Enteral nutrition protects children undergoing allogeneic hematopoietic stem cell transplantation from blood stream infections

[Advances in nutritional support for children undergoing hematopoietic stem cell transplantation]

Hematopoietic stem cell transplantation (HSCT) is a therapeutic option for various potentially life-threatening malignant and non-malignant diseases in children, such as malignancies, immunodeficiency syndromes, severe aplastic anemia, and inherited metabolic disorders. During transplantation, many factors can affect the nutritional status of the children, including radiotherapy, chemotherapy, gastrointestinal disorders, graft-versus-host disease, and medications. Malnutrition has been associated with decreased overall survival and increased complications in children undergoing HSCT, making nutritional support a crucial component of their management. However, currently, there is a lack of guidelines or consensus on nutritional support for children undergoing HSCT in China. Therefore, this review summarizes the progress in nutritional support for children undergoing HSCT, aiming to provide clinical guidance.

The Microbiome and Pediatric Transplantation

The microbial communities that inhabit our bodies have been increasingly linked to host physiology and pathophysiology. This microbiome, through its role in colonization resistance, influences the risk of infections after transplantation, including those caused by multidrug-resistant organisms. In addition, through both direct interactions with the host immune system and via the production of metabolites that impact local and systemic immunity, the microbiome plays an important role in the establishment of immune tolerance after transplantation, and conversely, in the development of graft-versus-host disease and graft rejection. This review offers a comprehensive overview of the evidence for the role of the microbiome in hematopoietic cell and solid organ transplant complications, drivers of microbiome shift during transplantation, and the potential of microbiome-based therapies to improve pediatric transplantation outcomes.

Epidemiologic and microbiologic evaluation of catheter-line bloodstream infection in a pediatric hematopoietic stem cell transplant center

BACKGROUND

Children who underwent hematopoietic stem cell transplant (HSCT) transplants are at high risk of developing central-line-associated bloodstream infections (CLABSIs). The present study aimed to identify possible risk factors for mortality by analyzing the clinical and laboratory characteristics of patients diagnosed with CLABSI in our pediatric hematopoietic stem cell transplant unit.

METHODS

The initial CLABSI episodes of 102 children were analyzed. Medical records of the patients were evaluated by preformed standardized surveys. Univariate analysis and multivariate logistic regression analysis were performed to identify risk factors for mortality.

RESULTS

Thirty-five patients (34.3%) were female. The median age was 48 months (3-204). The median time to onset of CLABSI was 19 days (4-150). The gram-negative and gram-positive bacteria ratio among the causative agents was 57.8% to 34.3%. The mortality rate was 12.6%. The presence of severe neutropenia, initiation of inappropriate empirical antibiotic therapy, the presence of hypotension, persistent bacteremia, pediatric intensive care unit admission, growth of carbapenemase-positive gram-negative microorganism and multidrug-resistant bacteria were significantly high in the mortality group when compared to survivors. The presence of hypotension, inappropriate empirical antibiotic therapy, and persistent bacteremia were found to be independent risk factors for mortality.

CONCLUSIONS

Rational use of antibiotics, active surveillance and screening of patients together with improved infection control practices may reduce the incidence and the consequences of CLABSIs.

Nutritional status and body mass index before hematopoietic stem cell transplantation (HSCT) and associated outcomes: a rapid review

PURPOSE

Hematopoietic stem cell transplantation (HSCT) recipients experience several post-HSCT complications affecting nutritional status, body mass index (BMI), and mortality that can potentially be mitigated by nutritional management. This rapid review examines the relationship between pre-HSCT nutritional status and BMI and post-HSCT survival.

METHODS

Articles were identified from PubMed, Scopus, and Embase. Two researchers independently completed the title, abstract, and full-text review. Inclusion criteria included the following: (1) randomized clinical trials or observational studies; (2) human subjects diagnosed with cancer and undergoing HSCT; (3) reported pre-HSCT nutritional status (e.g., diet recall, nutritional survey, dietitian session) or BMI; and (4) reported treatment related mortality and/or survival.

RESULTS

The initial search found 3036 articles, 28 were included in full-text review, and 18 met inclusion criteria. Articles had quasi-experimental (n = 2) and observational (n = 16) study designs. Of the studies, n = 5 reported nutritional intake decreased post-HSCT, and n = 2 reported nutrition intervention (i.e., controlled feeding) post-HSCT improved survival. Four studies reported having a BMI classified as underweight improved survival, while n = 5 reported having a BMI classified as overweight or obese improved survival.

CONCLUSION

Current research exploring the relationship between nutritional status and BMI with HSCT survival is mixed. Further research is needed to determine how nutritional status and BMI are associated withsurvival post-HSCT to inform future intervention work.

Impact of percutaneous endoscopic gastrostomy on pediatric bone marrow transplantation outcomes: Retrospectice single-center cohort study

BACKGROUND

Parenteral nutrition is commonly used to ensure nutrition support and prevent the harmful effects of malnutrition, which frequently occurs after allogeneic hematopoietic stem cell transplantation (aHSCT). Nevertheless, enteral nutrition supports the restoration of the gut barrier and microbiome as well as protects against infectious complications and acute graft-vs-host disease. Percutaneous endoscopic gastrostomy (PEG) may also be beneficial for gastric decompression and drug administration.

METHODS

We performed a retrospective cohort study to evaluate the impact of PEG on treatment outcomes in 75 children who underwent aHSCT with (n = 34) or without (n = 41) PEG from 2005 to 2016.

RESULTS

In 34 patients, PEG was used to ensure enteral nutrition support (n = 30), oral drug intake (n = 28), and abdominal decompression (n = 2). During the study period, we observed a beneficial association between PEG placement and transplant-related mortality as well as 5-year overall survival compared with the non-PEG group (12.9% vs 59.0%, P = 0.000; 85.3% vs 35.1%, P = 0.000, respectively). The beneficial impact of PEG was most prominent on 5-year overall survival in older children (12-17 years) with grafts from matched unrelated donors.

CONCLUSIONS

PEG placement had a positive association with transplant outcomes in pediatric patients undergoing aHSCT. To confirm these results, larger prospective studies are needed.

Administration of ciprofloxacin through a nasogastric tube in pediatric oncology and stem cell transplantation patients

Pediatric oncology and hematopoietic stem cell transplantation patients are facing many gastrointestinal side effects of chemotherapy, including nausea, vomiting, mucositis, and diarrhea. International guidelines advise early enteral tube feeding as the first option of nutritional support in children undergoing myeloablative hematopoietic stem cell transplantation. When using enteral feeding tubes for nutritional purposes as well as drug administration, some pharmaceutical, nursing, and technical issues have to be taken into account. Ciprofloxacin is a fluoroquinolone, widely used because of its broad spectrum antimicrobial activity and favorable pharmacokinetic properties. However, its co-administration with polyvalent cations (as present in enteral feeding) makes the absorption of ciprofloxacin more difficult and may alter the pharmacokinetic parameters. Literature data are conflicting on how long the enteral feeding should be discontinued for patients receiving ciprofloxacin via an enteral feeding tube, ranging from 2 h before to 6 h after the administration of ciprofloxacin. Our research question was guided by challenges and concerns of nurses about the delay time between ciprofloxacin administration and restart of the enteral feeding without compromising the nutritional intake of the children. Our guideline was adapted, nurses were instructed accordingly, and patient leaflets with correct information were created.

Adverse effects of antibiotics in children with cancer: are short-course antibiotics for febrile neutropenia part of the solution?

INTRODUCTION

Febrile neutropenia is a common complication experienced by children with cancer or those undergoing hematopoietic stem cell transplantation. Repeated episodes of febrile neutropenia result in cumulative exposure to broad-spectrum antibiotics with potential for a range of serious adverse effects. Short-course antibiotics, even in patients with high-risk febrile neutropenia, may offer a solution.

AREAS COVERED

This review addresses the known broad effects of antibiotics, highlights developments in understanding the relationship between cancer, antibiotics, and the gut microbiome, and discusses emerging evidence regarding long-term adverse antibiotic effects. The authors consider available evidence to guide the duration of empiric antibiotics in pediatric febrile neutropenia and directions for future research.

EXPERT OPINION

Broad-spectrum antibiotics are associated with antimicrobial resistance, Clostridioides difficile infection, invasive candidiasis, significant disturbance of the gut microbiome and may seriously impact outcomes in children with cancer or undergoing allogenic hematopoietic stem cell transplant. Short-course empiric antibiotics are likely safe in most children with febrile neutropenia and present a valuable opportunity to reduce the risks of antibiotic exposure.

Role of Nutrition in Pediatric Patients with Cancer

Children with cancer are at high risk for developing short-term and long-term nutritional problems related to their underlying disease and side effects of multimodal treatments. Nutritional status (NS) can influence several clinical outcomes, such as overall survival (OS) and event-free survival (EFS), treatment tolerance, risk of developing infections and quality of life (QoL). However, the importance of nutrition in children with cancer is still underestimated. This review focuses on alterations of NS that occurs in children during cancer treatment. In particular, we reviewed the pathogenesis of undernutrition in oncological children, as well as how NS affects treatment tolerance and response, the immune system and the risk of infections of children with cancer. Thanks to recent advances in all types of supportive therapy and to the progress of knowledge on this topic, it has been realized that NS is a modifiable prognostic factor that can be intervened upon to improve the outcome of these patients. Currently, there is a lack of a systematic approach and standard recommendations for nutritional care in the pediatric cancer population. Literature analysis showed that it is essential to define the NS and treat any alterations in a timely manner ensuring proper growth and development. Nutritional follow-up should become an integral part of the care pathway. Regular nutritional monitoring should be performed at diagnosis, during treatment and during follow-up. A close collaboration and sharing of expertise between pediatric oncologists and nutrition specialists, combined with careful and participatory sharing of the feeding experience with the family and the child (after age 6 years), is strongly required.

Levofloxacin prophylaxis and parenteral nutrition have a detrimental effect on intestinal microbial networks in pediatric patients undergoing HSCT

The gut microbiome (GM) has shown to influence hematopoietic stem cell transplantation (HSCT) outcome. Evidence on levofloxacin (LVX) prophylaxis usefulness before HSCT in pediatric patients is controversial and its impact on GM is poorly characterized. Post-HSCT parenteral nutrition (PN) is oftentimes the first-line nutritional support in the neutropenic phase, despite the emerging benefits of enteral nutrition (EN). In this exploratory work, we used a global-to-local networking approach to obtain a high-resolution longitudinal characterization of the GM in 30 pediatric HSCT patients receiving PN combined with LVX prophylaxis or PN alone or EN alone. By evaluating the network topology, we found that PN, especially preceded by LVX prophylaxis, resulted in a detrimental effect over the GM, with low modularity, poor cohesion, a shift in keystone species and the emergence of modules comprising several pathobionts, such as Klebsiella spp., [Ruminococcus] gnavus, Flavonifractor plautii and Enterococcus faecium. Our pilot findings on LVX prophylaxis and PN-related disruption of GM networks should be considered in patient management, to possibly facilitate prompt recovery/maintenance of a healthy and well-wired GM. However, the impact of LVX prophylaxis and nutritional support on short- to long-term post-HSCT clinical outcomes has yet to be elucidated.

Impact of Allogeneic Hematopoietic Stem Cell Transplantation on Nutritional Status and Intake in Children

OBJECTIVES

This study aimed to describe the impact of allogeneic/haploidentical hematopoietic stem cell transplantation on nutritional status and intake in a group of children aged 2 to 18 years.

METHODS

In an observational study, data were collected prospectively. Patients were prescribed individual nutritional support by hospital routines. Anthropometrics were measured pre-transplant at hospital admission and weekly from the day of transplant (day 0) until day +28. z scores for weight, height, and BMI were calculated using Norwegian growth references to assess nutritional status. Pre-transplant diet was assessed on the day of hospitalization. Nutrient provision from enteral nutrition (EN = oral and tube) and parenteral nutrition (PN) was assessed by daily records from day +1 until day +28, or previous discharge, and compared with recommendations (RI) from the Nordic Nutrition Recommendations and ESPGHAN guidelines. Total energy intake was presented as the percentage (%) of basal metabolic rate (BMR) calculated by the Schofield equation. Macro- and micronutrient provisions were presented as medians (interquartile range) and the % of RI.

RESULTS

Twenty-eight patients, mean age 10.3 years (range 3.5-16.6), were included. Two-thirds (n = 18) had malignant diseases. At admission, mean weight Z-score was -0.3, height z scores -0.7, and BMI Z-score 0.1. Eighteen percent (n = 5) were stunted and 25% (n = 7) had overweight. At admission, 25% (n = 7) had established tube feeding, and 7% (n = 2) also had PN. No significant changes in weight z scores were detected during the studied weeks ( P = 0.454). The median daily energy provision was 115% (110-123) of BMR and proteins 1.5 (1.3-1.8) g/kg. EN was provided during a median of 93% of the studied days and provided 21% of the energy. PN was given on a median of 96% of the studied days and provided 79% of energy. RI for vitamins, magnesium, and zinc was met. Provision of copper, iodine, selenium, calcium, and phosphate was below RI.

CONCLUSIONS

Combined EN and PN providing 115% of BMR and 1.5 g/kg protein ensured stable weight by day +28 and covered RI, except for trace elements and minerals.

Nutritional modulation of the gut microbiome in allogeneic hematopoietic stem cell transplantation recipients

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) represents a potentially curative strategy for many oncological and non-oncological diseases, but it is associated with marked morbidity and mortality. The disruption of gut microbiota (GM) eubiosis has been linked to major allo-HSCT complications, including infections and acute graft vs. host disease (aGvHD), and correlates with mortality. This increasing knowledge on the role of the GM in the allo-HSCT procedure has led to fascinating ideas for modulating the intestinal ecosystem in order to improve clinical outcomes. Nutritional strategies, either by changing the route of nutritional supplementation or by administering specific molecules, are increasingly being considered as cost- and risk-effective methods of modulating the GM. Nutritional support has also emerged in the past several years as a key feature in supportive care for allo-HSCT recipients, and deterioration of nutritional status is associated with decreased overall survival and higher complication rates during treatment. Herein we provide a complete overview focused on nutritional modulation of the GM in allo-HSCT recipients. We address how pre transplant diet could affect GM composition and its ability to withstand the upsetting events occurring during transplantation. We also provide a complete overview on the influence of the route of nutritional administration on the intestinal ecosystem, with a particular focus on the comparison between enteral and parenteral nutrition (PN). Moreover, as mounting evidence are showing how specific components of post-transplant diet, such as lactose, could drastically shape the GM, we will also summarize the role of prebiotic supplementation in the modulation of the intestinal flora and in allo-HSCT outcomes.

Oral Lactoferrin Supplementation during Induction Chemotherapy Promotes Gut Microbiome Eubiosis in Pediatric Patients with Hematologic Malignancies

Induction chemotherapy is the first-line treatment for pediatric patients with hematologic malignancies. However, several complications may arise, mainly infections and febrile neutropenia, with a strong impact on patient morbidity and mortality. Such complications have been shown to be closely related to alterations of the gut microbiome (GM), making the design of strategies to foster its eubiosis of utmost clinical importance. Here, we evaluated the impact of oral supplementation of lactoferrin (LF), a glycoprotein endowed with anti-inflammatory, immunomodulatory and antimicrobial activities, on GM dynamics in pediatric oncohematologic patients during induction chemotherapy. Specifically, we conducted a double blind, placebo-controlled trial in which GM was profiled through 16S rRNA gene sequencing before and after two weeks of oral supplementation with LF or placebo. LF was safely administered with no adverse effects and promoted GM homeostasis by favoring the maintenance of diversity and preventing the bloom of pathobionts (e.g., Enterococcus). LF could, therefore, be a promising adjunct to current therapeutic strategies in these fragile individuals to reduce the risk of GM-related complications.

Antiemetic Strategies in Patients Who Undergo Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an integral part of the treatment strategy in patients with a hematological disorder. Chemotherapy-induced nausea and vomiting (CINV) is still an issue in patients who undergo HSCT. While several guidelines for the antiemetic therapy against CINV have been published, there is no detailed information about appropriate antiemetic drugs for each conditioning regimen in HSCT. Various studies reported that the triplet of 5-HT3RA, NK1RA, and dexamethasone appears useful in HSCT. However, each antiemetic has unique adverse effects or interactions with specific drugs. Here, we review the literature relating to clinical trials on the prevention of CINV, and summarize the information to clarify the benefit of antiemetic regimens.

Gut Microbiome Suffers from Hematopoietic Stem Cell Transplantation in Childhood and Its Characteristics Are Positively Associated with Intra-Hospital Physical Exercise

Gut microbiome impairment is a serious side effect of cancer treatment. The aim of this study was to identify the effects of hematopoietic stem cell transplantation (HSCT) treatment on gut microbiota composition in children with acute lymphoblastic leukemia (ALL). Fecal microbiotas were categorized using specific primers targeting the V1-V3 region of 16S rDNA in eligible pediatric ALL patients after HSCT (n = 16) and in healthy controls (Ctrl, n = 13). An intra-hospital exercise program was also organized for child patients during HSCT treatment. Significant differences in gut microbiota composition were observed between ALL HSCT and Ctrl with further negative effects. Plasma C-reactive protein correlated positively with the pathogenic bacteria Enterococcus spp. and negatively with beneficial bacteria Butyriccocus spp. or Akkermansia spp., respectively (rs = 0.511, p = 0.05; rs = -0.541, p = 0.04; rs = -0.738, p = 0.02). Bacterial alpha diversity correlated with the exercise training characteristics. Therefore, specific changes in the microbiota of children were associated with systemic inflammation or the ability to exercise physically during HSCT treatment.

Nutritional support practices and opinions toward gastrostomy use in pediatric bone marrow transplant centers: A national survey

OBJECTIVE

Previous surveys have shown deviations in nutritional practices from international guidelines during bone marrow transplant (BMT). Guidelines recommend enteral nutrition first-line and nasogastric tubes are the mainstay for its provision. Gastrostomies provide an alternative, yet their use is less common. This national survey investigated nutrition support practices in pediatric allogeneic BMT centers and compared clinicians' opinions on gastrostomy use. The aim of this study was to identify the national picture of nutritional support practices across pediatric allogeneic BMT centers, including use and opinions of dietitians, clinical nurse specialists, and physicians, toward gastrostomy feeding.

METHODS

An online survey was administered to 12 centers. The lead dietitian answered questions regarding nutritional counseling, screening, assessment, and interventions. Questions regarding current use, perceived advantages, and problems of gastrostomies were answered by the dietitian, lead clinical nurse specialist, and physician.

RESULTS

A 100% response rate was achieved from 12 centers (N = 36 clinicians). Nutritional counseling was provided in 92% of centers before and routinely throughout admission, 83% screened on and regularly throughout admission, 83% assessed nutritional status before transplant, and 92% used enteral nutrition first-line. Forty-two percent of the centers used gastrostomies. In those not using gastrostomies, 76% of clinicians felt some children should be offered a gastrostomy. Clinicians perceived less displacements (78%) and cosmetic appearance (69%) as the most common advantages of gastrostomies over nasogastric tubes. Risks associated with surgery (92%) and tube/stoma complications (58%) were the most common perceived problems.

CONCLUSIONS

A similar approach was shown on many aspects of nutritional support. Gastrostomy use divided opinion with differences in use and perceived advantages, but agreement on potential complications. Despite their risks, clinicians wanted to use gastrostomies more. Placement requires careful consideration of the risks, benefits, and family preferences.

Gut microbiome in pediatric acute leukemia: from predisposition to cure

The gut microbiome (GM) has emerged as a key factor in the genesis and progression of many diseases. The intestinal bacterial composition also influences treatment-related side effects and even the efficacy of oncological therapies. Acute leukemia (AL) is the most common cancer among children and the most frequent cause of cancer-related death during childhood. Outcomes have improved considerably over the past 4 decades, with the current long-term survival for acute lymphoblastic leukemia being ∼90%. However, several acute toxicities and long-term sequelae are associated with the multimodal therapy protocols applied in these patients. Specific GM configurations could contribute to the multistep developmental hypothesis for leukemogenesis. Moreover, GM alterations occur during the AL therapeutic course and are associated with treatment-related complications, especially during hematopoietic stem cell transplantation. The GM perturbation could last even after the removal of microbiome-modifying factors, like antibiotics, chemotherapeutic drugs, or alloimmune reactions, contributing to several health-related issues in AL survivors. The purpose of this article is to provide a comprehensive review of the chronological changes of GM in children with AL, from predisposition to cure. The underpinning biological processes and the potential interventions to modulate the GM toward a potentially health-promoting configuration are also highlighted.

Fecal Microbiota Transplantation in Allogeneic Hematopoietic Stem Cell Transplantation Recipients: A Systematic Review

The disruption of gut microbiota eubiosis has been linked to major complications in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Various strategies have been developed to reduce dysbiosis and related complications. Fecal microbiota transplantation (FMT) consists of the infusion of fecal matter from a healthy donor to restore impaired intestinal homeostasis, and could be applied in the allo-HSCT setting. We conducted a systematic review of studies addressing the use of FMT in allo-HSCT patients. In the 23 papers included in the qualitative synthesis, FMT was used for the treatment of recurrent Clostridioides difficile infections or as a therapeutic strategy for steroid-resistant gut aGvHD. FMT was also performed with a preventive aim (e.g., to decolonize from antibiotic-resistant bacteria). Additional knowledge on the biological mechanisms underlying clinical findings is needed in order to employ FMT in clinical practice. There is also concern regarding the administration of microbial consortia in immune-compromised patients with altered gut permeability. Therefore, the safety profile and efficacy of the procedure must be determined to better assess the role of FMT in allo-HSCT recipients.

Microbiome-Derived Metabolites in Allogeneic Hematopoietic Stem Cell Transplantation

The gut microbiome has emerged as a major character in the context of hematopoietic stem cell transplantation. The biology underpinning this relationship is still to be defined. Recently, mounting evidence has suggested a role for microbiome-derived metabolites in mediating crosstalk between intestinal microbial communities and the host. Some of these metabolites, such as fiber-derived short-chain fatty acids or amino acid-derived compounds, were found to have a role also in the transplant setting. New interesting data have been published on this topic, posing a new intriguing perspective on comprehension and treatment. This review provides an updated comprehensive overview of the available evidence in the field of gut microbiome-derived metabolites and hematopoietic stem cell transplantation.

The role of microbiota in allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is commonly performed to treat a variety of benign and malignant hematological diseases. Acute graft-versus-host disease (GVHD) is a major life-threatening complication that often occurs following allo-HSCT. Recently, improvements in methods to characterize the microbiota have led to a greater appreciation for how frequently and profoundly an alteration in microbial composition, or dysbiosis, can occur in allo-HSCT recipients to better decipher the complex interplay between microbiota and allo-HSCT outcomes.

AREAS COVERED

This article reviews the current knowledge of the microbiota's impact on allo-HSCT outcomes, including effects of microbiota-derived metabolites, and crosstalk between commensals and the allogeneic immune response. This article also summarizes the effects of HSCT and transplant-related procedures on microbiota, and recent developments in interventional strategies.

EXPERT OPINION

A growing body of literature indicates that the composition of the intestinal microbiota can function as a predictive biomarker for the risk and severity of acute GVHD, as well as overall survival, in patients undergoing allo-HSCT. Mechanisms underpinning these associations, however, are not well understood, and clinical strategies that modulate the microbiome to improve outcomes have yet to be fully developed. There is an unmet need to determine mechanisms to improve the efficacy of allo-HSCT.

Food intake of children and adolescents submitted to allogeneic hematopoietic stem cells transplantation

ABSTRACT Objective Describe the dietary intake of children and adolescents submitted to allogeneic hematopoietic stem cell transplantation. Methods Data from 0 to 19-year-old patients’ medical records who were submitted to the procedure from January 2012 to September 2017 were used. These medical records provided anthropometric, food intake control and symptoms data for three moments: three days before infusion (M1), the infusion day (M2), and 25 days after the cell infusion (M3). This study was approved by the Ethics in Research Committee (17-0267). Results The patients presented weight loss (p>0.001) and a decrease in body mass index (p>0.001) in M1 versus M2 and M3. The means of calorie intake (p=0.031), protein (p=0.006), lipid (p=0.017), dietary fiber (p=0.035), calcium (p=0.005), iron (p=0.012), and sodium (p=0.022) had a reduction from M1 to M2 and an increase from M2 to M3. There was a decrease in mean intake of carbohydrates and calories per kilo from M1 to M2 and an increase from M2 to M3. The nutritional status was related to temperature above 37ºC (p<0.001) and to mucositis (p=0.001), in M1 and M2. There was a correlation of dietary intake with the presence of temperature above 37ºC (p=0.019) in M2 and M3. Conclusion Reduced intake and worsening of the patients’ previous nutritional status appear to interfere with allogeneic hematopoietic stem cell transplantation and its complications, such as the presence of temperature above 37ºC and mucositis.

Enteral versus Parenteral Nutrition as Nutritional Support after Allogeneic Hematopoietic Stem Cell Transplantation: a Systematic Review and Meta-Analysis

Nutritional support for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been widely debated. Enteral nutrition (EN) is recommended as first-line nutritional support by the main international guidelines. However, these recommendations are based on weak evidence, and there is wide variability in the types of nutritional support among transplantation centers, with the majority providing parenteral nutrition (PN) instead of EN. Here we provide an up-to-date systematic review and meta-analysis of studies comparing EN and PN for nutritional support during the neutropenic period after allo-HSCT. The literature search strategy identified 13 papers, of which 10 compared clinical transplantation outcomes, 2 compared gut microbiota (GM) compositions, and 1 compared systemic metabolic profiles. For the meta-analysis, among the 10 clinical studies, 8 studies in which 2 groups were compared were selected: in 1 group, EN was provided as primary nutritional support in the neutropenic phase after allo-HSCT with or without the addition of PN (EN group), whereas in the other group, only PN was provided as nutritional support. The incidence rates of acute graft-versus-host disease (aGVHD) (relative risk [RR], 0.69; 95% confidence interval [CI], 0.56 to 0.86; P = .0007), aGVHD grade III-IV (RR, 0.44; 95% CI, 0.30 to 0.64; P < .0001), and gut aGVHD (RR, 0.44; 95% CI, 0.30 to 0.66; P < .0001) were lower in the EN group than in the PN group. No differences were found between the 2 groups with regard to the incidence of severe oral mucositis (RR, 0.95; 95% CI, 0.83 to 1.09; P = .46) or overall survival at day +100 (RR, 1.07; 95% CI, 0.95 to 1.21; P = .29). Other variables were too heterogeneous to perform quantitative analyses. The results of the meta-analysis showed that EN reduced the incidence of aGVHD, specifically grade III-IV and gut aGVHD. This result should prompt improved efforts to implement EN as first-line nutritional support in patients undergoing allo-HSCT. Considering the emerging evidence regarding the association between GM dysbiosis and aGVHD onset, we speculate that this protective effect could be attributed to the improved gut eubiosis observed in enterally fed patients. Further studies are warranted to better address the relationship between the GM composition, aGVHD, and the nutritional administration route during HSCT.

Applications of gut microbiota in patients with hematopoietic stem-cell transplantation

Studies of the gut microbiota (GM) have demonstrated the close link between human wellness and intestinal commensal bacteria, which mediate development of the host immune system. The dysbiosis, a disruption of the microbiome natural balance, can cause serious health problems. Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) may cause significant changes in GM due to their underlying malignancies and exposure to extensive chemotherapy and systemic antibiotics, which may lead to different disorders. There are complex and multi-directional interactions among intestinal inflammation, GM and immune reactivity after HSCT. There is considerable effect of the human intestinal microbiome on clinical course following HSCT. Some bacteria in the intestinal ecosystem may be potential biomarkers or therapeutic targets for preventing relapse and improving survival rate after HSCT. Microbiota can be used as predictor of mortality in allo-HSCT. Two different strategies with targeted modulation of GM, preemptive and therapeutic, have been used for preventing or treating GM dysbiosis in patients with HSCT. Preemptive strategies include enteral nutrition (EN), prebiotic, probiotic, fecal microbiota transplantation (FMT) and antibiotic strategies, while therapeutic strategies include FMT, probiotic and lactoferrine usages. In this review, we summarize the advance of therapies targeting GM in patients with HSCT.

The gut microbiome in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation

The gut microbiome (GM) has been associated with different clinical outcomes in the context of allogeneic hematopoietic stem cell transplantation (HSCT). Large multicenter cohort studies in adults have found significant correlations with overall survival, relapse, and incidence of complications. Moreover, GM is already a promising target for therapeutic interventions. However, few data are available in children, a population presenting unique features and challenges. During childhood, the GM evolves rapidly with large structural fluctuations, alongside with the maturation of the immune system. Furthermore, the HSCT procedure presents significant differences in children. These considerations underline the importance of a specific focus on the pediatric setting, and the role of GM and its age-dependent trajectory in influencing the immunity reconstitution and clinical outcomes. This review provides a comprehensive overview of the available evidence in the field of GM and pediatric HSCT, highlighting age-specific issues and discussing GM-based therapeutic approaches.