Low diversity of bacteria may increase the risk for asthma

January 7, 2014

Low gut microbial diversity in the intestines of infants can increase the risk for asthma development. These are the findings of the age 7 follow-up in a multi-year study led by researchers at Linköping University in Sweden.

In 2011 the results of a comprehensive survey of the intestinal microbiota of allergic and healthy children were published. In the samples from the infancy period, the degree of variation and diversity of the bacteria strains was significantly lower among those who had developed allergic eczema when they were two years old.

A follow-up study was conducted when the 47 participating reached their seventh birthday. By then eight of them – 17% – were suffering from . 28% had hay fever, 26% still had eczema, and 34% reacted to the allergens in a skin prick test. But it was only the asthma cases that could be connected to low intestinal microbial diversity at the age of one week and one month, according to the results now being published in the scientific journal Clinical & Experimental Allergy.

It might seem a bit of a stretch to think the contents of the could influence what happens in the airways. The results of this study, however, give further credence to this connection, which has previously been demonstrated in animal studies.

"A high diversity of during the first months of life seems to be important for the maturation of the immune system," says Thomas Abrahamsson, paediatrician and researcher at Linköping University, and principal author of the article.

The hypothesis is that in order to function effectively, the immune system needs to be "trained" by large numbers of different microorganisms. In the absence of sufficient stimulation from large numbers of different bacteria, the system may overreact to innocuous antigens it encounters.

A high gut has also been shown to strengthen the barrier function of the mucous membrane.

"We are speculating that a deficient maturity of the at an earlier age and a less efficient mucosa barrier function can open the way to certain types of viral infection that can be linked to the development of asthma," says senior author Maria Jenmalm, professor of experimental allergology.

The analysis of the flora in the children's stools was carried out using a method known as 454 pyro sequencing at the Science for Life Laboratory, in conjunction with researchers Anders Andersson and Lars Engstrand. This is a powerful genetic method that identifies DNA sequences typical of different bacterial species, including those that cannot be cultivated in the traditional way.

Explore further: Cesareans weaken gut microbiota and increase risk of allergies

More information: "Low gut microbiota diversity in early infancy precedes asthma at school age." T Abrahamsson, H Jakobsson, A F Andersson, B Björkstén, L Engstrand and M C Jenmalm. Clinical & Experimental Allergy, in print 2014. onlinelibrary.wiley.com/doi/10 … 1/cea.12253/abstract

Related Stories

Cesareans weaken gut microbiota and increase risk of allergies

August 8, 2013
Children who came into the world by Caesarean section are more often affected by allergies than those born in the natural way. The reason for this may be that they have a less diverse gut microbiota, according to a study ...

Research shows how household dogs protect against asthma and infection

December 16, 2013
Children's risk for developing allergies and asthma is reduced when they are exposed in early infancy to a dog in the household, and now researchers have discovered a reason why.

Dietary fibres protect against asthma

January 6, 2014
The Western diet probably has more to do with the asthma epidemic than has been assumed so far because developing asthma is related to the amount of fruit and vegetables consumed. Gut bacteria ferment the dietary fibres contained ...

Human immune system shapes skin microbiome

October 29, 2013
Our skin plays host to millions of beneficial and potentially disease-causing microorganisms; however, whether our immune system influences these microbial communities to prevent disease is unknown. In a study published online ...

Eczema in infants linked to gut bacteria

January 22, 2013
Children with eczema have a more diverse set of bacteria in their guts than non affected children, finds a new study in BioMed Central's open access journal BMC Microbiology. The types of bacteria present were also more typical ...

Recommended for you

Immune cells may be key to better allergy, infection therapies

July 28, 2017
By learning how a recently discovered immune cell works in the body, researchers hope to one day harness the cells to better treat allergies and infections, according to new Cornell research.

Team finds link between backup immune defense, mutation seen in Crohn's disease

July 27, 2017
Genes that regulate a cellular recycling system called autophagy are commonly mutated in Crohn's disease patients, though the link between biological housekeeping and inflammatory bowel disease remained a mystery. Now, researchers ...

Co-infection with two common gut pathogens worsens malnutrition in mice

July 27, 2017
Two gut pathogens commonly found in malnourished children combine to worsen malnutrition and impair growth in laboratory mice, according to new research published in PLOS Pathogens.

Study sheds light on how body may detect early signs of cancer

July 26, 2017
Fresh insights into how cells detect damage to their DNA - a hallmark of cancer - could help explain how the body keeps disease in check.

How genetically engineered viruses develop into effective vaccines

July 26, 2017
Lentiviral vectors are virus particles that can be used as a vaccine to stimulate the immune system to fight against specific pathogens. The vectors are derived from HIV, rendered non-pathogenic, and then engineered to carry ...

Accounting for human immune diversity increases clinical relevance of fundamental immunological research

July 26, 2017
Mouse models have advanced our understanding of immune function and disease in many ways but they have failed to account for the natural diversity in human immune responses. As a result, insights gained in the lab may be ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.