Bacterial Gut Microbiota and Infections During Early Childhood

Abstract

Gut microbiota composition during the first years of life is variable, dynamic and influenced by both prenatal and postnatal factors, such as maternal antibiotics administered during labor, delivery mode, maternal diet, breastfeeding, and/or antibiotic consumption during infancy. Furthermore, the microbiota displays bidirectional interactions with infectious agents, either through direct microbiota-microorganism interactions or indirectly through various stimuli of the host immune system. Here we review these interactions during childhood until 5 years of life, focusing on bacterial microbiota, the most common gastrointestinal and respiratory infections and two well characterized gastrointestinal diseases related to dysbiosis (necrotizing enterocolitis and Clostridioides difficile infection). To date, most peer-reviewed studies on the bacterial microbiota in childhood have been cross-sectional and have reported patterns of gut dysbiosis during infections as compared to healthy controls; prospective studies suggest that most children progressively return to a “healthy microbiota status” following infection. Animal models and/or studies focusing on specific preventive and therapeutic interventions, such as probiotic administration and fecal transplantation, support the role of the bacterial gut microbiota in modulating both enteric and respiratory infections. A more in depth understanding of the mechanisms involved in the establishment and maintenance of the early bacterial microbiota, focusing on specific components of the microbiota-immunity-infectious agent axis is necessary in order to better define potential preventive or therapeutic tools against significant infections in children.

Epidemiology, Clinical Features, and Unusual Complications of Norovirus Infection in Taiwan: What We Know after Rotavirus Vaccines

“…The gut microbiota composition during infancy or early childhood is variable, dynamic, and influenced by both prenatal and postnatal factors [80]. Many studies have shown that intestinal viral infections may be associated with severe illness such as hemorrhagic enteritis and even necrotizing enterocolitis (NEC) [17,18,81,82].…”

“…Although studies mentioned previously indicated an episodic association of enteric viruses in NEC, one study by Skeath et al [83] in 2016 for 17 NEC infants without detection of any related viruses may suggest that viral etiology is unlikely to be causative for most sporadic forms of NEC. Understanding of the mechanisms in microbiota-immunity-infectious agent axis is necessary to define potential preventive or therapeutic tools against significant infections in children [80].…”

The impact of mass drug administration of antibiotics on the gut microbiota of target populations

“…and pro-inflammatory microbiome metabolic pathways may partly explain the sustained reductions in child mortality due to diarrhea and dysentery observed in those settings [ 111 – 113 ]. Gut microbiota composition is associated with both increased and reduced severity of enteric infections [ 114 ]. Limited evidence suggest that better or worse enteric infection outcomes may vary by microbiota composition and pathogen [ 114 ].…”

“…Gut microbiota composition is associated with both increased and reduced severity of enteric infections [ 114 ]. Limited evidence suggest that better or worse enteric infection outcomes may vary by microbiota composition and pathogen [ 114 ]. For example, mixed diarrheagenic E. coli and viral infections in children were associated with increased Bifidobacterium spp.…”

The PRObiotics in Pediatric Asthma Management (PROPAM) study: A post hoc analysis in preschoolers

“…4 In addition, it has been postulated that intestinal and respiratory dysbiosis has a role in respiratory infections and airway obstruction. 5,6 Dysbiosis can promote inflammatory pathways and impair immune defense against pathogens. 7 Probiotics are "live microorganisms which confer a beneficial effect on the host."…”