How Personalised Nutrition Combined with Functional Laboratory Testing Can Help Address Chronic Illness

Anna Papoutsa
Written by Anna Papoutsa

A chronic illness is any health condition or disease that is complex and persistent or otherwise ongoing in its effects. Examples of such conditions such as diabetes, heart disease, irritable bowel syndrome and arthritis, are just a few among a vast array of chronic diseases. Chronic conditions are complex, often requiring equally complex solutions.

Personalised nutrition (PN) is a targeted approach to nutrition planning specifically tailored to an individual’s unique physiological needs, lifestyle, and genetic profile. By accounting for these factors, personalised nutrition transcends the limitations of general dietary recommendations to provide bespoke nutritional guidance.

Functional laboratory testing is a critical element in this approach, offering valuable insights into an individual’s specific health status. It assesses various biological markers, such as vitamin levels, hormones, and markers that reflect the state of crucial biochemical functions in the body and help identify imbalances or deficiencies. This detailed information enables personalised nutrition practitioners to devise precise, evidence-based dietary interventions that promote optimal health and well-being.

Personalised nutrition combined with functional laboratory testing, offers a cutting-edge approach to managing chronic illnesses by tailoring dietary strategies to individual needs.

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Functional laboratory testing helps identify specific requirements, health issues and imbalances that can be addressed through diet and nutritional support. It does that by identifying nutrient deficiencies, assessing toxicity & oxidative stress, analysing the health of the gut, testing for food allergies and sensitivities, and with genetic testing. 

Identifying Nutrient Deficiencies

This is a nuanced process that goes beyond basic dietary analysis. Advanced nutritional status tests can detect subtle insufficiencies and suboptimal levels of nutrients before they manifest as clinical symptoms, enabling pre-emptive dietary interventions. For instance, insufficiency of vitamin B12 levels may impede nerve function and blood cell formation and can also masquerade as fatigue and concentration problems, often misleadingly attributed to modern lifestyle stress. Moreover, emerging research suggests that B12 status may influence genetic expression and epigenetic markers, affecting health in ways that are only beginning to be understood (Cassiano et al., 2023; Monasso et al., 2023). A PN practitioner uses biochemical data from laboratory testing to tailor recommendations such as introducing B12-rich foods or bioavailable supplements to address these complex, interconnected issues. This precision nutrition approach can potentially recalibrate systemic imbalances, highlighting the intricate relationship between micronutrients and holistic health.

Assessing Toxicity & Oxidative Stress

This involves the measurement of sophisticated biomarkers that reflect the balance between damaging free radicals and protective antioxidant systems within the body. This balance is critical, as oxidative stress is implicated in the disease development of numerous chronic illnesses and ageing processes. Personalised Nutrition practitioners can analyse these biomarkers to develop personalised interventions that support and promote the body’s own endogenous defence mechanisms, such as the glutathione and superoxide dismutase systems. This way nutritional therapy harnesses the body’s innate ability to detoxify and repair. Such strategic nutrition can potentially recalibrate the body’s response to environmental toxins and oxidative challenges, underscoring the dynamic role of diet in mitigating oxidative stress and its associated risks.

Analysing Gut Health

It involves a deep dive into the complex ecosystem of the gut microbiota, a teeming network of microorganisms that live in the gut that significantly influence human health. Cutting-edge genomic and metabolomic testing can unveil the diverse microbial species residing within the gut, offering a window into the symbiotic relationships that underpin the body’s metabolic, immune, and even neurological health. Uncovering imbalances or pathogenic bacteria through such precise laboratory tools enables nutritional therapists to devise sophisticated therapeutic strategies. These can include specialised probiotics that supply specific bacterial strains needed to restore equilibrium, or prebiotics that selectively nourish beneficial microbes. Substances produced by these gut bacteria, play a crucial role in preventing inflammation and chronic disease (Bander et al., 2020). Beyond the common advice of consuming fermented foods and fibre, interventions may also consider the timing, diversity, and combination of probiotic species and functional foods to synergistically enhance microbial diversity and resilience. This nuanced approach underscores the importance of a tailored diet in fostering a robust gut microbiome, paving the way for improved systemic health and disease prevention.

Detecting Food Allergies & Sensitivities

This is a critical aspect of personalised nutrition that helps understand how a person’s body might react to different foods or nutrients, and being precise is a key part of making sure the nutrition plan is just right for an individual. These tests can differentiate between testing for classic allergies, which cause immediate and more pronounced reactions, and sensitivities that are not classic allergies, which may lead to subtler, chronic symptoms. Understanding these distinctions allows for the development of a customised diet plan that not only avoids known allergens but also addresses the complex interplay between food triggers and the immune system. The avoidance of trigger foods is just the beginning; this strategy is complemented by interventions aimed at reinforcing gut integrity, re-balancing immune responses, and even potentially reintroducing foods through oral immunotherapy. Such comprehensive management may improve the quality of life, reduce chronic inflammation, and contribute to long-term health optimisation.

Utilising Genetic Tests

Genetic testing can find small differences in a person’s DNA that affect how they process and react to different foods and nutrients. For instance, someone might have a tiny variation in a specific gene (like the FADS1 gene) which changes how well they can use omega-3 fats from their diet (Mathias et al., 2014). This means they might need a special diet plan for their omega-3 needs to help their body cells work well and control inflammation. These genetic tests show how a person handles nutrients and vitamins, how their body reacts to fats in the diet, and even their taste preferences and feelings of fullness. PN practitioners can use this genetic information along with other health indicators to predict if a person might have too little or too much of certain nutrients. This helps them create a diet plan that could lower the risk of long-term health problems and improve overall health.

Using cardiovascular health as an example: Genetic testing can look for specific small changes in the genes, like those in the ApoE gene, which affect how the body handles cholesterol. If there is a certain version of this gene, known as ApoE4, an individual might be more susceptible to heart health issues because of higher cholesterol levels. Another important gene is MTHFR, which helps process a substance in the blood called homocysteine. If homocysteine levels increase which may be affected by this gene, it can impact the blood vessels and increase heart disease risk (Wang et al., 2022). So, testing for these gene changes can guide the practitioner to create a health plan that includes nutritional changes to improve cardiovascular system health.

Consider metabolic syndrome and the risk for diabetes as an example to illustrate the value of functional testing. The practitioner will focus on select markers to identify early signs of insulin resistance and glucose intolerance, critical predecessors to diabetes. Such detailed insights can pre-emptively address metabolic dysfunctions and support overall blood glucose regulation, preventing or managing diabetes more effectively.

Personalised nutrition, supported by functional laboratory testing, represents an essential tool in managing chronic illness. By focusing on individual differences in genetics, lifestyle, and biochemical imbalances, this approach provides targeted, effective, and natural solutions to improve health. It’s not just about eating healthier; it’s about eating smarter based on what one’s body specifically needs. As research continues to evolve, this personalised approach promises to transform how we think about diet and chronic disease management, offering hope for more effective, tailored healthcare solutions.


Bander, Z. Al, Nitert, M. D., Mousa, A., & Naderpoor, N. (2020). The Gut Microbiota and Inflammation: An Overview. International Journal of Environmental Research and Public Health, 17(20), 1–22.

Cassiano, L. M. G., Cavalcante-Silva, V., Oliveira, M. S., Prado, B. V. O., Cardoso, C. G., Salim, A. C. M., Franco, G. R., D’Almeida, V., Francisco, S. C., & Coimbra, R. S. (2023). Vitamin B12 attenuates leukocyte inflammatory signature in COVID-19 via methyl-dependent changes in epigenetic markings. Frontiers in Immunology, 14, 1048790.

Mathias, R. A., Pani, V., & Chilton, F. H. (2014). Genetic Variants in the FADS Gene: Implications for Dietary Recommendations for Fatty Acid Intake. Current Nutrition Reports, 3(2), 139.

Monasso, G. S., Hoang, T. T., Mancano, G., Fernández-Barrés, S., Dou, J., Jaddoe, V. W. V., Page, C. M., Johnson, L., Bustamante, M., Bakulski, K. M., Håberg, S. E., Ueland, P. M., Battram, T., Merid, S. K., Melén, E., Caramaschi, D., Küpers, L. K., Sunyer, J., Nystad, W., … Felix, J. F. (2023). A meta-analysis of epigenome-wide association studies on pregnancy vitamin B12 concentrations and offspring DNA methylation. Epigenetics, 18(1).

Wang, B., Mo, X., Wu, Z., & Guan, X. (2022). Systematic review and meta-analysis of the correlation between plasma homocysteine levels and coronary heart disease. Journal of Thoracic Disease, 14(3), 646–653.