In this post we will explore the role of nutrigenetics in managing gut health, particularly in relation to gluten and lactose, and also talk about the boundaries of nutrigenetic testing in this context.

Gluten Sensitivity

Genetic Markers: The most significant genetic markers linked to gluten sensitivity are found within the HLA-DQ gene region. Specifically, the HLA-DQ2 and HLA-DQ8 genetic variants are present in over 95% of those with the disease. While not everyone with these markers will develop gluten sensitivity, their presence significantly increases risk. Nutrigenetic testing can identify these markers, providing individuals with critical information about their potential sensitivity to gluten.

Implications for Dietary Management: For those with a genetic predisposition to gluten sensitivity, adopting a gluten-free diet can be a crucial measure. It’s important to note, however, that a positive genetic test does not mean a person will definitely be sensitive to gluten, it indicates risk (as with any complex genetic predisposition, it never means a person will 100% develop a condition). This is why individuals with genetic predisposition should not completely cut out gluten containing foods from their diet before consulting with a health care professional.

Lactose Intolerance

Lactase Persistence and Decline: Lactose intolerance is primarily associated with variations in the LCT gene, which influences lactase enzyme production. The lactase enzyme is essential for the digestion of lactose. A common variant, known as -13910*T, located upstream of the LCT gene, is linked to lactase persistence in adults. Conversely, the absence of this variant often correlates with lactase non-persistence, the primary genetic cause of lactose intolerance.

Nutrigenetic Testing for Lactose Intolerance: By identifying the presence or absence of the -13910*T variant, nutrigenetic tests can predict an individual’s likelihood of lactose intolerance. This information can guide individuals in making informed dietary choices, such as reducing or eliminating dairy products from their diet or opting for lactose-free alternatives.

The Value of Genetic Testing

Genetic testing for gluten and lactose sensitivities offers a personalised approach to nutrition and health management, allowing individuals to tailor their diets to their genetic makeup. This level of personalisation can lead to improved gut health, reduced symptoms, and a better quality of life for those with sensitivities or intolerances.

Case study

Sarah, a 41-year-old with chronic bloating and skin issues, struggled to identify the cause of her symptoms despite trying various diets. Opting for a nutrigenetic test, she discovered she had a genetic variant associated with lactase non-persistence, indicating lactose intolerance. By switching to dairy-free alternatives fortified with calcium, vitamins B, and D (important for bone health), Sarah significantly improved her symptoms.

This highlights how nutrigenetic test can help identify gut health issues where the cause is often tricky to pinpoint.


Limitations of nutrigenetic tests in gut health

However, it’s crucial to approach nutrigenetic testing as part of a broader health and nutritional strategy. While these tests can provide valuable insights into one’s predisposition to gluten and lactose sensitivities, they are not standalone diagnostic tools and their ability to predict gut response to other foods/nutrients may limited. Collaboration with healthcare providers and nutrition experts is essential to interpret test results accurately and develop a comprehensive dietary plan that considers genetic, environmental, and lifestyle factors.


Nutrigenetics offers a promising pathway to understanding and managing sensitivities to gluten and lactose. However, it’s essential to recognize the limitations of nutrigenetic testing in predicting dietary tolerances comprehensively. Embracing a holistic approach that combines genetic insights with other dietary and lifestyle considerations is key to optimising gut health and overall wellness.