Asthma – together with a common skin and food allergies has been linked with our gut bacteria in a number of studies. Now a new study – investigating this link has identified that conditions of asthma passed between a mother and child – previously thought to be genetic – may now be influenced by gut bacteria.
Increased Incidence of Asthma Suggests the Cause is not Purely Genetic
Asthma, which have risen steadily over the last 50 years, is now thought to effect 8% of the US population – and the symptoms of asthma often deteriorate in mothers during pregnancy.
The effect of asthma in pregnancy has also been tied to the health and birth weight of the new born and an increased likelihood that the child will develop asthma themselves -particularly in males. This increased incidence suggests the cause of asthma is not purely genetic.
These new findings suggest that it may be possible to develop new treatments for Asthma through the use of probiotics
In this latest study, published in the European respiratory journal investigated the link between asthma during pregnancy and the make up of the gut bacteria.
The researchers, led by Anita Kozyrskyj a microbiome epidemiologist at the University of Alberta— recruited 1,000 mothers and their infants consisting of mothers with asthma and a control group of mothers without asthma. Fecal samples were collected from each of the infants at between three and four months for analysis to measure and compare their gut bacteria.
Male Babies Born to Mothers with Asthma 30% More Likely to Have Altered Gut Bacteria
They found distinct patterns in the findings – in particular the male offspring of Caucasian mothers with asthma were 30% more likely to have specific characteristics in the gut bacteria – including a significant reduction in the Lactobacillus genus of bacteria – which includes many key friendly strains thought to be important in the establishment of an infants microbiome.
These findings wereeven more pronounced where the asthmatic mother also suffered from allergies or was excessive weight or obesity.
In previous studies it has been hard to pinpoint causality of these changes to the microbiome – as – for example asthmatic mothers may be more likely to be prescribed antibiotics or for their child to be born by c-section – which are known to affect the development of the gut bacteria in the child.
However in this study both of these factors were controlled for – together with a number of other factors including the weight of the mothers, their ethnicity, prevalence of any allergies, breast-feeding behavious and ethnicity.
Having accounted for all of these factors, the levels of the Lactobacillus genus were still found to be significantly lower in the babies of asthmatic mothers at 3-4 months after birth.
What was interesting however was that in the female offspring of mothers suffering from asthma during pregnancy – the gut bacteria was influenced differently.
Anita Kozyrskyj noted that “The Baby Girls were more likely to have more of the Bacteroidaceae genus of bacteria in their gut, which are important for maintaining the mucous barrier that protects intestinal cells – which may actually benefit female babies’ health.”
The researchers believe that this may explain why rates of asthma in female infants are less in early childhood.