Nutrigenomics paves the way for customized diets in lactose intolerance care

In a recent review published in Nutrients, researchers synthesized the current evidence on omics tools that allow for developing tailored nutrition strategies for individuals with lactose intolerance (LI).

They concluded that using a customized approach instead of the currently prevailing ‘one size fits all’ strategy can significantly improve the quality of life for people living with LI.

Study: Cow’s Milk: A Benefit for Human Health? Omics Tools and Precision Nutrition for Lactose Intolerance Management. Image Credit: Albina Gavrilovic/Shutterstock.com

The nutritional importance of CM

Nutritionally speaking, milk is a complete food rich in macronutrients like carbohydrates, proteins, lipids, minerals, and vitamins. Supplemented milk contains additional protein, calcium, and omega-3 fatty acids.

The proteins in CM contain high levels of essential amino acids such as histidine, isoleucine, lysine, methionine, phenylalanine, and valine.

Serum proteins include lactoglobulins and immunoglobulins. One part of milk proteins is insoluble, including caseins that carry calcium and phosphate. Some caseins increase inflammatory response and intestinal permeability.

Overall, studies suggest that caseins and lactoglobulins inhibit cell death and provide protection against oxidative damage to cells. They may, therefore, reduce skeletal muscle loss and prevent diseases associated with aging.

CM also contains various micronutrients, including selenium, zinc, iron, magnesium, potassium, phosphorus, calcium, carotenoids, and vitamins A and E. Many of these are also antioxidants, which can reduce the incidence of atherosclerosis, cancer, and diabetes.

While milk consumption is beneficial for human health, some studies have found no result for correlations between the consumption of dairy, and cardiovascular disease. In contrast, others suggest that it could increase the risk of hypertension and diabetes.

Despite this, CM’s biochemical and chemical composition makes it crucial for nutrition during early life.

Adverse reactions to CM

Despite the established medical benefits of CM consumption, its components, including milk proteins and lactose, can also cause several gastrointestinal disorders and severe discomfort, of which the most common are lactose intolerance (LI) and CM protein allergy (CMPA).

CMPA is a common food allergy in infants and young children, manifesting in 0.5%-3% of children. While most children develop tolerance to CM by the time they are 4; others may suffer from severe allergic reactions well into childhood, triggered by small amounts of exposure.

Three types of CMPA are defined based on whether the response is mediated by immunoglobulin-E (IgE), cell-mediated (non-IgE) primarily by T-cells, or mixed. Of these, IgE-mediated CMPA accounts for 60% of reactions.

The most common allergens contained in CM are whey proteins and caseins, which can trigger various manifestations of CMPA.

IgE-mediated responses can cause anaphylaxis, while non-IgE-mediated responses affect the gastrointestinal tract and cause discomfort, which can last for several days after ingestion with symptoms such as abdominal pain, chronic diarrhea, and nutrient malabsorption.

A combination of environment, genetics, and interactions between the two are risk factors for CMPA. For example, it is more common in male children and among black and Asian children compared to white children.

However, introducing a diversity of foods in early childhood may be protective against the development of CMPA and other food allergies.

The composition and integrity of the gut microbiota may also play a key role in reducing the impact of CMPA. At the same time, gastrointestinal complications arising from the consumption of CM may affect the microbiome adversely.

Current dietary recommendations for both LI and CMPA involve restricting dairy in the diet. The gut microbiome may be the key to improving the quality of life for people with CMPA and LI by using prebiotics and probiotics to improve gut health.

In contrast to CMPA, LI is caused by a deficiency in lactase which reduces the body’s ability to process lactose, which is high in galactose and glucose. Intestinal lactase is highest at birth but begins to decline after weaning.

Nearly seven in ten adults globally suffer either from lactose malabsorption (LM) caused by lactose deficiency (LD) which leads to LI. They suffer from diarrhea, gas, bloating, and dyspepsia after consuming lactose.

LI has been correlated with other gastrointestinal disorders such as celiac disease (CD), irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), and non-celiac gluten sensitivity (NCGS).

The role of nutrigenetics and epigenetics in managing LI

Epigenomics, genomics, metabolomics, and similar fields of study are called ‘omics’ technologies.

Metabolomics, specifically, allows for the precise chemical analyses of one thousand metabolites to identify food biomarkers of disease that can be targeted to improve metabolism. These tools can be used to quantify lactose serum levels in blood and urine after dairy consumption.

Metabolomics can allow for the analysis of the effect of a single nutrient and its metabolic products on an individual’s health to create a personalized nutrition (PN) program consisting of customized dietary recommendations.

For people with LI, this could be a low-lactose or lactose-free diet that is supplemented by probiotic strains or oral lactase enzymes.

PNs should also include diagnostic tools (such as the hydrogen breath test and lactose tolerance test) and psychological support for a condition that often has effects on mental health. However, individuals with milk allergies must remove dairy products from their diets.