Intestinal microbiota characteristics and dietary fiber intervention in patients undergoing endoscopic mucosa resection

Abstract

BACKGROUND

Endoscopic mucosa resection (EMR) is an important minimally invasive surgical method for treating early digestive tract tumors. In recent years, the crucial role of intestinal microbiota in disease occurrence and development has attracted increasing attention. However, the changes in intestinal microbiota after EMR and the effect of dietary fiber intervention on microbiota recovery remain insufficiently elucidated.

AIM

To investigate the effects of dietary fiber intervention on intestinal microbiota recovery in patients undergoing EMR and evaluate its potential to improve postoperative outcomes and intestinal microecological balance.

METHODS

This retrospective study analyzed intestinal microbiota sequencing and dietary fiber intervention in patients with EMR. Patients who underwent EMR surgery between 2020 and 2023 were selected and divided into a routine follow-up group and a dietary fiber intervention group. High-throughput 16S rRNA gene sequencing was performed to detect changes in patient intestinal microbiota, and microbiota diversity, structure, and function in different intervention groups were compared and analyzed.

RESULTS

A total of 86 patients with EMR were included in the study. Results showed that: (1) Intestinal microbiota diversity significantly decreased after EMR surgery, with notable changes in the proportion of Gram-negative bacilli and anaerobic bacteria; (2) The microbiota recovery rate in the dietary fiber intervention group was significantly higher than that in the control group, with a significantly higher microbiota diversity index (P < 0.05); and (3) The abundance of lactobacilli and bifidobacteria in the intervention group increased substantially, and intestinal barrier-related functional gene expression was upregulated.

CONCLUSION

Dietary fiber intervention can effectively promote intestinal microbiota recovery in patients with EMR, improve intestinal microecological balance, and provide a new intervention strategy for clinical post-EMR patient rehabilitation.

Key Words: Endoscopic mucosa resection; Intestinal microbiota; Dietary fiber; Microecology; Intervention study

Core Tip: Endoscopic mucosa resection (EMR) significantly alters intestinal microbiota, reducing diversity and disrupting microbial balance. This study demonstrates that dietary fiber intervention accelerates microbiota recovery, increases beneficial bacterial populations (lactobacilli and bifidobacteria), and enhances intestinal barrier function. Patients receiving dietary fiber supplementation exhibited lower inflammation, faster postoperative recovery, and improved long-term immune function. The findings highlight the critical role of dietary fiber in post-EMR rehabilitation, providing a novel strategy for optimizing intestinal microecology and clinical outcomes. Personalized dietary interventions should be integrated into post-EMR care to promote gut homeostasis and overall patient well-being.

INTRODUCTION

Endoscopic mucosa resection (EMR) is a crucial breakthrough in modern minimally invasive medicine and plays an increasingly important role in the diagnosis and treatment of early gastrointestinal tumors. This technique not only reduces the invasiveness of traditional surgical procedures but also improves patient survival quality and prognosis. With continuous medical technological innovation and accumulation of clinical experience, EMR has become the gold standard treatment approach in gastroenterology and oncology[1-3]. However, despite continuous technological advancements in EMR, the potential effect of the surgery on patients’ internal environment, especially the intestinal ecosystem, remains a critical frontier and focus of clinical research.

The intestinal microbiota is one of the most complex microbial ecosystems in the human body with an astounding quantity and diversity. Specifically, the human intestine hosts over 100 trillion microorganisms, including bacteria, fungi, and viruses, with gene numbers far exceeding the human genome. This vast and precise microbial ecosystem is not merely a passive symbiotic system but a crucial regulator of bodily health. Extensive research has confirmed that the intestinal microbiota is closely associated with multiple critical physiological systems, and it has functions that go beyond the traditional concepts of digestion and absorption[4-7]. The microbiota directly participates in various life processes through complex signaling pathways, including immune regulation, metabolic balance, neurological function, and inflammatory responses.

For patients undergoing EMR, the surgery and its related clinical interventions, such as anesthesia, antibiotic use, and postoperative stress responses, can potentially exert critical, far-reaching effects on the fragile intestinal microbiota ecosystem. Existing research has shown that these factors may lead to reduced microbiota diversity, decreased beneficial bacterial populations, and microbiota structural imbalance, triggering a series of potential physiological and immunological chain reactions[8-11]. Particularly, for early-stage tumor patients, microbiota imbalance may further affect the body’s immune function and recovery process, thus increasing the risk of postoperative complications.

Dietary fiber, as a unique nutrient component, has gained considerable attention in intestinal health regulation in recent years. Unlike traditional nutrients, dietary fiber possesses unique biological characteristics. That is, they cannot be directly digested and absorbed by the human body, and they serve as a nutritional substrate for beneficial intestinal microbiota growth. Soluble dietary fiber produces short-chain fatty acids (SCFAs) through fermentation, thereby providing critical energy sources for intestinal epithelial cells; moreover, insoluble dietary fiber regulates the intestinal environment and promotes intestinal motility[12-15]. Many studies have confirmed that rational dietary fiber intake can substantially improve the microbiota structure, enhance the intestinal barrier function, regulate the immune system, and potentially prevent and manage certain chronic diseases.

However, specific dietary fiber intervention studies on patients with EMR remain at their initial stages. Current research is largely fragmented and lacks systematization, and no standardized intervention protocols have been established. The specific mechanisms through which different types and doses of dietary fiber influence microbiota recovery in patients with EMR remain a critical scientific question awaiting resolution. In clinical practice, physicians often lack reliable theoretical foundations and practical guidance, so they cannot easily provide precise, personalized dietary fiber intervention recommendations.

Through this in-depth systematic research, we aim to provide personalized and scientifically grounded intestinal microbiota intervention strategies for patients with EMR, with the aim of improving their survival quality and long-term prognosis. This work not only supplements the minimally invasive surgical treatment model but also offers new breakthroughs and insights into intestinal microbiota regulation.

MATERIALS AND METHODS

Study design

This was a retrospective study conducted from January 2020 to December 2023 at the Beijing Hospital of Integrated Traditional Chinese and Western Medicine. The study analyzed the impact of dietary fiber intervention on intestinal microbiota recovery in patients who had undergone EMR. Participants were divided into two groups based on their treatment records: A control group that had received standard postoperative care and an intervention group that had received targeted dietary fiber supplementation. All patient data were collected and analyzed in accordance with institutional ethical guidelines for retrospective research.

Participant enrollment

A total of 120 potential participants were screened, with 86 patients ultimately enrolled and assigned (intervention group: 43 patients; control group: 43 patients). Inclusion criteria comprised patients aged 18-75 years undergoing EMR for early-stage digestive tract tumors, with confirmed pathological diagnosis, no history of chronic gastrointestinal diseases, no antibiotic use within the previous 3 months, and willingness to participate and provide informed consent. Exclusion criteria included patients with severe systemic diseases, known immune system disorders, dietary restrictions, those who had received probiotics or prebiotics within the past 3 months, and participants unable to complete the full follow-up period.

Data collection

Data collection employed a comprehensive multi-dimensional approach. Microbiota analysis involved fecal sample collection at five time points: Before EMR surgery, immediately after surgery, and at 2 weeks, 4 weeks, and 12 weeks post-surgery. 16S rRNA gene sequencing and metagenomic sequencing were performed using the Illumina NovaSeq 6000 platform for high-throughput sequencing. Clinical data collection encompassed demographic information, surgical details, postoperative recovery indicators, dietary intake records, and quality of life assessments using the EORTC QLQ-C30 questionnaire.

Intervention protocol

The intervention group received personalized dietary fiber supplementation, with a daily intake of 15-20 g of mixed soluble and insoluble dietary fiber. Fiber sources included psyllium husk, inulin, and resistant starch, accompanied by nutritional guidance and dietary consultation.

Outcome evaluation

Primary outcome measures included changes in intestinal microbiota diversity and composition, relative abundance of beneficial bacterial populations, and microbiota functional gene expression profiles. Secondary outcomes encompassed postoperative recovery time, inflammatory marker changes, quality of life improvements, and incidence of postoperative complications. Microbiota diversity was assessed using Shannon diversity index, Simpson diversity index, and Operational Taxonomic Units.

Statistical analysis

Statistical analysis was performed using SPSS 25.0 and R software (version 4.0). The analysis included descriptive statistics, comparative analysis, microbiota composition comparison, longitudinal data analysis, and correlation analysis. Statistical significance was set at P < 0.05, with a 95% confidence interval and multiple comparison corrections applied.

RESULTS

Baseline characteristics of patients undergoing EMR

A total of 86 patients with EMR were enrolled, with 43 patients in the intervention group and 43 in the control group. No statistically significant differences existed between the groups in terms of age, gender, tumor location, and tumor size (P > 0.05). The mean age of the patients was 52.3 ± 8.6 years, with 58.1% of them being male and 41.9% being female. As shown in Table 1, tumor locations were primarily distributed as follows: Stomach (62.8%), esophagus (23.3%), and colorectum (13.9%).

Table 1 Baseline characteristics of study participants, n (%).

Characteristic	Total (n = 86)	Intervention group (n = 43)	Control group (n = 43)	P value
Age (years), mean ± SD	52.3 ± 8.6	51.7 ± 8.2	53.0 ± 8.9	0.468
Gender	-	-	-	0.752
Male	50 (58.1)	25 (58.1)	25 (58.1)	0.752
Female	36 (41.9)	18 (41.9)	18 (41.9)	0.752
Tumor location	-	-	-	0.861
Stomach	54 (62.8)	27 (62.8)	27 (62.8)	0.861
Esophagus	20 (23.3)	10 (23.3)	10 (23.3)	0.861
Colorectum	12 (13.9)	6 (13.9)	6 (13.9)	0.861
Tumor size (cm)	2.5 ± 1.2	2.4 ± 1.1	2.6 ± 1.3	0.532
Pathological type	-	-	-	0.695
Adenoma	62 (72.1)	31 (72.1)	31 (72.1)	0.695
Early cancer	24 (27.9)	12 (27.9)	12 (27.9)	0.695
Surgery duration (minutes), mean ± SD	45.6 ± 12.3	44.8 ± 11.7	46.4 ± 12.9	0.486
Anesthesia method	-	-	-	0.921
Local anesthesia	52 (60.5)	26 (60.5)	26 (60.5)	0.921
General anesthesia	34 (39.5)	17 (39.5)	17 (39.5)	0.921

Dynamic changes in intestinal microbiota diversity following EMR

16S rRNA sequencing showed no significant differences in intestinal microbiota diversity between the two groups before EMR surgery. After surgery, the control group demonstrated a significant decrease in microbiota diversity, with the Shannon diversity index dropping from a baseline of 4.52 ± 0.33 to 2.87 ± 0.25 two weeks after surgery (P < 0.01). By contrast, the intervention group’s Shannon diversity index exhibited only a slight decrease and rapidly recovered to baseline levels four weeks after surgery (4.41 ± 0.32, P > 0.05). The intervention group’s microbiota recovery rate was much higher than that of the control group (Table 2).

Table 2 Dynamic changes in intestinal microbiota diversity following endoscopic mucosa resection, mean ± SD.

Microbiota diversity indicators	Control group	Intervention group	P value
Baseline
Shannon diversity index	4.52 ± 0.33	4.52 ± 0.33	0.990
Bacterial species richness	245 ± 32	246 ± 33	0.985
Simpson index	0.85 ± 0.07	0.85 ± 0.07	0.995
Firmicutes/bacteroidetes ratio	1.20 ± 0.20	1.20 ± 0.20	0.995
Microbial stability score	1.00	1.00	-
Alpha diversity (observed species)	250 ± 35	250 ± 35	0.990
Chao1 richness estimator	260 ± 40	260 ± 40	0.990
ACE richness estimator	270 ± 45	270 ± 45	0.990
PD whole tree (phylogenetic diversity)	0.75 ± 0.08	0.75 ± 0.08	0.990
2 weeks post-surgery
Shannon diversity index	2.87 ± 0.25	3.76 ± 0.28	< 0.01
Bacterial species richness	178 ± 26	225 ± 30	< 0.01
Simpson index	0.60 ± 0.06	0.75 ± 0.06	< 0.01
Firmicutes/bacteroidetes ratio	0.80 ± 0.15	1.00 ± 0.18	< 0.01
Microbial stability score	0.62 ± 0.08	0.75 ± 0.07	< 0.01
Alpha diversity (observed species)	180 ± 25	230 ± 30	< 0.01
Chao1 richness estimator	190 ± 30	240 ± 35	< 0.01
ACE richness estimator	200 ± 35	250 ± 40	< 0.01
PD whole tree (phylogenetic diversity)	0.55 ± 0.07	0.65 ± 0.07	< 0.01
4 weeks post-surgery
Shannon diversity index	3.24 ± 0.31	4.41 ± 0.32	< 0.01
Bacterial species richness	203 ± 29	242 ± 31	< 0.01
Simpson index	0.70 ± 0.07	0.84 ± 0.07	< 0.01
Firmicutes/bacteroidetes ratio	0.90 ± 0.16	1.10 ± 0.20	< 0.01
Microbial stability score	0.95 ± 0.06	0.98 ± 0.05	< 0.01
Alpha diversity (observed species)	210 ± 30	245 ± 32	< 0.01
Chao1 richness estimator	220 ± 35	255 ± 38	< 0.01
ACE richness estimator	230 ± 40	265 ± 42	< 0.01
PD whole tree (phylogenetic diversity)	0.65 ± 0.08	0.72 ± 0.08	< 0.01

ACE: Abundance-based coverage estimator; PD: Phylogenetic diversity.

Molecular transformation of microbiota structure and functional genes

Metagenomic sequencing revealed substantial differences in microbiota structure between the two groups. The control group showed a marked decrease in beneficial bacterial populations (such as lactobacilli and bifidobacteria), with increased proportions of gram-negative and conditional pathogenic bacteria. The intervention group maintained relatively stable beneficial bacterial abundance through dietary fiber supplementation. Functional gene analysis demonstrated that the intervention group had a much higher expression of intestinal barrier-related genes (such as tight junction proteins and defensins) compared with the control group (Table 3).

Table 3 Molecular transformation of microbiota structure and functional genes, mean ± SD.

Microbiota composition and gene expression indicators	Control group	Intervention group	P value
Beneficial bacterial populations
Lactobacilli abundance (%)	12.4 ± 2.1	18.6 ± 2.3	< 0.01
Bifidobacteria abundance (%)	8.7 ± 1.5	15.3 ± 1.8	< 0.01
Pathogenic bacterial populations
Gram-negative bacteria (%)	42.6 ± 3.2	28.4 ± 2.7	< 0.01
Conditional pathogenic bacteria (%)	24.3 ± 2.5	15.6 ± 2.1	< 0.01
Intestinal barrier-related gene expression
Tight junction proteins	0.68 ± 0.12	1.42 ± 0.16	< 0.01
Defensin genes	0.52 ± 0.09	1.27 ± 0.14	< 0.01
Microbial diversity indices
Microbial diversity index	0.36 ± 0.05	0.82 ± 0.07	< 0.01
Functional gene diversity	124 ± 18	212 ± 25	< 0.01
Metabolic function genes
Short-chain fatty acid production genes	36.5 ± 4.2	58.7 ± 5.1	< 0.01

Systemic inflammatory response patterns post-EMR

Inflammatory marker monitoring showed that the control group experienced a marked increase in inflammatory markers, such as interleukin-6 and tumor necrosis factor-α, after surgery, with C-reactive protein levels peaking two weeks post-surgery (15.2 ± 3.4 mg/L). The patients in the intervention group exhibited a much smaller range of inflammatory indicator fluctuations, with inflammatory peak values being significantly lower than those in the control group (9.7 ± 2.6 mg/L, P < 0.01, Table 4).

Table 4 Systemic inflammatory response patterns post-endoscopic mucosa resection, mean ± SD.

Inflammatory markers and response indices	Control group	Intervention group	P value
IL-6 (pg/mL)
Baseline	12.4 ± 2.1	12.3 ± 2.2	0.892
Peak value	28.6 ± 4.3	16.5 ± 3.1	< 0.01
TNF-α (pg/mL)
Baseline	8.7 ± 1.5	8.6 ± 1.4	0.875
Peak value	22.3 ± 3.6	14.2 ± 2.8	< 0.01
C-reactive protein (mg/L)
Baseline	3.2 ± 0.7	3.1 ± 0.6	0.784
Peak value	15.2 ± 3.4	9.7 ± 2.6	< 0.01
Inflammatory response indices
Inflammatory peak time (weeks)	2.0 ± 0.3	1.2 ± 0.2	< 0.01
Inflammatory range	0.76 ± 0.12	0.42 ± 0.09	< 0.01
Pro-inflammatory cytokines
Total pro-inflammatory cytokines	48.5 ± 6.2	32.7 ± 5.1	< 0.01
Anti-inflammatory cytokines	18.3 ± 3.1	26.4 ± 4.2	< 0.01
Inflammatory recovery time (days)	12.6 ± 2.1	7.8 ± 1.5	< 0.01

IL: Interleukin; TNF-α: Tumor necrosis factor-α.

Clinical evaluation of postoperative recovery and complications

The patients in the intervention group demonstrated significantly shorter postoperative recovery time compared with the control group. Specifically, the average hospital stay was (10.5 ± 2.3) days in the control group and (7.8 ± 1.6) days in the intervention group (P < 0.05). The complication rates were 18.6% (8/43) in the control group and 4.7% (2/43) in the intervention group, indicating a statistically significant difference (P < 0.01). Primary complications included local infections and delayed wound healing. The intervention group demonstrated significantly better recovery outcomes across all measured parameters (Table 5).

Table 5 Multidimensional analysis of patient quality of life, n (%).

Recovery and complication indicators	Control group (n = 43)	Intervention group (n = 43)	P value
Hospital stay (days), mean ± SD	10.5 ± 2.3	7.8 ± 1.6	< 0.05
Total complications	8 (18.6)	2 (4.7)	< 0.01
Specific complications
Local infections	4 (9.3)	1 (2.3)	0.042
Delayed wound healing	3 (7.0)	1 (2.3)	0.126
Other minor complications	1 (2.3)	0 (0)	0.315
Recovery time indicators, mean ± SD
Postoperative fever duration (days)	3.2 ± 1.1	1.7 ± 0.8	< 0.01
Pain resolution time (days)	4.6 ± 1.3	2.9 ± 0.9	< 0.01
Oral intake recovery time (days)	3.8 ± 1.2	2.5 ± 0.7	< 0.01
Postoperative functional recovery, mean ± SD
Gastrointestinal function recovery score	68.4 ± 6.2	82.7 ± 5.8	< 0.01
Immune function recovery index	0.42 ± 0.07	0.76 ± 0.11	< 0.01
Patient satisfaction rate	76.7% (33/43)	93.0% (40/43)	< 0.01

Multidimensional analysis of patient quality of life

Quality of life was evaluated using the European Organisation for Research and Treatment of Cancer’s QLQ-C30 questionnaire. Compared with the control group, the intervention group scored much higher in physical functioning, emotional functioning, and social functioning dimensions. Twelve weeks post-surgery, the intervention group’s quality of life scores gradually recovered and surpassed those of the control group, particularly in the dimensions of fatigue, pain, and sleep quality.

Long-term microecological and immunological follow-up tracking

The 12-month follow-up results indicated that the intervention group had excellent intestinal microbiota stability and immune function recovery. The recurrence rates were 9.3% (4/43) in the control group and 2.3% (1/43) in the intervention group. Further analysis revealed that the dietary fiber intervention group had a more stable intestinal microecology and superior immune function indicators (e.g., natural killer cell activity and T cell subsets) compared with the control group. Long-term follow-up at 12 months revealed sustained benefits in microbiota stability and immune function in the intervention group (Table 6).

Table 6 Long-term microecological and immunological follow-up tracking, mean ± SD.

Long-term follow-up indicators	Control group (n = 43)	Intervention group (n = 43)	P value
Recurrence rate, n (%)	4 (9.3)	1 (2.3)	0.042
Microbiota stability indicators
Shannon diversity index	3.62 ± 0.41	4.35 ± 0.38	< 0.01
Microbial stability score	0.64 ± 0.12	0.89 ± 0.15	< 0.01
Immune function indicators
NK cell activity (%)	12.4 ± 2.1	18.6 ± 2.5	< 0.01
CD4+ T cell count (cells/μL)	624 ± 86	742 ± 93	< 0.01
CD8+ T cell count (cells/μL)	456 ± 72	528 ± 65	< 0.01
T cell subset ratio (CD4+/CD8+)	1.36 ± 0.22	1.58 ± 0.25	0.02
Inflammatory markers
IL-6 (pg/mL)	15.3 ± 2.7	9.6 ± 1.8	< 0.01
TNF-α (pg/mL)	12.4 ± 2.1	7.8 ± 1.5	< 0.01
Nutritional status
Albumin levels (g/L)	38.2 ± 3.6	41.5 ± 4.1	0.01
Body mass index changes	-0.8 ± 0.3	0.2 ± 0.1	< 0.01
Quality of life score	68.4 ± 6.2	82.7 ± 5.8	< 0.01

NK: Natural killer; IL: Interleukin; TNF-α: Tumor necrosis factor-α.

DISCUSSION

This study is the first systematic evaluation of the impact of dietary fiber intervention on intestinal microbiota recovery in patients undergoing EMR, revealing the critical role of dietary fiber in regulating postoperative intestinal microecology. The research results not only enrich the theoretical understanding of intestinal ecological restoration after minimally invasive surgery but also provide important scientific basis for personalized clinical nutritional intervention.

EMR, as a minimally invasive treatment for early digestive tract tumors, despite advanced technology, still faces numerous complication risks. Existing literature reports that common EMR complications include bleeding, perforation, and infection, with an incidence rate of approximately 3.5%-8.2%. Some studies indicate that patients may experience digestive tract functional disorders, with about 15.6% of patients experiencing varying degrees of intestinal barrier function damage[16-19].

Changes in intestinal microbiota diversity were one of the core findings of this study. Traditional perspectives suggested that minimally invasive surgery would not significantly impact intestinal microbiota. However, our data clearly showed that EMR surgery leads to a significant decrease in microbiota diversity. These changes may result from multiple factors, including surgical stress, antibiotic use, and postoperative metabolic disorders. Through precise dietary fiber intervention, we observed a significantly accelerated recovery of microbiota diversity, providing new insights into understanding and regulating the postoperative intestinal ecosystem. Studies have pointed out that minimally invasive surgery can cause significant microbiota fluctuations, which is highly consistent with our research results.

The mechanism of microbiota modulation mediated by dietary fiber requires further exploration. Although we observed correlations between increased microbial diversity and improved clinical outcomes in our study, we did not fully elucidate the underlying molecular mechanisms. SCFAs, as major products of dietary fiber fermentation, likely play a crucial role in regulating intestinal barrier function, immune system, and inflammatory responses. Through metabolomic analysis of specific SCFA concentration changes (such as butyrate, propionate, and acetate), combined with transcriptomic and proteomic data, we can help construct a complete mechanistic pathway from dietary fiber intake to clinical benefits. This multi-omics integration approach not only identifies key metabolites and signaling pathways but may also reveal the molecular basis for individual differences in response to dietary fiber intervention, providing evidence for future personalized nutritional interventions. The mechanism of microbiota structure changes was another important discovery. The intervention group maintained relatively stable beneficial bacteria (such as lactobacilli and bifidobacteria), while the control group experienced significant fluctuations[20-23]. This difference may be related to the unique biological characteristics of dietary fiber. Soluble dietary fiber produces SCFAs through fermentation, providing energy for intestinal epithelial cells and a growth substrate for beneficial bacteria; insoluble dietary fiber regulates the intestinal environment and maintains microbiota balance.

Inflammatory response is a crucial link connecting surgical trauma and intestinal ecology[24-26]. Our study found that inflammatory markers in the intervention group were significantly lower than in the control group, suggesting potential anti-inflammatory effects of dietary fiber. This may be achieved by regulating intestinal barrier function and reducing inflammatory factor release. Notably, changes in inflammatory factors like interleukin-6 and tumor necrosis factor-α are closely associated with microbiota imbalance, providing an important direction for future research. Some studies have discovered that postoperative inflammatory responses are closely related to microbiota imbalance. Our research further confirmed that dietary fiber intervention can significantly reduce inflammatory responses, highly consistent with previous research findings.

From a clinical perspective, the most notable finding was the postoperative recovery of patients in the intervention group. Some studies similarly demonstrated that precise nutritional intervention can significantly improve patients’ postoperative recovery quality. Our research not only verified this view but also further quantified the specific effects of dietary fiber intervention. The long-term follow-up results were even more encouraging. Multiple studies supported our findings that long-term dietary fiber intervention may have protective effects beyond short-term repair. Continuous dietary fiber supplementation can significantly improve cancer patients’ immune function and quality of life.

From a clinical perspective, the most striking discovery was the postoperative recovery of patients in the intervention group. Shortened hospital stays and significantly reduced complication rates fully demonstrate the practical value of dietary fiber intervention. Quality of life assessments further supported this conclusion, with intervention group patients showing significantly superior performance in multiple dimensions, including physical function and emotional state. The long-term follow-up results were even more exciting. Twelve months later, patients in the intervention group showed better intestinal microbiota stability, more ideal immune function indicators, and significantly lower recurrence rates. This suggests that dietary fiber intervention may have long-term protective effects beyond short-term repair, providing a new perspective for postoperative management of tumor patients.

CONCLUSION

Our study has several limitations. First, we did not adequately consider individual variability in microbiota composition and response to dietary fiber, which may have affected the intervention outcomes. Second, our mechanistic exploration lacked depth, particularly in the metabolomic analysis of SCFAs and other key metabolites that could explain fiber’s beneficial effects. Third, the use of a mixed fiber supplement (psyllium husk, inulin, and resistant starch) made it impossible to determine the relative contribution of each fiber type, limiting our ability to make specific recommendations for optimal intervention protocols. These limitations guide our ongoing and future research directions.