Delay increased with longer durations of exposure to the antibiotics

Date:

November 28, 2017

Source:

McMaster University

Summary:

Antibiotics
administered during labour for Group B Streptococcus (GBS) affect the
development of gut bacteria in babies, according to a study. The gut bacteria
development of the infants was tested by researchers at four points over the
first 12 weeks of life, including at three days, 10 days, six weeks and 12
weeks.

Antibiotics administered
during labour for Group B Streptococcus (GBS) affect the development of
gut bacteria in babies, according to a study from McMaster University

The research showed that
babies exposed to the antibiotics for GBS during labour had a delay in the
maturation of their gut bacteria, known as microbiota. The data also showed
that this delay increased with longer durations of exposure to the antibiotics.

While the effects of
antibiotics for GBS on the gut bacteria in babies was dramatic at early time
points, they largely disappeared by 12 weeks of age.

The results were
published in the journal Scientific Reports.

“Early life
microbial colonization and succession is critically important to healthy
development, with impacts on metabolic and immunologic processes throughout
life,” said Jennifer Stearns, the study’s first author, an assistant
professor of medicine at McMaster University’s Michael G. DeGroote School of
Medicine and a scientist of the University’s Farncombe Family Digestive Health
Research Institute.

One out of every three or
four pregnant women test positive for Group B Streptococcus during routine
screening and the majority choose to receive antibiotic prophylaxis during
labour to prevent GBS transmission to their infant at birth. Infant infections
can lead to serious illness including meningitis and death in a very small
number of infants, and antibiotic treatment is an important prevention strategy.

“Our research
indicates there is a delay in the expansion of the dominant infant gut
colonizer, called Bifidobacterium, when infants are exposed to antibiotics for
GBS prevention during vaginal labour,” said Stearns.

“It’s a good sign
that bacterial groups recover by 12 weeks but it’s still unclear what these
findings mean for infant health, especially since early infancy is such an
important developmental time.”

The study utilized data
from 74 mother-infant pairs in the McMaster pilot cohort called Baby & Mi.
Participants came from low-risk populations in Hamilton and Burlington,
Ontario.

The gut bacteria
development of the infants was tested at four points over the first 12 weeks of
life, including at three days, 10 days, six weeks and 12 weeks.

The babies were healthy,
full-term, breast-fed babies predominantly born vaginally, with a small
percentage born by C-section that were also exposed to antibiotics to prevent
surgical infection. As in previous studies, babies born by C-section had
delayed expansion of the key gut colonizer compared to babies born vaginally
without exposure.

Researchers at McMaster
are using this study as a launching point for further research using the Baby
& Mi cohort.

“A larger study is
underway that will determine the long-term consequences of antibiotics
administered during labour for GBS on both microbial succession and on health
and disease risk,” said Stearns. “This will help us explore in
greater depth the influence of maternal and infant variables on the infant gut
microbiome.”

Story Source:

Materials provided by McMaster University. Note:
Content may be edited for style and length.

Journal Reference:

1.    Jennifer C. Stearns,
Julia Simioni, Elizabeth Gunn, Helen McDonald, Alison C. Holloway, Lehana
Thabane, Andrea Mousseau, Jonathan D. Schertzer, Elyanne M. Ratcliffe, Laura
Rossi, Michael G. Surette, Katherine M. Morrison, Eileen K. Hutton. Intrapartum
antibiotics for GBS prophylaxis alter colonization patterns in the early infant
gut microbiome of low risk infants. Scientific Reports, 2017; 7 (1)
DOI: 10.1038/s41598-017-16606-9