Histamine-2 receptor blockers alter the fecal microbiota in premature infants

Lactobacillus reuteri for Infants with Colic: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial

OBJECTIVE

To assess the safety of probiotic Lactobacillus reuteri strain Deutsche Sammlung von Mikroorganismen (DSM) 17938 with daily administration to healthy infants with colic and to determine the effect of L reuteri strain DSM 17938 on crying, fussing, inflammatory, immune, and microbiome variables.

STUDY DESIGN

We performed a controlled, double-blinded, phase 1 safety and tolerability trial in healthy breast-fed infants with colic, aged 3 weeks to 3 months, randomly assigned to L reuteri strain DSM 17938 (5 × 108 colony-forming units daily) or placebo for 42 days and followed for 134 days.

RESULTS

Of 117 screened infants, 20 were randomized to L reuteri strain DSM 17938 or placebo (sunflower oil) (in a 2:1 ratio) with 80% retention. Eleven of the 20 (55%) presented with low absolute neutrophil counts (<1500/mm3), which resolved in all subjects by day 176. L reuteri strain DSM 17938 produced no severe adverse events and did not significantly change crying time, plasma bicarbonate, or inflammatory biomarkers. Fecal calprotectin decreased rapidly in both groups. In the infants with dominant fecal gram negatives (Klebsiella, Proteus, and Veillonella), resolution of colic was associated with marked decreases in these organisms.

CONCLUSIONS

Daily administration of L reuteri strain DSM 17938 appears to be safe in newborn infants with colic, including those with neutropenia, which frequently coexists. A placebo response of 66% suggests that many infants with colic will have resolution within 3 weeks.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01849991.

Reducing Incidence of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a multifactorial disease that occurs when multiple risk factors and/or stressors overlap, leading to profound inflammation and intestinal injury. Due to its multifactorial nature, there has been much uncertainty in identifying clear strategies for prevention of NEC. Despite these obstacles, the incidence of NEC has gradually been decreasing over the past 10 years, in part due to quality improvement (QI) initiatives to prevent NEC. Current QI strategies primarily target the various predisposing conditions. This article reviews the evidence on which QI interventions to prevent NEC have been based and provides examples of successful QI interventions.

Necrotizing enterocolitis: Current concepts in practice

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants and continues to be a major cause of morbidity and mortality. The incidence of NEC as well as mortality from the disease has persisted at unacceptably high levels for decades as current understanding of the cause remains incomplete. Identifying infants at risk and preventing NEC are mainstays of care. This article briefly examines disease presentation and treatment, identifies gaps in current understanding of disease pathology, and highlights new research that may lead to a decrease in the incidence of NEC in the future.

Resetting microbiota by Lactobacillus reuteri inhibits T reg deficiency-induced autoimmunity via adenosine A2A receptors

Regulatory T (T reg) cell deficiency causes lethal, CD4+ T cell-driven autoimmune diseases. Stem cell transplantation is used to treat these diseases, but this procedure is limited by the availability of a suitable donor. The intestinal microbiota drives host immune homeostasis by regulating the differentiation and expansion of T reg, Th1, and Th2 cells. It is currently unclear if T reg cell deficiency-mediated autoimmune disorders can be treated by targeting the enteric microbiota. Here, we demonstrate that Foxp3+ T reg cell deficiency results in gut microbial dysbiosis and autoimmunity over the lifespan of scurfy (SF) mouse. Remodeling microbiota with Lactobacillus reuteri prolonged survival and reduced multiorgan inflammation in SF mice. L. reuteri changed the metabolomic profile disrupted by T reg cell deficiency, and a major effect was to restore levels of the purine metabolite inosine. Feeding inosine itself prolonged life and inhibited multiorgan inflammation by reducing Th1/Th2 cells and their associated cytokines. Mechanistically, the inhibition of inosine on the differentiation of Th1 and Th2 cells in vitro depended on adenosine A2A receptors, which were also required for the efficacy of inosine and of L. reuteri in vivo. These results reveal that the microbiota-inosine-A2A receptor axis might represent a potential avenue for combatting autoimmune diseases mediated by T reg cell dysfunction.

Safety of histamine-2 receptor blockers in hospitalized VLBW infants

BACKGROUND

Histamine-2 receptor (H2) blockers are often used in very low birth weight infants despite lack of population specific efficacy and safety data.

AIMS

We sought to describe safety and temporal trends in histamine-2 receptor (H2) blocker use in hospitalized very low birth weight (VLBW) infants.

STUDY DESIGN

We conducted a retrospective cohort study using a clinical database populated by an electronic health record shared by 348 neonatal intensive care units in the United States.

SUBJECTS

We included all VLBW infants without major congenital anomalies.

OUTCOME MEASURES

We used multivariable logistic regression with generalizing estimating equations to evaluate the association between days of H2 blocker exposure and risk of: 1) death or necrotizing enterocolitis (NEC); 2) death or sepsis; and 3) death, NEC, or sepsis.

RESULTS

Of 127,707 infants, 20,288 (16%) were exposed to H2 blockers for a total of 6,422,352days. Median gestational age for infants exposed to H2 blockers was 27weeks (25th 75th percentile 26, 29). H2 blocker use decreased from 18% of infants in 1997 to 8% in 2012 (p<0.001). On multivariable analysis, infants were at increased risk of the combined outcome of death, NEC, or sepsis on days exposed to H2 blockers (odds ratio=1.14) (95% confidence interval 1.08, 1.19).

CONCLUSIONS

H2 blocker use is associated with increased risk of the combined outcome of death, NEC, or sepsis in hospitalized VLBW infants.

Gut Microbiome and Kidney Disease in Pediatrics: Does Connection Exist?

Child development is a unique and continuous process that is impacted by genetics and environmental factors. Gut microbiome changes with development and depends on the stage of gut maturation, nutrition, and overall health. In spite of emerging data and active study in adults, the gut-renal axis in pediatrics has not been well considered and investigated. This review will focus on the current knowledge of gut microbiota impacts on kidney disease with extrapolation to the pediatric population.

The Developing Microbiome of the Preterm Infant

PURPOSE

To determine the importance of the neonatal microbiome in intestinal and overall health.

METHOD

A review of existing literature.

FINDINGS AND IMPLICATIONS

The microbiome is increasingly understood to have a significant role in health and disease. However, the microbiome of the preterm infant is unique, with simple microbial communities exposed to a consistent diet in a regulated environment, and development from naive to stable under the influence of the neonatal intensive care unit. This early microbiome encounters a still developing host and thus has the potential to program fundamental pathways with implications for neonatal and later outcomes.

Hypoallergenic formula with Lactobacillus rhamnosus GG for babies with colic: A pilot study of recruitment, retention, and fecal biomarkers

AIM

To investigate recruitment, retention, and estimates for effects of formula supplementation with Lactobacillus rhamnosus GG (LGG) on inflammatory biomarkers and fecal microbial community in infants with colic.

METHODS

A prospective, double-blind, placebo-controlled trial was conducted in otherwise healthy infants with colic. We screened 74 infants and randomized and analyzed results in 20 infants [9 receiving LGG (LGG+) and 11 not receiving LGG (LGG-)]. LGG was incorporated in the formula (Nutramigen(®)) (minimum of 3 × 10(7) CFU/d) in the LGG+ group. Fecal microbiota and inflammatory biomarkers, including fecal calprotectin (FC), plasma cytokines, circulating regulatory T cells (Tregs), and crying + fussing time were analyzed to determine optimal time points and effect sizes for a larger trial.

RESULTS

Recruitment in this population was slow, with about 66% of eligible infants willing to enroll; subject retention was better (75%). These rates were influenced by parents' reluctance to volunteer their infant for a clinical trial and by their tendency to change formulas. The maximal difference of crying + fussing time was observed at day 14, comparing the 2 groups, with a mean difference of -91 (95%CI: -76, 259) min (P = NS). FC showed no significant difference, but the optimal time to determine a potential effect was at day 90 [with a mean difference of 121 (95%CI: -48, 291) μg/g stool], observing a lower level of FC in the LGG+ group. The fecal microbial communities were chaotic, as determined by Shannon's diversity index and not apparently influenced by the probiotic. No significant change was observed in plasma inflammatory cytokines or Tregs, comparing LGG+ to LGG- groups.

CONCLUSION

Designing future colic trials involving a probiotic-supplemented formula for infants in the United States will require consideration for difficult enrollment. Infants with colic have major variations in feal microbiota and calprotectin, both of which improve with time, with optimal time points for measurement at days 14 and 90 after treatment.

Prevention of Necrotizing Enterocolitis Through Manipulation of the Intestinal Microbiota of the Premature Infant

PURPOSE

In spite of four decades of research, necrotizing enterocolitis (NEC) remains the most common gastrointestinal complication in premature infants with high mortality and long-term morbidity. The composition of the intestinal microbiota of the premature infant differs dramatically from that of the healthy term infant and appears to be an important risk factor for NEC.

METHODS

We review the evidence of an association between intestinal dysbiosis and NEC and summarize published English language clinical trials and cohort studies involving attempts to manipulate the intestinal microbiota in premature infants.

FINDINGS

Promising NEC prevention strategies that alter the intestinal microbiota include probiotics, prebiotics, synbiotics, lacteroferrin, and human milk feeding.

IMPLICATIONS

Shaping the intestinal microbiota of the premature infant through human milk feeding and dietary supplements decreases the risk of NEC. Further studies to identify the ideal microbial composition and the most effective combination of supplements are indicated.

Longitudinal Survey of Microbiota in Hospitalized Preterm Very-Low-Birth-Weight Infants

OBJECTIVES

The aim of the present study was to examine the changes in bacteria in hospitalized preterm infants during the first month of life.

METHODS

Rectal swabs were collected daily from 12 preterm infants. DNA was extracted from swabs from day of birth and weekly thereafter. Bacterial taxa were identified with next generation sequencing using universal bacterial primers targeted at the 16S ribosomal DNA on a 454 Roche titanium platform. Sequences were clustered into operational taxonomic units, and taxonomy was assigned against the Greengenes databank using Quantitative Insights Into Microbial Ecology version 1.4. Quantitative polymerase chain reaction was used to determine the abundance of Bifidobacterium spp. Functional assessment of the microbiome was performed with Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).

RESULTS

Average birth weight and gestational age were 1055 g and 28 weeks, respectively. There were 6 to 35 different bacterial families identified in the day-of-birth samples, unrelated to the mode of delivery. Richness decreased through hospitalization (week 1, 16.9 ± 7.7 vs weeks 3-5, 10.7 ± 3.4, P < 0.001). The Shannon diversity index demonstrated the lowest diversity at birth, an increase at week 2, followed by a rapid decline at weeks 3 to 5, suggesting the development of a more uniform microbiota composition after 2 weeks of stay at a neonatal intensive care unit. Enterobacteriaceae, Staphylococcaceae, and Enterococcaceae constituted the majority of the bacterial families. Bifidobacterium spp were infrequently detected at extremely low levels. PICRUSt analysis revealed the enhancement of peroxisome, PPAR, and adipocytokine signaling; plant-pathogen interaction; and aminobenzoate degradation pathways in week 1 samples.

CONCLUSIONS

Our results suggest that although preterm infants have individualized microbiota that are detectable at birth, the differences decrease during the neonatal intensive care unit hospitalization with increasing prominence of pathogenic microbiota.

Respiratory Microbiome of New-Born Infants

The respiratory tract, once believed to be sterile, harbors diverse bacterial communities. The role of microorganisms within health and disease is slowly being unraveled. Evidence points to the neonatal period as a critical time for establishing stable bacterial communities and influencing immune responses important for long-term respiratory health. This review summarizes the evidence of early airway and lung bacterial colonization and the role the microbiome has on respiratory health in the short and long term. The challenges of neonatal respiratory microbiome studies and future research directions are also discussed.

Probiotics and Innate and Adaptive Immune Responses in Premature Infants

Premature infants are at increased risk for morbidity and mortality due to necrotizing enterocolitis (NEC) and sepsis. Probiotics decrease the risk of NEC and death in premature infants; however, mechanisms of action are unclear. A wide variety of probiotic species have been evaluated for potential beneficial properties in vitro, in animal models, and in clinical trials of premature infants. Although there is variation by species and even strain, common mechanisms of protection include attenuation of intestinal inflammation, apoptosis, dysmotility, permeability, supplanting other gut microbes through production of bacteriocins, and more effective use of available nutrients. Here, we review the most promising probiotics and what is known about their impact on the innate and adaptive immune response.

Histamine H2 Receptor-Mediated Suppression of Intestinal Inflammation by Probiotic Lactobacillus reuteri

Probiotics and commensal intestinal microbes suppress mammalian cytokine production and intestinal inflammation in various experimental model systems. Limited information exists regarding potential mechanisms of probiotic-mediated immunomodulation in vivo. In this report, we demonstrate that specific probiotic strains of Lactobacillus reuteri suppress intestinal inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Only strains that possess the hdc gene cluster, including the histidine decarboxylase and histidine-histamine antiporter genes, can suppress colitis and mucosal cytokine (interleukin-6 [IL-6] and IL-1β in the colon) gene expression. Suppression of acute colitis in mice was documented by diminished weight loss, colonic injury, serum amyloid A (SAA) protein concentrations, and reduced uptake of [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) in the colon by positron emission tomography (PET). The ability of probiotic L. reuteri to suppress colitis depends on the presence of a bacterial histidine decarboxylase gene(s) in the intestinal microbiome, consumption of a histidine-containing diet, and signaling via the histamine H2 receptor (H2R). Collectively, luminal conversion of l-histidine to histamine by hdc⁺L. reuteri activates H2R, and H2R signaling results in suppression of acute inflammation within the mouse colon.

Probiotics are microorganisms that when administered in adequate amounts confer beneficial effects on the host. Supplementation with probiotic strains was shown to suppress intestinal inflammation in patients with inflammatory bowel disease and in rodent colitis models. However, the mechanisms of probiosis are not clear. Our current studies suggest that supplementation with hdc⁺L. reuteri, which can convert l-histidine to histamine in the gut, resulted in suppression of colonic inflammation. These findings link luminal conversion of dietary components (amino acid metabolism) by gut microbes and probiotic-mediated suppression of colonic inflammation. The effective combination of diet, gut bacteria, and host receptor-mediated signaling may result in opportunities for therapeutic microbiology and provide clues for discovery and development of next-generation probiotics.

Hospitalization Type and Subsequent Severe Sepsis

RATIONALE

Hospitalization is associated with microbiome perturbation (dysbiosis), and this perturbation is more severe in patients treated with antimicrobials.

OBJECTIVES

To evaluate whether hospitalizations known to be associated with periods of microbiome perturbation are associated with increased risk of severe sepsis after hospital discharge.

METHODS

We studied participants in the U.S. Health and Retirement Study with linked Medicare claims (1998-2010). We measured whether three hospitalization types associated with increasing severity of probable dysbiosis (non-infection-related hospitalization, infection-related hospitalization, and hospitalization with Clostridium difficile infection [CDI]) were associated with increasing risk for severe sepsis in the 90 days after hospital discharge. We used two study designs: the first was a longitudinal design with between-person comparisons and the second was a self-controlled case series design using within-person comparison.

MEASUREMENTS AND MAIN RESULTS

We identified 43,095 hospitalizations among 10,996 Health and Retirement Study-Medicare participants. In the 90 days following non-infection-related hospitalization, infection-related hospitalization, and hospitalization with CDI, adjusted probabilities of subsequent admission for severe sepsis were 4.1% (95% confidence interval [CI], 3.8-4.4%), 7.1% (95% CI, 6.6-7.6%), and 10.7% (95% CI, 7.7-13.8%), respectively. The incidence rate ratio (IRR) of severe sepsis was 3.3-fold greater during the 90 days after hospitalizations than during other observation periods. The IRR was 30% greater after an infection-related hospitalization versus a non-infection-related hospitalization. The IRR was 70% greater after a hospitalization with CDI than an infection-related hospitalization without CDI.

CONCLUSIONS

There is a strong dose-response relationship between events known to result in dysbiosis and subsequent severe sepsis hospitalization that is not present for rehospitalization for nonsepsis diagnoses.

Intestinal microbiota and its relationship with necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in infants born prematurely. After birth, the neonatal gut must acquire a healthy complement of commensal bacteria. Disruption or delay of this critical process, leading to deficient or abnormal microbial colonization of the gut, has been implicated as key risk factor in the pathogenesis of NEC. Conversely, a beneficial complement of commensal intestinal microbiota may protect the immature gut from inflammation and injury. Interventions aimed at providing or restoring a healthy complement of commensal bacteria, such as probiotic therapy, are currently the most promising treatment to prevent NEC. Shifting the balance of intestinal microbiota from a pathogenic to protective complement of bacteria can protect the gut from inflammation and subsequent injury that leads to NEC. Herein, we review the relationship of intestinal microbiota and NEC in preterm infants.

Bloodstream infections: epidemiology and resistance

Bloodstream infections in the neonatal intensive care unit (NICU) are associated with many adverse outcomes in infants, including increased length of stay and cost, poor neurodevelopmental outcomes, and death. Attention to the insertion and maintenance of central lines, along with careful review of when the catheters can be safely discontinued, can minimize central-line-associated bloodstream infections rates. Good antibiotic stewardship can further decrease the incidence of bloodstream infections, minimize the emergence of drug-resistant organisms or Candida as pathogens in the NICU, and safeguard the use of currently available antibiotics for future infants.

The human neonatal gut microbiome: a brief review

The field of genomics has expanded into subspecialties such as metagenomics over the course of the last decade and a half. The development of massively parallel sequencing capabilities has allowed for increasingly detailed study of the genome of the human microbiome, the microbial super organ that resides symbiotically within the mucosal tissues and integumentary system of the human host. The gut microbiome, and particularly the study of its origins in neonates, has become subtopics of great interest within the field of genomics. This brief review seeks to summarize recent literature regarding the origins and establishment of the neonatal gut microbiome, beginning in utero, and how it is affected by neonatal nutritional status (breastfed versus formula fed) and gestational age (term versus preterm). We also explore the role of dysbiosis, a perturbation within the fragile ecosystem of the microbiome, and its role in the origin of select pathologic states, specifically, obesity and necrotizing enterocolitis (NEC) in preterm infants. We discuss the evidence supporting enteral pre- and pro-biotic supplementation of commensal organisms such as Bifidobacterium and Lactobacillus in the neonatal period, and their role in the prevention and amelioration of NEC in premature infants. Finally, we review directions to consider for further research to promote human health within this field.

Bacterial diversity and Clostridia abundance decrease with increasing severity of necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating neonatal gastrointestinal disease that primarily affects premature infants. It is characterized by bowel inflammation and necrosis. In spite of extensive research, there has been little progress in decreasing the incidence or mortality of NEC over the past three decades. The exact etiology of NEC has not been identified. However, it is believed to result from an inappropriate immune response to gut microbiota. Using 454-pyrosequencing analyses of 16S rRNA genes that were PCR-amplified from stool DNA specimens, we compared the gut microbiota of infants with NEC to matched controls without NEC. The infants with NEC were then categorized into three subgroups based on severity: mild, severe, and lethal. We compared the microbiota among these subgroups and between each severity group and appropriate controls.

RESULTS

Bacterial diversity and the relative abundance of Actinobacteria and Clostridia were significantly lower in NEC specimens compared to controls. The absence of Clostridia was significantly associated with NEC. Microbial diversity and Clostridia abundance and prevalence decreased with increasing severity of NEC.

CONCLUSIONS

Low bacterial diversity in stool specimens may be indicative of NEC and the severity of NEC. The low bacterial diversity, and the lack of Clostridia in lethal specimens, could indicate that the presence of a diverse bacterial population in the gut as well as the presence of taxa such as Clostridia may play a role in attenuating inflammation leading to NEC.

The impact of the milk glycobiome on the neonate gut microbiota

Human milk is a complete source of nourishment for the infant. Exclusive breastfeeding not only sustains the infant's development but also guides the proliferation of a protective intestinal microbiota. Among the many components of milk that modulate the infant gut microbiota, the milk glycans, which comprise free oligosaccharides, glycoproteins, and glycolipids, are increasingly recognized as drivers of microbiota development and overall gut health. These glycans may display pleiotropic functions, conferring protection against infectious diseases and also acting as prebiotics, selecting for the growth of beneficial intestinal bacteria. The prebiotic effect of milk glycans has direct application to prevention of diseases such as necrotizing enterocolitis, a common and devastating disease of preterm infants. In this article, we review the impact of the human (and bovine) milk glycome on gut health through establishment of a milk-oriented microbiota in the neonate.

Bifidobacterium longum subsp. infantis in experimental necrotizing enterocolitis: alterations in inflammation, innate immune response, and the microbiota

BACKGROUND

Probiotics decrease the risk of necrotizing enterocolitis (NEC). We sought to determine the impact of Bifidobacterium longum subsp. infantis (B. infantis) in the established rat model of NEC.

METHODS

Rat pups delivered 1 d prior to term gestation were assigned to one of three groups: dam fed (DF), formula fed (FF), or fed with formula supplemented with 5 × 10(6) CFU B. infantis per day (FF+Binf). Experimental pups were exposed to hypoxia and cold stress. Ileal tissue was examined for pathology and expression of inflammatory mediators, antimicrobial peptides, and goblet-cell products. Ceca were assessed for bacterial composition by analysis of the 16S rRNA sequence.

RESULTS

Administration of B. infantis significantly reduced the incidence of NEC, decreased expression of Il6, Cxcl1, Tnfa, Il23, and iNOS, and decreased expression of the antimicrobial peptides Reg3b and Reg3g. There was significant microbial heterogeneity both within groups and between experiments. The cecal microbiota was not significantly different between the FF and FF+Binf groups. Bifidobacteria were not detected in the cecum in significant numbers.

CONCLUSION

In the rat model, the inflammation associated with NEC was attenuated by administration of probiotic B. infantis. Dysbiosis was highly variable, precluding determination of the precise role of the microbiota in experimental NEC.

Necrotizing enterocolitis: the road to zero

Necrotizing enterocolitis (NEC) continues to be the most severe gastrointestinal emergency facing the preterm neonate. The pathogenesis of NEC is still a complex and poorly understood process, but with increasing understanding of the role of enteral feeding, gut immunity and the altered gut microbiota, new opportunities to reduce overall NEC rates are now possible. Prevention strategies continue to lead as the most suitable approaches to reducing NEC, as early diagnosis and rapid effective treatment of NEC are still not optimal. Programmatic changes are equally important as subscribing to individual prevention strategies. The primary focus of this review is to summarize the best strategies we currently have to eliminate NEC within an institution.

Probiotic administration in congenital heart disease: a pilot study

OBJECTIVE

To investigate the impact of probiotic Bifidobacterium longum ssp. infantis on the fecal microbiota and plasma cytokines in neonates with congenital heart disease.

STUDY DESIGN

Sixteen infants with congenital heart disease were randomly assigned to receive either B. infantis (4.2 × 10(9) colony-forming units two times daily) or placebo for 8 weeks. Stool specimens from enrolled infants and from six term infants without heart disease were analyzed for microbial composition. Plasma cytokines were analyzed weekly in the infants with heart disease.

RESULTS

Healthy control infants had increased total bacteria, total Bacteroidetes and total bifidobacteria compared to the infants with heart disease, but there were no significant differences between the placebo and probiotic groups. Plasma interleukin (IL)10, interferon (IFN)γ and IL1β levels were transiently higher in the probiotic group.

CONCLUSION

Congenital heart disease in infants is associated with dysbiosis. Probiotic B. infantis did not significantly alter the fecal microbiota. Alterations in plasma cytokines were found to be inconsistent.

Pharmacological therapy of gastroesophageal reflux in preterm infants

Although gastroesophageal reflux (GER) is a very common phenomenon among preterm infants, its therapeutic management is still an issue of debate among neonatologists. A step-wise approach should be advisable, firstly promoting nonpharmacological interventions and limiting drugs to selected infants unresponsive to the conservative measures or who are suffering from severe GER with clinical complications. Despite of this, a concerning pharmacological overtreatment has been increasingly reported. Most of the antireflux drugs, however, have not been specifically assessed in preterm infants; moreover, serious adverse effects have been noticed in association to their administration. This review mainly aims to draw the state of the art regarding the pharmacological management of GER in preterm infants, analyzing the best piecies of evidence currently available on the most prescribed anti-reflux drugs. Although further trials are required, sodium alginate-based formulations might be considered promising; however, data regarding their safety are still limited. Few piecies of evidence on the efficacy of histamine-2 receptor blockers and proton pump inhibitors in preterm infants with GER are currently available. Nevertheless, a significantly increased risk of necrotizing enterocolitis and infections has been largely reported in association with their use, thereby leading to an unfavorable risk-benefit ratio. The efficacy of metoclopramide in GER's improvement still needs to be clarified. Other prokinetic agents, such as domperidone and erythromycin, have been reported to be ineffective, whereas cisapride has been withdrawn due to its remarkable cardiac adverse effects.