Effect of gut microbiota modulation on feeding tolerance of enterally fed critically ill adult patients: a systematic review

Current insights in ICU nutrition: tailored nutrition

PURPOSE OF REVIEW

To summarize recent research on critical care nutrition focusing on the optimal composition, timing, and monitoring of enteral feeding strategies for (post)-ICU patients. We provide new insights on energy and protein recommendations, feeding intolerance, and describe nutritional practices for coronavirus disease 2019 ICU patients.

RECENT FINDINGS

The use of indirect calorimetry to establish individual energy requirements for ICU patients is considered the gold standard. The limited research on optimal feeding targets in the early phase of critical illness suggests avoiding overfeeding. Protein provision based upon the absolute lean body mass is rational. Therefore, body composition measurements should be considered. Body impedance analysis and muscle ultrasound seem reliable, affordable, and accessible methods to assess body composition at the bedside. There is inadequate evidence to change our practice of continuous enteral feeding into intermittent feeding. Finally, severe acute respiratory syndrome coronavirus 2 patients are prone to underfeeding due to hypermetabolism and should be closely monitored.

SUMMARY

Nutritional therapy should be adapted to the patient's characteristics, diagnosis, and state of metabolism during ICU stay and convalescence. A personalized nutrition plan may prevent harmful over- or underfeeding and attenuate muscle loss. Despite novel insights, more research is warranted into tailored nutrition strategies during critical illness and convalescence.

Investigating the effect of oral synbiotic on enteral feeding tolerance in critically ill patients: A double-blinded controlled clinical trial of gut microbiota

BACKGROUND

Probiotics are beneficial live microorganisms that can modify the gut microbiota. It is assumed that they help improve enteral feeding intolerance (EFI) and nosocomial infections in critically ill patients. The present clinical trial aimed to investigate the efficacy of synbiotics in improving EFI and oropharyngeal aspiration in patients admitted to the intensive care unit (ICU).

METHODS

This randomized clinical trial was conducted on 105 critically ill patients admitted to the ICU of a tertiary referral hospital affiliated with a medical university. The patients were randomly assigned to either a synbiotic or control group and underwent 7 days of investigation. The primary end point was reduced gastric residual volume, which is suggestive of an improvement in EFI. The secondary end point included requirement for prokinetics, frequency of aspiration, duration of mechanical ventilation, length of ICU stay, and level of consciousness.

RESULTS

The present clinical trial showed that synbiotic intervention has resulted in a significantly diminished requirement for prokinetics (P = 0.019), fewer oropharyngeal aspirations (P = 0.01), improved volume of bolus administration, and decreased gastric residual volume during the 7-day follow-up period. The patients who received synbiotic had an improved level of consciousness (P = 0.01).

CONCLUSION

This clinical trial showed that the prescription of synbiotic from the initial days of enteral feeding has resulted in a significantly diminished requirement for prokinetics, less oropharyngeal aspiration, decreased gastric residual volume, improved volume of bolus administration, and hence, better tolerance of enteral feeding.

The effects of synbiotic supplementation on enteral feeding tolerance, protein homeostasis, and muscle wasting of critically ill adult patients: a randomized controlled trial

Background

Enteral feeding intolerance, energy-protein malnutrition, and muscle wasting are common conditions in the critical care setting. The primary aim of this study was to investigate the effect of synbiotic supplementation on enteral feed volume, energy and protein homeostasis, and muscle mass maintenance in critically ill adult patients.

Methods

A consecutive of 42 patients admitted to the Edalatian Medical ICU, requiring enteral nutrition (EN), were prospectively randomized to receive the synbiotic capsule (containing a combination of Lactobacillus, Bifidobacterium, Streptococcus, and fructooligosaccharides) or placebo (21 patients in each group) for a maximum of 14 days. Enteral intolerance and energy homeostasis were evaluated on a daily basis. Nitrogen balance and 24-h urine creatinine excretion were recorded on days 1 and 14. Mid-arm circumference was recorded every 3 days.

Results

Mean EN volume, energy, and protein intake per day were 962.5 ± 533.82 ml, 770 ± 427.05 kcal, and 38.5 ± 21.35 g (fourth day) vs. 590 ± 321.1 ml, 472 ± 256.81 kcal, and 23.6 ± 12.84 g (first day) in the synbiotic group (p < 0.05). Changes in the placebo group were not statistically significant. On day 1, nitrogen balance (NB) was − 19.84 ± 8.03 in the synbiotic vs. − 10.99 ± 9.12 in the placebo group (p = 0.003). On day 14, NB was − 14.18 ± 13.05 in the synbiotic and − 9.59 ± 7.71 in the placebo group (p = 0.41). Mid-arm circumference (MAC), 24-h urine creatinine, and creatinine-height index were almost steady in the synbiotic group, while they decreased in the placebo group.

Conclusion

Overall, it can be concluded that enteral nutrition supplemented with synbiotics has no statistically significant effect on energy and protein homeostasis and muscle mass maintenance of critically ill patients on day 14, but it can increase enteral feed volume and energy and protein intake during the first 4 days of ICU admission.

Trial registration

The trial protocol has been approved in Iranian Registry of Clinical Trials on March 17, 2019. The registration reference is IRCT20190227042857N1.

Gut Microbiome in Anesthesiology and Pain Medicine

The gut microbiome plays critical roles in human health and disease. Recent studies suggest it may also be associated with chronic pain and postoperative pain outcomes. In animal models, the composition of the gut microbiome changes after general anesthesia and affects the host response to medications, including anesthetics and opioids. In humans, the gut microbiome is associated with the development of postoperative pain and neurocognitive disorders. Additionally, the composition of the gut microbiome has been associated with pain conditions including visceral pain, nociplastic pain, complex regional pain syndrome, and headaches, partly through altered concentration of circulating bacterial-derived metabolites. Furthermore, animal studies demonstrate the critical role of the gut microbiome in neuropathic pain via immunomodulatory mechanisms. This article reviews basic concepts of the human gut microbiome and its interactions with the host and provide a comprehensive overview of the evidence linking the gut microbiome to anesthesiology, critical care, and pain medicine.

Management of gastrointestinal failure in the adult critical care setting

PURPOSE OF REVIEW

Gastrointestinal failure is a polymorphic syndrome with multiple causes. Managing the different situations from a practical, metabolic, and nutritional point of view is challenging, which the present review will try to address.

RECENT FINDINGS

Acute gastrointestinal injury (AGI) has been defined and has evolved into a concept of gastrointestinal dysfunction score (GIDS) built on the model of Sequential Organ Failure Assessment (SOFA) score, and ranging from 0 (no risk) to 4 (life threatening). But there is yet no specific, reliable and reproducible, biomarker linked to it. Evaluating the risk with the Nutrition Risk Screening (NRS) score is the first step whenever addressing nutrition therapy. Depending on the severity of the gastrointestinal failure and its clinical manifestations, nutritional management needs to be individualized but always including prevention of undernutrition and dehydration, and administration of target essential micronutrients. The use of fibers in enteral feeding solutions has gained acceptance and is even recommended based on microbiome findings. Parenteral nutrition whether alone or combined to enteral feeding is indicated whenever the intestine is unable to process the needs.

SUMMARY

The heterogeneity of gastrointestinal insufficiency precludes a uniform nutritional management of all critically ill patients but justifies its early detection and the implementation of individualized care.

Nutrition in the Intensive Care Unit-A Narrative Review

Background: While consent exists, that nutritional status has prognostic impact in the critically ill, the optimal feeding strategy has been a matter of debate. Methods: Narrative review of the recent evidence and international guideline recommendations focusing on basic principles of nutrition in the ICU and the treatment of specific patient groups. Covered topics are: the importance and diagnosis of malnutrition in the ICU, the optimal timing and route of nutrition, energy and protein requirements, the supplementation of specific nutrients, as well as monitoring and complications of a Medical Nutrition Therapy (MNT). Furthermore, this review summarizes the available evidence to optimize the MNT of patients grouped by primarily affected organ system. Results: Due to the considerable heterogeneity of the critically ill, MNT should be carefully adapted to the individual patient with special focus on phase of critical illness, metabolic tolerance, leading symptoms, and comorbidities. Conclusion: MNT in the ICU is complex and requiring an interdisciplinary approach and frequent reevaluation. The impact of personalized and disease-specific MNT on patient-centered clinical outcomes remains to be elucidated.