Metabolites in the gut reveal insights into childhood asthma

Published in issue: February 2019

The gut metabolome refers to the collection of metabolites, or small molecules, in the gut. These metabolites come from diverse sources including the diet, the microbes in the gut, or production in other parts of the body. As childhood asthma is influenced by a variety of exposures including nutritional factors and the microbiota, the gut metabolome could provide insight into how children with asthma differ from those without asthma.

In an original article recently published in The Journal of Allergy & Clinical Immunology (JACI), Lee-Sarwar and colleagues used mass spectrometry to measure metabolites in stool samples from 361 3 year-old children who participated in the Vitamin D Antenatal Asthma Reduction Trial, a multi-center study conducted in the United States. Children with a diagnosis of asthma were compared to those without a diagnosis of asthma.

The authors sought to identify gut metabolites that were associated with asthma. To learn more about the sources and functions of metabolites with relevance to asthma, they used statistical correlation methods to incorporate extensive data in their analyses. They included information on the diet from childhood food frequency questionnaires and questionnaires on feeding during infancy, data on the microbes present in the gut from microbial DNA sequencing, and measurement of the metabolites circulating in the children’s blood.

Several metabolites were associated with asthma. There was evidence that reduced breastfeeding in infancy or a diet rich in fried or processed meats in early childhood may influence the metabolites in the gut and thereby increase asthma risk. Specific bacteria in the gut, including those from a family of bacteria called Christensenellaceae; and metabolites in the blood, including vitamin E metabolites, were also associated with both asthma and with asthma-associated intestinal metabolites.

This study revealed significant interrelationships between the molecules in the gut, the molecules in the blood, the bacteria in the gut, and nutritional factors throughout early life. These relationships have relevance to asthma in childhood and shed light on some of the factors that may influence the risk of developing childhood asthma. The authors caution that their findings should be replicated in other groups of children before they are used to influence clinical practice.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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