How can improving our understanding about the gastrointestinal system help to improve pediatric outcomes for children with medical conditions?

Many medical conditions are associated with poorer quality of life and adverse emotional and behavioral outcomes in children. The multiple systems that children are embedded within are often disrupted during illness, altering the typical course of development, which can further exacerbate symptoms and their consequences. These potentially negative implications for child well-being can be viewed as an opportunity to enhance the psychosocial context and improve pediatric outcomes. The gut microbiome refers to the vast and diverse array of microorganisms residing in the gastrointestinal tract and their collective genomes. There is evidence that it contributes to both physical and mental health.

How is the microbiome related to physical and mental health?

Research results have indicated several associations between the microbiome and physical and mental health:

• Disruptions to the microbiome and gut development are related to a range of health conditions, including asthma, IBS, cystic fibrosis, inflammatory bowel disease, and infant colic.
• Gut microbiome composition is associated with autism.
• The instability and immaturity of the gut microbiome from infancy to adolescence means it is more vulnerable to environmental insults, such as antibiotic use, stress, and infection.

What can be concluded after systematically reviewing the available evidence on the connection between the gut microbiome and mental health in children with physical illness?

No consistent pattern emerged. The gut microbiome differences at baseline and following interventions varied across studies and depended on the physical health condition and type of analysis conducted.

• Infants with colic showed to have an atypical microbial profile, including lower levels of bifidobacterium. Intervention had no effect on measures of the whole microbiome in infants with colic or IBS, although this may be partially attributable to the shallow depth of analyses´ resolution.
• Targeted analyses of lactobacilli and/or bifidobacteria suggested that the interventions enriched these beneficial taxa, while results were mixed for E. coli.
• Findings on psychosocial functioning varied. Only about half of the captured studies showed a positive effect of intervention on measures of infant distress.