Study on Food Antibodies and Intolerance Diagnosis

Overview of the Research

A recent study published in BMC Gastroenterology examined the potential of using food antibodies to diagnose milk and wheat intolerance. The researchers focused on the relationship between serum antibodies against food antigens and perceived intolerance to milk and wheat among individuals with morbid obesity.

Understanding Milk and Wheat Intolerance

Milk and wheat intolerance ranks among the most frequently reported food intolerances globally. However, determining the exact number of individuals affected is challenging, as current studies often depend on self-reported sensitivities. While there are reliable tests available for food allergies, no dependable tests exist for food intolerances. The measurement of serum levels of food antibodies is becoming a popular laboratory method for assessing food intolerance. For instance, the detection of IgG and IgA antibodies against casein and gliadin—proteins found in milk and wheat—may indicate intolerance to these foods. Conversely, some studies argue that the presence of these antibodies may reflect immunological tolerance instead.

Impact of Food Intolerances on Health

Milk and wheat are primary triggers for gastrointestinal disorders like irritable bowel syndrome (IBS). Individuals classified as morbidly obese—those with a body mass index (BMI) exceeding 40 kg/m² or a BMI of 35 kg/m² accompanied by obesity-related complications—exhibit a high incidence of gastrointestinal disorders, including IBS. In cases of milk or wheat intolerance, exposure to these proteins can provoke an inflammatory response, gradually damaging the intestinal lining. Chronic inflammation can impair nutrient absorption and increase gut permeability, potentially resulting in a condition often referred to as “leaky gut.”

Details of the Study

Study Design and Participants

The study, conducted in Norway, included 97 participants with morbid obesity, averaging 45 years of age. Of these participants, 70 reported gastrointestinal problems. Researchers assessed the severity of gastrointestinal symptoms and recorded food-induced symptoms through questionnaires. Participants also completed food frequency questionnaires (FFQ) to evaluate their daily intake of certain foods.

Laboratory Analysis

Laboratory tests were performed to measure serum concentrations of IgG antibodies against cow’s milk, cheese, wheat, and gluten, as well as IgA antibodies against casein and gliadin. The findings revealed that 25 participants had IBS, while 22 and 20 reported intolerances to milk and wheat, respectively. Eleven participants indicated perceived intolerance to both.

Findings of the Study

Antibody Levels and Intolerance

The statistical analysis found no significant differences in food antibody levels between participants with and without perceived milk and wheat intolerance. Although participants who perceived milk intolerance reported lower dairy consumption, there was no significant difference in wheat intake among those with perceived wheat intolerance. Furthermore, the study did not establish a correlation between food antibodies and the type or severity of gastrointestinal symptoms.

Association with Hypothyroidism

Interestingly, post-hoc analysis indicated a correlation between hypothyroidism and wheat intolerance. Previous research has linked celiac disease with thyroid disease, but the relationship between food intolerance and thyroid conditions remains underexplored. This study identified a significant correlation between antibodies against wheat and hypothyroidism, suggesting a higher prevalence of hypothyroidism in individuals with perceived wheat intolerance.

Study Limitations and Strengths

The study’s strengths include the use of well-structured questionnaires, the exclusion of celiac disease patients, and a practical clinical setting. However, limitations such as potential inaccuracies in dietary reports due to recall bias and the lack of precise data on the exact amounts of grains consumed must be acknowledged.

Conclusion

In conclusion, the researchers determined that there is no association between perceived milk and wheat intolerance and the levels of IgG and IgA food antibodies in morbidly obese participants. Consequently, the presence of food antibodies does not correlate with reported food intolerance. The authors emphasize that there is insufficient evidence to support the use of food antibody levels in dietary planning for individuals with milk and wheat intolerance.

Written by Preeti Paul, MS Biochemistry
Reference: Kvehaugen et al. Is perceived intolerance to milk and wheat associated with corresponding IgG and IgA food antibodies? A cross-sectional study in subjects with morbid obesity and gastrointestinal symptoms. BMC Gastroenterology (2018) 18:22. DOI 10.1186/s12876-018-0750-x