New Delhi, April 5 : Babies treated with antibiotics in the first few weeks of their life are likely to show weaker immune responses to essential vaccines taken in childhood, according to a study.

Researchers from Flinders University in Australia explained that this is due to a decrease in the levels of Bifidobacterium -- a bacterial species that lives in the human gastrointestinal tract.

On the other hand, replenishing Bifidobacterium in the gut microbiome using probiotic supplements such as Infloran showed promising results in restoring the immune response, revealed the study published in the journal Nature.

'Our data suggest that microbiota-targeted interventions could mitigate the detrimental effects of early-life antibiotics on vaccine immunogenicity,' David J. Lynn from the Flinders Health and Medical Research Institute, at the varsity.

For the study, the team followed 191 healthy, vaginally born infants from their birth to 15 months. Of these 86 per cent infants received the hepatitis B vaccine at birth, and, by six weeks of age, began their routine childhood vaccinations.

Analysed of blood and stool samples revealed that children who were directly exposed to neonatal antibiotics, produced much lower levels of antibodies against multiple polysaccharides included in the 13-valent pneumococcal conjugate vaccine or PCV13 vaccine.

The PCV13 vaccine is taken to boost the immune system to fight Streptococcus pneumoniae -- a bacteria known for causing serious diseases like pneumonia, blood infections, and meningitis.

PCV13 vaccine produces antibodies by linking the polysaccharide capsule layer to proteins.

Exposure to neonatal antibiotics reduces antibody production against such polysaccharides, weakening the immune response, found the study.

Experiments on germ-free mice revealed that the lower immune response was linked to a reduced abundance of Bifidobacterium in the gut microbiome.

However, giving the mice a mix of Bifidobacterium species or Infloran, a commonly used infant probiotic, helped reverse the negative effects of antibiotics and regain the immune response to PCV13.

'Our results, which add to the findings of several important previous studies, indicate that immune responses to certain types of vaccine, particularly protein-polysaccharide conjugate vaccines such as PCV13, may be more dependent on signals from the gut microbiota than others,' the team said in the study. "Administering probiotics to infants exposed to neonatal antibiotics may be a feasible, cheap, and safe intervention to enhance responses to vaccination,' they added.

/IANS