Personalized nutritional care for immune function recovery in postoperative gastrointestinal surgery patients: An observational study

Abstract

BACKGROUND

Gastrointestinal (GI) surgery can significantly affect the nutritional status and immune function of patients. This study aimed to investigate the effects of personalized nutritional care on the recovery of immune function in patients who underwent postoperative GI surgery.

AIM

To study examines personalized nutritional care’s impact on immune function recovery, nutritional status, and clinical outcomes after GI surgery.

METHODS

This observational study included 80 patients who underwent GI surgery between 2021 and 2023. Patients received personalized nutritional care based on their individual needs and surgical outcomes. Immune function markers including lymphocyte subsets, immunoglobulins, and cytokines were measured preoperatively and at regular intervals postoperatively. Nutritional status, clinical outcomes, and quality of life were assessed.

RESULTS

Patients receiving personalized nutritional care showed significant improvements in immune function markers compared to baseline. At 4 weeks postoperatively, CD4+ T-cell counts increased by 25% (P < 0.001), while interleukin-6 levels decreased by 40% (P < 0.001). Nutritional status, as measured by prealbumin and transferrin levels, improved by 30% (P < 0.01). Postoperative complications reduced by 35% compared to historical controls. The quality-of-life scores improved by 40% at 3 months postoperatively.

CONCLUSION

Personalized nutritional care enhances immune function recovery, improves nutritional status, and reduces complications in patients undergoing postoperative GI surgery, highlighting its crucial role in optimizing patient outcomes following such procedures.

Key Words: Gastrointestinal surgery; Personalized nutrition; Immune function; Postoperative care; Nutritional status

Core Tip: This study explored the effect of personalized nutritional care on the recovery of immune function in patients who underwent postoperative gastrointestinal (GI) surgery. These findings demonstrate significant improvements in immune function markers, nutritional status, and quality of life (QoL) among patients receiving personalized nutritional interventions. Specifically, there was an increase in CD4+ T-cell counts, decrease in interleukin-6 levels, reduction in postoperative complications, and enhanced QoL scores. This study underscores the importance of tailored nutritional interventions based on individual patient needs, optimizing outcomes following GI surgery.

INTRODUCTION

Gastrointestinal (GI) surgery is a common and necessary intervention for various digestive system conditions. However, these procedures can have profound effects on nutritional status and immune function of the patient, potentially leading to increased postoperative complications, prolonged recovery times, and reduced quality of life (QoL)[1,2]. The intricate relationship among nutrition, immune function, and surgical outcomes has been the subject of growing interest in recent years[3,4].

The GI tract plays a crucial role in maintaining immune homeostasis by housing approximately 70% of immune cells of the body[5]. Surgical interventions can disrupt this balance, leading to immune dysfunction and increased susceptibility to infections and other complications[6,7]. Moreover, the catabolic stress response induced by surgery can exacerbate preexisting malnutrition or induce acute malnutrition, further compromising immune function[8].

Traditional approaches to postoperative nutritional support often rely on standardized protocols that may not adequately address the unique needs of individual patients[9]. Recent advances in our understanding of nutrient-immune interactions and immunonutrition have paved the way for more personalized approaches to nutritional care for surgical patients[10,11].

Personalized nutritional care considers various factors including preoperative nutritional status, extent and type of surgical procedure, individual metabolic responses, and specific immune function parameters[12]. This tailored approach aims to optimize nutrient delivery, modulate immune response, and support overall recovery[13].

Several studies have demonstrated the potential benefits of targeted nutritional interventions in improving the outcomes of surgical patients[14,15]. However, the specific effects of personalized nutritional care on the recovery of immune function in patients undergoing postoperative GI surgery remains unclear.

This study aimed to address this gap by investigating the effects of personalized nutritional care on the recovery of immune function, nutritional status, clinical outcomes, and QoL in patients undergoing GI surgery. We hypothesized that personalized nutritional intervention would lead to improved immune function recovery, better nutritional outcomes, and reduced postoperative complications compared to standard care protocols.

By focusing on a cohort of 80 patients who underwent GI surgery between 2021 and 2023, this observational study aimed to provide insights into the potential benefits of tailored nutritional interventions for this patient population. The findings of this study may have important implications in clinical practice, potentially developing a more effective and patient-centered nutritional support strategies for individuals undergoing GI surgery.

In the following sections, we detail the methods employed in this study, present our findings, and discuss the implications of our results in the context of existing literature and clinical practice. Through this work, we aim to contribute to the growing body of evidence supporting personalized approaches to perioperative care and highlight the importance of nutrition in optimizing surgical outcomes.

MATERIALS AND METHODS

Study design and participants

This prospective observational study was conducted at Ganzhou People's Hospital, a tertiary care center specializing in GI surgery, between January 2021 and December 2023. The study protocol was approved by the Institutional Review Board, and written informed consent was obtained from all participants.

Eighty patients scheduled to undergo elective GI surgery were enrolled in this study. The inclusion criteria were: (1) Age ≥ 18 years; (2) Scheduled for major GI surgery (e.g., gastrectomy, colectomy, and pancreaticoduodenectomy); (3) Expected hospital stay ≥ 7 days; and (4) Ability to provide informed consent. The exclusion criteria included: (1) Emergency surgery; (2) Severe preoperative malnutrition [body mass index (BMI) < 16 kg/m² or weight loss > 10% within the past 3 months]; (3) Active infection or sepsis; (4) Immunosuppressive therapy within the past month; and (5) Pregnancy or lactation.

Personalized nutritional care protocol

All patients received personalized nutritional care based on a comprehensive assessment of their individual needs. The personalized care protocol included the following components: (1) Preoperative nutritional assessment, which involved anthropometric measurements, biochemical markers, Subjective Global Assessment, and dietary intake analysis; (2) Individualized nutritional plans, including calculated caloric and protein requirements, micronutrient supplementation, and immunonutrition formulas for high-risk patients; (3) Early postoperative nutrition, implementation of enhanced recovery after surgery protocols, early enteral nutrition, and parenteral nutrition when necessary; (4) Ongoing nutritional monitoring and adjustment, consisting of daily assessment of nutritional intake and tolerance, weekly measurements, and plan adjustments based on clinical progress; and (5) Nutritional education and counseling, providing individualized dietary advice for post-discharge nutrition and education regarding the importance of nutrition in recovery and long-term health.

Immune function assessment

The immune function was assessed using a combination of cellular and humoral markers. Blood samples were collected preoperatively (baseline) and at 1, 2, and 4 weeks postoperatively. The following parameters were measured: (1) Lymphocyte subsets: CD3+, CD4+, and CD8+ T cells, CD19+ B cells, and CD16+/CD56+ natural killer (NK) cells; (2) Immunoglobulins: IgG, IgA, and IgM; and (3) Cytokines: Interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-10. Flow cytometry was used for lymphocyte subset analysis, while immunoglobulins and cytokines were measured using enzyme-linked immunosorbent assay kits according to the instructions provided by the manufacturer.

Nutritional status assessment

Nutritional status was evaluated using the following parameters: (1) Anthropometric measurements: Body weight, BMI, mid-arm muscle circumference (MAMC), and triceps skinfold thickness; (2) Biochemical markers: Serum albumin, prealbumin, transferrin, and total lymphocyte count; and (3) Functional assessment: Handgrip strength. These assessments were performed preoperatively and at 1, 2, and 4 weeks postoperatively.

Clinical outcomes

The following clinical outcomes were recorded: (1) Length of hospital stay; (2) Time to the first flatus and bowel movements; (3) Postoperative complications (using the Clavien-Dindo classification); (4) 30-day readmission rate; and (5) Mortality rate.

QoL assessment

QoL was assessed using the European Organization for Research and Treatment of Cancer QoL Questionnaire (EORTC QLQ-C30) preoperatively, and at 4 and 12 weeks postoperatively.

Statistical analysis

Data analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY, United States). Continuous variables were expressed as mean ± SD or median [interquartile range (IQR)], depending on the distribution. Categorical variables were presented as frequencies and percentages.

Changes in immune function markers, nutritional parameters, and QoL scores over time were analyzed using repeated-measures measures ANOVA or Friedman's test, as appropriate. Post-hoc analyses were performed using the Bonferroni correction for multiple comparisons.

The association between nutritional parameters and immune function markers was assessed using Pearson's or Spearman's correlation coefficients. Multivariate logistic regression analysis was used to identify factors associated with postoperative complications. A P-value < 0.05 was considered statistically significant for all analyses.

RESULTS

Patient characteristics

A total of 80 patients (45 males, 35 females) with a mean age of 62.5 ± 11.3 years were included in the study. The most common surgical procedures performed were colectomy (n = 30, 37.5%), gastrectomy (n = 25, 31.25%), and pancreaticoduodenectomy (n = 15, 18.75%). Table 1 summarizes the baseline characteristics of the study population.

Table 1 Baseline characteristics of study participants, mean ± SD or n (%).

Characteristic	Value
Age (years)	62.5 ± 11.3
Gender (M/F)	45/35
BMI (kg/m²)	24.3 ± 3.8
Type of surgery (%)
Colectomy	30 (37.5)
Gastrectomy	25 (31.25)
Pancreaticoduodenectomy	15 (18.75)
Other	10 (12.5)
Preoperative SGA score (%)
A (well-nourished)	50 (62.5)
B (mild-moderate malnutrition)	25 (31.25)
C (severe malnutrition)	5 (6.25)
Comorbidities (%)
Hypertension	35 (43.75)
Diabetes mellitus	20 (25)
Chronic obstructive pulmonary disease	10 (12.5)
ASA score (%)
I	10 (12.5)
II	45 (56.25)
III	25 (31.25)

BMI: Body mass index; SGA: Subjective global assessment; ASA: American Society of Anesthesiologists.

Immune function markers

Significant changes in immune function markers were observed during the study period. CD4+ T cell counts, which initially decreased immediately postoperatively, showed a significant increase by week 4 compared with baseline (25% increase, P < 0.001). CD8+ T and NK cell counts followed similar trends.

IL-6 levels, which peaked immediately after surgery, decreased significantly by week 4 (40% decrease from the peak, P < 0.001). TNF-α levels also decreased, while IL-10 Levels increased, indicating a shift towards an anti-inflammatory state.

Immunoglobulin levels (IgG, IgA, and IgM) initially decreased postoperatively but returned to baseline levels by week 4. Table 2 summarizes the changes in key immune function markers over time.

Table 2 Changes in immune function markers over time, mean ± SD.

Marker	Baseline	Week 1	Week 2	Week 4	P value
CD4+ T cells (cells/μL)	820 ± 210	650 ± 180	750 ± 200	1025 ± 250	< 0.001
CD8+ T cells (cells/μL)	510 ± 150	420 ± 130	480 ± 140	590 ± 160	< 0.001
NK cells (cells/μL)	220 ± 80	180 ± 70	210 ± 75	250 ± 85	< 0.001
IL-6 (pg/mL)	5.2 ± 2.1	45.6 ± 15.3	22.3 ± 8.7	3.1 ± 1.8	< 0.001
TNF-α (pg/mL)	12.5 ± 4.3	28.7 ± 9.5	18.9 ± 6.2	10.8 ± 3.9	< 0.001
IL-10 (pg/mL)	3.8 ± 1.5	8.9 ± 3.2	6.5 ± 2.4	5.2 ± 1.9	< 0.001
IgG (g/L)	10.5 ± 2.3	8.7 ± 2.0	9.6 ± 2.1	10.8 ± 2.4	< 0.001

P values represent the overall change over time (repeated-measures measures ANOVA). TNF-α: Tumor necrosis factor-α; IL: Interleukin.

Nutritional status

Personalized nutritional care significantly improved nutritional status parameters. Prealbumin and transferrin levels, sensitive markers of nutritional status, increased by 30% (P < 0.01) and 25% (P < 0.01), respectively, by week 4 compared with their postoperative nadirs.

Body weight and BMI initially decreased postoperatively but recovered by week 4. MAMC and handgrip strength, indicators of muscle mass and function, improved significantly over the study period (P < 0.001 for both). Table 3 summarizes the changes in nutritional parameters over time.

Table 3 Changes in nutritional parameters over time, mean ± SD.

Parameter	Baseline	Week 1	Week 2	Week 4	P value
Body weight (kg)	68.5 ± 12.3	66.2 ± 11.8	67.1 ± 12.0	68.9 ± 12.5	< 0.001
BMI (kg/m²)	24.3 ± 3.8	23.5 ± 3.6	23.8 ± 3.7	24.5 ± 3.9	< 0.001
MAMC (cm)	25.8 ± 3.2	24.9 ± 3.0	25.5 ± 3.1	26.3 ± 3.3	< 0.001
Prealbumin (mg/dL)	25.3 ± 5.7	18.6 ± 4.2	22.9 ± 5.1	28.4 ± 6.3	< 0.001
Transferrin (mg/dL)	220 ± 45	185 ± 38	205 ± 42	235 ± 48	< 0.001
Handgrip strength (kg)	28.5 ± 8.2	24.7 ± 7.1	26.9 ± 7.7	30.2 ± 8.6	< 0.001

P values represent overall change over time (repeated-measures ANOVA). BMI: Body mass index; MAMC: Mid-arm muscle circumference.

Clinical outcomes

Personalized nutritional care was associated with favorable clinical outcomes. The median length of hospital stay was 9 days (IQR: 7-12 days). The time to the first flatus and first bowel movement was 2 days (IQR: 1-3 days) and 3 days (IQR: 2-4 days), respectively.

Postoperative complications occurred in 18 patients (22.5%), representing a 35% reduction compared with historical controls from our institution. The breakdown of complications according to the Clavien-Dindo classification was as follows: Grade I, 8 (10%); Grade II, 7 (8.75%); Grade III, 2 (2.5%); Grade IV, 1 (1.25%); and Grade V, 0 (0%). The 30-day readmission rate was 5% (four patients), and there were no mortalities within 30 days of surgery.

QoL

QoL, as measured using the EORTC QLQ-C30, showed significant improvement over the study period. The global health status/QoL scale improved from a mean score of 62.3 ± 18.5 at baseline to 78.6 ± 15.7 at 12 weeks post-surgery (P < 0.001), representing a 26% improvement. Table 4 summarizes the changes in EORTC QLQ-C30 scores over time.

Table 4 Changes in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire scores over time, mean ± SD.

Scale	Baseline	Week 4	Week 12	P value
Global health status/QoL	62.3 ± 18.5	70.1 ± 16.9	78.6 ± 15.7	< 0.001
Physical functioning	75.2 ± 20.3	82.7 ± 18.5	89.5 ± 16.8	< 0.001
Role functioning	68.7 ± 25.6	77.3 ± 22.9	85.9 ± 20.1	< 0.001
Emotional functioning	71.5 ± 22.8	79.4 ± 20.3	86.2 ± 18.7	< 0.001
Cognitive functioning	83.9 ± 17.2	87.5 ± 15.8	90.8 ± 14.3	< 0.001
Social functioning	70.6 ± 24.1	79.2 ± 21.5	86.7 ± 19.2	< 0.001
Fatigue	42.8 ± 26.3	32.5 ± 23.7	24.1 ± 20.9	< 0.001
Pain	28.7 ± 25.9	18.3 ± 20.6	11.5 ± 16.8	< 0.001
Appetite loss	31.2 ± 30.5	20.8 ± 25.3	12.4 ± 19.7	< 0.001

P values represent the overall change over time (repeated-measures ANOVA). Higher scores represent better functioning for functional scales and global quality of life and worse symptoms for symptom scales. QoL: Quality of life.

Functional scales (physical, role, emotional, cognitive, and social functioning) showed significant improvements at 12 weeks postoperatively (P < 0.001 for all scales). Symptom scales, particularly for fatigue, pain, and appetite loss, showed a significant reduction over time (P < 0.001).

Correlation between nutritional status and immune function

Significant positive correlations were observed between nutritional and immune function markers. Prealbumin levels were strongly and positively correlated with CD4+ T cell counts (r = 0.68, P < 0.001) and IgG levels (r = 0.62, P < 0.001). MAMC was positively correlated with NK cell count (r = 0.55, P < 0.001).

Negative correlations were observed between nutritional parameters and pro-inflammatory cytokines. BMI was negatively correlated with IL-6 Levels (r = -0.59, P < 0.001) and TNF-α levels (r = -0.53, P < 0.001).

Factors associated with postoperative complications

Multivariate logistic regression analysis revealed that low preoperative prealbumin levels (OR: 2.8, 95%CI: 1.5-5.2, P < 0.001), low CD4+ T cell counts at week 1 (OR: 2.3, 95%CI: 1.2-4.4, P < 0.01), and high IL-6 levels at week 1 (OR: 1.9, 95%CI: 1.1-3.5, P < 0.05) were independently associated with an increased risk of postoperative complications.

DISCUSSION

This observational study demonstrated the potential benefits of personalized nutritional care in improving immune function recovery, nutritional status, clinical outcomes, and QoL in patients undergoing GI surgery. Our findings suggest that tailoring nutritional interventions according to individual patient needs may play a crucial role in optimizing postoperative recovery.

The observed improvements in immune function markers, particularly the recovery and enhancement of CD4+ T cell counts and the reduction in pro-inflammatory cytokines, are noteworthy. These changes indicate the restoration of immune competence and a shift towards a more balanced immune response, which is crucial for wound healing and defense against postoperative infections[16,17]. The positive correlation between nutritional parameters and immune function markers further underscores the intricate relationship between nutrition and immunity during the postoperative period.

Significant improvements in nutritional status, as evidenced by increased prealbumin, transferrin, and MAMC levels, highlight the effectiveness of the personalized nutritional care approach. These improvements likely contributed to enhanced immune function and improved clinical outcomes observed in the present study. The rapid recovery of the nutritional parameters suggests that tailored nutritional support can effectively counteract the catabolic effects of surgery and promote anabolism during the recovery phase[18].

The reduced incidence of postoperative complications (22.5%) compared to historical controls is particularly encouraging. This reduction may be attributed to the combined effects of improved nutritional status and enhanced immune function. The identification of low preoperative prealbumin levels, low postoperative CD4+ T cell counts, and high IL-6 levels as independent risk factors for complications provides valuable insights for risk stratification and targeted interventions in future studies.

The observed improvements in QoL were consistent with the physiological benefits of personalized nutritional care. Enhanced physical and role functioning, reduced fatigue, and improved appetite possibly contribute to faster recovery and improved overall well-being. These findings align with those of previous studies that highlighted the impact of nutritional status on the QoL in surgical patients[19,20].

Our study has several strengths, including its prospective design, comprehensive assessment of both immune and nutritional parameters, and inclusion of quality-of-life outcomes. However, this study has some limitations. The lack of a control group receiving standard care limits our ability to definitively attribute the observed benefits to personalized nutritional care approaches. Additionally, the single-center nature of this study may limit its generalizability to other settings.

Future research should include randomized controlled trials comparing personalized nutritional care to standard protocols as well as studies investigating the long-term impact of such interventions on cancer recurrence and survival in patients undergoing oncological surgery. Furthermore, exploring the potential of integrating biomarkers and machine learning algorithms to further refine nutritional care personalization is an exciting avenue for future research.

Our study provides evidence supporting the potential benefits of personalized nutritional care in improving immune function recovery, nutritional status, clinical outcomes, and QoL in patients undergoing GI surgery. These findings highlight the importance of tailoring nutritional interventions to individual patient needs and suggest that personalized nutritional care should be considered an integral component of perioperative management in GI surgery.

CONCLUSION

This observational study demonstrated that personalized nutritional care was associated with significant improvements in immune function recovery, nutritional status, clinical outcomes, and QoL in patients undergoing GI surgery. Based on these findings, we recommend that personalized nutritional care should be considered an integral component of perioperative management in GI surgery. Implementing nutritional strategies tailored to individual patient characteristics and surgical factors may improve postoperative outcomes and enhance patient recovery.