The infant microbiome and implications for central nervous system development

[Alterations in the intestinal microbiota of preterm infants with neurodevelopmental impairments: a prospective cohort study]

OBJECTIVES

To investigate the difference in intestinal microbiota between preterm infants with neurodevelopmental impairment (NDI) and those without NDI.

METHODS

In this prospective cohort study, the preterm infants who were admitted to the neonatal intensive care unit of Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from September 1, 2019 to September 30, 2021 were enrolled as subjects. According to the assessment results of Gesell Developmental Scale at the corrected gestational age of 1.5-2 years, they were divided into two groups: normal (n=115) and NDI (n=100). Fecal samples were collected one day before discharge, one day before introducing solid food, and at the corrected gestational age of 1 year. High-throughput sequencing was used to compare the composition of intestinal microbiota between groups.

RESULTS

Compared with the normal group, the NDI group had a significantly higher Shannon diversity index at the corrected gestational age of 1 year (P<0.05). The principal coordinate analysis showed a significant difference in the composition of intestinal microbiota between the two groups one day before introducing solid food and at the corrected gestational age of 1 year (P<0.05). Compared with the normal group, the NDI group had a significantly higher abundance of Bifidobacterium in the intestine at all three time points, a significantly higher abundance of Enterococcus one day before introducing solid food and at the corrected gestational age of 1 year, and a significantly lower abundance of Akkermansia one day before introducing solid food (P<0.05).

CONCLUSIONS

There are significant differences in the composition of intestinal microbiota between preterm infants with NDI and those without NDI. This study enriches the data on the characteristics of intestinal microbiota in preterm infants with NDI and provides reference for the microbiota therapy and intervention for NDI in preterm infants.

Associations between the human immune system and gut microbiome with neurodevelopment in the first 5 years of life: A systematic scoping review

The aim of this review was to map the literature assessing associations between maternal or infant immune or gut microbiome biomarkers and child neurodevelopmental outcomes within the first 5 years of life. We conducted a PRISMA-ScR compliant review of peer-reviewed, English-language journal articles. Studies reporting gut microbiome or immune system biomarkers and child neurodevelopmental outcomes prior to 5 years were eligible. Sixty-nine of 23,495 retrieved studies were included. Of these, 18 reported on the maternal immune system, 40 on the infant immune system, and 13 on the infant gut microbiome. No studies examined the maternal microbiome, and only one study examined biomarkers from both the immune system and the gut microbiome. Additionally, only one study included both maternal and infant biomarkers. Neurodevelopmental outcomes were assessed from 6 days to 5 years. Associations between biomarkers and neurodevelopmental outcomes were largely nonsignificant and small in effect size. While the immune system and gut microbiome are thought to have interactive impacts on the developing brain, there remains a paucity of published studies that report biomarkers from both systems and associations with child development outcomes. Heterogeneity of research designs and methodologies may also contribute to inconsistent findings. Future studies should integrate data across biological systems to generate novel insights into the biological underpinnings of early development.

Mortality and neurodevelopmental outcomes of infants with spontaneous intestinal perforation: a systematic review and meta-analysis

BACKGROUND

There is limited information about the mortality and neurodevelopmental outcomes of very preterm infants (<32 weeks) with spontaneous intestinal perforation (SIP).

OBJECTIVE

To explore the association between SIP and neurodevelopmental outcomes and mortality in very preterm infants.

DATA SOURCES

Medline, EMBASE, Cochrane Library, EMCARE and MedNar.

STUDY SELECTION

Databases were searched until September 2021. Studies comparing outcomes of 'SIP' versus 'no SIP or necrotising enterocolitis (NEC)' were included.

DATA EXTRACTION

Neurodevelopmental outcomes at ≥1 year corrected age were extracted as the main outcome measure. Data were pooled separately for adjusted and unadjusted ORs using the random-effects model. The evidence level was assessed using the GRADE (Grading of Recommendations, Assessments, Development and Evaluations) framework.

RESULTS

Eighteen cohort studies (13 606 infants) were included. Meta-analysis of unadjusted ORs showed that SIP was significantly associated with increased odds of mortality, cerebral palsy, composite outcome of death or disability, visual impairment and hearing impairment. However, pooling of adjusted ORs (aOR) found significant associations only for mortality (aOR (95% CI) 2.27 (2.07 to 2.49); I²: 0%; four studies (n=10 695)), severe disability (aOR (95% CI) 2.06 (1.38 to 3.08); I²: 0%; two studies (n=321)) and composite outcome of 'death or disability' (aOR (95% CI) 2.18 (1.55 to 3.06); I²: 0%; two studies (n=321)). The level of evidence was 'low' or 'very low'.

LIMITATIONS

Lack of information on aORs from many studies.

CONCLUSIONS

SIP in very preterm infants is associated with higher odds of mortality, severe disability, and death or disability.

Effect of family integrated care on physical growth and language development of premature infants: a retrospective study

BACKGROUND

Premature birth (PTB) increases the long-term risk of diseases such as hypertension, heart disease, and diabetes in adulthood. It is an independent disease with the largest global burden in terms of high mortality and lifelong negative health impacts. The purpose of this study was to analyze the physical growth and language development of premature infants (PIs) at the age of 18 months, and to explore the impact of family integrated care (FIcare) on PI.

METHODS

This study retrospectively included mothers and their PIs born in the Neonatal Pediatrics Department, Affiliated Hospital of Nantong University from January 2018 to September 2020 and hospitalized in the neonatal intensive care unit (NICU) within 24 hours after birth. The weight, head circumference, body length, and language development of each child were followed up at the age of 1, 3, 6, 12, and 18 months and recorded, and the relationship between FIcare and physical growth and language development of PIs was evaluated.

RESULTS

The development quotient (DQ) score and language development score of the FIcare group were always higher than those of the control group from 6 to 18 months, and the difference was statistically significant (P<0.05). Multiple regression analysis showed that the body length of the FIcare group participants was longer than that of control group participants. The head circumference of infants was positively correlated with gestational age, birth head circumference, and family average monthly income. The head circumference of FIcare group participants was longer than that of control group participants. The DQ score was positively correlated with gestational age, and the FIcare group participants scored higher than control group participants. Logistic regression analysis showed that early language milestone (ELM) scale score and gestational age were positively correlated with mother's education, and the score of FIcare group participants was higher than that of control group participants (P<0.05).

CONCLUSIONS

Compared with the traditional nursing model, the implementation of FIcare for the hospitalized PIs in the NICU can actively promote the physical growth and language development of infants.

The Developing Microbiome From Birth to 3 Years: The Gut-Brain Axis and Neurodevelopmental Outcomes

The volume and breadth of research on the role of the microbiome in neurodevelopmental and neuropsychiatric disorders has expanded greatly over the last decade, opening doors to new models of mechanisms of the gut-brain axis and therapeutic interventions to reduce the burden of these outcomes. Studies have highlighted the window of birth to 3 years as an especially sensitive window when interventions may be the most effective. Harnessing the powerful gut-brain axis during this critical developmental window clarifies important investigations into the microbe-human connection and the developing brain, affording opportunities to prevent rather than treat neurodevelopmental disorders and neuropsychiatric illness. In this review, we present an overview of the developing intestinal microbiome in the critical window of birth to age 3; and its prospective relationship with neurodevelopment, with particular emphasis on immunological mechanisms. Next, the role of the microbiome in neurobehavioral outcomes (such as autism, anxiety, and attention-deficit hyperactivity disorder) as well as cognitive development are described. In these sections, we highlight the importance of pairing mechanistic studies in murine models with large scale epidemiological studies that aim to clarify the typical health promoting microbiome in early life across varied populations in comparison to dysbiosis. The microbiome is an important focus in human studies because it is so readily alterable with simple interventions, and we briefly outline what is known about microbiome targeted interventions in neurodevelopmental outcomes. More novel examinations of known environmental chemicals that adversely impact neurodevelopmental outcomes and the potential role of the microbiome as a mediator or modifier are discussed. Finally, we look to the future and emphasize the need for additional research to identify populations that are sensitive to alterations in their gut microbiome and clarify how interventions might correct and optimize neurodevelopmental outcomes.