Emerging research is beginning to describe what we already feel in our bodies: the sensations we feel in our bellies are often interconnected with our thoughts, feelings, emotions, diet, behaviors, and our environments . Scientists refer to the ‘gut-brain axis’ to explain why digestive symptoms are often accompanied by changes in mood (depression/anxiety), immune health (autoimmunity/allergies), and hormone balance (weight gain, metabolic changes). The gut-brain axis helps explain why improving the health of the gut not only helps with conditions like irritable bowel syndrome and inflammatory bowel disease but also helps to heal mental emotional conditions like depression, anxiety, OCD, and disordered eating. And vice versa.
What is the Gut-Brain Axis?
The gut-brain axis describes the multi-directional communication network that connects the gut (the gastrointestinal system) and the brain. It is comprised of complex interactions between:
the central nervous system (the brain and spinal cord or CNS),
the nervous system embedded in the digestive tract, often called the ‘second brain’ or the enteric nervous system (ENS),
the gut microbiome (bacterial species present),
the endocrine system (hormones), and
the immune system.
How Does the Gut-Brain Axis Work?
The central nervous system, which includes the brain and spinal cord, communicates with the enteric nervous system (ENS), often referred to as the "second brain." The ENS is a complex network of neurons lining the walls of the gastrointestinal tract. Interestingly, the ENS is able to function independently of the central nervous system. The ENS controls digestion, absorption, and elimination processes. The CNS and ENS share communication through neural pathways, hormones, and immune signaling molecules.
The gut microbiome refers to the diverse community of microorganisms residing in the intestines. The microbiome plays a crucial role in the gut-brain axis producing various metabolites and neurotransmitters that can influence brain function and behavior. That means that it’s not only the quantities and types of microorganisms that are present in your gut that can affect your symptoms, but it’s also the metabolic byproducts that those species produce that can either protect or damage the health of the digestive tract. These metabolic byproducts communicate with the CNS and ENS through neural, immune, and endocrine pathways. Functional gut microbiome testing can be very helpful to determine the balance of species in your digestive tract and what kinds of therapeutic changes may be most helpful for you.
Overall, the gut-brain axis integrates signals from the digestive tract, including neurotransmitter production, metabolites from the gut microbiome, immune system activity, and hormonal influences, to regulate neurotransmitter balance in the CNS and the body as a whole.
What Happens When the Gut-Brain Axis is not Working Properly?
Imbalances in the gut-brain axis can perpetuate a state of pain and inflammation with or without the presence of a physical issue. An altered gut-brain axis, often present in conditions like IBS, sets up a positive feedback loop of heightened sensitivity to sensations in the digestive tract (‘visceral hypersensitivity’), uncoordinated gut motility (bowel movements moving either too fast or two slow), and altered pain processing.
It’s important to note that stress can deeply impact the gut-brain axis. Therefore, restoring balanced communication within the gut-brain axis can make a big difference in treating digestive symptoms.
Holistic Therapies that Address the Gut-Brain Axis
Holistic therapies can be effective precisely because they are able to address the multifaceted nature of the gut-brain axis (thoughts, beliefs, emotions, the nervous system, and our physiology).
Often times patients feel exasperated by feeling like they cannot pinpoint one particular cause for their symptoms (e.g. a specific food, or a specific type of stress). But, in fact, when we study the interconnected nature of the body’s anatomy, we can see that one of the biggest myths we’ve been sold is the idea of a one-pill-per-symptom paradigm; the body just isn’t set up to heal that way. Often incorporating many different treatment strategies in an integrated approach is what helps people improve their symptoms and regain a sense of overall well-being.
Treating the Gut Microbiome
Testing to determine the mix of microbial species in the intestines can illuminate underlying causes of ongoing digestive conditions. A healthy gut microbiome is made up of a diverse array of protective bacterial species whose metabolic byproducts support the intestinal lining and reduce inflammation. Functional gut microbiome testing can help identify the presence of pathogenic, opportunistic, or inflammatory species whose metabolic byproducts damage the digestive tract. Testing can reveal the presence of gas-producing species that cause persistent bloating, constipation, and abdominal distention (Saffouri, 2016). Further, there may be the presence of yeast, fungi, mold, or parasites. Test results can help provide immeasurable clarity on specific ways to heal digestion without all the guesswork.
Mind-Body Techniques
Practices that involve strengthening mind-body awareness show promising results in reducing chronic digestive and IBS symptoms. Any mind-body practice – such as yoga, therapy, gut-directed hypnotherapy, meditation/mindfulness based stress reduction, or visualization exercise—can be used to support the tone of the enteric nervous system and re-regulate the gut-brain axis.
Meditation: Research indicates that regular meditation or mindfulness practice can reduce pain severity, improve bowel movements, and enhance overall well-being in individuals with IBS.
Gut-Directed Hypnotherapy: Gut-directed hypnotherapy is a specialized form of therapy that focuses on using hypnosis to positively influence the gut-brain axis and alleviate symptoms of chronic digestive conditions, including Irritable Bowel Syndrome (IBS) as well as Inflammatory Bowel Disease (IBD).
Surprisingly, this mode of hypnotherapy is a well-established as an evidence-based approach with promising results. Research demonstrates its efficacy in reducing pain, bloating, and bowel irregularities in IBS patients and improving overall quality of life.
During gut-directed hypnotherapy sessions, a therapist guides individuals into a deeply relaxed state and from there, guides the patient to reframe some of their thoughts, perceptions, and emotions related to their digestion. The therapy shows how important it is to work on the conscious and unconscious communication patterns in the gut-brain axis (Peters, 2015).
Therapeutic Dietary Changes
What you eat impacts the gut-brain axis. Triggering foods vary widely from person-to-person, so it’s important to take an individual approach. Dietary modifications to improve symptoms of IBS include:
Avoiding processed foods and food additives especially presence of thickening agents, resins, colorants, and synthetic sweeteners. These substances may disrupt the microbiota and activate immune dysregulation and inflammation. (Rinninella, 2020)
Temporarily reducing high FODMAP foods. FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are fermentable carbohydrates (certain sugars) found in high quantities in certain foods such as dairy-based milk, yogurt and ice cream, wheat-based products, beans/lentils, and certain vegetables like asparagus, garlic, and onions. FODMAPS are hard for the small intestine to absorb and contribute to symptoms like bloating and gas. A FODMAP eating plan may be complicated and restrictive to follow, so it should be adopted only for a short time to reduce symptoms (and also, only after testing has ruled other causes of symptoms). Working with a naturopathic doctor or health practitioner can help people identify specific problems in the gut, pinpoint foods to eliminate, and tolerably expand the diet for the long-term.
It is important to know that people with chronic digestive issues tend to respond to fiber differently — so if you’re confused about how much and what kind of fiber works best for your symptoms, you are not alone. Gradually titrating your soluble and insoluble fiber intake overtime through the consumption of whole grains, fruits, and vegetables can help regulate and soften bowel movements. When healthy gut bacteria ferment dietary fibers they produce short chain fatty acids (SCFAs). SCFAs have been studied for their lasting anti-inflammatory and healing effects. SCFAs formed from fiber breakdown by gut bacteria feeds intestinal cells so they can heal, improve the integrity of the gut lining, and protect our immune health. If you find that you cannot tolerate increasing your fiber intake, look into functional gut microbiome testing to determine the cause. You may need work very slowly to increase specific kinds of fiber or consider supplementing with SCFAs.
Hands-On Therapies
Acupuncture: Research has demonstrated that acupuncture improves digestive symptoms by reducing abdominal pain, improved bowel habits, and reduced stress and anxiety associated with IBS. “In terms of treatment, acupuncture therapy can regulate the neuroendocrine-immune system of the body (the gut-brain axis) and improve the intestinal microenvironment, and it has the advantages of safety, economy, and effectiveness” (Sun, 2023). Data supports working with a practitioner over a series of treatment sessions to improve baseline mood levels (Han, 2022).
Visceral manipulation / Osteopathy: Patients with IBS experience both short-term and long-term improvements in the severity of symptoms with significant improvements in depression and anxiety scores (Müller, 2012).
Nutrient and Botanical Support
Certain herbs have shown efficacy in relieving IBS symptoms.
Peppermint oil has antispasmodic properties and can help alleviate abdominal pain and bloating.
Ginger possesses anti-inflammatory and antioxidant effects, which may reduce gut inflammation and improve digestion.
Chamomile has calming properties and can help reduce anxiety and promote relaxation, thereby benefiting the gut-brain axis.
Certain nutrients can specifically help heal the lining of the digestive tract, improving intestinal permeability and reducing inflammation, including:
L-Glutamine: 8 weeks of daily supplementation with a robust dose of L-Glutamine (5 g three times daily) has been shown to significantly decrease the symptom severity of IBS (Zhou, 2019). L-Glutamine is generally considered safe.
Short Chain Fatty Acids (SCFAs): Supplementation with prebiotic SCFAs has been shown to have lasting effects on maintaining health gut flora and have vast implications for a host of conditions from irritable bowel syndrome, inflammatory bowel disease, depression, obesity, diabetes, and cardiovascular disease (Wiley, 2016). SCFAs have also been shown to down-regulate stress signaling impacting depression and anxiety (Hills, 2019).
The gut-brain axis is a complex and intricate system that plays a crucial role in the development and management of IBS symptoms. Holistic therapies provide a comprehensive approach to IBS management by addressing physical and psychological aspects.
Working with a naturopathic doctor or qualified alternative medicine practitioner can help you evaluate the cause of your symptoms, rule out other potentially dangerous or difficult conditions, and help clarify specific areas needed for treatment. Many people with chronic digestive issues struggle for weeks, months, or years trying to troubleshoot symptoms on their own when a more effective diagnosis and treatment approach may be more effective.
REFERENCES
❍ Hills RD Jr. et. al. Gut Microbiome: Profound Implications for Diet and Disease. Nutrients. 2019. 11(7): 1613. doi: 10.3390/nu11071613.
❍ Müller, A. Effectiveness of Osteopathic Manipulative Therapy for Managing Symptoms of Irritable Bowel Syndrome: A Systematic Review. Journal of Osteopathic Medicine. 2014. 114(6): 470-479. doi.org/10.7556/jaoa.2014.098
❍ Li H. et. al. Mechanism of Acupuncture and Moxibustion on Promoting Mucosal Healing in Ulcerative Colitis. Chin J Integr Med. 2022. doi: 10.1007/s11655-022-3531-x.
❍ Saffouri, GB. et. al. Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders. Nature Communications. 2019. 2012(10). doi: 10.1038/s41467-019-09964-7
❍ Sun, Z. et. al. A review of neuroendocrine immune system abnormalities in IBS based on the brain–gut axis and research progress of acupuncture intervention. Frontiers in Neuroscience. 2023. 17:934341. doi: 10.3389/fnins.2023.934341.
❍ Peters SL. Review article: gut-directed hypnotherapy in the management of irritable bowel syndrome and inflammatory bowel disease. Aliment Pharmacol Ther. 2015. 41(11):1104-15. doi: 10.1111/apt.13202.
❍ Rinninella E. et. al. Food Additives, Gut Microbiota, and Irritable Bowel Syndrome: A Hidden Track. Int J Environ Res Public Health. 2020. 17(23): 8816. doi: 10.3390/ijerph17238816.
❍ Zhou Q. et. al. A Randomized Placebo-Controlled Trial of Dietary Glutamine Supplements for Post-Infectious Irritable Bowel Syndrome. Gut. 2019. 68(6): 996–1002. doi:10.1136/gutjnl-2017-315136
❍ Wiley, JW. Stress and glucocorticoid receptor transcriptional programming in time and space: Implications for the brain-gut axis. Neurogastroenteroly & Motility. 2016. 28: 12–25. doi: 10.1111/nmo.12706