Intestinal dysbiosis in preterm infants preceding necrotizing enterocolitis: a systematic review and meta-analysis

Digging deeper into necrotizing enterocolitis: bridging clinical, microbial, and molecular perspectives

Necrotizing Enterocolitis (NEC) is a severe, life-threatening inflammatory condition of the gastrointestinal tract, especially affecting preterm infants. This review consolidates evidence from various biomedical disciplines to elucidate the complex pathogenesis of NEC, integrating insights from clinical, microbial, and molecular perspectives. It emphasizes the modulation of NEC-associated inflammatory pathways by probiotics and novel biologics, highlighting their therapeutic potential. We further critically examine dysbiotic alterations within the gut microbiota, with a particular focus on imbalances in bacterial and viral communities, which may contribute to the onset of NEC. The intricate interactions among toll-like receptor 4 (TLR4), microvascular integrity, immune activation, and the inflammatory milieu are meticulously summarized, offering a sophisticated understanding of NEC pathophysiology. This academic review aims to enhance the etiological comprehension of NEC, promote the development of targeted therapeutic interventions, and impart the significant impact of perinatal factors on the formulation of preventive and curative strategies for the disease.

Goat milk oligosaccharides: regulating infant immunity by intervention in the gut microbiota

The health status of the growing infant is closely related to the development of the gut microbiota during infancy, which is also a major stimulator of the immune system. Goat milk oligosaccharides (gMOs) are a class of bioactive compounds in goat milk, which have attracted extensive research interest in recent years. Recent studies have highlighted that gMOs as prebiotics can regulate the gut microbiota, exhibit multiple health effects, and act as immunomodulators. This article outlines the structure, classification, and functions of gMOs. In addition, we also deeply explored the mechanism of gMO interaction with infant gut microbiota and regulation of infant immunity. Finally, the possibility of gMOs as an effective substitute for natural prebiotics in breast milk is revisited. We concluded that gMOs improve infant immune function by regulating intestinal beneficial bacteria (Bifidobacteria, Lactobacilli, etc.) and their metabolism. Therefore, gMOs are significant to infant immune health and are expected to become a substitute for human milk oligosaccharides (HMOs).

Neonatal microbiome in the multiomics era: development and its impact on long-term health

The neonatal microbiome has been the focus of considerable research over the past two decades and studies have added fascinating information in terms of early microbial patterns and how these relate to various disease processes. One difficulty with the interpretation of these relationships is that such data is associative and provides little in terms of proof of causality or the underpinning mechanisms. Integrating microbiome data with other omics such as the proteome, inflammatory mediators, and the metabolome is an emerging approach to address this gap. Here we discuss these omics, their integration, and how they can be applied to improve our understanding, treatment, and prevention of disease. IMPACT: This review introduces the concept of multiomics in neonatology and how emerging technologies can be integrated improve understanding, treatment, and prevention of disease. We highlight considerations for performing multiomic research in neonates and the need for validation in separate cohorts and/or relevant model systems. We summarise how the use of multiomics is expanding and lay out steps to bring this to the clinic to enable precision medicine.

The Impact of Storage Conditions on Stool Smellprints as Assessed by an Electronic Nose

Necrotizing enterocolitis (NEC) is a devastating disease of the neonatal gastrointestinal tract. Volatile organic compounds (VOCs), odoriferous compounds released as a byproduct of bacterial metabolism, can be used as a proxy for gut health. We hypothesized that patients with NEC would have different microbial profiles and elicit different VOC signatures as assessed by gas chromatography/mass spectrometry (GC/MS) or an electronic nose compared to controls. Furthermore, we hypothesized that the temperature of sample storage and the length of time in storage would impact the VOC signatures. Forty-five human stool samples were obtained from Neonatal Intensive Care Units. They were stored at -80 °C as part of the Necrotizing Enterocolitis Biorepository. The microbiome composition was determined by 16S-rRNA gene sequencing and VOC profiles were obtained with GC-MS and by analysis with the Cyranose 320 electronic nose. In separate experiments, fresh stool samples were collected from three different strains of mice. Samples were stored for different times and different temperatures, and VOC signals were compared. A p-value less than 0.05 was considered significant. 16S-rRNA sequencing found a difference in the microbiome composition (p = 0.025) between human NEC and control samples. There was also a difference observed between NEC and control samples identified by GC-MS (p = 0.001). However, there were no differences in VOC smellprints between NEC and controls when analyzed with an electronic nose. When mouse specimens were analyzed, principal component values changed significantly over time and with different storage temperatures. NEC is associated with a different gut microbiome and the VOC profile compared to age-matched controls. However, this difference was not appreciated when biobanked stool samples were compared via an electronic nose. Older samples may experience VOC decay, or the electronic nose may not be sensitive enough to detect NEC in stool samples. Further studies on fresh human stool samples are needed, but the findings herein may limit the use of electronic noses as diagnostic tools for NEC.

Effect of early antibiotic exposure on necrotizing enterocolitis and growth in extremely preterm infants

BACKGROUND

The relationship between early antibiotic exposure, necrotizing enterocolitis (NEC), and growth faltering (GF) in extremely preterm infants is unknown.

METHODS

We evaluated the association between peripartum and postnatal antibiotic exposure in the first week after birth with NEC and GF in this secondary analysis of Preterm Erythropoietin Neuroprotection Trial subjects. NEC was defined as Bell's stage ≥ IIA; GF was defined as decreased weight, length, or head circumference (HC) z-score from birth to discharge of < -0.8. Multivariable analyses were adjusted with maternal and infant factors.

RESULTS

A total of 891 infants survived the first week and were included in the NEC analyses, while 828 infants survived to discharge and were included in the growth analyses. For every 1-day increase in infant antibiotic exposure during the first week after birth, there was a significantly increased adjusted hazard of NEC (aHR/day 1.14 [1.01-1.28], p = 0.034). Antibiotics for 3-4 days and 5-7 days total in the first week were associated with increased odds of weight GF (aOR 1.90 [1.21-2.99], aOR 2.32 [1.44-3.74]), length GF (aOR 1.76 [1.22-2.59], aOR 1.88 [1.26-2.80]), and HC GF (aOR 1.75 [1.08-2.84], aOR 1.87 [1.14-3.08]).

CONCLUSION

Increased antibiotic exposure in the first week after birth was associated with NEC and GF risk.

IMPACT

In this post-hoc analysis of a large multi-site trial, we found infant antibiotic exposure in the first week after birth was associated with an increased hazard of necrotizing enterocolitis in the extremely preterm infant after adjusting for maternal and infant factors. First week antibiotic exposure in the extremely preterm infant was associated with an increased odds of weight, linear, and head circumference growth faltering after adjusting for maternal and infant factors. These findings encourage the judicious use of early antibiotics in extremely preterm infants.

Association of Placental Pathology and antibiotic exposure after birth with the Severity of Necrotizing Enterocolitis in Preterm infants - A Matched Case-Control Study

Objective

To determine the association between antibiotic exposure following birth and necrotizing enterocolitis (NEC) severity in preterm infants.

Methods

This single center matched case-control study included infants with NEC (n=107) and matched controls (n= 130) with antibiotic exposure =< 3 days and > 3 days after birth.

Results

Out of 212 infants,103 infants (48.5%) received antibiotics =< 3 days, and 109 infants (51.5%) received antibiotics >3 days. On the multivariate regression, Infants receiving antibiotics for >3 day had higher risk for medical NEC (aOR 2.61,95% CI 1.35 -5.16; p=0.005) and surgical NEC (aOR 3.33, CI 1.57-7.40; p=0.02) than controls. In NEC cohort, those receiving antibiotics for >3 days were like to die (OR 7.88,95% CI 1.99- 53.74; p=0.010) than those receiving antibiotics <3 days.

Conclusion

Infants exposed with early antibiotics >3 days after birth were more likely associated with NEC and were at greater risk of death.

Applications of Metabolomics and Lipidomics in the Neonatal Intensive Care Unit

The metabolome and lipidome comprise the thousands of molecular compounds in an organism. Molecular compounds consist of the upstream metabolic components of intracellular reactions or the byproducts of cellular pathways. Molecular and biochemical perturbations are associated with disorders in newborns and infants. The diagnosis of inborn errors of metabolism has relied on targeted metabolomics for several decades. Newer approaches offer the potential to identify novel biomarkers for common diseases of the newborn and infant. They may also elucidate novel predictive or diagnostic measures for a variety of health trajectories. Here, we review the relevance of the metabolome and lipidome for common disorders and highlight challenges and opportunities for future investigations.

Oxygenation and intestinal perfusion and its association with perturbations of the early life gut microbiota composition of children with congenital heart disease

Background

Early life gut microbiota is known to shape the immune system and has a crucial role in immune homeostasis. Only little is known about composition and dynamics of the intestinal microbiota in infants with congenital heart disease (CHD) and potential influencing factors.

Methods

We evaluated the intestinal microbial composition of neonates with CHD (n = 13) compared to healthy controls (HC, n = 30). Fecal samples were analyzed by shotgun metagenomics. Different approaches of statistical modeling were applied to assess the impact of influencing factors on variation in species composition. Unsupervised hierarchical clustering of the microbial composition of neonates with CHD was used to detect associations of distinct clusters with intestinal tissue oxygenation and perfusion parameters, obtained by the "oxygen to see" (O2C) method.

Results

Overall, neonates with CHD showed an intestinal core microbiota dominated by the genera Enterococcus (27%) and Staphylococcus (20%). Furthermore, a lower abundance of the genera Bacteroides (8% vs. 14%), Parabacteroides (1% vs. 3%), Bifidobacterium (4% vs. 12%), and Escherichia (8% vs. 23%) was observed in CHD compared to HCs. CHD patients that were born by vaginal delivery showed a lower fraction of the genera Bacteroides (15% vs. 21%) and Bifidobacterium (7% vs. 22%) compared to HCs and in those born by cesarean section, these genera were not found at all. In infants with CHD, we found a significant impact of oxygen saturation (SpO2) on relative abundances of the intestinal core microbiota by multivariate analysis of variance (F[8,2] = 24.9, p = 0.04). Statistical modeling suggested a large proportional shift from a microbiota dominated by the genus Streptococcus (50%) in conditions with low SpO2 towards the genus Enterococcus (61%) in conditions with high SpO2. We identified three distinct compositional microbial clusters, corresponding neonates differed significantly in intestinal blood flow and global gut perfusion.

Conclusion

Early life differences in gut microbiota of CHD neonates versus HCs are possibly linked to oxygen levels. Delivery method may affect microbiota stability. However, further studies are needed to assess the effect of potential interventions including probiotics or fecal transplants on early life microbiota perturbations in neonates with CHD.

Dietary supplementation with proanthocyanidins and rutin alleviates the symptoms of type 2 diabetes mice and regulates gut microbiota

Background

Obesity and high fasting blood glucose (FBG) resulting from high-fat diets (HFDs) have emerged as significant public health concerns, garnering increasing attention. Recently, gut microbiota has been linked with metabolic diseases such as type 2 diabetes (T2DM), and its mediating role in dietary supplements has been confirmed. Seeking various dietary supplements to lose body weight (BW) and decrease FBG and explaining the underlying mechanism have become the research hotspots in T2DM studies.

Methods

In this study, rutin and proanthocyanidins (PA) were selected as dietary supplements (200 mg/kg × day, oral gavage, 6 weeks) in T2DM mice induced with HFD to assess their efficacy in weight loss, FBG reduction, gut microbiota alterations, and the associated underlying mechanisms.

Results

Our findings indicate that rutin was more effective than PA in relieving inflammation and fat hypertrophy, although both significantly reduced BW and FBG within 2 weeks after the intervention. Analysis of 16S rRNA amplicons revealed substantial alterations in the gut microbial community composition of mice administered with PA and rutin compared to HFD-fed mice. Importantly, several core microbes, particularly a series of probiotics, such as Akkermansia, Lactococcus, Odoribacter, Faecalibaculum, and Roseburia were identified, which were significantly correlated with the changes in BW and FBG.

Conclusion

Overall, our study highlights that rutin and PA can reduce BW, FBG, and inflammation by modulating the gut microbiota composition, providing novel perspectives for managing and treating weight and FBG concerns in obesity and T2DM patients through dietary supplements in clinical treatment.

Efficacy of melatonin for treatment and prevention of neonatal necrotizing enterocolitis: a systematic review

The purpose of this study was to systematically review the available literature evaluating the use of melatonin for preventing and treating neonatal necrotizing enterocolitis (NEC). A systematic review of studies examining the effect of melatonin on neonatal NEC was conducted. The databases of Medline, Scopus, WOS, Embase, and Cochrane Central Register of Controlled Trials were searched for relevant studies. For risk of bias and applicability, The ROB2 tool was used for randomized controlled trials, and the ROBINS-I tool was used for non-randomized controlled trials. Three studies, comprising 106 preterm neonates, were included in the review, whose mean gestational ages ranged from 31.8 to 33.53 weeks. Melatonin doses varied among the studies. A randomized, double-blind, placebo-controlled study revealed that early administration of melatonin in preterm newborns resulted in a decrease in lipid peroxidation during the initial days of life. Two studies evaluated the role of melatonin in NEC. Both reported significant clinical and laboratory improvements in the melatonin groups, including reduced abdominal distension, metabolic acidosis, thrombocytopenia, hyponatremia, and lower mortality rates compared to control groups. This systematic review suggests that melatonin may be a potential therapeutic approach for NEC in preterm infants. However, further RCTS are needed to establish its therapeutic or preventive role.

Effect of probiotic supplementation on the gut microbiota in very preterm infants: a systematic review

OBJECTIVE

There is increasing evidence that probiotic supplementation in very preterm infants decreases the risk of necrotising enterocolitis (NEC), sepsis and mortality. The underlying mechanisms, including effects on the gut microbiota, are largely unknown. We aimed to systematically review the available literature on the effects of probiotic supplementation in very preterm infants on gut microbiota development.

DESIGN

A systematic review in Medline, Embase, Cochrane Library, CINAHL and Web of Science.

SETTING

Neonatal intensive care unit.

PATIENTS

Premature infants.

INTERVENTION

Probiotic supplementation.

MAIN OUTCOME MEASURES

Gut microbiota.

RESULTS

A total of 1046 articles were screened, of which 29 were included. There was a large heterogeneity in study design, dose and type of probiotic strains, timepoints of sample collection and analysing techniques. Bifidobacteria and lactobacilli were the most used probiotic strains. The effects of probiotics on alpha diversity were conflicting; however, beta diversity was significantly different between probiotic-supplemented infants and controls in the vast majority of studies. In most studies, probiotic supplementation led to increased relative abundance of the supplemented strains and decreased abundance of genera such as Clostridium, Streptococcus, Klebsiella and Escherichia.

CONCLUSIONS

Probiotic supplementation to preterm infants seems to increase the relative abundance of the supplemented strains with a concurrent decrease of potentially pathogenic species. These probiotic-induced microbial alterations may contribute to the decreased risk of health complications such as NEC. Future trials, including omics technologies to analyse both microbiota composition and function linked to health outcomes, are warranted to identify the optimal mixture and dosing of probiotic strains.

PROSPERO REGISTRATION NUMBER

CRD42023385204.

AI models in clinical neonatology: a review of modeling approaches and a consensus proposal for standardized reporting of model performance

Artificial intelligence (AI) is a rapidly advancing area with growing clinical applications in healthcare. The neonatal intensive care unit (NICU) produces large amounts of multidimensional data allowing AI and machine learning (ML) new avenues to improve early diagnosis, enhance monitoring, and provide highly-targeted treatment approaches. In this article, we review recent clinical applications of AI to important neonatal problems, including sepsis, retinopathy of prematurity, bronchopulmonary dysplasia, and others. For each clinical area, we highlight a variety of ML models published in the literature and examine the future role they may play at the bedside. While the development of these models is rapidly expanding, a fundamental understanding of model selection, development, and performance evaluation is crucial for researchers and healthcare providers alike. As AI plays an increasing role in daily practice, understanding the implications of AI design and performance will enable more effective implementation. We provide a comprehensive explanation of the AI development process and recommendations for a standardized performance metric framework. Additionally, we address critical challenges, including model generalizability, ethical considerations, and the need for rigorous performance monitoring to avoid model drift. Finally, we outline future directions, emphasizing the importance of collaborative efforts and equitable access to AI innovations.

Bifidobacterium longum subsp infantis (EVC001) is associated with reduced incidence of necrotizing enterocolitis stage ≥2 and bloody stools in premature babies

OBJECTIVE

To utilize an evidence-based probiotic protocol to achieve a 50% reduction in necrotizing enterocolitis (NEC) ≥ stage 2 and bloody stools.

STUDY DESIGN

From January 2022 through September 2023, daily enteral Bifidobacterium longum ssp. infantis EVC001 (B. infantis EVC001) was administered to babies ≤ 33 6/7 weeks gestation until 36 weeks post menstrual age. Feeding tolerance and complications were compared to babies admitted during the prior two-year period. Fisher's Exact test was used to analyze proportional data and t test was used for continuous variables.

RESULTS

A total of 265 babies received EVC001, and a total of 277 babies formed the pre-probiotic cohort. Probiotic use was associated with decreased NEC ≥ stage 2 (p = 0.0058), reduced bloody stools (p < 0.0001), decreased time to full enteral feeds (p < 0.0001), and decreased total parenteral nutrition (TPN) days (p < 0.0001).

CONCLUSION

Administration of B. infantis EVC001 was associated with a decrease in NEC, a decrease in bloody stools, and improvement in feeding tolerance in premature babies.

A weighted and cumulative point system for accurate scoring of intestinal pathology in a piglet model of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a serious condition in premature infants, in which a portion of the intestine undergoes inflammation and necrosis. The preterm pig develops NEC spontaneously, making it a suitable model for exploring novel NEC treatments. We aimed to revise the intestinal scoring system to more accurately describe the diversity of NEC lesions in the preterm piglet model. We included 333 preterm piglets from four experiments, each delivered via cesarean section. The piglets were fed either a gently processed (GP) or harshly processed (HP) milk formula for 96 h before euthanasia. At necropsy, the gastrointestinal tract was assessed with 1) an established 6-grade score and 2) a descriptive approach focusing on the distribution and severity of hyperemia, hemorrhage, pneumatosis intestinalis (intramural gas), and necrosis. Subsequently, the descriptive registrations were converted into a weighted and cumulative point (WCP) score. Compared to the 6-grade score, the WCP score enabled a greater segregation of severity levels, especially among organs with more prominent NEC lesions. IL-1β in small intestinal lesions and both IL-8 and IL-1β in colon lesions correlated positively with the WCP scale. A histopathological grade system (0-8) was established and revealed mucosal pathology in lesion biopsies, which were not recognized macroscopically. Finally, the WCP score showed a higher NEC-promoting effect of the HP formula compared to the GP formula. The descriptive registrations and extended score range of this revised intestinal scoring system enhance the accuracy of describing NEC lesions in preterm pigs. This approach may increase the efficiency of preclinical NEC experiments.

Prolonged premature rupture of membranes with increased risk of infection is associated with gut accumulation of Pseudomonas from the environment

Background

Preterm premature rupture of membranes (PPROM) contributes to over one-third of preterm births, and PPROM infants are more susceptible to infections. However, the risk factors remain poorly understood. We here aim to investigate the association of duration of premature rupture of membranes (PROM) and environmental microbiota with the gut microbiota and infection in PPROM infants.

Methods

Forty-six premature infants were recruited from two hospitals, and infant fecal and environmental samples were collected. 16 s rRNA sequencing was performed to analyze the fecal and environmental microbiome. Human inflammatory cytokines in cord vein plasma were measured.

Results

The gut microbiota composition of PPROM infants was different from that of non-PPROM infants, and the microbiome phenotypes were predicted to be associated with a higher risk of infection, further evidenced by the significantly increased levels of IL-6 and IL-8 in cord vein plasma of PPROM infants. The diversity of the gut microbiota in PPROM infants increased significantly as the duration of PROM excessed 12 h, and Pseudomonas contributed significantly to the dynamic changes. The Pseudomonas species in the gut of PPROM infants were highly homologous to those detected in the ward environment, suggesting that prolonged PROM is associated with horizontal transmission of environmental pathogens, leading to a higher risk of infection.

Conclusions

This study highlights that the duration of PROM is associated with the accumulation of environmental pathogens in the gut of PPROM infants, which is a risk factor for nosocomial infections. Improving environmental hygiene could be effective in optimizing the clinical care of PPROM infants.

Long-term changes in the gut microbiota before and after bismuth quadruple therapy or concomitant therapy in children with peptic ulcers receiving Helicobacter pylori eradication

Background

Helicobacter pylori (H. pylori) is a gram-negative spiral bacterium that can cause peptic ulcers. The effects of bismuth quadruple therapy and concomitant therapy on fecal ecology among children with peptic ulcers remain largely unknown. According to guidelines, these patients should be treated. Therefore, the aim of this study is to investigate the short- and long-term effects of bismuth quadruple therapy and concomitant therapy on gut microbiota in children with peptic ulcer disease (PUD).

Methods

Forty-two patients with PUD were enrolled and collected their fecal samples in Shanghai. A 16S ribosomal RNA (rRNA)-based analysis was conducted. The impacts of bismuth quadruple therapy and concomitant therapy on the gut microbiota were compared before eradication and at 2, 6 and 52 weeks (12 months) after eradication.

Results

Whatever bismuth quadruple therapy and concomitant therapy, the diversity and richness of gut microbiota markedly decreased and fecal microbiota structure markbly changed at week 2. At week 6, the composition a returned to the baseline level; nevertheless, the diversity and richness gradually returned to baseline until week 52. Compared to those in the healthy control group, the relative abundances of 90% (18/20) of the bacterial genera differed at week 2, 15% (3/20) of the bacterial genera differed at week 6, and 10% (2/20) of the bacterial genera were not restored at week 52.

Conclusions

Both bismuth-containing therapy and concomitant therapy resulted in transient changes of the gut microbiota in Chinese children, and these changes nearly returned to pre-eradication levels 1 year after eradication, suggesting the long-term safety of H. pylori therapy in children with peptic ulcers.

Network-Based Bioinformatics Highlights Broad Importance of Human Milk Hyaluronan

Human milk (HM) is rich in bioactive factors promoting postnatal small intestinal development and maturation of the microbiome. HM is also protective against necrotizing enterocolitis (NEC), a devastating inflammatory condition predominantly affecting preterm infants. The HM glycosaminoglycan, hyaluronan (HA), is present at high levels in colostrum and early milk. Our group has demonstrated that HA with a molecular weight of 35 kDa (HA35) promotes maturation of the murine neonatal intestine and protects against two distinct models of NEC. However, the molecular mechanisms underpinning HA35-induced changes in the developing ileum are unclear. CD-1 mouse pups were treated with HA35 or vehicle control daily, from P7 to P14, and we used network and functional analyses of bulk RNA-seq ileal transcriptomes to further characterize molecular mechanisms through which HA35 likely influences intestinal maturation. HA35-treated pups separated well by principal component analysis, and cell deconvolution revealed increases in stromal, Paneth, and mature enterocyte and progenitor cells in HA35-treated pups. Gene set enrichment and pathway analyses demonstrated upregulation in key processes related to antioxidant and growth pathways, such as nuclear factor erythroid 2-related factor-mediated oxidative stress response, hypoxia inducible factor-1 alpha, mechanistic target of rapamycin, and downregulation of apoptotic signaling. Collectively, pro-growth and differentiation signals induced by HA35 may present novel mechanisms by which this HM bioactive factor may protect against NEC.

Research focus and emerging trends of the gut microbiome and infant: a bibliometric analysis from 2004 to 2024

Background

Over the past two decades, gut microbiota has demonstrated unprecedented potential in human diseases and health. The gut microbiota in early life is crucial for later health outcomes. This study aims to reveal the knowledge collaboration network, research hotspots, and explore the emerging trends in the fields of infant and gut microbiome using bibliometric analysis.

Method

We searched the literature on infant and gut microbiome in the Web of Science Core Collection (WOSCC) database from 2004 to 2024. CiteSpace V (version: 6.3.R1) and VOSview (version: 1.6.20) were used to display the top authors, journals, institutions, countries, authors, keywords, co-cited articles, and potential trends.

Results

A total of 9,899 documents were retrieved from the Web of Science Core Collection. The United States, China, and Italy were the three most productive countries with 3,163, 1,510, and 660 publications. The University of California System was the most prolific institution (524 publications). Van Sinderen, Douwe from University College Cork of Ireland was the most impactful author. Many studies have focused on atopic dermatitis (AD), necrotizing enterocolitis (NEC), as well as the immune mechanisms and microbial treatments for these diseases, such as probiotic strains mixtures and human milk oligosaccharides (HMOs). The mother-to-infant microbiome transmission, chain fatty acids, and butyrate maybe the emerging trends.

Conclusion

This study provided an overview of the knowledge structure of infant and gut microbiome, as well as a reference for future research.

Multi-strain probiotic administration decreases necrotizing enterocolitis severity and alters the epigenetic profile in mice

BACKGROUND

Probiotic administration may decrease the incidence of necrotizing enterocolitis (NEC) through mechanisms that are largely unknown. We investigated the effects of probiotics on intestinal epigenetics and assessed their effects on intestinal inflammation and motility using both ileum-predominant and combined ileo-colitis mouse NEC models.

METHODS

C57BL/6 J mice were gavage-fed a multi-strain probiotic from postnatal days 3-11, consisting of B. infantis, B. lactis, and S. thermophilus. From p8, mice were exposed to ileo-colitis NEC involving formula containing NEC bacteria and 0.5% DSS. DNA methylation was measured using the Infinium Methylation Assay. Gastrointestinal motility was assessed by 70 Kd FITC-dextran transit time. Probiotic colonization was measured in probiotic-fed mice by qPCR.

RESULTS

Probiotic administration caused significant changes in the small intestine's epigenetic signature, a reduction in NEC severity, and improved intestinal motility. The effects of probiotics were more pronounced in the ileo-colitis NEC model.

CONCLUSIONS

These findings shed light on the role of probiotics in two clinically relevant models of NEC, add additional insights into their underlying mechanism of action, and reveal unanticipated epigenetic modifications to the intestinal mucosa after their use.

IMPACT

These findings shed light on the role of multi-strain probiotics in two clinically relevant animal models of NEC, and add additional insights into their underlying mechanism of action This study provides a new, clinically relevant model for the study of NEC including administration of 0.5% DSS, to include ileal dominant and ileo-colonic dominant phenotypes of the disease. These results reveal that clinically relevant strains of probiotic bacteria can exert epigenetic effects on the small intestine in mice, and can attenuate the epigenetic changes induced by NEC.

Lactobacillus rhamnosus modulates murine neonatal gut microbiota and inflammation caused by pathogenic Escherichia coli

BACKGROUND

Pathogenic Escherichia coli strains produce neonatal septicemia after colonizing the neonatal gut. While the probiotic Lactobacillus rhamnosus GG (LGG) effectively reduces neonatal sepsis, LGG's effects on the neonatal intestinal microbiota alterations and inflammation triggered by E. coli are incompletely understood. We hypothesized that LGG significantly modulates the specific neonatal gut microbial populations changes and the inflammatory response elicited by the enteral introduction of septicemia-producing E. coli. To test this hypothesis, newborn rats were pretreated orally with LGG or placebo prior to infection with the neonatal E. coli septicemia clinical isolate SCB34. Amplicon 16S rRNA gene sequencing was performed on intestinal samples. Intestinal injury and expression of inflammatory mediators and apoptosis were determined.

RESULTS

Alpha diversity of gut microbiota was greater in SCB34-infected pups in comparison to sham-infected pups, these changes were not modified by LGG pretreatment. Beta diversity analyses also showed differences between SCB34-infected vs. uninfected pups. LGG pretreatment before SCB34 infection did not result in significant beta diversity changes compared to placebo. Moreover, individual genera and species abundance analyses by linear discriminant analysis effect size (LEfSe) showed significant changes in Gram-negative, Gram-positive, and anaerobic populations resulting from LGG pretreatment and SCB34 infection. LGG significantly suppressed the expression of inflammatory cytokines but did not attenuate SCB34-induced apoptosis or histologic injury.

CONCLUSIONS

LGG modulates clinically significant microbiota features and inflammation triggered by pathogenic E. coli intestinal infection shortly after birth. This new knowledge can potentially be harnessed to design novel interventions against gut-derived neonatal sepsis.

Clinical and Growth Correlates of Retinopathy of Prematurity in Preterm Infants with Surgical Necrotizing Enterocolitis and Intestinal Perforation

OBJECTIVE

 This study aimed to identify the clinical and growth parameters associated with retinopathy of prematurity (ROP) in infants with necrotizing enterocolitis (NEC) and spontaneous ileal perforation (SIP).

STUDY DESIGN

 We conducted a retrospective cohort study that compared clinical data before and after NEC/SIP onset in neonates, categorizing by any ROP and severe ROP (type 1/2) status.

RESULTS

 The analysis included 109 infants with surgical NEC/SIP. Sixty infants (60/109, 55%) were diagnosed with any ROP, 32/109 (29.3%) infants (22% type 1 and 7.3% type 2) with severe ROP. On univariate analysis, those with severe ROP (32/109, 39.5%) were of lower median gestational age (GA, 23.8 weeks [23.4, 24.6] vs. 27.3 [26.3, 29.0], p < 0.001), lower median birth weight (625 g [512, 710] vs. 935 [700, 1,180], p < 0.001) and experienced higher exposure to clinical chorioamnionitis (22.6 vs. 2.13%, p < 0.006), and later median onset of ROP diagnosis (63.0 days [47.0, 77.2] vs. 29.0 [19.0, 41.0], p < 0.001), received Penrose drain placement more commonly (19 [59.4%] vs. 16 [34.0%], p = 0.04), retained less residual small bowel (70.0 cm [63.1, 90.8] vs. 90.8 [72.0, 101], p = 0.007) following surgery, were exposed to higher FiO2 7 days after birth (p = 0.001), received ventilation longer and exposed to higher FiO2 at 2 weeks (p < 0.05) following NEC and developed acute kidney injury (AKI) more often (25 [86.2%] vs. 20 [46.5%], p = 0.002) than those without ROP. Those with severe ROP had lower length, weight for length, and head circumference z scores. In an adjusted Firth's logistic regression, GA (adjusted odds ratio [aOR] = 0.51, 95% confidence interval [CI]: [0.35, 0.76]) and diagnosis at later age (aOR = 1.08, 95% CI: [1.03, 1.13]) was shown to be significantly associated with any ROP.

CONCLUSION

 Infants who develop severe ROP following surgical NEC/SIP are likely to be younger, smaller, have been exposed to more O2, develop AKI, and grow poorly compared with those did not develop severe ROP.

KEY POINTS

· Thirty percent of infants with NEC/SIP had severe ROP.. · Those with severe ROP had poor growth parameters before and after NEC/SIP.. · Risk factors based ROP prevention strategies are needed to have improved ophthalmic outcomes..

Evolutionary bridges: how factors present in amniotic fluid and human milk help mature the gut

Necrotizing enterocolitis (NEC) continues to be a leading cause of morbidity and mortality in preterm infants. As modern medicine significantly improves the survival of extremely premature infants, the persistence of NEC underscores our limited understanding of its pathogenesis. Due to early delivery, a preterm infant's exposure to amniotic fluid (AF) is abruptly truncated. Replete with bioactive molecules, AF plays an important role in fetal intestinal maturation and preparation for contact with the environment, thus its absence during development of the intestine may contribute to increased susceptibility to NEC. Human milk (HM), particularly during the initial phases of lactation, is a cornerstone of neonatal intestinal defense. The concentrations and activities of several bioactive factors in HM parallel those of AF, suggesting continuity of protection. In this review, we discuss the predominant overlapping bioactive components of HM and AF, with an emphasis on those associated with intestinal growth or reduction of NEC.

Effect of Probiotics on Gastrointestinal Health Through the Aryl Hydrocarbon Receptor Pathway: A Systematic Review

Probiotics are living microorganisms recognized for conferring health benefits on the host by modulating the gut microbiota. They interact with various signaling pathways, including the aryl hydrocarbon receptor (AhR), which plays a crucial role in maintaining intestinal homeostasis and immune function. The activation of AhR by probiotics has been associated with benefits such as improved intestinal barrier function, reduced inflammation, and modulation of immune responses. This systematic review aims to summarize current knowledge on the signaling of AhR, mediated by probiotics in physiological conditions and gastrointestinal pathologies. We conducted a comprehensive search across databases, including PubMed and Embase, up until July 2024. Out of 163 studies screened, 18 met the inclusion criteria. Our findings revealed in healthy populations that probiotic consumption increases the production of AhR ligands promoting intestinal immune tolerance. Furthermore, in populations with gastrointestinal pathologies, probiotics ameliorated symptoms through AhR activation by Trp metabolites, leading to the upregulation of the anti-inflammatory response.

Lilja H. Risk of neurodevelopmental impairment in Swedish preterm children treated for necrotizing enterocolitis: retrospective cohort study

BACKGROUND

As the survival of preterm infants has increased, the management of long-term complications, especially neurodevelopmental impairment, becomes increasingly important. The aim of this study was to investigate the risk of neurodevelopmental disorders in preterm babies receiving medical or surgical treatment for necrotizing enterocolitis, compared with other preterm babies and preterm babies who received abdominal surgery for other indications.

METHODS

In this nationwide Swedish cohort study, including all liveborn preterm babies born between 1998 and 2019, the risk of attention deficit (and hyperactivity) disorder, autism spectrum disorders, cerebral palsy and intellectual disability was assessed by multivariable Cox regression, expressed as hazard ratios and 95% confidence intervals (c.i.).

RESULTS

Of the surgically (n = 384) and medically (n = 709) treated preterm infants with necrotizing enterocolitis, neurodevelopmental disorders were present in 32% (HR 2.24, 95% c.i. 1.86 to 2.69) and 22% respectively (HR 1.40, 95% c.i. 1.19 to 1.65), compared with 21% (HR 1.63, 95% c.i. 1.40 to 1.91) in the abdominal surgery group (n = 844) and 13% (reference) among other preterm infants (n = 78 972). The highest relative increases were for intellectual disability (HR 3.60, 95% c.i. 2.65 to 4.89) in the surgical necrotizing enterocolitis group and abdominal surgery group (HR 2.84, 95% c.i. 2.12 to 3.80) compared with the control preterm group, and for cerebral palsy (respectively HR 2.74, 95% c.i. 2.04 to 3.68 and HR 2.54, 95% c.i. 1.87 to 3.44). Medically treated necrotizing enterocolitis was associated with autism (HR 1.67, 95% c.i. 1.34 to 2.08), without significant increases for the other specific outcomes. Both surgically treated groups were also strongly associated with both attention deficit (and hyperactivity) disorder and autism.

CONCLUSION

Surgically treated necrotizing enterocolitis, medically treated necrotizing enterocolitis and abdominal surgery for other indications in preterm infants were all associated with an increased risk of impaired neurodevelopmental outcomes, compared with other preterm infants.

Gut Microbiota-Derived Metabolites and Their Role in the Pathogenesis of Necrotizing Enterocolitis in Preterm Infants: A Narrative Review

Background: Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that occurs predominantly in premature infants and is characterized by the inflammation and necrosis of the intestine, showing high morbidity and mortality rates. Despite decades of research efforts, a specific treatment is currently lacking, and preventive strategies are the mainstays of care. This review aims to help understand the complex interplay between gut microbiota and their metabolites in NEC pathogenesis. In particular, we focused on how these factors can influence gut health, immune responses, and intestinal barrier integrity. Discussion: Current research has increasingly focused on the role of the gut microbiota and their metabolites in NEC pathogenesis, thanks to their involvement in modulating gut health, immune responses, and intestinal barrier integrity. Conclusions: A deeper understanding of the interplay between gut microbiota and their metabolites is essential for developing personalized strategies to prevent NEC. By targeting these microbial interactions, new therapeutic approaches may emerge that offer improved outcomes for preterm infants at a high risk of NEC.

Impact of Bifidobacterium longum Subspecies infantis on Pediatric Gut Health and Nutrition: Current Evidence and Future Directions

Background: the intestinal microbiota, a complex community vital to human health, is shaped by microbial competition and host-driven selective pressures. Among these microbes, Bifidobacterium plays a crucial role in early gut colonization during neonatal stages, where Bifidobacterium longum subspecies infantis (B. infantis) predominates and is particularly prevalent in healthy breastfed infants. Objectives: as we embark on a new era in nutrition of the pediatric population, this study seeks to examine the existing understanding regarding B. infantis, encompassing both preclinical insights and clinical evidence. Methods: through a narrative disceptation of the current literature, we focus on its genetic capacity to break down various substances that support its survival and dominance in the intestine. Results: using "omics" technologies, researchers have identified beneficial mechanisms of B. infantis, including the production of short-chain fatty acids, serine protease inhibitors, and polysaccharides. While B. infantis declines with age and in various diseases, it remains a widely used probiotic with documented benefits for infant and child health in numerous studies. Conclusions: the current scientific evidence underscores the importance for ongoing research and clinical trials for a deeper understanding of B. infantis's role in promoting long-term health.

Hospitalization throws the preterm gut microbiome off-key

Environmental exposures substantially influence the infant gut microbiome. In this issue of Cell Host & Microbe, Thänert et al.1 characterize how medical interventions in the neonatal intensive care unit (NICU) shape gut microbiome dynamics in the first months of life by analyzing over 2,500 fecal samples with metagenomics and metatranscriptomics.

Clinical sequelae of gut microbiome development and disruption in hospitalized preterm infants

Aberrant preterm infant gut microbiota assembly predisposes to early-life disorders and persistent health problems. Here, we characterize gut microbiome dynamics over the first 3 months of life in 236 preterm infants hospitalized in three neonatal intensive care units using shotgun metagenomics of 2,512 stools and metatranscriptomics of 1,381 stools. Strain tracking, taxonomic and functional profiling, and comprehensive clinical metadata identify Enterobacteriaceae, enterococci, and staphylococci as primarily exploiting available niches to populate the gut microbiome. Clostridioides difficile lineages persist between individuals in single centers, and Staphylococcus epidermidis lineages persist within and, unexpectedly, between centers. Collectively, antibiotic and non-antibiotic medications influence gut microbiome composition to greater extents than maternal or baseline variables. Finally, we identify a persistent low-diversity gut microbiome in neonates who develop necrotizing enterocolitis after day of life 40. Overall, we comprehensively describe gut microbiome dynamics in response to medical interventions in preterm, hospitalized neonates.

Global Insights and Key Trends in Gut Microbiota Research for Premature Infants: A Bibliometric and Visualization Study

Background

Premature infants, defined as those born before 37 weeks of gestation, face numerous health challenges due to their underdeveloped systems. One critical aspect of their health is the gut microbiota, which plays a vital role in their immune function and overall development. This study provides a comprehensive bibliometric analysis of research trends, influential contributors, and evolving themes in the study of gut microbiota in premature infants over the past two decades.

Methods

We conducted a bibliometric analysis using the Web of Science Core Collection database, covering publications from January 1, 2004, to June 17, 2024. We employed VOSviewer, the R package "bibliometrix", and Citespace for data visualization and analysis, focusing on co-authorship, co-citation, and keyword co-occurrence networks.

Results

The temporal analysis revealed a significant increase in research output on gut microbiota in premature infants, particularly in the last decade. Early research primarily focused on characterizing the gut microbiota of premature infants, identifying less diversity and a higher prevalence of pathogenic bacteria compared to full-term infants. Key research themes identified include probiotics, necrotizing enterocolitis (NEC), and breastfeeding. Probiotic studies highlighted the potential of strains like Bifidobacterium and Lactobacillus in reducing NEC and sepsis incidences. Breastfeeding research consistently showed the benefits of human milk in fostering a healthier gut microbiota profile. Co-authorship and co-citation analyses identified key contributors and influential studies, emphasizing strong international collaborations, particularly among researchers from the United States, China, and European countries.

Conclusion

This bibliometric analysis underscores the growing recognition of the gut microbiota's crucial role in the health of premature infants. The field has seen significant advancements, particularly in understanding how interventions like probiotics and breastfeeding can modulate gut microbiota to improve health outcomes. Continued research and international collaboration are essential to further unravel the complexities of gut microbiota in premature infants and develop effective therapeutic strategies.

Wide use of broad-spectrum antibiotics in very low birth weight infants with spontaneous focal intestinal perforation-is it really justified?

PURPOSE

Very low birth weight (VLBW) infants are at a risk of spontaneous focal intestinal perforation (FIP). Treatment includes supportive care, antibiotics, and drainage with/without surgery. Broad-spectrum antibiotic agents like carbapenems are applied frequently, although their use is not well-supported by the limited evidence of causal pathogens. We hypothesize that the use of carbapenems may not be necessary in VLBW infants with FIP. Our primary objective was to evaluate the antimicrobial use in VLBW infants with FIP in a cohort of the German Neonatal Network (GNN). The secondary objective was to characterize a subset in detail as a benchmark for future targets of stewardship.

METHODS

Data on VLBW infants with FIP was collected prospectively within the GNN, a collaboration of 68 neonatal intensive care units (NICU). With regards to the primary objective, patient characteristics and antimicrobial treatment were extracted from the predefined GNN database. To address our secondary objective, an additional on-site assessment of laboratory and microbiological culture results were performed.

RESULTS

In the GNN cohort, 613/21,646 enrolled infants (2.8%) developed FIP requiring surgery. They were frequently treated with carbapenems (500/613 (81.6%)) and vancomycin (497/613 (81.1%)). In a subset of 124 VLBW infants, 77 (72.6%) had proof of gram-positive bacteria in the abdominal cavity, coagulase-negative staphylococci (CoNS) predominantly. Despite the low prevalence of gram-negative bacteria (n = 6 (4.8%)), the combination of meropenem and vancomycin was prescribed most frequently (n = 96 (78.0%)).

CONCLUSION

The use of carbapenems as broad-spectrum antimicrobials agents might not be justified in most VLBW infants with FIP. Knowledge on the development of the neonatal gut microbiota, local resistance patterns and individual microbiological findings should be taken into consideration when implementing antimicrobial stewardship programs (ASPs).

Visceral adipose tissue predicts severity and prognosis of acute pancreatitis in obese patients

Acute pancreatitis is a common systemic inflammatory disease, manifested by a spectrum of severity, ranging from mild in the majority of patients to severe acute pancreatitis. Patients with severe acute pancreatitis suffer from severe local and systemic complications and organ failure, leading to a poor prognosis. The early recognition of the severe condition is important to improve prognosis. Obesity has risen in tandem with an increase in the severity of acute pancreatitis in recent years. Studies have revealed that adipose tissue, particularly visceral adipose tissue is associated with the prognosis of acute pancreatitis. This review discussed the role of visceral adipose tissue in obese patients with acute pancreatitis and explored the possible mechanism involved.

The microbiome in pregnancy and early life-Highlights from the 11th Maria Delivoria-Papadopoulos Perinatal Symposium

This review was based on a symposium that examined novel aspects of the microbiome during pregnancy and early life and explored papers published by the lecturers. For example, it showed that bacterial extracellular vesicles derived from the microbiome harboured in various maternal niches, carried bacterial deoxyribonucleic acid, were isolated from the placenta and may have confounded placental microbiome studies. Maternal diet was responsible for the composition and diversity of breast milk microbiota, and may have shaped the offspring's microbiome and influenced their immune components. Probiotics and antibiotics administered perinatally may have had beneficial but also long-lasting adverse effects on offspring.

Understanding necrotizing enterocolitis endotypes and acquired intestinal injury phenotypes from a historical and artificial intelligence perspective

Necrotizing enterocolitis (NEC) remains a devastating disease in preterm and term neonates. Despite significant progress made in understanding NEC pathogenesis over the last 50 years, the inability of current definitions to discriminate the various pathophysiological processes underlying NEC has led to an umbrella term that limits clinical and research progress. In this mini review, we provide a historical perspective on how NEC definitions and pathogenesis have evolved to our current understanding of NEC endotypes. We also discuss how artificial intelligence-based approaches are influencing our knowledge of risk-factors, classification and prognosis of NEC and other neonatal intestinal injury phenotypes.

Struggling to Understand the NEC Spectrum-Could the Integration of Metabolomics, Clinical-Laboratory Data, and Other Emerging Technologies Help Diagnosis?

Necrotizing enterocolitis (NEC) is the most prevalent and potentially fatal intestinal injury mainly affecting premature infants, with significant long-term consequences for those who survive. This review explores the scale of the problem, highlighting advancements in epidemiology, the understanding of pathophysiology, and improvements in the prediction and diagnosis of this complex, multifactorial, and multifaced disease. Additionally, we focus on the potential role of metabolomics in distinguishing NEC from other conditions, which could allow for an earlier and more accurate classification of intestinal injuries in infants. By integrating metabolomic data with other diagnostic approaches, it is hoped to enhance our ability to predict outcomes and tailor treatments, ultimately improving care for affected infants.

Comparison of One-Year Post-Operative Evolution of Children Born of COVID-19-Positive Mothers vs. COVID-19-Negative Pregnancies Having Congenital Gastrointestinal Malformation and Having Received Proper Parenteral Nutrition during Their Hospital Stay

Background: The long-term effects on neonates born of COVID-19-positive pregnancies are still unclear. Congenital gastrointestinal malformations (CGIMs) often require urgent surgical intervention and antibiotic coverage. We aim to compare the health status at one-year post-surgical follow-up of cases of CGIM born of COVID-19-positive pregnancies to those of non-COVID-19 pregnancies. Methods: We conducted a comparative, observational study of 41 patients who underwent surgery at our hospital for congenital gastrointestinal malformations in 2022. They were initially treated with antibiotics and parenteral nutrition, which was later replaced with enteral nutrition gradually after the surgery. We then analyzed the data related to their growth and development during their 12-month follow-up visit at our outpatient clinic. We classified the children born of COVID-19-positive mothers as Group 1 (n = 14) and those born of mothers without COVID-19 symptoms or with unconfirmed status as Group 2 (n = 33). Results: Forty-one patients showed up for a one-year follow-up (between 11 and 13 months of life). Hence, the final Group 1 comprised 12 and Group 2 comprised 29 children. The patients were categorized based on their anatomical location. Of the cohort, 56.09% were preemies, and 43.91% were full-term newborns. We used seven parameters to evaluate both groups based on growth and developmental milestones: verbal skills, cognitive development, weight gain, height achieved, fine motor movements, gross motor movements, and social/emotional behavior. Group 1 children showed a significant decrease in height and weight compared to Group 2 children. In Group 1, 83.33% of patients were prescribed antibiotics, while only 10.34% in Group 2 were in the same situation. There were no cases of malabsorption syndrome in Group 2, but 16.66% of patients in Group 1 had it, with patients being operated on for duodenal malformations. None of the infants had necrotizing enterocolitis, post-surgical complications, or sepsis. All the children received antibiotics to prevent infection before and after surgery. No mortality was noted. Conclusions: In our one-year follow-up study, it was seen that even after surgical correction of congenital gastrointestinal malformations, children born of COVID-19-positive pregnancies can suffer serious growth and developmental delays, and gastrointestinal health issues might be more common. Since the long-term effects of COVID-19-positive pregnancies are not yet clear, larger cohort-based studies are required in this domain. Antibiotics destroy gut microbiota, especially in cases of gastrointestinal malformations and surgical resections. Growth and developmental milestones can not only be affected by CGIMs but also be further delayed by COVID-19 infections.

Gut microbiome and inflammation in response to increasing intermittent hypoxia in the neonatal rat

BACKGROUND

Intermittent hypoxia (IH) and oxidative stress play key roles in gut dysbiosis and inflammation. We tested the hypothesis that increasing numbers of daily IH episodes cause microbiome dysbiosis and severe gut injury.

METHODS

Neonatal rats were exposed to hyperoxia (Hx), growth restriction, and IH. For IH, pups were exposed to 2-12 daily episodes from birth (P0) to postnatal day 7 (7D) or P0-P14 (14D), with or without recovery in room air (RA) until P21. Animals raised in RA from P0 to P21 served as normoxia controls. Stool was expressed from the large intestines for microbiome analysis, and tissue samples were assessed for histopathology and biomarkers of inflammation.

RESULTS

Hx and IH caused a significant reduction in the number and diversity of organisms. The severity of gut injury and levels of inflammatory cytokines and TLR4 increased, while total glutathione (tGSH) declined, with increasing daily IH episodes. The number of organisms correlated with the villi number (p < 0.05) and tGSH depletion (p < 0.001).

CONCLUSIONS

The critical number of daily IH episodes that the newborn gut may sustain is 6, beyond which irreversible damage occurs. The immature gut is highly susceptible to IH-induced injury, and IH may contribute to pathological outcomes in the immature gut.

IMPACT STATEMENT

1. The neonatal gut at birth is highly susceptible to intermittent hypoxia (IH) injury. 2. IH causes gut dysbiosis, inflammation, and glutathione depletion. 3. The severity of gut injury worsens as a function of increasing daily IH episodes. 4. The critical number of daily IH episodes that the newborn gut may sustain is 6, beyond which irreversible damage occurs.

Mother's milk microbiota is associated with the developing gut microbial consortia in very-low-birth-weight infants

Mother's milk contains diverse bacterial communities, although their impact on microbial colonization in very-low-birth-weight (VLBW, <1,500 g) infants remains unknown. Here, we examine relationships between the microbiota in preterm mother's milk and the VLBW infant gut across initial hospitalization (n = 94 mother-infant dyads, 422 milk-stool pairs). Shared zero-radius operational taxonomic units (zOTUs) between milk-stool pairs account for ∼30%-40% of zOTUs in the VLBW infant's gut. We show dose-response relationships between intakes of several genera from milk and their concentrations in the infant's gut. These relationships and those related to microbial sharing change temporally and are modified by in-hospital feeding practices (especially direct breastfeeding) and maternal-infant antibiotic use. Correlations also exist between milk and stool microbial consortia, suggesting that multiple milk microbes may influence overall gut communities together. These results highlight that the mother's milk microbiota may shape the gut colonization of VLBW infants by delivering specific bacteria and through intricate microbial interactions.

Metabolite-based inter-kingdom communication controls intestinal tissue recovery following chemotherapeutic injury

Cytotoxic chemotherapies have devastating side effects, particularly within the gastrointestinal tract. Gastrointestinal toxicity includes the death and damage of the epithelium and an imbalance in the intestinal microbiota, otherwise known as dysbiosis. Whether dysbiosis is a direct contributor to tissue toxicity is a key area of focus. Here, from both mammalian and bacterial perspectives, we uncover an intestinal epithelial cell death-Enterobacteriaceae signaling axis that fuels dysbiosis. Specifically, our data demonstrate that chemotherapy-induced epithelial cell apoptosis and the purine-containing metabolites released from dying cells drive the inter-kingdom transcriptional re-wiring of the Enterobacteriaceae, including fundamental shifts in bacterial respiration and promotion of purine utilization-dependent expansion, which in turn delays the recovery of the intestinal tract. Inhibition of epithelial cell death or restriction of the Enterobacteriaceae to homeostatic levels reverses dysbiosis and improves intestinal recovery. These findings suggest that supportive therapies that maintain homeostatic levels of Enterobacteriaceae may be useful in resolving intestinal disease.

Intrauterine Shaping of Fetal Microbiota

Mechanisms resulting from the physiological immaturity of the digestive system in children delivered before 32 weeks of gestation and, in particular, different interactions between the microbiome and the body have not been fully elucidated yet. Next-generation sequencing methods demonstrated the presence of bacterial DNA in the placenta and amniotic fluid, which may reflect bacterial populations that initiate intestinal colonization in utero. Numerous studies confirmed the hypothesis stating that intestinal bacteria played an important role in the pathogenesis of necrotizing enterocolitis (NEC) early- and late-onset neonatal sepsis (EONS and LONS). The model and scale of disorders within the intestinal microbiome are the subject of active research in premature infants. Neonatal meconium was primarily used as an indicator defining the environment in utero, as it is formed before birth. Metagenomic results and previous data from microbiological bacterial cultures showed a correlation between the time from birth to sample collection and the detection of bacteria in the neonatal meconium. Therefore, it may be determined that the colonization of the newborn's intestines is influenced by numerous factors, which may be divided into prenatal, perinatal, and postnatal, with particular emphasis put on the mode of delivery and contact with the parent immediately after birth. Background: The aim of this review was to collect available data on the intrauterine shaping of the fetal microbiota. Methods: On 13 March 2024, the available literature in the PubMed National Library of Medicine search engine was reviewed using the following selected keywords: "placental microbiome", "intestinal bacteria in newborns and premature infants", and "intrauterine microbiota". Results: After reviewing the available articles and abstracts and an in-depth analysis of their content, over 100 articles were selected for detailed elaboration. We focused on the origin of microorganisms shaping the microbiota of newborns. We also described the types of bacteria that made up the intrauterine microbiota and the intestinal microbiota of newborns. Conclusions: The data presented in the review on the microbiome of both term newborns and those with a body weight below 1200 g indicate a possible intrauterine colonization of the fetus depending on the duration of pregnancy. The colonization occurs both via the vaginal and intestinal route (hematogenous route). However, there are differences in the demonstrated representatives of various types of bacteria, phyla Firmicutes and Actinobacteria in particular, taking account of the distribution in their abundance in the individual groups of pregnancy duration. Simultaneously, the distribution of the phyla Actinobacteria and Proteobacteria is consistent. Considering the duration of pregnancy, it may also be concluded that the bacterial flora of vaginal origin dominates in preterm newborns, while the flora of intestinal origin dominates in term newborns. This might explain the role of bacterial and infectious factors in inducing premature birth with the rupture of fetal membranes.

From vacant to vivid: The nutritional landscape drives infant gut microbiota establishment

From the moment of birth, the newborn gastrointestinal tract is infiltrated by various bacteria originating from both maternal and environmental sources. These colonizing bacteria form a complex microbiota community that undergoes continuous changes until adulthood and plays an important role in infant health. The maturation of the infant gut microbiota is driven by many factors and follows a distinct patterned trajectory, with specific bacterial taxa establish in the intestine in accordance with developmental milestones as the infant grows. In this review, we highlight how elements such as diet and host physiology select for specific microbial functions and shape the composition of the bacterial community in the large intestine.

The impact of gut microbiota on morbidities in preterm infants

The gut microbiota undergoes substantial development from birth, and its development in the initial years of life has a potentially lifelong effect on the health of the individual. However, various factors can disrupt the development of the gut microbiota, leading to a condition known as dysbiosis, particularly in preterm infants. Current studies involving adults have suggested that the gut microbiota not only influences the gut but also has multidimensional effects on remote organs; these pathways are often referred to as the gut-organ axis. Imbalance of the gut microbiota may lead to the development of multiple diseases. Recent studies have revealed that gut dysbiosis in preterm infants may cause several acute morbidities-such as necrotizing enterocolitis, late-onset sepsis, bronchopulmonary dysplasia, and retinopathy of prematurity-and it may also influence long-term outcomes including neurodevelopment and somatic growth. This review mainly presents the existing evidence regarding the relationships between the gut microbiota and these morbidities in preterm infants and explores the role of the gut-organ axis in these morbidities. This paper thus offers insights into the future perspectives on microbiota interventions for promoting the health of preterm infants.

Is choline deficiency an unrecognized factor in necrotizing enterocolitis of preterm infants?

We undertook this review to determine if it is plausible that choline or phosphatidylcholine (PC) deficiency is a factor in necrotizing enterocolitis (NEC) after two clinical trials found a dramatic and unexpected reduction in NEC in an experimental group provided higher PC compared to a control group. Sources and amounts of choline/PC for preterm infants are compared to the choline status of preterm infants at birth and following conventional nutritional management. The roles of choline/PC in intestinal structure, mucus, mesenteric blood flow, and the cholinergic anti-inflammatory system are summarized. Low choline/PC status is linked to prematurity/immaturity, parenteral and enteral feeding, microbial dysbiosis and hypoxia/ischemia, factors long associated with the risk of developing NEC. We conclude that low choline status exists in preterm infants provided conventional parenteral and enteral nutritional management, and that it is plausible low choline/PC status adversely affects intestinal function to set up the vicious cycle of inflammation, loss of intestinal barrier function and worsening tissue hypoxia that occurs with NEC. In conclusion, this review supports the need for randomized clinical trials to test the hypothesis that additional choline or PC provided parenterally or enterally can reduce the incidence of NEC in preterm infants. IMPACT STATEMENT: Low choline status in preterm infants who are managed by conventional nutrition is plausibly linked to the risk of developing necrotizing enterocolitis.

Prevention Strategies and Management of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a serious intestinal disease which primarily affects preterm infants. The pathogenesis of NEC is multifactorial. Thus, it is complicated to study, prevent, and manage.

Purpose of Review

The purpose of this review is to provide a comprehensive summary of recent research and provide recommendations for the prevention and management of NEC. Currently, management is supportive and non-specific and long-term outcomes for surgical NEC are poor.

Recent Findings

The most important strategy to prevent NEC is to provide preterm infants with a human milk diet, minimize exposure to antibiotics and avoid medications that disturb the intestinal microbiome.

Summary

Strategies to optimize the infant's intestinal microbiome are critical, as disturbances in the intestinal microbiome composition are a major factor in the pathogenesis of this disease. Optimizing maternal health is also vital to prevent prematurity and neonatal morbidity. Ongoing research holds promise for the implementation of new diagnostic modalities, preventive strategies, and medical treatment options to improve outcomes for premature infants.

Gut microbiome in the first 1000 days and risk for childhood food allergy

OBJECTIVE

To summarize recent data on the association between gut microbiome composition and food allergy (FA) in early childhood and highlight potential host-microbiome interactions that reinforce or abrogate oral tolerance.

DATA SOURCES

PubMed search of English-language articles related to FA, other atopic disease, and the gut microbiome in pregnancy and early childhood.

STUDY SELECTIONS

Human studies published after 2015 assessing the relationship between the gut bacteriome and virome in the first 2 years of life and FA or food sensitization development in early childhood were prioritized. Additional human studies conducted on the prenatal gut microbiome or other atopic diseases and preclinical studies are also discussed.

RESULTS

Children who developed FA harbored lower abundances of Bifidobacterium and Clostridia species and had a less mature microbiome during infancy. The early bacterial microbiome protects against FA through production of anti-inflammatory metabolites and induction of T regulatory cells and may also affect FA risk through a role in trained immunity. Infant enteric phage communities are related to childhood asthma development, though no data are available for FA. Maternal gut microbiome during pregnancy is associated with childhood FA risk, potentially through transplacental delivery of maternal bacterial metabolites, though human studies are lacking.

CONCLUSION

The maternal and infant microbiomes throughout the first 1000 days of life influence FA risk through a number of proposed mechanisms. Further large, longitudinal cohort studies using taxonomic, functional, and metabolomic analysis of the bacterial and viral microbiomes are needed to provide further insight on the host-microbe interactions underlying FA pathogenesis in childhood.

The Role of the Microbiome in Pediatric Respiratory Diseases

Numerous studies have examined the role of the microbiome and microbiome-based therapeutics in many childhood airway and lung diseases. In this narrative review, the authors first give a brief overview of the current methods used in microbiome research. The authors then review the literature linking the microbiome with (1) early-life acute respiratory infections due to respiratory syncytial virus, (2) childhood asthma onset, (3) cystic fibrosis, and (4) bronchopulmonary dysplasia, focusing on recent studies that have used culture-independent methods to characterize the respiratory or gut microbiome in the pediatric population.

Effects of inulin on intestinal flora and metabolism-related indicators in obese polycystic ovary syndrome patients

CONTEXT

Polycystic ovary syndrome (PCOS), a common endocrine disorder in women of reproductive age, is closely associated with chronic low-grade inflammation and metabolic disturbances. In PCOS mice, dietary inulin has been demonstrated to regulate intestinal flora and inflammation. However, the efficacy of dietary inulin in clinical PCOS remains unclear.

OBJECTIVE

The intestinal flora and related metabolic indexes of obese patients with polycystic ovary syndrome (PCOS) after 3 months of inulin treatment were analyzed.

SETTING AND DESIGN

To analyze the intestinal flora and related metabolic indexes in healthy controls and obese patients with polycystic ovary syndrome after 3 months of inulin treatment.

RESULTS

The results showed that dietary inulin improved sex hormone disorders, reduced BMI and WHR levels in obese women with PCOS. In addition, the inulin intervention reduced plasma TNF-α, IL-1β, IL-6, and MCP-1levels. Inulin intervention increased the abundance of Actinobacteria, Fusobacteria, Lachnospira, and Bifidobacterium, as well as decreased the ratio of F/B and the abundance of proteobacteria, Sutterella, and Enterobacter. Correlation analyses showed a strong relationship among plasma inflammatory factors, sex steroid hormones, and the intestinal flora of patients.

CONCLUSIONS

Dietary inulin may improve obese PCOS women disease through the gut flora-inflammation-steroid hormone pathway.

THE CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-IOR-17012281.

Reduced Gut Bacterial Diversity in Early Life Predicts Feeding Intolerance in Preterm Neonates

Microbiota plays a crucial role in intestinal maturation in preterm newborns. The clinical manifestation of the immaturity of the gastro-intestinal tract is called feeding intolerance (FI). This condition may resolve spontaneously or dramatically evolve into necrotizing enterocolitis. One of the most challenging tasks for the neonatologist is to identify those neonates that will develop the disease early in order to adequately provide nutrition to these patients, from the very first hours of life. A close interplay between the maturity of the gastro-intestinal tract and gut microbiota has been described; however, in preterm neonates, this relationship is still undefined. We analyzed the bacterial composition of stool samples, collected early in life, from 30 preterm newborns classified as intolerant or tolerant according to the degree of readiness of the gastro-intestinal tract to receive enteral nutrition. The Pielou evenness index was significantly increased in intolerant compared with tolerant newborns. Data corrected for confounding variables confirmed that the occurrence of gut maturation was independently influenced by Pielou evenness at birth. A lower bacterial diversity very early in life is associated with improved feeding tolerance in preterm newborns. The abundance analysis showed that neonates not ready to receive enteral nutrition for feeding intolerance show, after birth, an increased abundance of Proteobacteria, Lachnospiracae, Enterobacter and Acinetobacter. We can argue that those are the taxa that prevent the establishment of pioneer bacteria. A lower alpha-diversity, in the first days of life, may facilitate the seeding of beneficial pioneer bacteria that, in turn, drive healthy microbial colonization during neonatal life.

The skin microbiota of preterm infants and impact of diaper change frequency

OBJECTIVE

To evaluate the impact of diaper change frequency, clinical characteristics, and skin health metrics on development of the skin microbiota in preterm infants.

DESIGN

A randomized controlled parallel design was used.

METHODS

Medically stable preterm infants born <33 weeks' gestation were randomized to receive diaper changes at a frequency of every 3-hours or every 6-hours. Skin swabs were collected longitudinally from the diapered skin (buttocks) and chest. Skin pH and transepidermal water loss were measured with each sample collection. Stool samples were collected from the diaper. The microbiome at each site was characterized by 16S rRNA gene sequencing. Associations between microbiome features, diaper change frequency, and other covariates were examined using mixed effect models and redundancy analysis.

RESULTS

A total of 1179 samples were collected from 46 preterm infants, beginning at a median postnatal age of 44 days and continuing through hospital discharge. Alpha-diversity of the skin microbiota increased over time, but did not differ significantly between 3-hour (n = 20) and 6-hour (n = 26) diaper change groups. Alpha-diversity of the skin microbiota was inversely correlated with skin pH, but not transepidermal water loss. Microbiota community structure differed significantly between body sites (buttocks, chest, and stool) and between individuals. Among samples collected from the diapered skin, diaper change frequency, infant diet, antibiotic exposure, and delivery mode accounted for minor proportions of the variation in microbiota community structure between samples. Relative abundances of multiple genera differed between 3- and 6-hour diaper change groups over time.

DISCUSSION/CONCLUSION

The diversity and composition of the diapered skin microbiota is dynamic over time and differs from other body sites. Multiple factors including interindividual effects, diaper change frequency, diet, and antibiotics contribute to variation in the diapered skin microbiota.

Risk of Fat Mass- and Obesity-Associated Gene-Dependent Obesogenic Programming by Formula Feeding Compared to Breastfeeding

It is the purpose of this review to compare differences in postnatal epigenetic programming at the level of DNA and RNA methylation and later obesity risk between infants receiving artificial formula feeding (FF) in contrast to natural breastfeeding (BF). FF bears the risk of aberrant epigenetic programming at the level of DNA methylation and enhances the expression of the RNA demethylase fat mass- and obesity-associated gene (FTO), pointing to further deviations in the RNA methylome. Based on a literature search through Web of Science, Google Scholar, and PubMed databases concerning the dietary and epigenetic factors influencing FTO gene and FTO protein expression and FTO activity, FTO's impact on postnatal adipogenic programming was investigated. Accumulated translational evidence underscores that total protein intake as well as tryptophan, kynurenine, branched-chain amino acids, milk exosomal miRNAs, NADP, and NADPH are crucial regulators modifying FTO gene expression and FTO activity. Increased FTO-mTORC1-S6K1 signaling may epigenetically suppress the WNT/β-catenin pathway, enhancing adipocyte precursor cell proliferation and adipogenesis. Formula-induced FTO-dependent alterations of the N6-methyladenosine (m6A) RNA methylome may represent novel unfavorable molecular events in the postnatal development of adipogenesis and obesity, necessitating further investigations. BF provides physiological epigenetic DNA and RNA regulation, a compelling reason to rely on BF.