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Antibiotics have always been a concern to mankind, due to its prolonged effects on humans, or either its war with microbial resistance. Many researchers have been studying for years to understand the effects on antibiotics and one such group in University of Toronto and The Hospital for Sick Children have seen some findings with respect to breast milk microbiota in preterm infants (babies born before 37th week of pregnancy).

Microbiota is a very essential part for the baby's immunity, metabolism and growth. The researchers there observed shocking findings, that antibiotics change the microbiota, its diversity and abundance in breast milk, even if exposed for a short period of time. Antibiotics have been taken by about 60% of preterm mothers on a regular basis for various cases of mastitis, blood infections and early rupture of membranes, showing its importance upon overuse.

Deborah O'Connor, professor and chair of nutritional sciences at U of T and senior associate scientist at SickKids added to this by stating the message is antibiotics are often an essential treatment for mothers of preterm infants, clinicians and patients should be wise in their use.

They carried out this experiment by observing 490 breast milk samples from about 86 mothers of preterm children (during the first 8 weeks after delivery). The effects of antibiotics were more striking and lasted for weeks, even though the body mass index of the mother and the mode of delivery affected the microbiota too.

The antibiotics played a key role in effecting the main microbes in gut health and metabolic processes where there was a decrease in these metabolic pathways that help in babies growth and development. There was also an increase in more pathogenic bacteria pathways over time. The main author of the paper Michelle Asbury, a doctoral student in O'Connor's lab also stated that there was some link between antibiotics and Pseudomonas (from phylum Proteobacteria). When there is an increase in Proteobacteria in preterm infants they can lead to a disease where bacteria invades the intestine and causes local inflammation and infection that destroys the bowel called necrotizing enterocolitis and about 7% of infants succumb to this disease. There are also findings that say that the class of antibiotics called cephalosporins have an affect on the diversity of the breast milk microbiota.

The future study will check whether the changes in the mothers milk microbiome are imposing actually any risk on the infant’s gut health, by comparing their finding with stool samples from the preterm infants of the study. Even though Sharon Unger is a co-author on the study and a professor of paediatrics at U of T, as well as a scientist and neonatologist at Sinai Health and SickKids states that the breastfeeding might overweigh the effects of the modified diversity of microbiota, it's important to try to narrow down the spectrum of antibiotics, and its exposure duration and also to improve it with quicker diagnosis of infection and better treatments to avoid more antibiotic exposure.

It is very important mothers keep a track of what medication they are taking and what is necessary for their and the babies health.

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