of probiotics should be used more than other strains, as more research needs to be done in this area. But with many choices on the market, it is recommended to choose a high quality human sourced bacteria, as they have high survival rates when travelling through the stomach to the intestines. Periodically, switching to different combinations of probiotics would be beneficial to receive those various strains in various amounts over a patient’s lifetime.
Largely known to help with depression and mood regulation but vitamin D also is important for the modulation of gut bacteria.27 and something that many patients are familiar with taking and another relatively cost effective supplement with wide ranging health benefits.
The following aspect of dietary changes can be added in to the treatment plan:
- Naturally fermented foods (ie. kombucha, tempeh, natural yogurts, sauerkraut, miso etc.) to obtain various probiotic strains.
- Whole food based, anti-inflammatory diet and overall less chemicals (i.e. organic)
- Perhaps checking for food sensitivities or proceeding with the elimination diet to reduce inflammatory states caused by some foods that would affect gut health
It is widely known that moving the body in any form is beneficial for many health conditions, but regular exercise can also have a positive impact on gut health and microorganisms.28 and should be included in the treatment protocol for anxiety and other mental health concerns.
In naturopathic practice, most of my patients are experiencing stress, anxiety and/or depression. I find that a multi-faceted approach works best to include various dimensions of the naturopathic modalities depending on where the patient is at, what they are willing to do and what makes the most sense to start with. I also take time to educate about the stress response, adrenal system and the gut-brain connection and how it could be contributing to the symptomatology. I also like to address that is is a normal part of the human experience that have some periods of anxiety, nervousness and even low mood. This is not necessarily a problem to be fixed until it becomes pervasive and affects daily functioning.
Case Study #1:
A 50 year old female, with main concerns of stress, mood issues and weight gain came to me wanting to focus on the mainly on the stress and mood, with weight loss being an ‘added bonus’. We began with regular acupuncture appointments to help with stress reduction and then added in a homeopathic to help with symptomatic relief of her mood issues, namely low mood which worked very well. In the meantime, discussing the patient’s gut health revealed the following issues: Acid reflux, bloating and irregular bowel movements. We have added in a probiotic, removed dairy and wheat and lowered sugar from the diet. The patient started an exercise regime at a local gym as she realized that her acid reflux was stressed induced and exercise improved her stress response and mood. After 3 months of treatment on this regime, the patient reported a marked improvement in her anxiety. Her acid reflux would still occur, but the bloating was gone, her bowel movements were regular and she lost about 10lbs. She was overall happier and felt better suited to handle stressful situations than before treatment.
Case Study #2
A 3 year old female whose mother noticed an increase in anxiety and nervousness. We added in a probiotic due to complaints of ‘tummy aches’ and gave omega 3’s, and castor oil belly rubs. After two weeks, the patient’s anxiety was slightly improved. Upon further questioning the mother reported that the patient was having regular nightmares that occured at the same time every night which included her waking up and screaming. I prescribed a homeopathic that matched her symptoms and the mother said the nightmares stopped that same night the remedy was introduced. The mother also reported that the child was less anxious about 2 weeks after the remedy and no reports of tummy aches.
Increasingly mental health ( i.e. stress, anxiety and depression) and digestive concerns are some of the most frequently presented health issues in medical professional offices. Many times, these conditions are looked at and treated as independent entities. In light of much research, it is becoming apparent that medical professionals must address both mental and digestive health concerns together in order to bring about long lasting wellness and successful treatment outcomes.
One easy addition to health and wellness treatment protocols are various probiotics strains, that allow for proper physiology functioning of digestive and nervous system. More research needs to be done in the area of certain probiotic strains and the subsequent neuronal area it affects, to help direct treatment of specific digestive and mental health concerns.
In addition, assessing and treating by relative lab tests results, vitamin D, anti-inflammatory diets and exercise all have roles to play in allowing the modulation of the gut bacteria, and providing the gut and brain with the nutrients it requires to function optimally.
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- Halvorson HA, Schlett CD, Riddle MS. (2006). Postinfectious irritable bowel syndrome—a meta-analysis.The American Journal of Gastroenterology. 101:1894–1899.
- Schwille-Kiuntke J, Enck P, Zendler Cet al. (2011). Postinfectious irritable bowel syndrome: follow-up of a patient cohort of confirmed cases of bacterial infection with Salmonella or Campylobacter. Neurogastroenterology and Motility. 23:e479–e488.
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