Influence of nutritional status on postoperative outcome in patients with colorectal cancer - the emerging role of the microbiome

Effect of preoperative immunonutrition on fecal microbiota in colon cancer patients: a secondary analysis of a randomized controlled trial

BACKGROUND/OBJECTIVES

This study aimed to evaluate the effect of preoperative immunonutrition on the composition of fecal microbiota following a colon cancer surgery.

MATERIALS/METHODS

This study was a secondary analysis of a randomized controlled trial assessing the impact of preoperative immunonutrition on the postoperative outcomes of colon cancer surgery. Patients with primary colon cancer were enrolled and randomly assigned to receive additional preoperative immunonutrition or a normal diet alone. Oral nutritional supplementation (400 mL/day) with arginine and ω-3 fatty acids were administered to patients in the immunonutrition group for 7 days prior to surgery. Thirty-two fecal samples were collected from 16 patients in each group, and the composition of fecal microbiota was compared between the 2 groups.

RESULTS

At the phylum level, no significant difference was observed in the composition of microbiota between the 2 groups (Firmicutes, 69.1% vs. 67.5%, P = 0.624; Bacteroidetes, 19.3% vs. 18.1%, P = 0.663; Actinobacteria, 6.7% vs. 10.6%, P = 0.080). The Firmicutes/Bacteroidetes ratio (4.43 ± 2.32 vs. 4.55 ± 2.51, P = 0.897) was also similar between the 2 groups. At the genus level, the proportions of beneficial bacteria such as Faecalibacterium spp. (8.1% vs. 6.4%, P = 0.328) and Prevotella spp. (6.9% vs. 4.8%, P = 0.331) were higher, while that of Clostridium spp. was lower (0.5% vs. 1.2%, P = 0.121) in the immunonutrition group, but the difference was not significant.

CONCLUSIONS

Immunonutrition showed no significant association with the composition of fecal microbiota. The relationship between immunonutrition and the fecal microbiota should be investigated further in large-scale studies.

Malnutrition management in oncology: An expert view on controversial issues and future perspectives

Cancer and anticancer treatments can lead to several negative side effects, including malnutrition. Despite the recognized need for adequate nutritional support in cancer patients, in daily clinical practice, nutrition is still not considered one of the first aspects to be considered. Malnutrition negatively affects the clinical outcomes, treatment response, and overall survival of cancer patients. In this study, three of the most controversial issues related to malnutrition, which emerged during an Italian Consensus Conference, were addressed specifically for patients with head and neck as well as gastrointestinal cancer. The timing of nutritional evaluation and intervention, extension of the Enhanced Recovery after Surgery (ERAS^®) protocols, and cost-effectiveness of nutritional interventions have been considered. This study aimed to illustrate the state-of-the art of each issue and hypothesize future perspectives and actions to be taken, trying to suggest a new nutritional management model for cancer patients in Italy that overcomes the critical issues encountered. Of note, the timely diagnosis of nutritional issue appears to be essential to ensure the correct management of malnourished cancer patients as well as those who are at high risk of malnutrition. Standardized protocols, screening tests, and the inclusion of nutritional parameters in patient medical records would help to achieve good clinical outcomes. Finally, appropriate nutritional support is also associated with cost savings, and it seems necessary to promote its clinical and economic value to obtain improvements in both outcomes and management costs.

The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

The therapy of gastrointestinal carcinomas includes surgery, chemo- or immunotherapy, and radiation with diverse complications such as surgical-site infection and enteritis. In recent years, the microbiome’s influence on different diseases and complications has been studied in more detail using methods such as next-generation sequencing. Due to the relatively simple collectivisation, the gut microbiome is the best-studied so far. While certain bacteria are sometimes associated with one particular complication, it is often just the loss of alpha diversity linked together. Among others, a strong influence of Fusobacterium nucleatum on the effectiveness of chemotherapies is demonstrated. External factors such as diet or specific medications can also predispose to dysbiosis and lead to complications. In addition, there are attempts to treat developed dysbiosis, such as faecal microbiota transplant or probiotics. In the future, the underlying microbiome should be investigated in more detail for a better understanding of the precipitating factors of a complication with specific therapeutic options.

The effect of trimodal prehabilitation on the physical and psychological health of patients undergoing colorectal surgery: a randomised clinical trial

Prehabilitation aims to increase the endurance capacity of patients who are awaiting major surgery. However, there are no studies investigating the implementation of this demanding and expensive intervention in low-income countries. This study aimed to assess the impact of a 4-week trimodal prehabilitation program on the physical and psychological health of patients waiting for colorectal surgery compared with a control group managed according to enhanced recovery after surgery principles supplemented by nutritional care. This study was a single-centre, randomised controlled trial. The primary outcome measures for the physical aspects were 6-minute walking distance (6MWD) and incentive spirometry, whereas the psychological elements were measured using the 36-item short form survey questionnaire and the hospital anxiety and depression score. In total, data from 149 patients were analysed (77 in the prehabilitation group and 72 in the control group). At the time of surgery, patients in the prehabilitation group had improved 6MWD and incentive spirometry compared with the control group (median (IQR [range]) percentage improvement 131% (112-173 [68-376]) vs. 107% (99-120 [63-163]); p < 0.001 and 113% (100-125 [75-200]) vs. 100% (100-112 [86-167]); p < 0.001 respectively). Patients in the prehabilitation group also had reduced anxiety scores compared with the control group (mean (SD) anxiety score (4 (3) vs. 5 (3) respectively; p = 0.032). However, these effects did not translate into improvements in postoperative mortality and morbidity, or a reduction in duration of hospital stay. Trimodal (physical, emotional and nutritional) prehabilitation is able to improve functional status as well as some parameters of emotional and physical well-being of patients waiting for colorectal surgery.

Effect of preoperative immunonutrition on outcomes of colon cancer surgery: study protocol for a randomized controlled trial

Background

Current guidelines recommend the prescription of immune-enriched oral nutritional supplements for malnourished patients before major gastrointestinal surgery. However, the benefit of preoperative immunonutrition is still controversial. This randomized controlled trial aims to evaluate the effect of preoperative immunonutrition on the outcomes of surgery for colon cancer.

Methods/design

Patients with primary colon cancer will be included as study participants after screening. They will be randomly assigned (in a ratio of 1:1) to receive preoperative immunonutrition added to the normal diet (experimental arm) or consume normal diet alone (control arm). Patients in the experimental arm will receive oral supplementation (400 mL/day) with arginine and ω-3 fatty acids for 7 days before elective surgery. The primary endpoint is the rate of infectious complications, while the secondary endpoints are postoperative complication rate, change in body weight, length of hospital stay, and nature of fecal microbiome. The authors hypothesize that the rate of infectious complications would be 13% in the experimental arm and 30% in the control arm. With a two-sided alpha of 0.05 and a power of 0.8, the sample size is calculated as 176 patients (88 per arm).

Discussion

Although there have been many studies demonstrating significant benefits of preoperative immunonutrition, these were limited by a small sample size and potential publication bias. Despite the recommendation of immunonutrition before surgery in nutritional guidelines, its role in reduction of rate of infectious complications is still controversial. This trial is expected to provide evidence for the benefits of administration of preoperative immunonutrition in patients with colon cancer.

Trial registration

Clinical Research Information Service KCT0003770. Registered on 15 April 2019.