White Matter Injury in Preterm Infants: Pathogenesis and Potential Therapy From the Aspect of the Gut–Brain Axis

Effects of two-stage preterm formulas on growth, nutritional biomarkers, and neurodevelopment in preterm infants

Background

Formula-fed preterm infants require nutrient-enriched formulas with optimized protein levels to support growth and neurodevelopment. The purpose of this study was to evaluate the safety, tolerability, and effectiveness of a new liquid two-staged formula system designed to provide tailored nutrition during hospital stay and after discharge.

Methods

Male and female very-low-birth-weight preterm infants (birth weight ≤1,500 g; gestational age ≤32 weeks) were recruited from three neonatal units in Poland and Slovakia in a prospective, open-label, interventional study. Stage 1 formula providing 3.6 g intact protein/100 kcal was consumed from enrollment until reaching 1,800 g, followed by a post-discharge (PD) Stage 2 formula with 2.8 g/100 kcal protein, which was consumed for 30 days. Weight gain velocity (WGV in g/kg/day) between the first day of achieving full enteral feeding (FEF D1 rate of 150 ml/kg/day and cessation of parenteral feeding) and day reaching 1,800 g was compared to the minimally required WGV (15 g/kg/day) for non-inferiority (primary endpoint), and to the Fenton median growth rate for superiority (17.3 g/kg/day), adjusting for sex, gestational age, site, visit, and WGV. Changes in z-scores, feeding tolerance, nutritional biomarker status, and safety were also assessed from FEF D1 to 30 days PD. In an observational follow-up at 2 years of age, neurodevelopment was evaluated using the Bayley Scales of Infant and Toddler Development (BSID-III).

Results

Adjusted weight gain velocity (95% CI) between the first day of full enteral feeding and day reaching 1,800 g in per protocol (PP, N = 18) was 23.0 (20.1-25.9) g/kg/day; lower limit of the 95% CIs exceeded the non-inferiority margin (15 g/kg/day, p < 0.001) and the superiority margin (17.3 g/kg/day, p < 0.001). Mean stool frequency ranged from 2.5 to 3.3 stools per day. The two-stage formula supported adequate growth patterns throughout the study and nutritional biomarkers of protein and mineral status were within normal ranges. At 24 months corrected age, the mean ± SD of the BSID cognitive scale was 97.3 ± 13.9 in PP, with all infants achieving a score >70. None of the adverse events reported were related to the study formulas.

Conclusion

The two-stage preterm formulas supported postnatal weight gain, adequate growth, cognitive development within normal ranges, and a safe profile of protein and bone biomarkers.

Clinical Trial Registration

Clinicaltrials.gov registration, NCT03728764, NCT04962035.

Potential Role of Endoplasmic Reticulum Stress in Modulating Protein Homeostasis in Oligodendrocytes to Improve White Matter Injury in Preterm Infants

Preterm white matter injury (WMI) is a demyelinating disease with high incidence and mortality in premature infants. Oligodendrocyte cells (OLs) are a specialized glial cell that produces myelin proteins and adheres to the axons providing energy and metabolic support which susceptible to endoplasmic reticulum protein quality control. Disruption of cellular protein homeostasis led to OLs dysfunction and cell death, immediately, the unfolded protein response (UPR) activated to attempt to restore the protein homeostasis via IRE1/XBP1s, PERK/eIF2α and ATF6 pathway that reduced protein translation, strengthen protein-folding capacity, and degraded unfolding/misfolded protein. Moreover, recent works have revealed the conspicuousness function of ER signaling pathways in regulating influenced factors such as calcium homeostasis, mitochondrial reactive oxygen generation, and autophagy activation to regulate protein hemostasis and improve the myelination function of OLs. Each of the regulation modes and their corresponding molecular mechanisms provides unique opportunities and distinct perspectives to obtain a deep understanding of different actions of ER stress in maintaining OLs' health and function. Therefore, our review focuses on summarizing the current understanding of ER stress on OLs' protein homeostasis micro-environment in myelination during white matter development, as well as the pathophysiology of WMI, and discussing the further potential experimental therapeutics targeting these factors that restore the function of the UPR in OLs myelination function.

A Multiplanar Radiomics Model Based on Cranial Ultrasound to Predict the White Matter Injury in Premature Infants and an Analysis of its Correlation With Neurodevelopment

OBJECTIVES

To develop and evaluate a multiplanar radiomics model based on cranial ultrasound (CUS) to predict white matter injury (WMI) in premature infants and explore its correlation with neurodevelopment.

METHODS

We retrospectively reviewed 267 premature infants. The radiomics features were extracted from five standard sections of CUS. The Spearman's correlation coefficient combined with the least absolute shrinkage and selection operator (LASSO) was applied to select features and build radiomics signature, and a multiplanar radiomics model was constructed based on the radiomics signature of five planes. The performance of the model was evaluated using the area under the receiver operating characteristic curve (AUC). Infants with WMI were re-examined by ultrasound at 2 and 4 weeks after birth, and the recovery degree of WMI was evaluated using multiplanar radiomics. The relationship between WMI and the recovery degree and neurodevelopment was analyzed.

RESULTS

The AUC of the multiplanar radiomics in the training and validation sets were 0.94 and 0.91, respectively. The neurodevelopmental function scores in infants with WMI were significantly lower than those in healthy preterm infants and full-term newborns (P < .001). There were statistically significant differences in the neurodevelopmental function scores of infants between the 2- and 4-week lesion disappearance and 4-week lesion persistence (P < .001).

CONCLUSIONS

The multiplanar radiomics model showed a good performance in predicting the WMI of premature infants. It can not only provide objective and accurate results but also dynamically monitor the degree of recovery of WMI to predict the prognosis of premature infants.

Targeting the gut-microbiota-brain axis in irritable bowel disease to improve cognitive function - recent knowledge and emerging therapeutic opportunities

The brain-gut axis forms a bidirectional communication system between the gastrointestinal (GI) tract and cognitive brain areas. Disturbances to this system in disease states such as inflammatory bowel disease have consequences for neuronal activity and subsequent cognitive function. The gut-microbiota-brain axis refers to the communication between gut-resident bacteria and the brain. This circuits exists to detect gut microorganisms and relay information to specific areas of the central nervous system (CNS) that in turn, regulate gut physiology. Changes in both the stability and diversity of the gut microbiota have been implicated in several neuronal disorders, including depression, autism spectrum disorder Parkinson's disease, Alzheimer's disease and multiple sclerosis. Correcting this imbalance with medicinal herbs, the metabolic products of dysregulated bacteria and probiotics have shown hope for the treatment of these neuronal disorders. In this review, we focus on recent advances in our understanding of the intricate connections between the gut-microbiota and the brain. We discuss the contribution of gut microbiota to neuronal disorders and the tangible links between diseases of the GI tract with cognitive function and behaviour. In this regard, we focus on irritable bowel syndrome (IBS) given its strong links to brain function and anxiety disorders. This adds to the growing body of evidence supporting targeted therapeutic strategies to modulate the gut microbiota for the treatment of brain/mental-health-related disease.

Early-life gut microbiota and neurodevelopment in preterm infants: a narrative review

Infants born preterm are at a high risk of both gut microbiota (GM) dysbiosis and neurodevelopmental impairment. While the link between early dysbiosis and short-term clinical outcomes is well established, the relationship with long-term infant health has only recently gained interest. Notably, there is a significant overlap in the developmental windows of GM and the nervous system in early life. The connection between GM and neurodevelopment was first described in animal models, but over the last decade a growing body of research has also identified GM features as one of the potential mediators for human neurodevelopmental and neuropsychiatric disorders. In this narrative review, we provide an overview of the developing GM in early life and its prospective relationship with neurodevelopment, with a focus on preterm infants. Animal models have provided evidence for emerging pathways linking early-life GM with brain development. Furthermore, a relationship between both dynamic patterns and static features of the GM during preterm infants' early life and brain maturation, as well as neurodevelopmental outcomes in early childhood, was documented. Future human studies in larger cohorts, integrated with studies on animal models, may provide additional evidence and help to identify predictive biomarkers and potential therapeutic targets for healthy neurodevelopment in preterm infants.

The influence of nutrition on white matter development in preterm infants: a scoping review

White matter (WM) injury is the most common type of brain injury in preterm infants and is associated with impaired neurodevelopmental outcome (NDO). Currently, there are no treatments for WM injury, but optimal nutrition during early preterm life may support WM development. The main aim of this scoping review was to assess the influence of early postnatal nutrition on WM development in preterm infants. Searches were performed in PubMed, EMBASE, and COCHRANE on September 2022. Inclusion criteria were assessment of preterm infants, nutritional intake before 1 month corrected age, and WM outcome. Methods were congruent with the PRISMA-ScR checklist. Thirty-two articles were included. Negative associations were found between longer parenteral feeding duration and WM development, although likely confounded by illness. Positive associations between macronutrient, energy, and human milk intake and WM development were common, especially when fed enterally. Results on fatty acid and glutamine supplementation remained inconclusive. Significant associations were most often detected at the microstructural level using diffusion magnetic resonance imaging. Optimizing postnatal nutrition can positively influence WM development and subsequent NDO in preterm infants, but more controlled intervention studies using quantitative neuroimaging are needed. IMPACT: White matter brain injury is common in preterm infants and associated with impaired neurodevelopmental outcome. Optimizing postnatal nutrition can positively influence white matter development and subsequent neurodevelopmental outcome in preterm infants. More studies are needed, using quantitative neuroimaging techniques and interventional designs controlling for confounders, to define optimal nutritional intakes in preterm infants.

Association of Brain Microstructure and Functional Connectivity With Cognitive Outcomes and Postnatal Growth Among Early School-Aged Children Born With Extremely Low Birth Weight

Importance

Postnatal growth may be associated with longitudinal brain development in children born preterm.

Objective

To compare brain microstructure and functional connectivity strength with cognitive outcomes in association with postnatal growth among early school-aged children born preterm with extremely low birth weight.

Design, Setting, and Participants

This single-center cohort study prospectively enrolled 38 children 6 to 8 years of age born preterm with extremely low birth weight: 21 with postnatal growth failure (PGF) and 17 without PGF. Children were enrolled, past records were retrospectively reviewed, and imaging data and cognitive assessments occurred from April 29, 2013, through February 14, 2017. Image processing and statistical analyses were conducted through November 2021.

Exposure

Postnatal growth failure in the early neonatal period.

Main Outcomes and Measures

Diffusion tensor images and resting-state functional magnetic resonance images were analyzed. Cognitive skills were tested using the Wechsler Intelligence Scale; executive function was assessed based on a composite score calculated from the synthetic composite of the Children's Color Trails Test, STROOP Color and Word Test, and Wisconsin Card Sorting Test; attention function was evaluated using the Advanced Test of Attention (ATA); and the Hollingshead Four Factor Index of Social Status-Child was estimated.

Results

Twenty-one children born preterm with PGF (14 girls [66.7%]), 17 children born preterm without PGF (6 girls [35.3%]), and 44 children born full term (24 girls [54.5%]) were recruited. Attention function was less favorable in children with PGF than those without PGF (mean [SD] ATA score: children with PGF, 63.5 [9.4]; children without PGF, 55.7 [8.0]; P = .008). Significantly lower mean (SD) fractional anisotropy in the forceps major of the corpus callosum (0.498 [0.067] vs 0.558 [0.044] vs 0.570 [0.038]) and higher mean (SD) mean diffusivity in the left superior longitudinal fasciculus-parietal bundle (8.312 [0.318] vs 7.902 [0.455] vs 8.083 [0.393]; originally calculated as millimeter squared per second and rescaled 10 000 times as mean diffusivity × 10 000) were seen among children with PGF compared with children without PGF and controls, respectively. Decreased resting-state functional connectivity strength was observed in the children with PGF. The mean diffusivity of the forceps major of the corpus callosum significantly correlated with the attention measures (r = 0.225; P = .047). Functional connectivity strength between the left superior lateral occipital cortex and both superior parietal lobules correlated with cognitive outcomes of intelligence (right superior parietal lobule, r = 0.262; P = .02; and left superior parietal lobule, r = 0.286; P = .01) and executive function (right superior parietal lobule, r = 0.367; P = .002; and left superior parietal lobule, r = 0.324; P = .007). The ATA score was positively correlated with functional connectivity strength between the precuneus and anterior division of the cingulate gyrus (r = 0.225; P = .048); however, it was negatively correlated with functional connectivity strength between the posterior cingulate gyrus and both superior parietal lobules (the right superior parietal lobule [r = -0.269; P = .02] and the left superior parietal lobule [r = -0.338; P = .002]).

Conclusions and Relevance

This cohort study suggests that the forceps major of the corpus callosum and the superior parietal lobule were vulnerable regions in preterm infants. Preterm birth and suboptimal postnatal growth could have negative associations with brain maturation, including altered microstructure and functional connectivity. Postnatal growth may be associated with differences in long-term neurodevelopment among children born preterm.

Nutrition and Immunity in Perinatal Hypoxic-Ischemic Injury

Perinatal hypoxia ischaemia (PHI), acute and chronic, may be associated with considerable adverse outcomes in the foetus and neonate. The molecular and cellular mechanisms of injury and repair associated with PHI in the perinate are not completely understood. Increasing evidence is mounting for the role of nutrients and bioactive food components in immune development, function and repair in PHI. In this review, we explore current concepts around the neonatal immune response to PHI with a specific emphasis on the impact of nutrition in the mother, foetus and neonate.