The intestinal microbiome of infants and the use of probiotics

Impact of probiotic on anxiety and depression symptoms in pregnant and lactating women and microbiota of infants: A systematic review and meta-analysis

Background

Probiotics are non-invasive therapies composed of live bacteria and yeast. Administration of prebiotics improved the health status of pregnant and lactating women, as well as newborns. This review aimed to appraise the evidence concerning the effectiveness of probiotics on the mental health of pregnant women, lactating mother and the microbiota of the newborn.

Methods

This systematic review and meta-analysis ascertained quantitative studies published in Medline (PubMed), Clinical Key, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and Google scholar. Two authors independently screened and extracted the data from the primary studies that analysed the efficacy of probiotics on the mental health of pregnant and lactating women and the microbiota of the newborn. We adopted Cochrane Collaboration guidelines and reported using the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) statement. The qualities of included trials were assessed by Cochrane collaboration's risk of bias tool (ROB-2).

Results

Sixteen trials comprised 946 pregnant women, 524 were lactating mothers, and 1678 were infants. The sample size of primary studies ranged from 36 to 433. Probiotics were administered as interventions, using either a single strain of Bifidobacterium or Lactobacillus or a double-strain combination of Lactobacillus and Bifidobacterium. Probiotics supplementation reduced anxiety in pregnant (n = 676, standardised mean difference (SMD) = 0.01; 95% confidence interval (CI) = -0.28,0.30, P = 0.04, I² = 70) and lactating women (n = 514, SMD = -0.17; 95% CI = -1.62,1.27, P = 0.98, I² = 0). Similarly, probiotics decreased depression in pregnant (n = 298, SMD = 0.05; 95% CI = -0.24,0.35, P = 0.20, I² = 40) and lactating women (n = 518, SMD = -0.10; 95% CI = -1.29,-1.05, P = 0.11, I² = 60%). Similarly, probiotics supplementation improved the gut microbiota and reduced the duration of crying, abdominal distension, abdominal colic and diarrhoea.

Conclusion

Non-invasive probiotic therapies are more useful to pregnant and lactating women and newborns.

Registration

The review protocol was registered with PROSPERO (CRD42022372126).

Inhibitory Effect of Lactococcus lactis subsp. lactis HFY14 on Diphenoxylate-Induced Constipation in Mice by Regulating the VIP-cAMP-PKA-AQP3 Signaling Pathway

Aim

The naturally fermented yak yogurt of pastoralists in the Tibetan Plateau, China, because of its unique geographical environment and the unique lifestyle of Tibetan pastoralists, is very different from other kinds of sour milk, and the microorganisms it contains are special. Lactococcus lactis subsp. lactis HFY14 (LLSL-HFY14) is a new lactic acid bacterium isolated from naturally fermented yak yogurt. The purpose of this study was to study the inhibitory effect of the bacterium on constipation.

Methods

Constipation was induced in ICR mice with diphenoxylate, and the constipated mice were treated with LLSL-HFY14. The weight and feces of the mice were visually detected. Colonic tissues were observed on hematoxylin and eosin-stained sections. Serum indices were detected with kits. mRNA expression in the colon was determined by quantitative polymerase chain reaction assay.

Results

Constipation caused weight loss, the number of defecation granules, defecation weight, fecal water content decreased, and the first black stool excretion time increased. LLSL-HFY14 alleviated these symptoms, and the effects were similar to those of lactulose (drug). The pathological examination revealed that constipation caused pathological changes in the colon, and LLSL-HFY14 effectively alleviated the disease. LLSL-HFY14 increased serum levels of motilin, gastrin, endothelin, substance P, acetylcholinesterase, and vasoactive intestinal peptide (VIP) and decreased serum levels of somatostatin in constipated mice. In addition, LLSL-HFY14 upregulated VIP, cAMP, protein kinase A, and aquaporin 3 expression in colonic tissues of constipated mice in a dose-dependent manner.

Conclusion

LLSL-HFY14 inhibited constipation, similar to lactulose, and has the potential to become a biological agent.

Implications of Probiotics on the Maternal-Neonatal Interface: Gut Microbiota, Immunomodulation, and Autoimmunity

Probiotics are being investigated for the treatment of autoimmune disease by re-balancing dysbiosis induced changes in the immune system. Pregnancy is a health concern surrounding autoimmune disease, both for the mother and her child. Probiotics for maternity are emerging on the market and have gained significant momentum in the literature. Thus far, evidence supports that probiotics alter the structure of the normal microbiota and the microbiota changes significantly during pregnancy. The interaction between probiotics-induced changes and normal changes during pregnancy is poorly understood. Furthermore, there is emerging evidence that the maternal gut microbiota influences the microbiota of offspring, leading to questions on how maternal probiotics may influence the health of neonates. Underpinning the development and balance of the immune system, the microbiota, especially that of the gut, is significantly important, and dysbiosis is an agent of immune dysregulation and autoimmunity. However, few studies exist on the implications of maternal probiotics for the outcome of pregnancy in autoimmune disease. Is it helpful or harmful for mother with autoimmune disease to take probiotics, and would this be protective or pathogenic for her child? Controversy surrounds whether probiotics administered maternally or during infancy are healthful for allergic disease, and their use for autoimmunity is relatively unexplored. This review aims to discuss the use of maternal probiotics in health and autoimmune disease and to investigate their immunomodulatory properties.

The effects of probiotics supplementation on metabolic health in pregnant women: An evidence based meta-analysis

The prevalence of maternal obesity and gestational diabetes mellitus (GDM) is increasing rapidly. Probiotics supplementation have been shown to improve metabolic health in humans. In our study, we aimed to evaluate the effects of probiotics supplementation on metabolic health and pregnancy complications in pregnant women. The literature search, data extraction and quality assessment were performed, and data were synthesized in accordance with standardized guidelines. Ten randomized clinical trials with eligible data were included in our meta-analysis. For pregnant women with GDM, we found negative correlations between probiotics supplementation and fasting serum insulin (OR -2.94, 95%CI [-5.69, -0.20], p = 0.04) and homoeostasis model assessment for insulin resistance (HOMA-IR) (OR -0.65, 95%CI [-1.18, -0.11], p = 0.02). There were no significant correlations between probiotics supplementation and lipid levels in women with GDM, including total cholesterol (OR -2.72, 95%CI [-17.18, 11.74], P = 0.71), high density lipoprotein cholesterol (HDL-c) (OR -0.29, 95%CI [-3.60, 3.03], P = 0.87), low density lipoprotein cholesterol (LDL-c) (OR -0.38, 95%CI [-18.54, 17.79], P = 0.97), or triglycerides (OR -12.83, 95%CI [-36.63, 10.97], P = 0.29). For healthy pregnant women, probiotics supplementation were negatively associated with fasting serum insulin (OR -3.76, 95%CI [-4.29, -3.23], P < 0.00001) and HOMA-IR (OR -0.57, 95%CI [-1.08, -0.06], p = 0.03). However, no significant correlations were observed between probiotics supplementation and fasting plasma glucose (FPG) (OR -2.02, 95%CI [-5.56, 1.52], p = 0.26). Thus, our study revealed that probiotics supplementation during pregnancy have beneficial effects on glucose metabolism, rather than lipid metabolism among pregnant women.

Integrated Role of Bifidobacterium animalis subsp. lactis Supplementation in Gut Microbiota, Immunity, and Metabolism of Infant Rhesus Monkeys

To investigate the impact of probiotic supplementation of infant formula on immune parameters, intestinal microbiota, and metabolism, five individually housed infant rhesus monkeys exclusively fed standard infant formula supplemented with probiotics (Bifidobacterium animalis subsp. lactis HN019) from birth until 3 months of age were compared with five standard formula-fed and five breast-fed monkeys. Anthropometric measurements, serum insulin, immune parameters, fecal microbiota, and metabolic profiles of serum, urine, and feces were evaluated. Consumption of B. lactis-supplemented formula reduced microbial diversity, restructured the fecal microbial community, and altered the fecal metabolome at the last two time points, in addition to increasing short-chain fatty acids in serum and urine. Circulating CCL22 was lower and threonine, branched-chain amino acids, urea, and allantoin, as well as dimethylglycine in serum and urine, were increased in the group supplemented with B. lactis compared with the standard formula-fed group. These results support a role of probiotics as effectors of gut microbial activity regulating amino acid utilization and nitrogen cycling. Future risk-benefit analyses are still needed to consolidate the existing knowledge on the long-term consequences of probiotic administration during infancy. IMPORTANCE Probiotics are becoming increasingly popular due to their perceived effects on health, despite a lack of mechanistic information on how they impart these benefits. Infant formula and complementary foods are common targets for supplementation with probiotics. However, different probiotic strains have different properties, and there is a lack of data on long-term health effects on the consumer. Given the increasing interest in supplementation with probiotics and the fact that the gastrointestinal tracts of infants are still immature, we sought to determine whether consumption of infant formula containing the probiotic Bifidobacterium animalis subsp. lactis HN019 for 3 months starting at birth would impact gut microbial colonization, as well as infant immunity and metabolism, when compared with consumption of formula alone.

Barriers to Knowledge Translation Regarding the Use of Probiotics as a Risk-Reduction Strategy for Necrotizing Enterocolitis

BACKGROUND

Increasingly, evidence supports enteral probiotics are an important risk-reduction strategy for necrotizing enterocolitis (NEC) among very low birth-weight and extremely low birth-weight preterm infants. Yet, the majority of providers remain reluctant to implement practice changes.

PURPOSE

The aim of this study was to better understand the discrepancy between the available evidence and clinical practice regarding the use of probiotics and other NEC prevention strategies in New Jersey.

METHODS

Using an exploratory descriptive design, a multimodal interprofessional survey was developed and executed to elicit intensive care nursery provider knowledge, views, and current practice.

RESULTS

Although the sample size was small (N = 29), approximately one-half of respondents familiar with the literature rated the quality of the evidence regarding probiotics as "above average" to "excellent." These respondents were "very likely" to "extremely likely" to recommend probiotics as an NEC prevention strategy; however, none actually prescribed this intervention. The most important reason respondents did not prescribe probiotics was the focus on providing exclusive maternal and donor breast milk feedings. Other confounding factors included provision of oral colostrum care, standardized feeding protocols, and withholding feedings during blood transfusion.

IMPLICATIONS FOR PRACTICE

Study results suggested that some providers (primarily nurses) were not familiar with probiotic literature, which may contribute to deficits in knowledge translation to practice.

IMPLICATIONS FOR RESEARCH

Areas for future study include identifying improved mechanisms for knowledge dissemination, recognizing and addressing barriers and facilitators to knowledge translation, and understanding how probiotics fit and/or contrast with other NEC risk-reduction strategies in the research and clinical settings.

Priming for health: gut microbiota acquired in early life regulates physiology, brain and behaviour

The infant gut microbiome is dynamic, and radical shifts in composition occur during the first 3 years of life. Disruption of these developmental patterns, and the impact of the microbial composition of our gut on brain and behaviour, has attracted much recent attention. Integrating these observations is an important new research frontier.

CONCLUSION

Early-life perturbations of the developing gut microbiota can impact on the central nervous system and potentially lead to adverse mental health outcomes.

Aggressive Nutrition of the Preterm Infant

Nutrition of preterm infants should result in growth similar to that of normally growing fetuses of the same gestational age. Unfortunately, most preterm infants are not fed enough to achieve this objective; as a result they are growth restricted by term gestation. Recent studies have demonstrated that early and enhanced "aggressive" nutrition of preterm infants can reduce postnatal growth failure and improve longer-term outcomes, particularly for the brain and its cognitive functions. When preterm infants are fed more aggressively (earlier onset of intravenous and enteral feeding, earlier achievement of full enteral feeding) cumulative energy and protein deficits are reduced and they consistently regain birth weight sooner, the incidence of necrotizing enterocolitis and late-onset sepsis is unchanged or reduced, and they achieve discharge criteria and go home sooner, with overall shorter hospital stays, and have improved anthropometrics by term gestation. More research is needed, however, to determine optimum feeding of preterm infants, particularly during periods of illness and physiological instability.

Efficacy of Saccharomyces boulardii on necrotizing enterocolitis or sepsis in very low birth weight infants: a randomised controlled trial

BACKGROUND

Probiotics have strain specific effects and the effects of fungi in preventing diseases in preterm infants have been investigated poorly. Saccharomyces boulardii is a yeast which acts both as a probiotic and a polyamine producer.

AIM

The objective of this study was to investigate the efficacy of S. boulardii in preventing necrotizing enterocolitis (NEC) or sepsis in very low birth weight infants.

STUDY DESIGN AND SUBJECTS

A prospective, double blind, placebo controlled trial was conducted in preterm infants (≤ 32 GWs, ≤ 1500 g birth weight). They were randomized either to receive feeding supplementation with S. boulardii 50 mg/kg every 12 h or placebo, starting with the first feed until discharged.

OUTCOME MEASURES

Necrotizing enterocolitis (NEC) or sepsis and NEC or death.

RESULTS

Birth weight and gestational age of the study (n = 104) and the control (n = 104) groups were 1126 ± 232 vs 1162 ± 216 g and 28.8 ± 2.2 vs 28.7 ± 2.1 weeks, respectively. Neither the incidence of stage ≥ 2 NEC or death nor stage ≥ 2 NEC or late onset culture proven sepsis was significantly lower in the study group when compared with the control group (9.6% vs 7.7%, p = 0.62; 28.8% vs 23%, p = 0.34). Time to reach 100 mL/kg/day of enteral feeding (11.9 ± 7 vs 12.6 ± 7 days, p = 0.37) was not different between the groups.

CONCLUSIONS

Saccharomyces boulardii did not decrease the incidence of NEC or sepsis.

Bifidobacteria: their impact on gut microbiota composition and their applications as probiotics in infants

This review is aimed at describing the most recent advances in the gut microbiota composition of newborns and infants with a particular emphasis on bifidobacteria. The newborn gut microbiota is quite unstable, whereas after weaning, it becomes more stable and gets closer to the typical adult microbiota. The newborn and infant gut microbiota composition is impaired in several enteric and non-enteric pathologies. The core of this review is the description of the most recent documented applications of bifidobacteria to newborns and infants for their prevention and treatment. Acute diarrhea is the most studied disease for which bifidobacteria are applied with great success, Bifidobacterium longum and Bifidobacterium breve being the most applied species. Moreover, the most recent updates in the use of bifidobacteria for the prevention and treatment of pathologies typical of newborns, such as necrotizing enterocolitis, colics, and streptococcal infections, are presented. In addition, a number of not strictly enteric pathologies have in recent years evidenced a strict correlation with an aberrant gut microbiota in infants, in particular showing a reduced level of bifidobacteria. These diseases represent new potential opportunities for probiotic applications. Among them, allergic diseases, celiac disease, obesity, and neurologic diseases are described in this review. The preliminary use of bifidobacteria in in vitro systems and animal models is summarized as well as preliminary in vivo studies. Only after validation of the results via human clinical trials will the potentiality of bifidobacteria in the prevention and cure of these pathologies be definitely assessed.

A neurobiological model for cry-fuss problems in the first three to four months of life

Although problem crying in the first three to four months of life is usually self-limiting, it is not a trivial condition. Early intervention is important, yet families receive conflicting advice from health professionals. The past decade has seen significant advances in neuroscience, lactation science, and developmental psychology, including new insights into the significance of developmentally sensitive windows. We propose a neurobiological model to explain the mechanisms of cry-fuss problems in the first months of life, and the mechanisms which underlie effective intervention, with a view to facilitating research collaboration and consistency of advice across health disciplines. We hypothesise that crying in the first three to four neurodevelopmentally sensitive months signals activation of the hypothalamic-pituitary-adrenal axis and adrenergic neuronal circuitry in response to perceptions of discomfort or threat. Susceptible infants may be conditioned by early stress, for example, by unidentified feeding difficulties, into a sensitised stress response, which usually settles at three to four months of age with neurodevelopmental maturity. Bouts of prolonged and unsoothable crying result from positive feedback loops in the hypothalamic-pituitary-adrenal and adrenergic systems. Importantly, epigenetic modulation of the infant's limbic neuronal circuitry may explain correlations between regulatory problems in the first months of life, and behavioural problems including feeding problems in later childhood.

Relations between feeding intolerance and stress biomarkers in preterm infants

OBJECTIVES

Feeding intolerance (FI) in preterm infants is common but the etiology remains unclear. This study examined FI as a stress-related disease involving brain-gut interactions and tested the model of allostatic load and complications of prematurity. Specific aims were to describe demographic/medical variables and biomarker levels at each time and over time for the sample; describe/compare variables and biomarker levels at each time for infants with/without FI; and compare biomarker interquartile/interpercentile distributions between infants with/without FI.

METHODS

Preterm infants <32 weeks' gestation were recruited. The primary outcome was FI by day 7 defined as a feeding withheld, discontinued, or decreased because the infant was not tolerating enteral feedings. Allostatic load was operationalized using cortisol and 8-hydroxydeoxyguanosine (8-OHdG) from cord blood and from saliva and urine on days 1, 7, and 14. Descriptive statistics and comparative analyses were performed.

RESULTS

Seven of 31 infants enrolled met criteria for FI. Infants with FI had lower median urinary cortisol on day 1 (P = 0.007) and trended to have lower cortisol in the cord blood (P = 0.056). Interquartile distributions were significantly different between infants with/without FI for urinary cortisol on day 1 (P = 0.034) and trended for differences in 8-OHdG on day 14 (P = 0.087). Interpercentile distributions were significantly different in salivary cortisol on day 14 (P = 0.034) and trended for differences in 8-OHdG on day 1 (P = 0.079).

CONCLUSIONS

Results support further testing of the model in a larger sample; investigation of the cellular mechanisms associated with the stress and the free radical/antioxidant systems; and inclusion of prenatal factors.

Proteomics as a Quality Control Tool of Pharmaceutical Probiotic Bacterial Lysate Products

Probiotic bacteria have a wide range of applications in veterinary and human therapeutics. Inactivated probiotics are complex samples and quality control (QC) should measure as many molecular features as possible. Capillary electrophoresis coupled to mass spectrometry (CE/MS) has been used as a multidimensional and high throughput method for the identification and validation of biomarkers of disease in complex biological samples such as biofluids. In this study we evaluate the suitability of CE/MS to measure the consistency of different lots of the probiotic formulation Pro-Symbioflor which is a bacterial lysate of heat-inactivated Escherichia coli and Enterococcus faecalis. Over 5000 peptides were detected by CE/MS in 5 different lots of the bacterial lysate and in a sample of culture medium. 71 to 75% of the total peptide content was identical in all lots. This percentage increased to 87–89% when allowing the absence of a peptide in one of the 5 samples. These results, based on over 2000 peptides, suggest high similarity of the 5 different lots. Sequence analysis identified peptides of both E. coli and E. faecalis and peptides originating from the culture medium, thus confirming the presence of the strains in the formulation. Ontology analysis suggested that the majority of the peptides identified for E. coli originated from the cell membrane or the fimbrium, while peptides identified for E. faecalis were enriched for peptides originating from the cytoplasm. The bacterial lysate peptides as a whole are recognised as highly conserved molecular patterns by the innate immune system as microbe associated molecular pattern (MAMP). Sequence analysis also identified the presence of soybean, yeast and casein protein fragments that are part of the formulation of the culture medium. In conclusion CE/MS seems an appropriate QC tool to analyze complex biological products such as inactivated probiotic formulations and allows determining the similarity between lots.

The intestinal microbiome and necrotizing enterocolitis

PURPOSE OF REVIEW

Necrotizing enterocolitis (NEC) continues to be a major cause of morbidity and mortality in low birth weight infants. Although decades of research point to a role for gut bacteria in the pathogenesis of the disease, the exact relationship between microbes and NEC has not been elucidated. In this review, we describe recent advances in the use of molecular methods to compare gut bacteria in infants with and without NEC.

RECENT FINDINGS

Our understanding of how bacteria contribute to NEC pathogenesis has been limited by the use of traditional, culture-based investigations. Recent advances in microbial ecology and DNA sequencing have made it possible to comprehensively study gut bacterial populations and to understand their physiologic importance. Several studies have identified differences in the microbiota among infants with and without NEC, but the findings have often varied across studies.

SUMMARY

To date, no single change in the gut microbiota has definitively been identified as a risk factor or cause of NEC. The findings at present suggest that NEC does not result from growth of a single causative pathogen, but rather that the disease results from a generalized disturbance of normal colonization patterns in the developing gut.

Robustness of gut microbiota of healthy adults in response to probiotic intervention revealed by high-throughput pyrosequencing

Probiotics are live microorganisms that potentially confer beneficial outcomes to host by modulating gut microbiota in the intestine. The aim of this study was to comprehensively investigate effects of probiotics on human intestinal microbiota using 454 pyrosequencing of bacterial 16S ribosomal RNA genes with an improved quantitative accuracy for evaluation of the bacterial composition. We obtained 158 faecal samples from 18 healthy adult Japanese who were subjected to intervention with 6 commercially available probiotics containing either Bifidobacterium or Lactobacillus strains. We then analysed and compared bacterial composition of the faecal samples collected before, during, and after probiotic intervention by Operational taxonomic units (OTUs) and UniFrac distances. The results showed no significant changes in the overall structure of gut microbiota in the samples with and without probiotic administration regardless of groups and types of the probiotics used. We noticed that 32 OTUs (2.7% of all analysed OTUs) assigned to the indigenous species showed a significant increase or decrease of ≥10-fold or a quantity difference in >150 reads on probiotic administration. Such OTUs were found to be individual specific and tend to be unevenly distributed in the subjects. These data, thus, suggest robustness of the gut microbiota composition in healthy adults on probiotic administration.

Short term outcomes after extreme preterm birth in England: comparison of two birth cohorts in 1995 and 2006 (the EPICure studies)

OBJECTIVE

To determine survival and neonatal morbidity for babies born between 22 and 26 weeks' gestation in England during 2006, and to evaluate changes in outcome since 1995 for babies born between 22 and 25 weeks' gestation.

DESIGN

Prospective national cohort studies.

SETTING

Maternity and neonatal units in England.

PARTICIPANTS

3133 births between 22 and 26 weeks' gestation in 2006; 666 admissions to neonatal units in 1995 and 1115 in 2006 of babies born between 22 and 25 weeks' gestation.

MAIN OUTCOME MEASURES

Survival to discharge from hospital, pregnancy and delivery outcomes, infant morbidity until discharge.

RESULTS

In 2006, survival of live born babies was 2% (n=3) for those born at 22 weeks' gestation, 19% (n=66) at 23 weeks, 40% (n=178) at 24 weeks, 66% (n=346) at 25 weeks, and 77% (n=448) at 26 weeks (P<0.001). At discharge from hospital, 68% (n=705) of survivors had bronchopulmonary dysplasia (receiving supplemental oxygen at 36 weeks postmenstrual age), 13% (n=135) had evidence of serious abnormality on cerebral ultrasonography, and 16% (n=166) had laser treatment for retinopathy of prematurity. For babies born between 22 and 25 weeks' gestation from March to December, the number of admissions for neonatal care increased by 44%, from 666 in 1995 to 959 in 2006. By 2006 adherence to evidence based practice associated with improved outcome had significantly increased. Survival increased from 40% to 53% (P<0.001) overall and at each week of gestation: by 9.5% (confidence interval -0.1% to 19%) at 23 weeks, 12% (4% to 20%) at 24 weeks, and 16% (9% to 23%) at 25 weeks. The proportions of babies surviving in 2006 with bronchopulmonary dysplasia, major cerebral scan abnormality, or weight and/or head circumference <-2 SD were similar to those in 1995, but the proportion treated for retinopathy of prematurity had increased from 13% to 22% (P=0.006). Predictors of mortality and morbidity were similar in both cohorts.

CONCLUSION

Survival of babies born between 22 and 25 weeks' gestation has increased since 1995 but the pattern of major neonatal morbidity and the proportion of survivors affected are unchanged. These observations reflect an important increase in the number of preterm survivors at risk of later health problems.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common acquired gastrointestinal disease of premature neonates and is a serious cause of morbidity and mortality. NEC is one of the leading causes of death in neonatal intensive care units. Surgical treatment is necessary in patients whose disease progresses despite medical therapy. Surgical options include peritoneal drainage and laparotomy, with studies showing no difference in outcome related to approach. Survivors, particularly those requiring surgery, face serious sequelae.

The crying baby: what approach?

PURPOSE OF REVIEW

Cry-fuss problems are among the most common clinical presentations in the first few months of life and are associated with adverse outcomes for some mothers and babies. Cry-fuss behaviour emerges out of a complex interplay of cultural, psychosocial, environmental and biologic factors, with organic disturbance implicated in only 5% of cases. A simplistic approach can have unintended consequences. This article reviews recent evidence in order to update clinical management.

RECENT FINDINGS

New research is considered in the domains of organic disturbance, feed management, maternal health, sleep management, and sensorimotor integration. This transdisciplinary approach takes into account the variable neurodevelopmental needs of healthy infants, the effects of feeding management on the highly plastic neonatal brain, and the bi-directional brain-gut-enteric microbiota axis. An individually tailored, mother-centred and family-centred approach is recommended.

SUMMARY

The family of the crying baby requires early intervention to assess for and manage potentially treatable problems. Cross-disciplinary collaboration is often necessary if outcomes are to be optimized.

Colonization of the Gastrointestinal Tract in Neonates

Bacterial colonization of the neonatal gastrointestinal tract has emerged as an issue involving nutrition, immunity, and overall mortality. Bacterial organisms colonizing the gastrointestinal tract play a vital role in maintaining intestinal homeostasis, including digestion, nutrient absorption, and immunological mechanisms. In neonates, these bacteria are essential in postnatal development of intestinal mucosa and gut-associated lymphoid tissue critical for immunological protection. Colonization of bacteria is thought to occur over the first 1 to 2 weeks of life. Delivery mode, feeding method, and environment affect the succession and establishment of the beneficial bacteria in the neonate. Neonates delivered vaginally are colonized by the bacteria from the mother, whereas neonates delivered via caesarean section initially colonize with bacteria from the environment. Feeding method is another factor; Bifidobacterium species are believed to dominate the microflora of breastfed infants by day of life 2 to 3 and are thought to be critical in postnatal immunology. Formula-fed infants often have a more diverse microflora and a less obvious presence of the Bifidobacterium. Compared with healthy, term neonates, preterm infants have a significant delay in bacterial colonization. The effects of an immature gastrointestinal track, lack of enteral feeding, and the frequent use of antibiotic therapy are believed to contribute to the delay and imbalance in the microflora of preterm infants. Prolonged exposure to hospital bacteria increases the risk of colonization with strains specific to hospital flora.