The gut resistome in infancy: A systematic review

Abstract

The infant gut microbiome alongside the resistome play central roles in infants' health, with the composition of the microbiome strongly influencing the resistome, emphasizing the crucial interplay between microbial ecology and antimicrobial resistance. The neonatal resistome, the collection of ARG encoded by the gut microbiota, is influenced and derived from maternal and environmental origins. Recognition of these influences is crucial as they may impact maturation and cause dysbiotic states of the gut microbiome and resistome in infants. This study aims to review the existing literature on the impact of early life factors, such as antibiotics, gestational age (GA), delivery mode, feeding type, and geography, on how they influence and shape the infant gut resistome.

In our review, we collected evidence from a total of 18 metagenomics studies that reported findings on the infant resistome. The studies were conducted globally, encompassing a total of 2201 infants and 309 mothers. Our review included study designs with randomized control trials (RCTs), cohort studies, and cross-sectional studies.

Key findings indicate that the infant resistome is established mainly at birth, highly dynamic, and shaped by early life factors. Antibiotics appear to be a key driver of resistome composition, inflating the resistome burden, alongside modifiable factors such as Caesarean section (C-section), formula feeding, and low GA.

To conclude, reducing excessive antibiotic administration and promoting breastfeeding and vaginal delivery whenever possible may help limit the establishment of antimicrobial resistance during this critical neonatal period, consequently lowering the infants resistome burden.

The infant gut microbiome alongside the resistome play central roles in infants' health, with the composition of the microbiome strongly influencing the resistome, emphasizing the crucial interplay between microbial ecology and antimicrobial resistance. The neonatal resistome, the collection of ARG encoded by the gut microbiota, is influenced and derived from maternal and environmental origins. Recognition of these influences is crucial as they may impact maturation and cause dysbiotic states of the gut microbiome and resistome in infants. This study aims to review the existing literature on the impact of early life factors, such as antibiotics, gestational age (GA), delivery mode, feeding type, and geography, on how they influence and shape the infant gut resistome.

In our review, we collected evidence from a total of 18 metagenomics studies that reported findings on the infant resistome. The studies were conducted globally, encompassing a total of 2201 infants and 309 mothers. Our review included study designs with randomized control trials (RCTs), cohort studies, and cross-sectional studies.

Key findings indicate that the infant resistome is established mainly at birth, highly dynamic, and shaped by early life factors. Antibiotics appear to be a key driver of resistome composition, inflating the resistome burden, alongside modifiable factors such as Caesarean section (C-section), formula feeding, and low GA.

To conclude, reducing excessive antibiotic administration and promoting breastfeeding and vaginal delivery whenever possible may help limit the establishment of antimicrobial resistance during this critical neonatal period, consequently lowering the infants resistome burden.