The presence of bacteria that break down fibre in a mother’s gut is linked to a reduced risk of food allergies in her child’s first year of life

The presence of bacteria that break down fibre in a mother’s gut is linked to a reduced risk of food allergies in her child’s first year of life

By Gege Li
Certain bacteria in a mother’s microbiome are linked to lower risk of food allergies for her child
Tetra Images, LLC / Alamy
The presence of certain bacteria in a mothers gut is linked to a decreased risk of their baby developing food allergies in the first year of life.
Prevotella copri is a bacterium that ferments fibre from our diet into fatty acids, and it has been linked to reduced allergic reactions in the offspring of mice with a high-fibre diet. Peter Vuillermin at Deakin University in Australia, and his colleagues examined whether this association happened in humans, in whom the fatty acids are thought to help regulate inflammation.
The team analysed data from a study of Australian mothers and infants collected between 2010 and 2013. Faecal samples were collected from mothers when they were 36 weeks pregnant, and from infants at months 1, 6 and 12 after birth.
DNA from faecal samples of 58 infants with a diagnosed food allergy were compared to that of 236 infants without allergies.
The team found that around 20 per cent of babies without any allergies had P. copri in their faecal samples, compared to 8 per cent of those with allergies to egg, peanut and cows milk, among others.
The presence and abundance of P. copri in the mothers stool was also associated with a decreased risk of allergy in fact, only one mother with an infant who had allergies had more than 0.03 per cent of the bacterium detected in her stool sample.
Analysis showed that when a woman had twice as much P. copri as another as shown by the expression of a specific P. copri gene in their stool it was associated with an 8 per cent decrease in the risk of food allergy in her child.
P. copri might be able to protect against non-food allergies such as hay fever, says Vuillermin, especially because childhood food allergies can make subsequent allergies more likely.
He adds that large households were a strong forecaster of P. copri in the mothers microbiome, probably because there are more people to share microbiota with, which boosts microbiome diversity.
P. copri is less prevalent in Western countries due to a range of factors including generally smaller households and a greater use of antibiotics, which the bacterium is sensitive to, says Vuillermin.
Journal reference: Nature Communications, DOI: 10.1038/s41467-020-14552-1
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