Gastrectomy impact on the gut microbiome in patients with gastric cancer: A comprehensive review

Comparative Changes in Fecal Microbiome After Endoscopic Resection and Surgical Resection in Gastric Cancer Patients

Background/Objectives: Gastric cancer treatments can lead to significant alterations to patients' gastrointestinal microbiome. However, differences in microbial impacts between gastrectomy and endoscopic submucosal dissection (ESD) remain underexplored. This study investigates how these treatments influence microbial diversity and composition in patients with stage I gastric cancer. Methods: Patients with pathologically confirmed stage I gastric cancer were recruited from Chung-Ang University Hospital between December 2016 and December 2019. This study analyzed fecal samples from 13 patients (ESD: n = 5; gastrectomy: n = 8) before and after treatment using 16S rRNA gene sequencing. Microbial diversity indices and taxonomic composition were compared, with follow-up extending up to two years. Results: In the total cohort, alpha diversity significantly decreased post-treatment (p < 0.05), and beta diversity analysis showed distinct clustering between pre- and post-treatment samples (p < 0.05). At the genus level, Bacteroides significantly decreased (p < 0.05), while Lactobacillus, Bifidobacterium, and Blautia showed significant increases (p < 0.05). Comparative analyses revealed that in the ESD group, alpha diversity remained unchanged, although beta diversity showed significant clustering (p < 0.05), without notable changes in major taxa. In contrast, surgical resection resulted in a significant reduction in alpha diversity (p < 0.05) and beta diversity clustering (p < 0.05), with increased abundances of Streptococcus and Blautia and decreased abundance of Bacteroides (p < 0.05). Conclusions: Surgical gastrectomy exerts significant effects on microbiome diversity and composition, while ESD has a more limited impact. These findings underscore the importance of considering microbiome changes in postoperative management.

Changes in gut microbiota after gastric cancer surgery: a prospective longitudinal study

Background

This study was designed to characterize gut microbiota changes of the patients with gastric cancer before and after the gastrectomy during their hospital staying periods.

Methods

16S ribosomal RNA (rRNA) gene sequencing was used to evaluate differences in gut microbiota among patients with gastric cancer before and after the gastrectomy by comparing gut microbiota α diversity, β diversity, and structure composition at different taxonomic levels.

Results

A total of 120 fecal specimens were collected from 60 patients. There was no significant difference in Chao1 index, Shannon index, and Simpson index before and after gastrectomy (all P > 0.05). At the phylum level, the gut microbiota in the gastrectomy group showed less abundance of Bacteroidota, Synergistota, and Verrucomicrobiota but with higher abundance of Campylobacter, Actinobacteria, and Bacillota. At the genus level, the gut microbiota in the gastrectomy group showed less abundance of flora Bacteroides, Faecalibacterium, Blautia, and Lachnospiraceae nk4a136 group but with higher abundance of Campylobacter, Porphyromona, Finegordia, Dialist, Anaerococcus, and Corynebacterium.

Conclusions

There was no significant change in the diversity of intestinal flora before and after surgery. However, significant changes in the structure of intestinal flora before and after surgery were occurred.

Nutritional support via feeding jejunostomy in esophago-gastric cancers: proposal of a common working strategy based on the available evidence

Malnutrition is common in patients affected by esophago-gastric cancers and has a negative impact on both clinical and economic outcomes. Yet not all patients at risk of malnutrition are routinely assessed and receive appropriate support. Further, available research does not provide a mean for standardization of timing, route, and dosage for nutritional support, and this is particularly true for enteral nutrition via feeding jejunostomy. Herein, we provide an overview of the current evidence and use the gathered knowledge as a starting point for a consensus proposal. As a result, we aim to facilitate the development of appropriate and uniformed interventions, thus fulfilling the need for a multimodal therapeutic approach in these set of cancer patients.

The Impact of Gastrectomy on Inflammatory Bowel Disease Risk in Gastric Cancer Patients: A Critical Analysis

Gastrectomy, a prevalent surgical procedure for gastric cancer, results in substantial alterations to the gastrointestinal tract, including reduced gastric acid production and significant modifications to the gut microbiota. These changes can impair postoperative recovery, influence metabolic functions, and predispose patients to inflammatory bowel disease (IBD). Studies have shown an increased risk of IBD, particularly Crohn's disease (CD) and ulcerative colitis (UC), in patients following gastrectomy and bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). For instance, patients undergoing RYGB have a higher hazard ratio for developing CD, while SG patients show an increased risk for UC. The surgical alteration of the gastrointestinal tract promotes dysbiosis, with a significant increase in pathogenic bacteria and a decrease in beneficial microbial populations. This dysbiosis can impair the intestinal mucosal barrier and promote systemic inflammation. Understanding the mechanisms behind these changes and their clinical implications is essential for developing effective postoperative management strategies. Probiotics and enhanced recovery after surgery (ERAS) protocols have shown promise in mitigating these adverse effects, improving gut microbiota balance, and enhancing patient outcomes. Further research is necessary to fully elucidate the long-term impacts of gastrectomy on gastrointestinal health and to refine therapeutic approaches for postoperative care.

Incidence of Postoperative Diabetes Mellitus After Roux-en-Y Reconstruction for Gastric Cancer: Retrospective Single-Center Cohort Study

Background

Sleeve gastrectomy is an effective surgical option for morbid obesity, and it improves glucose homeostasis. In patients with gastric cancer and type 2 diabetes mellitus (DM), gastrectomy, including total gastrectomy, is beneficial for glycemic control.

Objective

This study aims to clarify the effects of gastrectomy and different reconstructive techniques on the incidence of postoperative DM in patients with gastric cancer.

Methods

This retrospective, single-center, cohort study included 715 patients without DM who underwent total gastrectomy at the Tokyo Metropolitan Bokutoh Hospital between August 2005 and March 2019. Patients underwent reconstruction by Roux-en-Y (RY) gastric bypass or other surgical techniques (OT), with DM onset determined by hemoglobin A1c levels or medical records. Analyses included 2-sample, 2-tailed t tests; χ2 tests; and the Kaplan-Meier method with log-rank tests to compare the onset curves between the RY and OT groups, along with additional curves stratified by sex. A Swimmer plot for censoring and new-onset DM was implemented.

Results

Stratified data analysis compared the RY and OT reconstruction methods. The hazard ratio was 1.52 (95% CI 1.06-2.18; P=.02), which indicated a statistically significant difference in the incidence of new-onset diabetes between the RY and OT groups in patients with gastric cancer. The hazard ratio after propensity score matching was 1.42 (95% CI 1.09-1.86; P=.009).

Conclusions

This first-of-its-kind study provides insight into how different methods of gastric reconstruction affect postoperative diabetes. The results suggest significant differences in new-onset DM after surgery based on the reconstruction method. This research highlights the need for careful surgical planning to consider potential postoperative DM, particularly in patients with a family history of DM. Future studies should investigate the role of gut microbiota and other reconstructive techniques, such as laparoscopic jejunal interposition, in developing postoperative DM.

Postoperative delayed gastric emptying: may gut microbiota play a role?

Postoperative delayed gastric emptying is a prevalent complication following surgical procedures, imposing heavy physical and financial burdens on patients. However, current treatment options remain suboptimal. In recent years, an increasing number of studies have highlighted that the gut microbiota and its metabolites are closely associated with postoperative complications. Various factors can disrupt the gut microbiome after surgery. This review discusses the potential mechanisms by which the gut microbiota and their metabolites may contribute to the pathogenesis of postoperative delayed gastric emptying. However, the current knowledge base is limited in terms of fully understanding the exact mechanisms involved. It is therefore evident that further research is required to fully elucidate the role of the gut microbiome in postoperative delayed gastric emptying, with the aim of uncovering new possibilities for preventive measures and therapeutic treatments.

Probiotic Compounds Enhanced Recovery after Surgery for Patients with Distal Gastric Cancer: A Prospective, Controlled Clinical Trial

BACKGROUND

Enhanced recovery after surgery (ERAS) for radical distal gastrectomy needs to be improved urgently. We investigated the effects of probiotic compounds (including Lactobacillus plantarum, L. rhamnosus, L. acidophilus, and Bifidobacterium animalis subsp.lactis) on enhance recovery after gastrectomy.

METHODS

The patients in this prospective study were divided into probiotic group (PG group, n = 36) and placebo group (CG group, n = 38), taking corresponding capsule according to the protocol during the perioperative period. We compared the trends in perioperative hematologic findings and the postoperative outcomes. Patients' feces were collected for bacterial 16S rRNA sequencing. Patients were followed up at 1 month postoperatively.

RESULTS

After the application of probiotics, the patients' postoperative inflammatory response level was reduced, and the trend of postoperative NLR decrease was significantly faster in the patients of the PG group than in the CG group (P = 0.047, partial η2 = 0.054). The trend of postoperative increase in serum albumin concentration in the patients of the PG group was significantly better than that in the CG group (P = 0.016, partial η2 = 0.078). In addition, patients in the PG group met discharge criteria earlier postoperatively and had fewer medical expenses. The quality of life of PG group was improved postoperatively. Postoperative inflammation-related markers, including the ratio of Firmicutes/Bacteroidetes, were increasing in untreated patients. In addition, the postoperative microbial diversity and abundance in the PG group remained stable.

CONCLUSIONS

Probiotic compounds can reduce the inflammatory response after gastrectomy and enhance the recovery of the DGC patients by maintaining the stability of the gut microbiota.

Fatal Community-Acquired Clostridioides difficile Infection as a Cause of Listeria Meningitis: A Case Report

A 77-year-old woman with a history of total gastrectomy was transferred to our hospital with complaints of fever and consciousness disturbance for five days. She had fever and consciousness disturbance with positive meningeal signs. Laboratory findings indicated an elevated inflammatory response and hypoalbuminemia, and computed tomography (CT) of the body indicated intestinal gas retention and mild ascites. Cerebrospinal fluid analysis revealed pleocytosis with elevated protein levels and a diagnosis of Listeria meningitis was made. Treatment with ampicillin/sulbactam was started, and her fever and consciousness disturbance resolved on day 2. However, on day 3, her fever and conscious disturbance deteriorated, and she went into shock subsequently. Laboratory findings revealed deteriorated inflammatory response and hypoalbuminemia. Body CT showed an obvious distended bowel loop and intestinal edema. A stool culture revealed positive Clostridioides difficile toxin B, and we diagnosed her with Clostridioides difficile infection (CDI). Although intravenous metronidazole was initiated, she died due to prolonged hypovolemic shock. We considered she had community-acquired CDI because her CDI emerged immediately after the initiation of antibiotics, symptom deterioration within 48 hours of admission, and abnormal abdominal CT findings at admission. Listeria meningitis can develop based on community-acquired CDI. Because CDI can have a very rapid and fatal course and is sometimes complicated by other infectious diseases, clinicians should pay attention to this complication.

Unveiling the Gastrointestinal Microbiome Symphony: Insights Into Post-Gastric Cancer Treatment Microbial Patterns and Potential Therapeutic Avenues

This review delved into the intricate relationship between the gastrointestinal microbiome and gastric cancer, particularly focusing on post-treatment alterations, notably following gastrectomy, and the effects of anticancer therapies. Following gastrectomy, analysis of fecal samples revealed an increased presence of oral cavity aerotolerant and bile acid-transforming bacteria in the intestine. Similar changes were observed in the gastric microbiome, highlighting significant alterations in taxon abundance and emphasizing the reciprocal interaction between the oral and gastric microbiomes. In contrast, the impact of chemotherapy and immunotherapy on the gut microbiome was subtle, although discernible differences were noted between treatment responders and non-responders. Certain bacterial taxa showed promise as potential prognostic markers. Notably, probiotics emerged as a promising approach for postgastrectomy recovery, displaying the capacity to alleviate inflammation, bolster immune responses, and maintain a healthy gut microbiome. Several strains, including Bifidobacterium, Lactobacillus, and Clostridium butyricum, exhibited favorable outcomes in postoperative patients, suggesting their potential roles in comprehensive patient care. In conclusion, understanding the intricate interplay between the gastrointestinal microbiome and gastric cancer treatment offers prospects for predicting responses and enhancing postoperative recovery. Probiotics, with their positive impact on inflammation and immunity, have emerged as potential adjuncts in patient care. Continued research is imperative to fully harness the potential of microbiome-based interventions in the management of gastric cancer.

Gastrointestinal Symptoms After Resection of Esophagogastric Cancer: A Longitudinal Study on Their Incidence and Impact on Patient-Reported Outcomes

BACKGROUND

This study assesses the incidence of gastrointestinal symptoms in the first year after resection of esophageal or gastric cancer and its association with health-related quality of life (HRQoL), functioning, work productivity, and daily activities.

PATIENTS AND METHODS

Patients diagnosed with esophageal or gastric cancer between 2015 and 2021, who underwent a resection, and completed ≥ 2 questionnaires from the time intervals prior to resection and 0-3, 3-6, 6-9, and 9-12 months after resection were included. Multivariable generalized linear mixed models were used to assess changes in gastrointestinal symptoms over time and the impact of the number of gastrointestinal symptoms on HRQoL, functioning, work productivity, and daily activities for patients who underwent an esophagectomy or gastrectomy separately.

RESULTS

The study population consisted of 961 (78.8%) and 259 (21.2%) patients who underwent an esophagectomy and gastrectomy, respectively. For both groups, the majority of gastrointestinal symptoms changed significantly over time. Most clinically relevant differences were observed 0-3 after resection compared with prior to resection and included increased diarrhea, appetite loss, and eating restrictions, and specifically after esophagectomy dry mouth, trouble with coughing, and trouble talking. At 9-12 after resection one or more severe gastrointestinal symptoms were reported by 38.9% after esophagectomy and 33.7% after gastrectomy. A higher number of gastrointestinal symptoms was associated with poorer functioning, lower HRQoL, higher impairment in daily activities, and lower work productivity.

CONCLUSIONS

This study shows that gastrointestinal symptoms are frequently observed and burdensome after esophagectomy or gastrectomy, highlighting the importance to address these sequelae for high quality survivorship.

Changes in salivary microbiota due to gastric cancer resection and its relation to gastric fluid microbiota

Gastric cancer is one of the leading causes of death worldwide, and resections are performed to cure the disease. We have previously reported the changes in the gastric microbiota after gastric cancer resection, which may be associated with the oral microbiota; however, the changes in the oral microbiota remain uncharacterized. This study aimed to characterize the changes in the salivary microbiota caused by gastric cancer resection and to evaluate their association with the gastric fluid microbiota. Saliva and gastric fluid samples were collected from 63 patients who underwent gastrectomy before and after surgery, and a 16S rRNA metagenomic analysis was performed to compare the microbiota composition. The number of bacterial species in the salivary microbiota decreased, and the bacterial composition changed after the resection of gastric cancer. In addition, we identified several bacterial genera that varied significantly in the salivary microbiota, some of which also showed similar changes in the gastric fluid microbiota. These findings indicate that changes in the gastric environment affect the oral microbiota, emphasizing the close association between the oral and gastric fluid microbiota. Our study signifies the importance of focusing on the oral microbiota in the perioperative period of gastrectomy in patients with gastric cancer.

Comparisons of nutritional status and complications between patients with and without postoperative feeding jejunostomy tube in gastric cancer: a retrospective study

Background

Feeding jejunostomy tube (FJT) enables early postoperative nutritional supply for gastric cancer patients undergoing surgery. However, the nutritional benefit of FJT may be accompanied by potential risk of increased complications, so both the nutritional improvement and the complication rates associated with FJT should be assessed.

Methods

From January 2009 to December 2014, 715 consecutive patients underwent gastric cancer resection at the Peking Union Medical College Hospital in China. The perioperative nutritional index and incidence of complications in patients with FJT placement were retrospectively compared to those in patients without FJT placement. Nutritional data including albumin, prealbumin, hemoglobin, and high sensitivity C-reactive protein, the neutrophil-to-lymphocyte ratio (NLR), and Onodera's prognostic nutrition index (OPNI) were recorded at the following 3 timepoints: preoperatively, 1-week postoperatively, and 1-month postoperatively. Postoperative complications including surgical site infection, intra-abdominal infections, anastomotic leaks and gastroparesis were assessed. Multivariate logistic regression was used to study the association between FJT and complications.

Results

A total of 715 patients were included in the study. The mean age was 60.4 years and 72.2% were male. The overall characteristics between FJT and no-FJT groups were comparable. Of the 247 total gastrectomy cases, 98 (39.7%) had a FJT placed. Compared to the total gastrectomy patients without a FJT, the 98 patients with a FJT had a lower hemoglobin level (P=0.048) and NLR (P=0.030) preoperatively, and higher albumin (P=0.005), prealbumin (P<0.001), and hemoglobin (P=0.014) levels, a higher OPNI (P=0.027), and a lower NLR (P=0.005) 1-month postoperatively. Of the 468 subtotal gastrectomy cases, 87 (18.6%) had a FJT placed. Compared to the subtotal gastrectomy patients without a FJT, these 87 patients had a lower NLR (P=0.006) 1-week postoperatively, and a higher albumin level (P=0.009) 1-month postoperatively. In the multivariate analysis, FJT placement was not associated with postoperative adverse outcomes, including surgical site infection [odds ratio (OR) =1.21, P=0.79], intra-abdominal infection (OR =0.38, P=0.11), anastomotic leak (OR =0.58, P=0.53), reoperation (OR =0.22, P=0.23), gastroparesis (OR =6.35, P=0.08), or hospitalization for more than 30 days (OR =0.58, P=0.32).

Conclusions

Early enteral nutritional support by FJT after gastrectomy tended to improve the nutritional status of patients, while it did not appear to increase the incidence rate of postoperative complications.

Association between preoperative nutritional status, inflammation, and intestinal permeability in elderly patients undergoing gastrectomy: a prospective cohort study

Background

Malnutrition is relatively common among elderly patients with gastric cancer. This study sought to analyze whether preoperative nutritional status, inflammatory cytokines, and intestinal permeability were correlated in elderly gastric cancer patients undergoing surgery, and their effects on postoperative recovery.

Methods

This study was a single-center prospective cohort study. Patients aged 65-90 years who underwent gastrectomy were included. Preoperative nutritional status was assessed by the Mini Nutritional Score (MNA), Nutritional Risk Screening-2002 (NRS2002), body mass index (BMI), free fatty acids (FFAs), albumin, and prealbumin concentrations. Intestinal permeability was assessed by D-lactate and intestinal fatty acid-binding protein (i-FABP). The inflammatory factors included interleukin (IL)-6, IL-10, neutrophil, and lymphocyte counts. The time to first defecation, time to first liquid diet, length of hospital stay (LOS), and postoperative complications were recorded.

Results

A total of 134 patients were included. According to the MNA, 50.7% and 32.1% of the cohort had mild to moderate malnutrition, and severe malnutrition, respectively. According to the NRS2002, 38.8% of the patients scored >4 points. I-FABP was significantly negatively correlated with albumin (r=-0.409, P<0.001) and prealbumin (r=-0.397, P<0.001), and significantly positively correlated with MNA (r=0.291, P=0.001), the NRS2002 (r=0.284, P=0.001), and LOS (r=0.245, P=0.004). D-lactate was significantly negatively correlated with BMI (r=-0.229, P=0.008), albumin (r=-0.426, P<0.001), and prealbumin (r=-0.358, P<0.001), and significantly positively correlated with the NRS2002 (r=0.187, P=0.030), time to first defecation (r=0.264, P=0.002), and LOS (r=0.409, P<0.001). There were significant differences in BMI, prealbumin, FFAs, i-FABP, time to first defecation, and time to first fluid diet (P<0.05) among groups based on MNA score. The multivariate logistic analysis showed that D-lactate was an independent risk factor of postoperative complications [odds ratio (OR) =1.354, 95% confidence interval (CI): 1.099-1.669, P=0.004].

Conclusions

The preoperative intestinal permeability indicators (i.e., D-lactate and i-FABP) are significantly correlated with some nutritional indicators and postoperative recovery indicators. The preoperative D-lactate level is an independent risk factor of postoperative complications, suggesting that altered gut barrier function before surgery could to some extent influence postoperative recovery in the elderly.

Host miRNAs-microbiota interactions in gastric cancer

It is widely acknowledged that gastric cancer seriously affects the quality of life and survival of patients. The correlation between the microbiota and gastric cancer has attracted extensive attention in recent years, nonetheless the specific mechanism of its impact on gastric cancer remain largely unclear. Recent studies have shown that in addition to its role in the host’s inflammatory and immune response, the microbiota can also affect the occurrence and development of gastric cancer by affecting the expression of miRNAs. This paper brings together all currently available data on miRNAs, microbiota and gastric cancer, and preliminarily describes the relationship among them.