Nose-dwelling bacteria may affect a baby's first cold

A new research on the types of bacteria living in babies' noses offered clues as to why some recover quickly from their first cough or cold, while others suffer for longer.

The study, conducted by the researchers at the University Children's Hospital of Basel, suggested that babies who have a wide variety of different bacteria living in their noses tend to recover more quickly from their first respiratory virus, compared to those who have less variety and more bacteria from either the Moraxellaceae or Streptococcaceae family.

The findings of the study are published in the Journal of ERJ Open Research.

The researchers stated that their findings do not offer an immediate solution to help babies recover more quickly from coughs and colds. However, the results helped scientists understand the importance of the bacteria living in the respiratory tract, and how they influence infections and long-term conditions such as asthma.

"It is well known that different types of bacteria live in our gut. The respiratory tract is also home to a wide variety of bacteria and we are beginning to understand that the types and numbers of these bacteria, what we refer to as the microbiota, can influence our respiratory health," explained Roland P Neumann, one of the researchers of the study.

Babies often suffer with coughs, runny noses, sore throats and ear infections, and in some babies, the symptoms seem to drag on for weeks. These are usually caused by a virus such as the common cold.

Parents who took part in the study were asked to contact the researchers as soon as their babies developed symptoms of their first respiratory infection. This included more than two consecutive days when their babies were coughing, had a runny nose, signs of an ear infection or a sore throat.

Researchers took swabs from the noses of babies at that point and then took swabs again three weeks later. They then analysed the swabs by testing for the presence of respiratory viruses, such as the common cold, and for the types of numbers of different bacteria.

On average, the babies' symptoms lasted around two weeks. Babies who were free of symptoms by the time the three-week swab was taken were more likely to have a wider mixture of bacteria in their noses and a microbiota that was not dominated by bacteria from the Moraxellaceae or Streptococcaceae family.

Among babies whose symptoms lasted three weeks or longer, researchers found less variety in the types of bacteria living in the babies' noses and the microbiota were more likely to be dominated by bacteria from the Moraxellaceae or Streptococcaceae family.