The immune system is a dynamic and multifaceted defence network that protects the body from pathogens, mutated cells, and environmental threats. Comprising immune cells, chemical messengers, and surveillance pathways, it operates through a finely tuned balance of reactivity and tolerance.1 As we enter the colder months, practitioners are uniquely positioned to support clients in optimising immune function to reduce susceptibility to seasonal infections and promote faster recovery when illness occurs.
The immune system consists of two major branches, the innate (nonspecific) immune system and the adaptive (specific) immune system. Both work synergistically to identify, respond to, and remember invading organisms and abnormal cells.1 A naturopathic approach to immune support involves a holistic understanding of nutrition, herbal medicine, gut integrity, and lifestyle, all of which influence immune performance and regulation.2
Innate immunity, the first line of defence
The innate immune system is the body’s immediate response mechanism, offering broad-spectrum protection through physical barriers of the skin and mucous membranes, chemical defences of stomach acid, and phagocytic immune cells like macrophages and neutrophils.1 To ensure proper functioning of this first line of defence the following factors need to be considered.
Support physical barriers
Physical barriers such as the skin and mucous membranes rely on essential micronutrients, including vitamin A, vitamin C, zinc, and omega-3 fatty acids, to maintain their structural integrity and function.³,⁴ Adequate hydration is also crucial, as it supports mucosal secretions and enhances the resilience of the skin barrier. Additionally, certain herbs including Calendula (Calendula officinalis), Chamomile (Matricaria chamomilla), and Aloe Vera have soothing properties and can aid in repairing damaged skin and mucous membranes.⁵
Optimise chemical defences
Digestive bitter herbs including Gentian (Gentiana lutea), Dandelion root (Taraxacum officinale) and Globe artichoke (Cynara scolymus), stimulate gastric secretions, reinforcing the stomach’s acidic barrier against pathogens.6 Additionally, encouraging mindful eating and stress reduction is essential in maintaining optimal digestive health. Stress has a well-documented impact on the gastrointestinal system, often leading to the suppression of digestive functions such as enzyme secretion, gut motility, and blood flow to the digestive organs. When a person eats mindlessly or while stressed, the body’s “fight or flight” response can override the “rest and digest” mode, impairing the efficient breakdown and absorption of nutrients. Stress can decrease the production of stomach acid, which plays a critical role not only in digestion but also in killing harmful pathogens ingested with food. Reduced stomach acid levels can therefore compromise the body’s natural defence system, increasing susceptibility to pathogens.7
Activate phagocytic immune cells
Medicinal mushrooms such as Cordyceps, Reishi and Turkey Tail modulate innate immune cells and enhance cytokine activity.8 Immune-stimulating herbs like Echinacea (Echinacea purpurea), Andrographis (Andrographis paniculata), and Astragalus (Astragalus membranaceus) enhance macrophage activity and overall immune vigilance.9, 10
Promote Lifestyle Foundations
Adequate sleep, gentle exercise, and effective stress management are fundamental to maintaining a healthy innate immune system. Sleep supports immune regulation by enhancing the production of cytokines and improving immune cell function. 11 Regular moderate exercise increases blood circulation, facilitates toxin removal through sweat, and promotes lymphatic flow, which helps clear pathogens and waste products from the body.12 Adaptogenic herbs such as Ashwagandha (Withania somnifera) and Holy Basil (Ocimum sanctum) help support neuroendocrine-immune balance by modulating stress responses.13 Hydrotherapy can further enhance innate immunity by improving circulation and lymphatic movement, thus boosting immune surveillance and function.14
Adaptive Immunity, targeted and long-lasting
The adaptive immune system provides antigen-specific responses and long-term immunity. It involves B cells, which produce antibodies and T cells, which destroy infected cells and regulate the immune response. This system is slower to activate but forms immunological memory that allows for a more robust response upon re-exposure.2 To ensure proper functioning of this second line of defence the following factors need to be considered.
Nutritional support for B and T cells
- Zinc is essential for lymphocyte development and function.
- Vitamin D modulates immune tolerance and reduces the risk of autoimmune activation.
- Vitamin C and vitamin E protect immune cells from oxidative damage.
- Omega-3 fatty acids mitigate excessive inflammation and support immune modulation.3,4,15
The gut microbiota
The gastrointestinal tract is home to 70–80% of immune cells called GALT.16 Probiotics, particularly Lactobacillus and Bifidobacterium strains, along with a fibre-rich diet, support immune education and tolerance.3 Fermented foods, sauerkraut, kefir and miso can be introduced to naturally reinforce microbial diversity. Secretory IgA (sIgA) is the predominant antibody in the gut's mucosal surfaces and plays a critical role in immune defence by neutralising pathogens and maintaining the balance of the gut microbiota. sIgA binds to microbes and antigens, preventing them from crossing the intestinal barrier, and helps maintain immune homeostasis.17
Lymphatic system support:
Encouraging movement therapies such as walking, yoga, and rebounding is an effective way to stimulate lymphatic flow and support immune function. The lymphatic system relies on muscular movement, diaphragmatic breathing, and gravity to circulate lymphatic fluid as it lacks its own pump.18 Walking activates skeletal muscles to compress lymph vessels, promoting fluid movement and enhancing immune cell circulation.19 Yoga combines stretching, deep breathing, and inversions that encourage lymph drainage and reduce inflammation. Rebounding, or gentle bouncing on a mini trampoline, uses gravitational shifts and rhythmic motion to stimulate lymphatic valves and increase circulation, which may improve detoxification and immune response.20 Cleavers (Galium aparine) is a depurative and helps support the movement and decongestion of lymph fluid around the body.21 Echinacea (Echinacea purpurea) is a lymphatic herb which means it supports the lymphatic system to help detoxify and move the lymph around the body.22
Stress adaptation
Chronic stress is a known suppressor of adaptive immune function. Integrate adaptogens including Schisandra, Ashwagandha, Holy Basil and mind-body practices like meditation and breathwork to reduce inflammatory signalling and support immunological balance.
The gut-immune connection
The gut microbiota plays a critical role in shaping both innate and adaptive immune responses. Disruptions to the microbial ecosystem from antibiotics, poor dietary patterns, C-section births, or lack of environmental microbial exposure can impair immune education, reduce tolerance, and contribute to immune-mediated disorders.2 Microbial metabolites, including short-chain fatty acids (SCFAs), lipopolysaccharides, and peptidoglycans, are central to immune modulation. These compounds interact directly with immune cells, influencing cytokine expression, inflammation, and barrier integrity.2 Supporting microbiota diversity through prebiotic fibres, probiotics, polyphenol-rich foods, and antibiotic stewardship is a key naturopathic intervention for enhancing immune resilience.
Clinical takeaways
As practitioners we must consider the multifactorial influences on immune health. Diet, sleep, stress, physical activity, toxic exposure, gut health, and even psychosocial dynamics all influence how the immune system responds to pathogens and regulates itself. Nutrient deficiencies, particularly in vitamins C, D, zinc, and iron can significantly impair immune function, while a whole-food, antioxidant-rich diet, sufficient rest, and regular exercise promote immune resilience.
Through a naturopathic lens, immune support is not about overstimulation, but modulation, resilience, and balance. Supporting both the innate and adaptive arms of the immune system with herbs, nutrients, and lifestyle therapies allows for comprehensive care, particularly critical during the winter months, when immune demand is heightened.
References:
- Institute for Quality and Efficiency in Health Care (IQWiG). (2023, August 14). In brief: The innate and adaptive immune systems. In InformedHealth.org. https://www.ncbi.nlm.nih.gov/books/NBK279396/
- Henchtman, L. (2020). Advanced Clinical Naturopathy. Elsevier Australia.
- Parke, M. A., Perez-Sanchez, A., Zamil, D. H., & Katta, R. (2021). Diet and Skin Barrier: The Role of Dietary Interventions on Skin Barrier Function. Dermatology practical & conceptual, 11(1), e2021132. https://doi.org/10.5826/dpc.1101a132
- Gombart, A. F., Pierre, A., & Maggini, S. (2020). A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection. Nutrients, 12(1), 236. https://doi.org/10.3390/nu12010236
- Fisher, C. (2018). Materia medica of Western herbs. Elsevier Australia.
- Czerwony, B. (2022, March 7). What to know before you try digestive bitters. Cleveland Clinic. https://health.clevelandclinic.org/digestive-bitters
- Brigham Young University Counseling and Psychological Services. (n.d.). Stress and the digestive system. Retrieved June 5, 2025, from https://caps.byu.edu/stress-and-the-digestive-system
- Guggenheim, A. G., Wright, K. M., & Zwickey, H. L. (2014). Immune Modulation From Five Major Mushrooms: Application to Integrative Oncology. Integrative medicine (Encinitas, Calif.), 13(1), 32–44.
- Brush, J., Mendenhall, E., Guggenheim, A., Chan, T., Connelly, E., Soumyanath, A., Buresh, R., Barrett, R., & Zwickey, H. (2006). The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans. Phytotherapy research : PTR, 20(8), 687–695. https://doi.org/10.1002/ptr.1938
- Wang, W., Wang, J., Dong, S. F., Liu, C. H., Italiani, P., Sun, S. H., Xu, J., Boraschi, D., Ma, S. P., & Qu, D. (2010). Immunomodulatory activity of andrographolide on macrophage activation and specific antibody response. Acta pharmacologica Sinica, 31(2), 191–201. https://doi.org/10.1038/aps.2009.205
- Besedovsky, L., Lange, T., & Born, J. (2012). Sleep and immune function. Pflugers Archiv - European Journal of Physiology, 463(1), 121–137. https://doi.org/10.1007/s00424-011-1044-0
- Nieman, D. C., & Wentz, L. M. (2019). The compelling link between physical activity and the body’s defense system. Journal of Sport and Health Science, 8(3), 201–217. https://doi.org/10.1016/j.jshs.2018.09.009
- Panossian, A., & Wikman, G. (2010). Effects of adaptogens on the central nervous system and the molecular mechanisms associated with their stress—Protective activity. Pharmaceuticals, 3(1), 188–224. https://doi.org/10.3390/ph3010188
- Mooventhan, A., & Nivethitha, L. (2014). Scientific evidence-based effects of hydrotherapy on various systems of the body. North American journal of medical sciences, 6(5), 199–209. https://doi.org/10.4103/1947-2714.132935
- Shankar, A. H., & Prasad, A. S. (2023). Zinc and immune function: The biological basis of altered resistance to infection. The American Journal of Clinical Nutrition, 68(2), 447S–463S. https://doi.org/10.1093/ajcn/68.2.447S
- Malaty, L. (2025, May 23). Why your gut immune system holds the key to better health. AustinMD Clinic. https://austinmdclinic.com/gut-immune-system-key-better-health/
- Pietrzak, B., Tomela, K., Olejnik-Schmidt, A., Mackiewicz, A., & Schmidt, M. (2020). Secretory IgA in Intestinal Mucosal Secretions as an Adaptive Barrier against Microbial Cells. International journal of molecular sciences, 21(23), 9254. https://doi.org/10.3390/ijms21239254
- Ozdowski, L., & Gupta, V. (2023, May 1). Physiology, lymphatic system. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557833/
- Cancer Research UK. (n.d.). Exercise and the lymphatic system. https://www.cancerresearchuk.org/about-cancer/coping/physically/lymphoedema-and-cancer/treating/exercise
- Cugusi, L., Manca, A., Serpe, R., Romita, G., Bergamin, M., Cadeddu, C., Solla, P., Mercuro, G., & Working Group of Gender Cardiovascular Disease of the Italian Society of Cardiology (2018). Effects of a mini-trampoline rebounding exercise program on functional parameters, body composition and quality of life in overweight women. The Journal of sports medicine and physical fitness, 58(3), 287–294. https://doi.org/10.23736/S0022-4707.16.06588-9
- Papantoniou, C. (2022, April 7). Cleavers: Lymphatic spring cleanse. CNM College of Naturopathic Medicine. https://www.naturopathy-uk.com/herbal-recipes/blog/2022/04/07/cleavers-lymphatic-spring-cleanse/
- Bone, K. (2003). A clinical guide to blending liquid herbs: Herbal formulations for the individual patient. Churchill Livingstone