Tolerability of proactive enteral nutrition post allogeneic haematopoietic progenitor cell transplant: A randomised comparison to standard care

Proactive enteral nutrition for patients undergoing allogeneic stem cell transplantation- implementation and clinical outcomes

BACKGROUND/ OBJECTIVES

Nutrition support is frequently required post allogeneic haematopoietic progenitor cell transplantation (HPCT) however the tolerance of enteral nutrition (EN) can vary. This mixed methods study aimed to explore staff perceptions, barriers and enablers to the use of EN post HPCT and report the implementation and outcomes of a nutrition protocol.

SUBJECT/ METHODS

A survey on barriers and enablers to the use of EN was developed and distributed to medical and nursing staff. Data on nutrition and clinical outcomes was collected for 12 months post implementation of a new nutrition protocol.

RESULTS

Thirty staff completed the survey, key barriers identified included uncertain EN tolerance, lack of confidence in nasogastric tube placement and insufficient training and resources. Eighty-four patients commenced EN, 23 changed to PN (27%) and 61 received EN only (73%). In total 36 patients received PN and eight patients oral nutrition support only. There was a difference in type of conditioning (p = 0.025) and nutritional status (p = 0.016) between patients who received PN vs EN only, with a higher proportion of malnourished patients receiving PN (23% vs 5%). Patients who received PN had a longer length of hospital stay (median 22 vs 19 days, p = 0.012) and lower rate of survival to day 100 (81% vs 95%, p = 0.036) than patients who received EN.

CONCLUSION

The use of EN may lead to improved clinical outcomes compared to PN therefore should be implemented as first line nutrition support.

Use and safety of enteral nutrition protocols in acute care: A scoping review of literature and retrospective audit of practice

AIM

Standardised enteral nutrition protocols are recommended in critical care, however their use and safety are not well described in other inpatient populations. This mixed methods study reports on the use and safety of enteral nutrition protocols for non-critically ill adults.

METHODS

A scoping review of published literature was conducted. In addition a retrospective audit of practice at an Australian tertiary teaching hospital with an existing hospital-wide standardised enteral nutrition protocol was performed. Data on use, safety and adequacy of enteral nutrition prescription were collected from medical records for patients receiving enteral nutrition on acute wards (January-March 2020).

RESULTS

Screening of 9298 records yielded six primary research articles. Studies were generally low quality. Published literature suggested that protocols may reduce time to enteral nutrition initiation and goal rate, and improve adequacy of nutrition provision. No adverse outcomes were reported. From the local audit of practice (105 admissions, 98 patients), enteral nutrition commencement was timely (median 0 (IQR 0-1) days from request; goal rate: median 1 (IQR 0-2) days from commencement and adequate (nil underfeeding), without prior dietitian review in 82% of cases. Enteral nutrition was commenced per protocol in 61% of instances. No adverse events, including refeeding syndrome, were observed.

CONCLUSIONS

Most inpatients requiring enteral nutrition can be safely and adequately managed on enteral nutrition protocols. Evaluation of protocols outside of the critical care setting remains a gap in the literature. Standardised enteral nutrition protocols may improve delivery of nutrition to patients, whilst allowing dietitians to focus on those with specialised nutrition support needs.

Nutrition support and clinical outcomes following allogeneic stem cell transplantation

Nutrition support is frequently required post allogeneic stem cell transplantation (SCT) and while there is some evidence on the benefits of enteral nutrition (EN), parenteral nutrition (PN) is widely used in practice. The study aimed to examine the impact of EN versus PN on early outcomes following SCT. All patients who underwent allogeneic SCT over 2.5 years were included in the analysis. Data was retrospectively collected on mode of nutrition support with clinical outcome data obtained from an existing database. Clinical outcomes were compared between groups by logistic, poisson and negative binomial regression, with adjustment for baseline confounders as appropriate. Patients who received EN then changed to PN had a longer length of hospital stay compared to those who received EN only (IR 1.24, 95% CI: 1.11-1.38, p < 0.001). Compared to those who received EN only, patients who received EN that changed to PN or PN only had a longer time to neutrophil engraftment (IR 1.11, 95% CI: 1.02-1.20, p = 0.016 and IR 1.16, 95% CI: 1.03-1.30, p = 0.017) and platelet engraftment (IR 1.20, 95% CI 1.08-1.33, p < 0.001 and IR 1.24, 95% CI 1.08-1.42, p = 0.002). Enteral nutrition should be first line nutritional support for patients undergoing allogeneic SCT.

Medical nutrition therapy during intensive remission-induction treatment and hematopoietic stem cell transplantation in acute myeloid leukemia patients: Hematologists' experiences and perspectives

BACKGROUND & AIMS

The European Societies for Clinical Nutrition and Metabolism (ESPEN) and Blood and Marrow Transplantation (EBMT) recommend enteral nutrition (EN) as the first-choice medical nutrition therapy in acute myeloid leukemia (AML) patients undergoing intensive treatments, including high-dose remission-induction chemotherapy and hematopoietic stem cell transplantation (HSCT). However, parenteral nutrition (PN) remains the preferred method of nutrition support in current clinical practice. The aim of this qualitative study was to gain insight into hematologists' experiences and perspectives regarding the choice and ESPEN/EBMT recommendations on EN versus PN.

METHODS

Online semi-structured interviews were conducted with one hematologist from each of the 21 hospitals offering intensive AML treatments in the Netherlands, using Microsoft Teams. Interviews were audio-recorded, transcribed verbatim and thematically analyzed using Atlas. ti. One hundred nineteen hematologists working in the same hospitals were invited to complete a short online questionnaire survey (SurveyMonkey®) regarding their knowledge and opinion on the ESPEN/EBMT guidelines recommending EN over PN during intensive AML treatments. The results of this survey are presented in a descriptive way.

RESULTS

Fifty-nine hematologists participated in this study (42% overall response rate), of which 21 in the semi-structured interviews (response rate 100%) and 38 in the online survey (response rate 32%). Hematologists considered medical nutrition therapy important for prevention and treatment of malnutrition and associated adverse outcomes in AML patients undergoing intensive remission-induction treatment and HSCT. However, opposed to the ESPEN/EBMT guidelines, the vast majority of hematologists were hesitant or reluctant to use EN instead of PN as the first-choice medical nutrition therapy in these patients. The most frequently cited barriers to use EN were the expected low feasibility and tolerance of EN, feeding tube-related discomfort and bleeding risk, and patient refusal. Other barriers to follow the guidelines on EN were related to personal factors, including hematologists' knowledge (lack of awareness and familiarity) and attitude (lack of agreement, outcome expectancy, experience, success, motivation, and learning culture), guideline-related factors (lack of evidence and applicability), and external factors (lack of collaboration and resources). Facilitators included strategies for nutrition education and dissemination of nutritional guidelines, interprofessional and patient collaboration, availability of feeding tubes that can be inserted without endoscopy and stronger scientific evidence.

CONCLUSIONS

Hematologists recognized the importance of medical nutrition therapy for reducing malnutrition and related negative outcomes during intensive AML treatments. However, contrary to the ESPEN/EBMT guidelines, they preferred PN instead of EN as the medical nutrition therapy of first choice. To reduce compliance barriers, interventions should focus on improving hematologists' knowledge of medical nutrition therapy and dietary guidelines, enhancing success rates of EN by adequately triaging patients eligible for EN and inserting duodenal feeding tubes using an electromagnetic sensing device without endoscopy, developing decision aids and multidisciplinary guidelines and care pathways. Furthermore, future trials should focus on the feasibility and benefits of EN versus PN both during remission-induction treatment and HSCT.

The European Society for Blood and Marrow Transplantation (EBMT) roadmap and perspectives to improve nutritional care in patients undergoing hematopoietic stem cell transplantation on behalf of the Cellular Therapy and Immunobiology Working Party (CTIWP) and the Nurses Group (NG) of the EBMT

Malnutrition is the most common comorbidity during the continuum of hematopoietic stem cell transplant (HSCT) and negatively impacts clinical outcomes, response to therapy, quality of life, and costs. The intensive conditioning regimen administered before transplant causes inflammatory damages to the gastrointestinal system, which themselves contribute to trigger graft versus host disease (GvHD) in the allogeneic setting. GvHD and other post-transplant complications such as infections adversely affect food intake and gut absorption of nutrients. Consequently, patients exhibit signs of malnutrition such as weight loss and muscle wasting, thus triggering a "vicious circle" that favours additional complications. Among HSCT centres, there is marked variability in nutritional care, from screening for malnutrition to nutritional intervention. The present paper, elaborated by the Cellular Therapy and Immunobiology Working Party and the Nurses Group of the European Society for Blood and Marrow Transplantation, aims at defining a roadmap that identifies the main nutritional critical issues in the field of HSCT. This document will be propaedeutic to the development of clinical algorithms to counteract risk factors of malnutrition, based on scientific evidence and shared among HSCT centres, and thus maximize transplant outcomes.

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.

When is enteral nutrition indicated?

Enteral nutrition (EN) is a vital component of nutrition around the world. EN allows for delivery of nutrients to those who cannot maintain adequate nutrition by oral intake alone. Common questions regarding EN are when to initiate and in what scenarios it is safe. The answers to these questions are often complex and require an evidence-based approach. The Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) established an Enteral Nutrition Committtee to address the important questions surrounding the indications for EN. Consensus recommendations were established based on eight extremely clinically relevant questions regarding EN indications as deemed by the Enteral Nutrition Committee. These consensus recommendations may act as a guide for clinicians and stakeholders on difficult questions pertaining to indications for EN. This paper was approved by the ASPEN Board of Directors.

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.

The outcome and complications of total parenteral nutrition in pediatric hematopoietic stem cell transplantation

BACKGROUND

Nutritional support posthematopoietic stem cell transplantation (HSCT) with total parenteral nutrition (TPN) or nasogastric tube feeding (NGT) in pediatric patients is associated with benefits and risks.

METHODS

We retrospectively reviewed the indication of TPN use in our pediatric HSCT patients and its impact on survival and possible related complications.

RESULTS

A total of 228 HSCTs were performed during the study period. TPN was used in 144 patients (63.2%) for a median of 14 days, while 8.8% had NGT feeding and 28% were able to tolerate oral feeding. Severe mucositis was seen in 104 TPN patients (72.2%) in comparison with 22 patients (26.2%) who were on Enteral Nutrition (EN) (p = <.001). Sinusoidal obstruction syndrome (SOS) was seen in 19 (13.2%) patients who had TPN compared to none in the patients who received EN (p = .001). The majority of patients who had SOS received myeloablative conditioning (MAC) therapy for hemoglobinopathy. Acute graft-versus-host disease (aGVHD) was seen in 24.8% of TPN patients and 9.1% of non-TPN patients (p = .01). However, there were no statistically significant differences in chronic GVHD, bacteremia, and patients' survival between both groups.

CONCLUSIONS

TPN is commonly used after pediatric HSCT in cases of severe mucositis. NGT feeding was found to be the least used nutritional support method. SOS and aGVHD were associated more frequently in TPN patients compared to EN patients. This suggests the possible disadvantages of TPN and importance of SOS preventative measures in high-risk patients.

Nutrition-related problems, nutritional support practices and barriers to adherence to nutritional guidelines during intensive treatment for acute myeloid leukemia: Patients' and hematology nurses' perspectives and experiences

BACKGROUND & AIMS

The updated guidelines of the European Society for Clinical Nutrition and Metabolism (ESPEN) and for Blood and Marrow Transplantation (EBMT) on nutrition in intensively treated acute myeloid leukemia (AML) patients recommend enteral nutrition (EN) instead of parenteral nutrition (PN) as the first-choice medical nutrition therapy. Despite this, PN remains the preferred route of nutrition administration in daily practice. The aim of this qualitative study was to gain insight into the patients' and hematology nurses' experiences and perceptions regarding nutritional problems and nutritional support and the reasons for the low adherence to the ESPEN/EBMT guidelines.

METHODS

Semi-structured interviews were conducted in 23 patients from various Dutch hospitals who had completed intensive AML treatment. Interviews with 22 patients were audio-recorded and transcribed, one interview was summarized. The transcripts and summary were thematically analyzed using Atlas.ti. From each of the 22 Dutch hospitals providing intensive AML treatment, one hematology nurse participated in a telephone questionnaire survey. The results of this survey are presented in a descriptive way.

RESULTS

Nutritional problems were a major source of distress in most participating patients. Nutritional support often led to peace of mind and less concerns, provided that there were no conflicting nutritional support practices among treating hospitals. Patients perceived PN and EN as a life-line and necessary for the prevention of or recovery from physical decline, but they also experienced loss of independence, limited mobility, fear of unwanted body weight gain and problems related to the feeding equipment. Both patients and hematology nurses regarded PN as an easy method of nutrition administration, while EN was often seen as a necessary evil or was even refused by patients, owing to tube-related physical discomfort and EN intolerance. Both patients' and hematology nurses' reluctance to administer EN proved to be barriers to the ESPEN/EBMT nutritional guideline adherence. Among the surveyed hematology nurses, barriers to adherence included personal factors related to their knowledge (lack of awareness) and attitudes (negative outcome expectancy and lack of agreement), guideline-related factors (lack of evidence) and external factors (lack of collaboration).

CONCLUSION

Individualized nutritional support, including EN and PN, may reduce nutrition-related distress in intensively treated AML patients, provided that conflicting nutritional support practices among hospitals are avoided or explained. The barriers to adherence to the ESPEN/EBMT guidelines on EN and PN in this patient group may be reduced by enhancing hematology nurses' awareness and knowledge of the guidelines, incorporating the guidelines into multidisciplinary clinical pathways, improving outcome of EN by proper triage of patients eligible for EN and increasing the level of evidence of the guidelines.

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.

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.

Possible clinical outcomes using early enteral nutrition in individuals with allogeneic hematopoietic stem cell transplantation: A single-center retrospective study

OBJECTIVES

Intensive nutritional support during allogeneic hematopoietic stem cell transplantation (allo-HSCT) yields improved clinical outcomes. However, the clinical implications of early enteral nutrition (EN) in allo-HSCT remain unclear. This retrospective study was conducted to determine the significance of early EN in individuals who underwent allo-HSCT, and the association between early nutritional intervention and clinical outcomes, including the status of the intestinal microbiome.

METHODS

Thirty-one participants received EN before conditioning. The intestinal microbiota was examined by meta 16S rRNA gene sequencing of fecal samples.

RESULTS

The median body mass variation was only -0.35 kg on day 60. The probability of 2-y overall survival was 61.1%. The cumulative incidence of treatment-related mortality was 17.4%, and those of acute graft-versus-host disease were 32.3% (grades II-IV) and 3.2% (grades III-IV). Chronic graft-versus-host disease was observed in four participants. Dysbiosis of the intestines and acute graft-versus-host disease occurred simultaneously, and Enterococcus species were abundant.

CONCLUSIONS

Our results suggest that early nutritional support can improve the outcomes for individuals who have undergone allo-HSCT and can maintain homeostasis of their intestinal microbiome. Future prospective clinical trials are required to elucidate the role of EN in allo-HSCT and the association between the intestinal microbiome and EN.

Optimization of nutrition support practices early after hematopoietic cell transplantation

Nutrition support is often required during hematopoietic cell transplant (HCT) given the gastrointestinal toxicity that frequently precludes adequate protein-calorie intake. This article reviews the latest evidence for enteral versus parenteral nutrition in the adult and pediatric HCT population and addresses key considerations as well as barriers to implement this in practice. Registered Dietitian Nutritionists are key members of the interdisciplinary team to proactively manage enteral nutrition support to provide timely, adequate protein and calories to help prevent malnutrition, loss of lean body mass, and functional decline as well as provide evidence-based diet recommendations. This article also reviews emerging research supporting the role of luminal nutrients to maintain microbiotal diversity.

Adherence to guidelines on nutrition support during intensive treatment of acute myeloid leukemia patients: A nationwide comparison

BACKGROUND & AIMS

The level of adherence to the updated guidelines of The European Societies for Clinical Nutrition and Metabolism (ESPEN) and for Blood and Marrow Transplantation (EBMT) on nutrition in intensively treated adult acute myeloid leukemia (AML) patients in clinical practice is unknown. The aim of this nationwide survey was to investigate ESPEN/EBMT nutritional guideline adherence during intensive AML treatment, variation in nutrition support practices among hospitals and whether these practices changed after guideline publication.

METHODS

All 22 Dutch hospitals providing (aftercare following) high-dose chemotherapy and/or hematopoietic stem cell transplantation for adult AML patients were surveyed on nutrition support practices during these intensive AML treatments. We used an online questionnaire in 2015 and semi-structured telephone interviews in 2018-2019. Both surveys were completed by registered dieticians and addressed the use of enteral (EN) and parenteral (PN) nutrition. The ESPEN/EBMT nutritional guideline adherence was investigated through the telephone interviews.

RESULTS

High-level ESPEN/EBMT guideline adherence and/or uniformity among hospitals regarding nutrition support practices during intensive AML treatment were observed for nutritional screening, -aims, safe food handling and exercise training. Adherence to ESPEN/EBMT recommendations that were not implemented into national guidelines, including nutritional assessment and use of medical nutrition, was poor. All hospitals assessed nutritional intake, -impact symptoms and body weight, but muscle mass, physical performance and degree of systemic inflammation were rarely and variably monitored. Although the number of hospitals using EN as first-choice nutritional intervention increased from 3 hospitals in 2015 to 8 in 2019, PN remained the preferred method of nutrition support. Furthermore, the timing of medical nutrition varied.

CONCLUSIONS

Although the use of EN increased after publication of the updated ESPEN/EBMT nutritional guidelines, adherence to these standards was limited and there was heterogeneity in nutrition support practices during intensive AML treatment among hospitals. Incorporating international nutritional standards into national guidelines by nutrition expert groups immediately upon publication may improve adherence.

Pilot study investigating the effect of enteral and parenteral nutrition on the gastrointestinal microbiome post-allogeneic transplantation

Nutrition support is frequently required post-allogeneic haematopoietic progenitor cell transplantation (HPCT); however, the impact of mode of feeding on the gastrointestinal microbiome has not been explored. This study aimed to determine if there is a difference in the microbiome between patients receiving enteral nutrition (EN) and parenteral nutrition (PN) post-allogeneic HPCT. Twenty-three patients received either early EN or PN when required. Stool samples were collected at 30 days post-transplant and analysed with shotgun metagenomic sequencing. There was no difference in microbial diversity between patients who received predominantly EN (n = 13) vs. PN (n = 10) however patients who received predominantly EN had greater abundance of Faecalibacterium (P < 0·001) and ruminococcus E bromii (P = 0·026). Patients who had minimal oral intake for a longer duration during provision of nutrition support had a different overall microbial profile (P = 0·044), lower microbial diversity (P = 0·004) and lower abundance of faecalibacterium prausnitzii_C (P = 0·030) and Blautia (P = 0·007) compared to patients with greater oral intake. Lower microbial diversity was found in patients who received additional beta lactam antibiotics (P = 0·042) or had a longer length of hospital stay (P = 0·019). Post-HPCT oral intake should be encouraged to maintain microbiota diversity and, if nutrition support is required, EN may promote a more optimal microbiota profile.