Open research questions in Clinical Nutrition and Gastroenterology

What the literature leaves open

• Abstract Background Nutrition therapy is essential in critically ill patients, yet large randomised trials have shown inconsistent results regarding the effect of an evidence-based feeding protocol.

  Association between age and outcomes of evidence-based feeding protocol versus usual care in critically ill patients: secondary analysis of a multicenter cluster-randomised controlled trial · 2026 · DOI

• Abstract Nutritional rehabilitation in children with complicated acute malnutrition involves dynamic shifts in resting energy expenditure (REE), yet directly measured REE data remain limited and variable.

  Mapping Resting Energy Expenditure in Malnourished Children During Nutritional Rehabilitation: A Scoping Review · 2026 · DOI

• ABSTRACT Despite recent advances in bacterial profiling across the three anatomical types of pediatric short bowel syndrome (SBS), the gut multi-kingdom remains unexplored.

  Multi-kingdom gut microbiota analyses identify biomarkers of different types of pediatric short bowel syndrome · 2026 · DOI

• Larger multicenter trials are warranted to confirm the effects on infection rates, liver failure, and long-term survival.

  Clinical impact of early enteral nutrition support on gastrointestinal function, nutritional status, liver function, and immune function in liver cancer patients · 2026 · DOI

• While global HPN programs are well-established, data specific to South Korea remain scarce.

  A single-center experience of home parenteral nutrition for pediatric intestinal failure · 2025 · DOI

• BACKGROUND: The optimal timing of enteral nutrition for critically ill septic patients in the intensive care unit (ICU) who require invasive mechanical ventilation has not been determined, and the influence of early enteral nutrition on clinical outcomes is unclear.

  Association between early enteral nutrition and 28-Day mortality in mechanically ventilated patients with sepsis: a retrospective analysis of the MIMIC-IV database · 2025 · DOI

• Background Early enteral nutrition (EN) is recommended for sepsis management, but its optimal timing and clinical benefits remain uncertain.

  Early versus delayed enteral nutrition in ICU patients with sepsis: a propensity score-matched analysis based on the MIMIC-IV database · 2024 · DOI

• This article provides a reference for the implementation of nutrition of pediatric ECMO patients and further research on nutritional support.

  Research progress on nutritional support in the neonatal and pediatric populations receiving extracorporeal membrane oxygenation · 2024 · DOI

• However, nutritional support strategies for considering the metabolic phase are not well established.

  Application of metabolic phase-specific modified nutrition risk in critically ill score: a prospective observational study in critically ill patients · 2024 · DOI

• However, the mechanistic role of these changes in inflammatory bowel disease remains unclear.

  Parenteral Nutrition, Inflammatory Bowel Disease, and Gut Barrier: An Intricate Plot · 2024 · DOI

• The study highlights recent guidelines using the GRADE approach, supplemented by relevant adult studies, current clinical practices, challenges, gaps in knowledge, and future directions for research aimed at improving nutritional interventions.

  Personalized Nutrition in the Pediatric ICU: Steering the Shift from Acute Stress to Metabolic Recovery and Rehabilitation · 2024 · DOI

• Data regarding the prognosis of patients receiving enteral feeding in geriatric medical settings is lacking.

  Characteristics of older adults receiving enteral feeding at a geriatric medical center · 2024 · DOI

• Autonomic dysfunction following CNS injury. Impaired autonomic regulation of gut motility. Limited understanding of the relationship between gut microbiota and GLP-1 in FI.

  GLP-1–gut microbiotal axis and enteral feeding intolerance in critically ill neurological patients · 2026 · DOI

• The underlying mechanisms of FI remain unclear. The relationship between gut microbiota and GLP-1 in FI is unclear. There is a need for further research into the pathogenesis of FI.

  GLP-1–gut microbiotal axis and enteral feeding intolerance in critically ill neurological patients · 2026 · DOI

• ICU-AW is a complex and multifactorial syndrome. Early identification and intervention are crucial to prevent or mitigate the effects of ICU-AW. There is a need to develop effective strategies for prevention and treatment of ICU-AW.

  Mapping the research landscape and evolving hotspots of intensive care unit-acquired weakness: a dual-database bibliometric analysis · 2026 · DOI

• There is a need to summarize and map the existing literature to clarify the temporal and spatial distribution, interconnections, and emerging trends in ICU-AW research. There is a lack of understanding of the core authors, journals, and countries that have contributed to research in this field.

  Mapping the research landscape and evolving hotspots of intensive care unit-acquired weakness: a dual-database bibliometric analysis · 2026 · DOI

• The complex interactions between the gut and extraintestinal organs in sepsis-associated acute gastrointestinal injury and paralytic ileus. The need to consider the gut as both a driver and a target of injury in sepsis-associated acute gastrointestinal injury and paralytic ileus. The limited understanding of the mechanisms of gut-extraintestinal organ crosstalk in sepsis-associated acute gastrointestinal injury and paralytic ileus.

  Source-stratified gut–extraintestinal organ crosstalk in sepsis-associated acute gastrointestinal injury and paralytic ileus: the gut as both driver and target · 2026 · DOI

• The gut is not only a passive target of distant organ injury in sepsis, but also an active participant in the pathogenesis of sepsis-associated acute gastrointestinal injury and paralytic ileus. The mechanisms of gut-extraintestinal organ crosstalk in sepsis-associated acute gastrointestinal injury and paralytic ileus are not fully understood.

  Source-stratified gut–extraintestinal organ crosstalk in sepsis-associated acute gastrointestinal injury and paralytic ileus: the gut as both driver and target · 2026 · DOI

• The review's findings are limited by the heterogeneity of the included studies. The definition of early enteral nutrition varied across studies, with timing thresholds ranging from within 24 hours to within 72 hours of ICU admission or mechanical ventilation initiation.

  What is The Effect of Early Enteral Nutrition on Mortality in Critically Ill Patients Receiving Vasopressor Support? : A Systematic Review · 2026 · DOI

• The effect of early enteral nutrition on mortality in critically ill patients requiring vasopressor support remains debated due to conflicting trial results. There is a need for a comprehensive synthesis of the evidence to guide clinical practice.

  What is The Effect of Early Enteral Nutrition on Mortality in Critically Ill Patients Receiving Vasopressor Support? : A Systematic Review · 2026 · DOI

• Gastrointestinal intolerance remains a major challenge in routine clinical practice. Diarrhea and feeding interruption are common complications. The lack of studies comparing homemade and commercial enteral nutrition.

  Risk of gastrointestinal intolerance and complications associated with homemade versus commercial enteral nutrition in critically ill patients: a single-center retrospective cohort study · 2026 · DOI

• The lack of studies comparing homemade and commercial enteral nutrition. The need to evaluate the associations between different EN sources and gastrointestinal tolerance.

  Risk of gastrointestinal intolerance and complications associated with homemade versus commercial enteral nutrition in critically ill patients: a single-center retrospective cohort study · 2026 · DOI

• further studies are needed to confirm the findings, - evaluation of the practical attainability of the target and the patient characteristics associated with successful attainment in routine ICU practice, - investigation of the association between energy adequacy and outcomes in different patient populations

  Timing of Achieving 70% of Energy Requirements in Critically Ill Patients: Association with In-Hospital Mortality and Predictors in a Real-World Medical ICU · 2026 · DOI

• The risk of malnutrition due to insufficient nutrient intake after major thoracic surgery. The need for effective and safe methods for blind nasoenteric tube placement.

  Clinical value of the water injection, dilution, and drainage method for blind nasoenteric tube placement in patients receiving sequential enteral nutrition support after major thoracic surgery · 2026 · DOI

• The lack of alternative reliable functional markers for evaluating feed tolerance at the bedside. The need for a standardized approach to GRV monitoring and management.

  Applying gastric residual volume as one of the indicators for enteral feeding intolerance: A scoping review · 2026 · DOI

Most-cited papers in Clinical Nutrition and Gastroenterology

• THE MAINTENANCE NEED FOR WATER IN PARENTERAL FLUID THERAPY · PEDIATRICS · 1957 · 790 citations
• Benefits of supplementary tube feeding after fractured neck of femur: a randomised controlled trial. · BMJ · 1983 · 398 citations
• Nutritional and other postoperative management of neonates with short bowel syndrome correlates with clinical outcomes · The Journal of Pediatrics · 2001 · 393 citations
• The effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicentre, pragmatic, registry-based randomised trial · The Lancet · 2023 · 379 citations
• Practice Parameter: The Management of Acute Gastroenteritis in Young Children · PEDIATRICS · 1996 · 369 citations
• MORTALITY IN SECOND AND THIRD DEGREE MALNUTRITION · Journal of Tropical Pediatrics · 1956 · 342 citations
• Overfeeding Macronutrients to Critically Ill Adults · Journal of the American Dietetic Association · 1998 · 287 citations
• Long-term parenteral nutritional support and intestinal adaptation in children with short bowel syndrome: A 25-year experience · The Journal of Pediatrics · 2004 · 275 citations
• Low versus standard calorie and protein feeding in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group trial (NUTRIREA-3) · The Lancet Respiratory Medicine · 2023 · 243 citations
• Influence of bacterial overgrowth and intestinal inflammation on duration of parenteral nutrition in children with short bowel syndrome · The Journal of Pediatrics · 1997 · 229 citations

Most recent work

• Nutrition Therapy in Critically Ill Adults · New England Journal of Medicine · 2026
• Gastric Residual Volume Assessment in Critically Ill Children · JAMA · 2026
• Pediatric post-intensive care malnutrition—risk factors and their association with long-term functional outcomes 1 year after discharge: a retrospective cohort study in Thailand · Acute and Critical Care · 2026
• Validity of Predictive Energy Equations Compared With Indirect Calorimetry for Hospitalized Adults: An Evidence Analysis Library Scoping Review · Journal of the Academy of Nutrition and Dietetics · 2026
• GLP-1–gut microbiotal axis and enteral feeding intolerance in critically ill neurological patients · Frontiers in Medicine · 2026
• Mapping the research landscape and evolving hotspots of intensive care unit-acquired weakness: a dual-database bibliometric analysis · Frontiers in Neurology · 2026
• Source-stratified gut–extraintestinal organ crosstalk in sepsis-associated acute gastrointestinal injury and paralytic ileus: the gut as both driver and target · Frontiers in Medicine · 2026
• What is The Effect of Early Enteral Nutrition on Mortality in Critically Ill Patients Receiving Vasopressor Support? : A Systematic Review · The International Journal of Medical Science and Health Research · 2026
• Risk of gastrointestinal intolerance and complications associated with homemade versus commercial enteral nutrition in critically ill patients: a single-center retrospective cohort study · Frontiers in Nutrition · 2026
• Restrictive nutrition in shock: reassuring renal signals—but no proof of safety · Intensive Care Medicine · 2026

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