The gut microbiota and gastrointestinal surgery

Prior antibiotics exposure is associated with an elevated risk of surgical site infections, including anastomotic leakage, after colon cancer but not rectal cancer surgery: A register-based study of 38,839 patients

Gut microbiota composition has been implicated in surgical site complications after colorectal cancer surgery. Antibiotics affect gut microbiota, but evidence for a role in surgical site complications is inconclusive. We aimed to investigate use of prescription antibiotics during the years before surgery in relation to the risk of surgical site infections, including anastomotic leakage, within 30 days after surgery. Cardiovascular/neurological complications and the urinary antiseptic methenamine hippurate, for which there is no clear link with the microbiota, were used as negative controls. We conducted a patient cohort study using complete population data from Swedish national registers between 2005 and 2020. The final study population comprised 26,527 colon cancer and 12,312 rectal cancer cases with a 4.5 year exposure window. In colon cancer patients, antibiotics use was associated with a higher risk of surgical site infections (adjusted odds ratio (aOR) for any versus no use = 1.20, 95% confidence interval (CI) 1.10-1.33) and anastomotic leakage in particular (aOR =1.19, 95% CI 1.03-1.36), both with dose-response relationships for increasing cumulative antibiotics use (Ptrend = <0.001 and Ptrend = 0.047, respectively). Conversely, associations in rectal cancer patients, as well as for the negative controls cardiovascular/neurological complications and methenamine hippurate, were null. In conclusion, prescription antibiotics use up to 4.5 years before colorectal cancer surgery is associated with a higher risk of surgical site infections, including anastomotic leakage, after colon cancer but not rectal cancer surgery. These findings support a role for antibiotics-induced intestinal dysbiosis in surgical site infections.

The History of Critical Care Nutrition: Seventy-Five Years of Evolution

In its infancy during the formation of the specialty of critical care medicine, the need for safe and effective nutritional therapy was recognized as a key component of the care for severely ill patients admitted to an intensive care unit. The origin of modern critical care nutrition can be traced back to the invention of total parenteral nutrition, which enabled the delivery of long-term nutritional support to critically ill adults who had insufficient absorption or access to the gastrointestinal tract. This report discusses the rationale for these innovations and summarizes the events leading up to our current state of patient management in critical care nutrition.

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery

Background/Aims

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI.

Methods

Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay.

Results

The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups.

Conclusions

Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

Oral antibiotic prophylaxis induces changes in the microbiology of surgical site infection after colorectal surgery. A matched comparative study

AIM

Oral antibiotic prophylaxis (OAP) lowers rates of surgical site infection (SSI) and may aid anastomotic healing in colorectal surgery. The aim of this study was to analyse the understudied impact of OAP on SSI microbiology after colorectal surgery.

METHOD

A post hoc analysis was performed on a previous prospective, multicentre study of elective colorectal surgery. For 1000 patients with SSI, this study compared the microbiology of SSIs in procedures without OAP (SSI/OAP-) and with OAP (SSI/OAP+).

RESULTS

There were 340 patients in the SSI/OAP- group and 660 in the SSI/OAP+ group. The use of OAP increased the presence of Gram-positive cocci (GPC) (OR 1.542, 95% CI 1.153-2.062) and fungi (OR 2.037, 95% CI 1.206-3.440), but reduced rates of Gram-negative bacteria (GNB) (OR 1.461, 95% CI 1.022-2.088) and anaerobe isolation (OR 0.331, 95% CI 0.158-0.696). Specifically, it led to increases in the isolation of Enterococcus faecium (OR 1.450, 95% CI 0.812-2.591), methicillin-resistant Staphylococcus aureus (OR 2.000, 95% CI 1.043-3.834) and Candida spp. (OR 2.037, 95% CI 1.206-3.440). In colon surgery with OAP, GPC infections were more likely (OR 1.461, 95% CI 1.022-2.088). In rectal surgery, organ/space SSIs had a higher risk of harbouring GPC (OR 1.860, 95% CI 1.153-2.999) and a lower risk of GNB (OR 0.321, 95% CI 0.200-0.515).

CONCLUSION

OAP reduced the presence of anaerobes and GNB in SSIs, but increased the isolation of GPCs and fungi, with E. faecium and Candida being of particular concern. This information should guide empirical antibiotic therapy for postoperative colorectal SSIs in patients who have received preoperative OAP.

A Smart Semi-Implantable Device Integrating Microchannel-Enhanced Sampling and Multiplex Biochemical Testing for Deep Wound Monitoring and Pathogen Identification

Monitoring deep wounds is challenging but necessary for high-quality medical treatment. Current methodologies for deep wound monitoring are typically limited to indirect clinical symptoms or costly non-real-time imaging diagnosis. Herein, a smart system is proposed that enables in situ monitoring of deep wounds' status through a semi-implantable device composed of 2 seamlessly connected functional components: 1) the well-designed, microchannel-structured sampling needles that efficiently and conveniently collect samples from deep wound anatomical locations, and 2) the multiplex biochemical testing compartment that facilitates the immediate and persistent detection of multiple biochemical indicators based on a color image processing software accessible to a conventional smartphone. With the 3 representative preclinical deep wound models, the study demonstrates the device's potential to monitor wound infection, inflammation, healing progress, and reduce inflammation when applied to deep skin injury, surgical implantation, and postoperative intestinal leakage. The device's capability to rapidly and accurately identify pathogenic bacteria is also demonstrated both in vitro and in vivo, potentially facilitating precise intervention in infected wounds. Coupled with the device's favorable biocompatibility and cost-effectiveness, this intelligent system emerges as a promising tool for safe and effective management of complicated deep wounds.

Impact of antibiotic prophylaxis on gut microbiota in colorectal surgery: insights from an Eastern European stewardship study

Introduction

Antibiotic overuse is driving a global rise in antibiotic resistance, highlighting the need for robust antimicrobial stewardship (AMS) initiatives to improve prescription practices. While antimicrobials are essential for treating sepsis and preventing surgical site infections (SSIs), they can inadvertently disrupt the gut microbiota, leading to postoperative complications. Treatment methods vary widely across nations due to differences in drug choice, dosage, and therapy duration, affecting antibiotic resistance rates, which can reach up to 51% in some countries. In Romania and the Republic of Moldova, healthcare practices for surgical antibiotic prophylaxis differ significantly despite similarities in genetics, culture, and diet. Romania's stricter healthcare regulations result in more standardized antibiotic protocols, whereas Moldova's limited healthcare funding leads to less consistent practices and greater variability in treatment outcomes.

Methods

This study presents the results of a prospective cross-border investigation involving 86 colorectal cancer patients from major oncological hospitals in Romania and Moldova. We analyzed fecal samples collected from patients before and 7 days post-antibiotic treatment, focusing on the V3-V4 region of the 16S rRNA gene.

Results

Our findings indicate that inconsistent antibiotic prophylaxis policies-varying in type, dosage, or therapy duration-significantly impacted the gut microbiota and led to more frequent dysbiosis compared to stricter prophylactic antibiotic practices (single dose, single product, limited time).

Discussion

We emphasize the need for standardized antibiotic prophylaxis protocols to minimize dysbiosis and its associated risks, promoting more effective antimicrobial use, particularly in low- and middle-income countries (LMICs).

Endoscopic surgery affects the gut microbiota and its metabolism in breast cancer patients

Background

Despite the advantages of endoscopic surgery in reducing trauma and enhancing recovery for breast cancer patients, its impact on gut microbiota, which is crucial for health and estrogen metabolism, remains unclear. Further investigation is necessary to fully understand this impact and its implications.

Materials and methods

Between June and December 2022, fecal samples were collected from 20 patients who underwent endoscopic surgery. The gut microbiota composition was determined using 16S rRNA sequencing, while the metabolites were analyzed through liquid chromatography-tandem mass spectrometry (LC-MS/MS). Bioinformatics and statistical analyses were employed to identify significant alterations in microbial taxa abundance and to assess intergroup differences. These analyses included t-tests for pairwise comparisons, one-way ANOVA for multiple group comparisons, and chi-square tests for categorical data analysis.

Results

Endoscopic surgery in breast cancer patients subtly changed gut microbiota diversity and composition. Post-surgery, there was a reduction in Lachnospiraceae, Monoglobaceae and Firmicutes to Bacteroides ratios. Shifts in metabolites were also observed, the changed metabolites impacted pathways such as primary bile biosynthesis and Ascorbate and aldarate metabolism, with PE(PGD1/18:1(9Z)) identified as a key differential metabolite that increased post-surgery. Azasetron, tyramine glucuronide, DL-DOPA, phthalide, acetophenazine, aciclovir, creatinine bicarbonate, and 4-oxo-L-proline being associated with distinct bacterial taxa.

Conclusion

Breast cancer patients undergoing endoscopic surgery experience a shift in their gut microbiota and metabolic profiles. Therefore, postoperative management, with a particular focus on the adjustment of the gut microbiota, is crucial for enhancing patient recovery and health outcomes.

Microbiota profiling in esophageal diseases: Novel insights into molecular staining and clinical outcomes

Gut microbiota is recognized nowadays as one of the key players in the development of several gastro-intestinal diseases. The first studies focused mainly on healthy subjects with staining of main bacterial species via culture-based techniques. Subsequently, lots of studies tried to focus on principal esophageal disease enlarged the knowledge on esophageal microbial environment and its role in pathogenesis. Gastro Esophageal Reflux Disease (GERD), the most widespread esophageal condition, seems related to a certain degree of mucosal inflammation, via interleukin (IL) 8 potentially enhanced by bacterial components, lipopolysaccharide (LPS) above all. Gram- bacteria, producing LPS), such as Campylobacter genus, have been found associated with GERD. Barrett esophagus (BE) seems characterized by a Gram- and microaerophils-shaped microbiota. Esophageal cancer (EC) development leads to an overturn in the esophageal environment with the shift from an oral-like microbiome to a prevalently low-abundant and low-diverse Gram--shaped microbiome. Although underinvestigated, also changes in the esophageal microbiome are associated with rare chronic inflammatory or neuropathic disease pathogenesis. The paucity of knowledge about the microbiota-driven mechanisms in esophageal disease pathogenesis is mainly due to the scarce sensitivity of sequencing technology and culture methods applied so far to study commensals in the esophagus. However, the recent advances in molecular techniques, especially with the advent of non-culture-based genomic sequencing tools and the implementation of multi-omics approaches, have revolutionized the microbiome field, with promises of implementing the current knowledge, discovering more mechanisms underneath, and giving insights into the development of novel therapies aimed to re-establish the microbial equilibrium for ameliorating esophageal diseases..

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.

A review of perioperative immune-modulating and metabolic-modulating nutrition strategies for bowel resection surgery

Focused perioperative nutrition strategies have proven benefits on the outcomes for patients undergoing major abdominal surgery. In this brief article, we will review these strategies and the evidence to support them with a focus on gastrointestinal anastomotic healing. We will elaborate the risks and benefits of enteral feeds, immune- and metabolic-modulating formulas, prebiotics and probiotics, and prehabilitation in preparation for surgery. Additionally, we will discuss the role of fish oils (eicosapentaenoic acid and docosahexaenoic acid) in the surgical patient and new data on specialized proresolving mediators in inflammation resolution. Finally, this article will consider the harmful impact surgical trauma has on the microbiome and the potential for perioperative dietary modulation to attenuate these negative effects.

Oral Antibiotics Alone versus Oral Antibiotics Combined with Mechanical Bowel Preparation for Elective Colorectal Surgery: A Propensity Score-Matching Re-Analysis of the iCral 2 and 3 Prospective Cohorts

The evidence regarding the role of oral antibiotics alone (oA) or combined with mechanical bowel preparation (MoABP) for elective colorectal surgery remains controversial. A prospective database of 8359 colorectal resections gathered over a 32-month period from 78 Italian surgical units (the iCral 2 and 3 studies), reporting patient-, disease-, and procedure-related variables together with 60-day adverse events, was re-analyzed to identify a subgroup of 1013 cases (12.1%) that received either oA or MoABP. This dataset was analyzed using a 1:1 propensity score-matching model including 20 covariates. Two well-balanced groups of 243 patients each were obtained: group A (oA) and group B (MoABP). The primary endpoints were anastomotic leakage (AL) and surgical site infection (SSI) rates. Group A vs. group B showed a significantly higher AL risk [14 (5.8%) vs. 6 (2.5%) events; OR: 3.77; 95%CI: 1.22-11.67; p = 0.021], while no significant difference was recorded between the two groups regarding SSIs. These results strongly support the use of MoABP for elective colorectal resections.

Scoping review: The terminology used to describe major abdominal surgical procedures

BACKGROUND

Major abdominal surgery (MAS) can have a profound impact on the patient but there is currently no consensus as to which surgical procedures constitute MAS. The main objective of this work is to ascertain the terminology used to describe MAS procedures and to apply these findings in order to propose a definition of MAS.

METHODS

The following databases were searched: Ovid MEDLINE (R) ALL, Embase Classic and Embase (via OvidSP), Global Health (via OvidSP), Health Management Information Consortium (via OvidSP), APA PsycInfo (via OvidSP), PubMed and Web of Science. Original research articles, published between 1980 and April 26, 2022 that contained a description of MAS procedure were included in this study. Article screening and data extraction was undertaken independently by 3 authors. Content analysis was performed to identify key terminology used to describe MAS.

RESULTS

Five thousand six hundred and sixty three articles were identified, of which 767 underwent full-text review and 312 were included in the scoping review. Content analysis resulted in 4 main categories: (1) pre-operative factors, (2) intraoperative factors, (3) operation-related factors, (4) post-operative factors. Operation-related factors was the predominant category (1137 references coded). The gastrointestinal resection made the vast majority of the references coded (591).

CONCLUSIONS

Based on these results, the term "major abdominal surgery" should be defined as an intra-peritoneal operation with no primary involvement of the thorax, involving either luminal resection and/or resection of a solid organ associated with the gastrointestinal tract. However, further work is required to verify this definition using real world data.

Changes in HLA-B27 Transgenic Rat Fecal Microbiota Following Tofacitinib Treatment and Ileocecal Resection Surgery: Implications for Crohn's Disease Management

The therapeutic management of Crohn's disease (CD), a chronic relapsing-remitting inflammatory bowel disease (IBD), is highly challenging. Surgical resection is sometimes a necessary procedure even though it is often associated with postoperative recurrences (PORs). Tofacitinib, an orally active small molecule Janus kinase inhibitor, is an anti-inflammatory drug meant to limit PORs in CD. Whereas bidirectional interactions between the gut microbiota and the relevant IBD drug are crucial, little is known about the impact of tofacitinib on the gut microbiota. The HLA-B27 transgenic rat is a good preclinical model used in IBD research, including for PORs after ileocecal resection (ICR). In the present study, we used shotgun metagenomics to first delineate the baseline composition and determinants of the fecal microbiome of HLA-B27 rats and then to evaluate the distinct impact of either tofacitinib treatment, ileocecal resection or the cumulative effect of both interventions on the gut microbiota in these HLA-B27 rats. The results confirmed that the microbiome of the HLA-B27 rats was fairly different from their wild-type littermates. We demonstrated here that oral treatment with tofacitinib does not affect the gut microbial composition of HLA-B27 rats. Of note, we showed that ICR induced an intense loss of bacterial diversity together with dramatic changes in taxa relative abundances. However, the oral treatment with tofacitinib neither modified the alpha-diversity nor exacerbated significant modifications in bacterial taxa induced by ICR. Collectively, these preclinical data are rather favorable for the use of tofacitinib in combination with ICR to address Crohn's disease management when considering microbiota.

Gut microbiome-based therapies for alleviating cognitive impairment: state of the field, limitations, and future perspectives

Cognitive impairment (CI) is a multifaceted neurological condition that can trigger negative emotions and a range of concurrent symptoms, imposing significant public health and economic burdens on society. Therefore, it is imperative to discover a remedy for CI. Nevertheless, the mechanisms behind the onset of this disease are multifactorial, which makes the search for effective amelioration difficult and complex, hindering the search for effective measures. Intriguingly, preclinical research indicates that gut microbiota by influencing brain function, plays an important role in the progression of CI. Furthermore, numerous preclinical studies have highlighted the potential of probiotics, prebiotics, fecal microbiota transplantation (FMT), and diet in modulating the gut microbiota, thereby ameliorating CI symptoms. This review provides a comprehensive evaluation of CI pathogenesis, emphasizing the contribution of gut microbiota disorders to CI development. It also summarizes and discusses current strategies and mechanisms centered on the synergistic role of gut microbiota modulation in the microbiota-gut-brain axis in CI development. Finally, problems with existing approaches are contemplated and the development of microbial modulation strategies as therapeutic approaches to promote and restore brain cognition is discussed. Further research considerations and directions are highlighted to provide ideas for future CI prevention and treatment strategies.

Influence of pancreaticoduodenectomy for periampullary carcinoma on intestinal microbiome and metabolites

Recent growing evidence suggests a role for intestinal microbiome and metabolites in patients' postoperative recovery. Therefore, there is a need to gain insight into the impact of pancreaticoduodenectomy for periampullary carcinoma on microbiome and metabolites and the potential impact of their changes on patients' condition. Based on 16S rDNA gene sequencing and untargeted metabolomic analysis, we found that the diversity and abundance of intestinal microbiome were significantly higher in patients preoperatively than postoperatively, and the level of intestinal probiotics was significantly lower after surgery compared with preoperatively. In addition, the choline metabolism level was increased and the amino acid metabolism level was decreased after surgery. A total of 53 differential microbiome and 52 differential metabolites were detected, and the differential metabolites were mapped to approximately 60 different KEGG metabolic pathways, of which 13 KEGG metabolic pathways had a differential metabolite number greater than 5. A total of 88 colony-metabolite pairs with significant positive correlation and 69 colony-metabolite pairs with significant negative correlation were identified. Our results reveal alterations in intestinal microbiome after pancreaticoduodenectomy, suggesting its association with postoperative complications. Moreover, the elevated choline metabolism level in postoperative patients may predict their poorer prognosis. At the same time, the decreased abundance of such probiotic bacteria as Prevotella spp. in the postoperative intestine of patients will affect the amino acid metabolism of the organism to some extent.

Adverse impacts of environmentally relevant PFOS alternatives on mice pancreatic tissues

Perfluorooctane sulfonate (PFOS) alternatives are chemicals that are used to make a range of products. Researchers have found that PFOS alternatives are probably no less toxic than PFOS, which has aroused concern. It has also revealed that the pancreas may be harmed by exposure to PFOS alternatives. However, there is insufficient evidence to demonstrate the toxicity mechanisms of PFOS alternatives. This study demonstrates the adverse effects of three PFOS alternatives on the pancreatic health of mice. After subchronic exposure to PFOS alternatives at environmentally relevant concentrations (800 μg/L perfluorohexanesulfonate, 800 μg/L perfluorobutanesulfonate, and 3 μg/L sodium ρ-perfluorous nonenoxybenzene sulfonate) via drinking water for 6 weeks, toxicity mechanisms were elucidated by examining histopathology, immunity, endoplasmic reticulum stress, 16S rRNA, and short-chain fatty acid targeted metabolomics. Sodium ρ-perfluorous nonenoxybenzene sulfonate significantly increased levels of TNF-α, IL-6, p-PERK, and ATF-4 and decreased the abundance of Akkermansia muciniphila and Lactobacillus reuteri. In addition, the three PFOS alternatives changed the composition of the gut microbiota in mice. Short-chain fatty acids, which are metabolites of the gut microbiota, also significantly decreased. Correlation analysis demonstrates that the alteration of gut microbes is related to the adverse effects on the mice pancreas. Results suggest that the murine pancreas may be toxic endpoints of PFOS alternatives. This study alerts the threats to human health and accelerates the toxicology research of an increasing number of emerging PFOS alternatives.

Longitudinal dynamics of gut bacteriome and mycobiome interactions pre- and post-visceral surgery in Crohn's disease

Introduction

Alterations of the gut microbiome are involved in the pathogenesis of Crohn's disease (CD). The role of fungi in this context is unclear. This study aimed to determine postoperative changes in the bacterial and fungal gut communities of CD patients undergoing intestinal resection, and to evaluate interactions between the bacteriome and mycobiome and their impact on the patients' outcome.

Methods

We report a subgroup analysis of a prospective cohort study, focusing on 10 CD patients whose fecal samples were collected for bacterial 16S rRNA and fungal ITS2 genes next-generation sequencing the day before surgery and on the 5th or 6th postoperative day.

Results

No significant differences in bacterial and fungal diversity were observed between preoperative and postoperative stool samples. By in-depth analysis, significant postoperative abundance changes of bacteria and fungi and 17 interkingdom correlations were detected. Network analysis identified 13 microbial clusters in the perioperative gut communities, revealing symbiotic and competitive interactions. Relevant factors were gender, age, BMI, lifestyle habits (smoking, alcohol consumption) and surgical technique. Postoperative abundance changes and identified clusters were associated with clinical outcomes (length of hospital stay, complications) and levels of inflammatory markers.

Conclusions

Our findings highlight the importance of dissecting the interactions of gut bacterial and fungal communities in CD patients and their potential influence on postoperative and disease outcomes.

Effect of Surgery on Postoperative Levels of the Gut Homeostasis-Regulating Enzyme Intestinal Alkaline Phosphatase

BACKGROUND

Intestinal homeostasis is a crucial factor for complication-free short- and long-term postoperative recovery. The brush border enzyme intestinal alkaline phosphatase (IAP) is an important regulator of gut barrier function and intestinal homeostasis and prevents endotoxemia by detoxifying lipopolysaccharides (LPSs). As IAP is predominantly secreted by enterocytes in the duodenum, we hypothesized that pancreaticoduodenectomy (PD) leads to a significantly stronger decrease in IAP than other major abdominal surgery.

STUDY DESIGN

Pre- and postoperative blood, stool, and intestinal samples were collected from patients undergoing PD, as well as other major surgical procedures without duodenectomy. The samples were analyzed using enzyme histochemistry, the para -nitrophenyl phosphate method for IAP, and the limulus amebocyte lysate assay for LPS.

RESULTS

Overall, 88 patients were prospectively enrolled in the study. Fecal IAP activity negatively correlated with serum LPS (r = -0.3603, p = 0.0006). PD led to a significant decline in IAP compared to preoperative baseline levels (p < 0.0001). The decline in IAP correlated with the length of proximal small intestinal resection (r = 0.4271, p = 0.0034). Compared to controls, PD was associated with a much more pronounced reduction in IAP-also after adjusting for surgical trauma (operative time, blood loss; r = 0.4598, p = 0.0086). Simultaneously, PD triggered a clearly more prominent increase in serum LPS compared to controls (p = 0.0001). Increased postoperative LPS was associated with an elongated hospitalization (r = 0.7534, p = 0.0062) and more prominent in pancreatic cancer (p = 0.0009).

CONCLUSIONS

Based upon the functional roles for IAP, supplementation with exogenous IAP might be a new treatment option to improve short- and long-term outcome after PD.

Role of Microbiome in the Outcomes Following Surgical Repair of Perianal Fistula: Prospective Cohort Study Design and Preliminary Results

BACKGROUND

Anal fistulae are common, predominantly cryptoglandular, and almost invariably require surgical treatment. Recurrences are common for procedures other than fistulotomy regardless of technique and adequacy of repair. Growing evidence supports the pivotal role of specific intestinal bacteria in anastomotic failures after bowel resection. Anal crypts harbor colonic microbiota suggesting that similar mechanisms to anastomotic healing might prevail after anal fistula repair and hence influence healing. This study aims at assessing the potential role of the intestinal microbiome in the clinical outcomes after surgical repair of cryptoglandular anal fistula.

METHODS

This is a pilot prospective cohort study enrolling patients with anal fistula undergoing endoanal advancement flap. For microbiome analysis, stool samples are taken via rectal swab before the procedure; additionally, a portion of the fistula is collected intraoperatively after fistulectomy. Samples from groups with treatment failure are compared to samples from patients who healed after surgical repair. Alpha and beta diversities and differential abundance of microbial taxa are determined and compared between groups with DADA2 analytical pipeline.

RESULTS

Five patients have been enrolled to date (one female, four male). At median follow-up of 6 months (2-11), one patient experienced disease recurrence at 3 months. DNA from the 5 rectal swab and tissue samples was extracted, showing increased relative abundance of Enterococcus faecalis in samples from the patient who developed a recurrent fistula but not in those without recurrence.

CONCLUSION

These very preliminary data suggest that intestinal microbiome may represent a crucial determinant of the surgical outcomes after anal fistula surgery.

Prediagnostic Prescription Antibiotics Use and Survival in Patients with Colorectal Cancer: A Swedish National Register-Based Study

BACKGROUND

Antibiotics use is associated with higher colorectal cancer risk, but little is known regarding any potential effects on survival.

METHODS

We conducted a nationwide cohort study, using complete-population data from Swedish national registers between 2005 and 2020, to investigate prediagnostic prescription antibiotics use in relation to survival in colorectal cancer patients.

RESULTS

We identified 36,061 stage I-III and 11,242 stage IV colorectal cancer cases diagnosed between 2010 and 2019. For stage I-III, any antibiotics use (binary yes/no variable) was not associated with overall or cancer-specific survival. Compared with no use, moderate antibiotics use (total 11-60 days) was associated with slightly better cancer-specific survival [adjusted HR (aHR) = 0.93; 95% confidence interval (CI), 0.86-0.99)], whereas very high use (>180 days) was associated with worse survival [overall survival (OS) aHR = 1.42; 95% CI, 1.26-1.60, cancer-specific survival aHR = 1.31; 95% CI, 1.10-1.55]. In analyses by different antibiotic types, although not statistically significant, worse survival outcomes were generally observed across several antibiotics, particularly macrolides and/or lincosamides. In stage IV colorectal cancer, inverse relationships between antibiotics use and survival were noted.

CONCLUSIONS

Overall, our findings do not support any substantial detrimental effects of prediagnostic prescription antibiotics use on cancer-specific survival after colorectal cancer diagnosis, with the possible exception of very high use in stage I-III colorectal cancer. Further investigation is warranted to confirm and understand these results.

IMPACT

Although the study findings require confirmation, physicians probably do not need to factor in prediagnostic prescription antibiotics use in prognosticating patients with colorectal cancer.

Novel Clean End-to-End Anastomosis Method, Without Opening the Stomach Lumen, in Totally Laparoscopic or Robotic Pylorus-Preserving Gastrectomy

PURPOSE

Intra-abdominal infection is a common postoperative complication of laparoscopic pylorus-preserving gastrectomies (PPGs). Many studies have reported that intra-abdominal infectious complications after gastrectomy adversely affect patient survival outcomes. To prevent gastric fluid leakage into the abdominal cavity, we developed a novel anastomosis method in which the stomach lumen is not opened (termed the non-opened clean end-to-end anastomosis method [NoCEAM]) and evaluated its feasibility.

MATERIALS AND METHODS

Subsequent to lymphadenectomy, the oral and anal resection lines were sutured using an intraoperative endoscope. After closing the stomach circumferentially with clips, the specimen was rolled outward like a "donut." We resected the specimen circumferentially using a linear stapler, and anastomosis was completed simultaneously. We examined the feasibility of this procedure ex vivo, using three porcine stomachs, and in vivo, using one pig. Subsequently, we applied the procedure to 13 consecutive patients with middle-third early gastric cancer utilizing laparotomic, laparoscopic, and robotic PPG.

RESULTS

NoCEAM was completed in all porcine models and human cases. In the human cases, the mean operation time (±standard deviation) was 279±51 minutes, and mean blood loss volume was 22±45 mL. The mean number of linear staples used was 5.06±0.76. None of the patients had complications, and all were discharged on the eighth postoperative. The serum total protein, serum albumin, and hemoglobin levels did not change significantly after surgery.

CONCLUSIONS

NoCEAM is feasible and safe for performing totally laparoscopic or robotic PPG. It may reduce postoperative complications, such as intra-abdominal infections.

How to reduce the colorectal anastomotic leakage? The MIRACLe protocol experience in a cohort in a single high-volume centre

This article reports the results of a novel perioperative treatment implementing the gut microbiota to prevent anastomotic fistula and leakage (AL) in patients undergoing laparoscopic colorectal resections for cancer and represents the continuation of our pilot study on 60 cases. A series of 131 patients underwent elective colorectal surgery at the S. Eugenio Hospital (Rome-Italy) between December 1, 2020, and November 30, 2022, and received a perioperative preparation following the Microbiota Implementation to Reduce Anastomotic Colorectal Leaks (MIRACLe) protocol comprising oral antibiotics, mechanical bowel preparation and perioperative probiotics. The results obtained in the MIRACLe group (MG) were compared to those registered in a Control group (CG) of 500 patients operated on between March 2015 and November 30, 2020, who received a standard ERAS protocol. Propensity score-matching (PSM) analysis was performed to overcome patients' selection bias. Patients were categorised according to perioperative preparation (MIRACLe protocol vs standard ERAS protocol) into two groups: 118 patients were in post-matched MIRACLe group (pmMG) and 356 were in post-matched Control group (pmCG). In the pmMG, only 2 anastomotic leaks were registered, and the incidence of AL was just 1.7% vs. 6.5% in the pmCG (p = 0.044). The incidence of surgical site infections (1.7% vs. 3.1%; p = 0.536), reoperations (0.8% vs. 4.2%; p = 0.136) and postoperative mortality (0% vs. 2.0%; p = 0.200) was lower in pmMG. Additionally, the postoperative outcomes were better: the times to first flatus, to first stool and to oral feeding were shorter (1 vs. 2, 2 vs. 3 and 2 vs. 3 days, respectively; p < 0.001). The postoperative recovery was faster, with a shorter time to discharge (5 vs. 6 days; p < 0.001). The MIRACLe protocol was confirmed to be safe and significantly able to reduce anastomotic leaks in patients receiving elective laparoscopic colorectal surgery for cancer.

Dysbiosis of gut microbiota during fecal stream diversion in patients with colorectal cancer

BACKGROUND

The effect of fecal stream diversion on the gut microbiota is still uncertain. The present study was designed to assess the effect of fecal stream diversion on the composition of the gut microbiota in patients with colorectal cancer. We included patients undergoing left-sided colorectal cancer surgery with (ileostomy group) or without (control group) diverting ileostomy. Fecal samples were collected from 10 patients in each group before surgery (t1) and after ileostomy repair in the ileostomy group and 6-12 months after the initial surgery in the control group (t2). The fecal microbiota was assessed using 16S rRNA sequencing, and changes in the composition of the fecal microbiota were compared between the two groups.

RESULTS

Alpha diversity analysis revealed that the complexity of fecal microbiota decreased between t1 and t2 only in the ileostomy group. Beta diversity analysis also showed dissimilarity between t1 and t2 only in the ileostomy group. The composition of the microbiota was similar between the two groups at t1. However, at t2, the ileostomy group had lower proportion of beneficial bacteria (Lachnospiraceae, 3.8% vs. 29.9%, p < 0.001; Ruminococcaceae, 0.6% vs. 18.4%, p < 0.001; Blautia, 0.1% vs. 9.1%, p < 0.001; Faecalibacterium, 0.2% vs. 7.5%, p < 0.001) and a higher proportion of harmful bacteria (Proteobacteria, 17.9% vs. 5.1%, p = 0.006; Clostridium, 16.2% vs. 1.1%, p = 0.013; Streptococcus, 17.7% vs. 1.6%, p = 0.002) than the control group.

CONCLUSIONS

Fecal stream diversion was closely associated with less diversity and dysbiosis of the gut microbiota.

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.

Gut microbiota influence anastomotic healing in colorectal cancer surgery through modulation of mucosal proinflammatory cytokines

OBJECTIVE

Colorectal cancer (CRC) is the third most diagnosed cancer, and requires surgical resection and reconnection, or anastomosis, of the remaining bowel to re-establish intestinal continuity. Anastomotic leak (AL) is a major complication that increases mortality and cancer recurrence. Our objective is to assess the causal role of gut microbiota in anastomotic healing.

DESIGN

The causal role of gut microbiota was assessed in a murine AL model receiving faecal microbiota transplantation (FMT) from patients with CRC collected before surgery and who later developed or not, AL. Anastomotic healing and gut barrier integrity were assessed after surgery. Bacterial candidates implicated in anastomotic healing were identified using 16S rRNA gene sequencing and were isolated from faecal samples to be tested both in vitro and in vivo.

RESULTS

Mice receiving FMT from patients that developed AL displayed poor anastomotic healing. Profiling of gut microbiota of patients and mice after FMT revealed correlations between healing parameters and the relative abundance of Alistipes onderdonkii and Parabacteroides goldsteinii. Oral supplementation with A. onderdonkii resulted in a higher rate of leaks in mice, while gavage with P. goldsteinii improved healing by exerting an anti-inflammatory effect. Patients with AL and mice receiving FMT from AL patients presented upregulation of mucosal MIP-1α, MIP-2, MCP-1 and IL-17A/F before surgery. Retrospective analysis revealed that patients with AL present higher circulating neutrophil and monocyte counts before surgery.

CONCLUSION

Gut microbiota plays an important role in surgical colonic healing in patients with CRC. The impact of these findings may extend to a vast array of invasive gastrointestinal procedures.

Effect of the gut microbiota and their metabolites on postoperative intestinal motility and its underlying mechanisms

Gut microbiota is closely related to human health and disease because, together with their metabolites, gut microbiota maintain normal intestinal peristalsis. The use of antibiotics or opioid anesthetics, or both, during surgical procedures can lead to dysbiosis and affect intestinal motility; however, the underlying mechanisms are not fully known. This review aims to discuss the effect of gut microbiota and their metabolites on postoperative intestinal motility, focusing on regulating the enteric nervous system, 5-hydroxytryptamine neurotransmitter, and aryl hydrocarbon receptor.

The unrestricted global effort to complete the COOL trial

BACKGROUND

Severe complicated intra-abdominal sepsis (SCIAS) has an increasing incidence with mortality rates over 80% in some settings. Mortality typically results from disruption of the gastrointestinal tract, progressive and self-perpetuating bio-mediator generation, systemic inflammation, and multiple organ failure. A further therapeutic option may be open abdomen (OA) management with negative peritoneal pressure therapy (NPPT) to remove inflammatory ascites and attenuate the systemic damage from SCIAS, although there are definite risks of leaving the abdomen open whenever it might possibly be closed. This potential therapeutic paradigm is the rationale being assessed in the Closed Or Open after Laparotomy (COOL trial) ( https://clinicaltrials.gov/ct2/show/NCT03163095 ). Initially, the COOL trial received Industry sponsorship; however, this funding mandated the use of a specific trademarked and expensive NPPT device in half of the patients allocated to the intervention (open) arm. In August 2022, the 3 M/Acelity Corporation without consultation but within the terms of the contract canceled the financial support of the trial. Although creating financial difficulty, there is now no restriction on specific NPPT devices and removing a cost-prohibitive intervention creates an opportunity to expand the COOL trial to a truly global basis. This document describes the evolution of the COOL trial, with a focus on future opportunities for global growth of the study.

METHODS

The COOL trial is the largest prospective randomized controlled trial examining the random allocation of SCIAS patients intra-operatively to either formal closure of the fascia or the use of the OA with an application of an NPPT dressing. Patients are eligible if they have free uncontained intraperitoneal contamination and physiologic derangements exemplified by septic shock OR severely adverse predicted clinical outcomes. The primary outcome is intended to definitively inform global practice by conclusively evaluating 90-day survival. Initial recruitment has been lower than hoped but satisfactory, and the COOL steering committee and trial investigators intend with increased global support to continue enrollment until recruitment ensures a definitive answer.

DISCUSSION

OA is mandated in many cases of SCIAS such as the risk of abdominal compartment syndrome associated with closure, or a planned second look as for example part of "damage control"; however, improved source control (locally and systemically) is the most uncertain indication for an OA. The COOL trial seeks to expand potential sites and proceed with the evaluation of NPPT agnostic to device, to properly examine the hypothesis that this treatment attenuates systemic damage and improves survival. This approach will not affect internal validity and should improve the external validity of any observed results of the intervention.

TRIAL REGISTRATION

National Institutes of Health ( https://clinicaltrials.gov/ct2/show/NCT03163095 ).

The unrestricted global effort to complete the COOL trial

BACKGROUND

Severe complicated intra-abdominal sepsis (SCIAS) has an increasing incidence with mortality rates over 80% in some settings. Mortality typically results from disruption of the gastrointestinal tract, progressive and self-perpetuating bio-mediator generation, systemic inflammation, and multiple organ failure. A further therapeutic option may be open abdomen (OA) management with negative peritoneal pressure therapy (NPPT) to remove inflammatory ascites and attenuate the systemic damage from SCIAS, although there are definite risks of leaving the abdomen open whenever it might possibly be closed. This potential therapeutic paradigm is the rationale being assessed in the Closed Or Open after Laparotomy (COOL trial) ( https://clinicaltrials.gov/ct2/show/NCT03163095 ). Initially, the COOL trial received Industry sponsorship; however, this funding mandated the use of a specific trademarked and expensive NPPT device in half of the patients allocated to the intervention (open) arm. In August 2022, the 3 M/Acelity Corporation without consultation but within the terms of the contract canceled the financial support of the trial. Although creating financial difficulty, there is now no restriction on specific NPPT devices and removing a cost-prohibitive intervention creates an opportunity to expand the COOL trial to a truly global basis. This document describes the evolution of the COOL trial, with a focus on future opportunities for global growth of the study.

METHODS

The COOL trial is the largest prospective randomized controlled trial examining the random allocation of SCIAS patients intra-operatively to either formal closure of the fascia or the use of the OA with an application of an NPPT dressing. Patients are eligible if they have free uncontained intraperitoneal contamination and physiologic derangements exemplified by septic shock OR severely adverse predicted clinical outcomes. The primary outcome is intended to definitively inform global practice by conclusively evaluating 90-day survival. Initial recruitment has been lower than hoped but satisfactory, and the COOL steering committee and trial investigators intend with increased global support to continue enrollment until recruitment ensures a definitive answer.

DISCUSSION

OA is mandated in many cases of SCIAS such as the risk of abdominal compartment syndrome associated with closure, or a planned second look as for example part of "damage control"; however, improved source control (locally and systemically) is the most uncertain indication for an OA. The COOL trial seeks to expand potential sites and proceed with the evaluation of NPPT agnostic to device, to properly examine the hypothesis that this treatment attenuates systemic damage and improves survival. This approach will not affect internal validity and should improve the external validity of any observed results of the intervention.

TRIAL REGISTRATION

National Institutes of Health ( https://clinicaltrials.gov/ct2/show/NCT03163095 ).

The Role of the Gut Microbiome on the Development of Surgical Site Infections

Despite advances in antisepsis techniques, surgical site infection remains the most common and most costly reason for hospital readmission after surgery. Wound infections are conventionally thought to be directly caused by wound contamination. However, despite strict adherence to surgical site infection prevention techniques and bundles, these infections continue to occur at high rates. The contaminant theory of surgical site infection fails to predict and explain most postoperative infections and still remains unproven. In this article we provide evidence that the process of surgical site infection development is far more complex than what can be explained by simple bacterial contamination and hosts' ability to clear the contaminating pathogen. We show a link between the intestinal microbiome and distant surgical site infections, even in the absence of intestinal barrier breach. We discuss the Trojan-horse mechanisms by which surgical wounds may become seeded by pathogens from within one's own body and the contingencies that need to be met for an infection to develop.

What Is the Microbiome? A Description of a Social Network

The gut microbiome has coevolved with its hosts over the years, forming a complex and symbiotic relationship. It is formed by what we do, what we eat, where we live, and with whom we live. The microbiome is known to influence our health by training our immune system and providing nutrients for the human body. However, when the microbiome becomes out of balance and dysbiosis occurs, the microorganisms within can cause or contribute to diseases. This major influencer on our health is studied intensively, but it is unfortunately often overlooked by the surgeon and in surgical practice. Because of that, there is not much literature about the microbiome and its influence on surgical patients or procedures. However, there is evidence that it plays a major role, showing that it needs to be a topic of interest for the surgeon. This review is written to show the surgeon the importance of the microbiome and why it should be taken into consideration when preparing or treating patients.

Efficiency of probiotics in elderly patients undergoing orthopedic surgery for postoperative cognitive dysfunction: a study protocol for a multicenter, randomized controlled trial

BACKGROUND

Postoperative cognitive dysfunction (POCD) refers to a neurological dysfunction after a major surgery and anesthesia. It is common in elderly patients and is characterized by impairment in consciousness, orientation, thinking, memory, and executive function after surgical anesthesia. However, at present, there is no definite preventive or treatable strategy for it. Previous animal experiments showed that giving probiotics to mice before operation can prevent POCD, but there is a lack of clinical evidence. This study aims to intervene with the intestinal flora imbalance using probiotics during the perioperative period to reduce the incidence of POCD in elderly patients after orthopedic surgery and to provide new ideas and methods for the clinical prevention and treatment of POCD.

METHODS

A multicenter, double-blind, placebo-controlled clinical trial will be performed to evaluate the efficacy of probiotics in elderly patients undergoing orthopedic surgery. Participants (n = 220) will receive probiotics (Peifeikang, Live Combined Bifidobacterium, 210 mg per capsule, twice a day, four capsules each time, which contains Bifidobacterium longum, Lactobacillus acidophilus and Streptococcus faecalis no less than 1.0 × 10⁷ CFU viable bacteria respectively) or placebo from 1 day before surgery to 6 days after surgery. Neuropsychological tests will be performed 1 day before surgery and 1 week and 1 month after surgery. The main outcome of this study is the incidence of POCD 7 days after surgery. Our secondary objective is to assess the incidence of POCD 1 month after surgery; the cognitive status will be determined based on a telephone interview and will be evaluated via TICS-m; postoperative delirium will be assessed 7 days after surgery using the Confusion Assessment Method (CAM).

DISCUSSION

Discovering the correlation between the intestinal microbiota and POCD is an important breakthrough. Based on the key role of the intestinal microbiota in other cognitive disorders, we hope that probiotics can reduce its incidence in elderly orthopedic patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04017403. Registered on August 15, 2019.

The Role of Antibiotic Prophylaxis in Anastomotic Leak Prevention during Elective Colorectal Surgery: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction: Despite several perioperative care advancements and innovations in surgical procedures and technologies, the incidence rate of anastomotic leaks (ALs) after colorectal surgery has not substantially decreased. Gut microbiota can play a critical role in the healing process of anastomotic tissue and alterations in its composition may be largely to blame for anastomotic insufficiency. The use of specific antibiotics for preoperative large bowel decontamination could significantly influence the rate of ALs. The aim of this study was to systematically assess the various antibiotic prophylactic regimen strategies for primary prevention of ALs during colorectal surgery, in view of the available evidence. Methods: A systematic review of the literature was conducted, and randomized clinical trials (RCTs) analyzing prophylactic antibiotic bowel preparation in colorectal surgery were included. PubMed, Embase, the Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials were searched from inception through to 30 November 2022. The methodological quality of the included trials was evaluated. The primary outcome was AL rate; secondary outcomes were superficial/deep surgical site infections (SSIs). The PRISMA guidelines were used to carry out the present systematic review. Results: Thirteen RCTs published between 1977 and 2022, with a total of 4334 patients were included in the meta-analysis. Antibiotic prophylaxis was administered orally in 11/13 studies and intravenously in 2 studies. Patients randomly assigned to antibiotic prophylaxis, regardless of the regimen, had a reduced risk of ALs (p = 0.003) compared to mechanical bowel preparation (MBP) alone. The use of antibiotic prophylaxis was also more effective in significantly reducing SSIs (p < 0.001). Conclusions: The evidence points to an advantage of oral antibiotic prophylaxis in terms of AL rate, a significant contributor to perioperative morbidity, mortality, and rising healthcare expenditures. In light of such results, the use of antibiotic prophylaxis should be strongly encouraged prior to colorectal surgery.

Antibiotic use in gastrointestinal surgery patients at a Vietnamese national hospital

BACKGROUND

Invasive gastrointestinal surgery may be performed as an open or endoscopic procedure, such as laparoscopic semi-colon surgery, laparoscopic appendectomy, laparoscopic gastrectomy, and anal surgery, among other such operations. Regardless of the approach, the operative procedure interferes with the patient's gastrointestinal tract, necessitating the rational use of prophylactic antibiotics to improve treatment outcomes and minimize postoperative infections.

OBJECTIVE

To investigate the prophylactic and postoperative antibiotic usage in patients who underwent invasive gastrointestinal surgery, and to identify factors associated with postoperative infection.

DESIGN

This descriptive, cross-sectional study included 112 patients who underwent invasive gastrointestinal surgery at the Department of Gastroenterology, Thong Nhat Hospital. We conducted a cross-sectional study in all inpatients aged 18 years and older, who underwent invasive gastrointestinal surgery between January 2020 and December 2020. We recorded patient characteristics, the administration and appropriateness of antibiotics, as well as treatment outcomes. The appropriateness of prophylactic and postoperative antibiotic usage was assessed based on 2015 Vietnamese national guideline for antibiotic use. Multivariable logistic regression analysis was used to determine the factors associated with postoperative infection.

RESULTS

Patients' mean age was 59.7 ± 17.2 years. Most surgeries (89.3%) were clean-contaminated procedures. The rates of appropriate types of antibiotics selected, doses, and overall rates of appropriateness of antibiotic prophylaxis were 68.0%, 76.4% and 54.7%, respectively. Of the patients investigated, 34.8% had at least one sign of postoperative infection; the overall appropriate rate of postoperative antibiotic was 38.5%. Old age was associated with postoperative infection and longer length of hospitalization.

CONCLUSION

Implementation of the guidelines recommended for the prophylactic and therapeutic use of antibiotics is essential to improve treatment outcomes.

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

Characteristics of gut microbiota in patients with gastric cancer by surgery, chemotherapy and lymph node metastasis

BACKGROUND

Gastric cancer (GC) is a malignant gastrointestinal tumor that can result in high mortality. Surgery and chemotherapy are often used for the effective treatment of GC. In addition, lymph node metastasis is a significant factor affecting the therapy of GC. Current researches have revealed that gut microbiota has the potential as biomarkers to distinguish healthy people and GC patients. However, the relationship between surgery, chemotherapy, and lymph node metastasis is still unclear.

METHODS

In this study, 16S rRNA sequencing was used to investigate 157 GC fecal samples to identify the role of surgery, chemotherapy, and lymph node metastasis. Immunohistochemical analysis was used to value the expression of Ki67, HER2 in GC patient tissues.

RESULTS

There exist some gut microbiotas which can distinguish surgery from non-surgery GC patients, including Enterococcus, Megasphaera, Corynebacterium, Roseburia, and Lachnospira. Differences between lymph node metastasis and chemotherapy in GC patients are not significant. Moreover, we found the abundance of Blautia, Ruminococcus, Oscillospira were related to the expression of Ki67 and the abundance of Prevotella, Lachnospira, Eubacterium, Desulfovibiro were correlated with the expression of HER2.

CONCLUSIONS

The choice of treatment has a certain impact on the intestinal flora of patients with gastric cancer. Our research shows that surgery has a great effect on the intestinal flora of patients with gastric cancer. However, there were no significant differences in the characteristics of intestinal flora in patients with gastric cancer whether they received chemotherapy or whether they had lymph node metastasis. In addition, the association of gut microbiota with Ki67 and HER2 indicators is expected to provide the possibility of gut microbiota as a tumor prognostic marker.

New understanding of gut microbiota and colorectal anastomosis leak: A collaborative review of the current concepts

Anastomotic leak (AL) is a life-threatening postoperative complication following colorectal surgery, which has not decreased over time. Until now, no specific risk factors or surgical technique could be targeted to improve anastomotic healing. In the past decade, gut microbiota dysbiosis has been recognized to contribute to AL, but the exact effects are still vague. In this context, interpretation of the mechanisms underlying how the gut microbiota contributes to AL is significant for improving patients' outcomes. This review concentrates on novel findings to explain how the gut microbiota of patients with AL are altered, how the AL-specific pathogen colonizes and is enriched on the anastomosis site, and how these pathogens conduct their tissue breakdown effects. We build up a framework between the gut microbiota and AL on three levels. Firstly, factors that shape the gut microbiota profiles in patients who developed AL after colorectal surgery include preoperative intervention and surgical factors. Secondly, AL-specific pathogenic or collagenase bacteria adhere to the intestinal mucosa and defend against host clearance, including the interaction between bacterial adhesion and host extracellular matrix (ECM), the biofilm formation, and the weakened host commercial bacterial resistance. Thirdly, we interpret the potential mechanisms of pathogen-induced poor anastomotic healing.

Has network meta-analysis resolved the controversies related to bowel preparation in elective colorectal surgery?

AIM

There are discrepancies in the guidelines on preparation for colorectal surgery. While intravenous antibiotics (IV) are usually administered, the use of mechanical bowel preparation (MBP) and/or oral antibiotics (OA) is controversial. A recent network meta-analysis (NMA) demonstrated that the addition of OA reduced incisional surgical site infections (iSSIs) by more than 50%. We aimed to perform a NMA including only the highest quality randomized clinical trials (RCTs) in order to determine the ranking of different treatment strategies and assess these RCTs for methodological problems that may affect the conclusions of the NMAs.

METHOD

A NMA was performed according to PRISMA guidelines. RCTs of adult patients undergoing elective colorectal surgery with appropriate antibiotic cover and with at least 250 participants recruited, clear definition of endpoints and duration of follow-up extending beyond discharge from hospital were included. The search included Medline, Embase, Cochrane and SCOPUS databases. Primary outcomes were iSSI and anastomotic leak (AL). Statistical analysis was performed in Stata v.15.1 using frequentist routines.

RESULTS

Ten RCTs including 5107 patients were identified. Treatments compared IV (2218 patients), IV + OA (460 patients), MBP + IV (1405 patients), MBP + IV + OA (538 patients) and OA (486 patients). The likelihood of iSSI was significantly lower for IV + OA (rank 1) and MBP + IVA + OA (rank 2), reducing iSSIs by more than 50%. There were no differences between treatments for AL. Methodological issues included differences in definition, assessment and frequency of primary endpoint infections and the limited number of participants included in some treatment options.

CONCLUSION

While this NMA supports the addition of OA to IV to reduce iSSI it also highlights unanswered questions and the need for well-designed pragmatic RCTs.

Identifying factors associated with detection of sessile gastric polyps in patients with familial adenomatous polyposis

Background and study aims  Gastric cancer (GC) is increasingly reported and a leading cause of death in patients with familial adenomatous polyposis (FAP). Identifying features in patients with FAP who harbor sessile gastric polyps, likely precursors to GC, may lead to alterations in endoscopic surveillance in those patients and allow endoscopic intervention to decrease the risk of GC. The aim of this study was to identify demographic and clinical factors in patients with FAP who harbor sessile gastric polyps. Patients and methods  We retrospectively compared demographic, clinical, and endoscopic features in consecutive adult patients with FAP who presented for a surveillance endoscopy at a tertiary-care center with a FAP registry who harbor sessile gastric polyps to those without them. Sessile gastric polyps included pyloric gland adenomas, gastric adenomas, hyperplastic polyps, and fundic gland polyps with high-grade dysplasia. We also display the location of germline APC pathogenic variants in patients with and without sessile gastric polyps. Results  Eighty patients with FAP were included. Their average age was 48 years and 70 % were male . Nineteen (24 %) had sessile gastric polyps. They were older ( P  < 0.03), more likely to have a family history of GC ( P  < 0.05), white mucosal patches in the proximal stomach ( P  < 0.001), and antral polyps ( P  < 0.026) compared to patients without a gastric neoplasm. No difference in Spigelman stage, extra-intestinal manifestations, or surgical history was note. 89 % of patients with a gastric neoplasm had an APC pathogenic variant 5' to codon 1309. Conclusions  Specific demographic, endoscopic, and genotypic features are associated with patients with FAP who harbor sessile gastric polyps. We recommend heightened awareness of these factors when performing endoscopic surveillance of the stomach with resection of gastric neoplasia when identified.

The Low-density Lipoprotein Receptor-related Protein 6 Pathway in the Treatment of Intestinal Barrier Dysfunction Induced by Hypoxia and Intestinal Microbiota through the Wnt/β-catenin Pathway

Our study is to explore the key molecular of Low-density lipoprotein receptor-related protein 6 (LRP6) and the related Wnt/β-catenin pathway regulated by LRP6 during the intestinal barrier dysfunction. Colorectal protein profile analysis showed that LRP6 expression was decreased in dextran sulfate sodium (DSS)-induced colitis mice, and mice received fecal bacteria transplantation from stroke patients. Mice with intestinal hypoxia and intestinal epithelial cells cultured in hypoxia showed decreased expression of LRP6. Overexpression of LPR6 or its N-terminus rescued the Wnt/β-catenin signaling pathway which was inhibited by hypoxia and endoplasmic reticulum stress. In mice overexpressing of LRP6, the expression of β-catenin and DKK1 increased, Bcl2 decreased, and Bax increased. Mice with LRP6 knockout showed an opposite trend, and the expression of Claudin2, Occludin and ZO-1 decreased. Two drugs, curcumin and auranofin could alleviate intestinal barrier damage in DSS-induced colitis mice by targeting LRP-6. Therefore, gut microbiota dysbiosis and hypoxia can inhibit the LRP6 and Wnt/β-catenin pathway, and drugs targeting LRP6 can protect the intestinal barrier.

Role of gut microbiota-derived signals in the regulation of gastrointestinal motility

The gastrointestinal (GI) tract harbors trillions of commensal microbes, called the gut microbiota, which plays a significant role in the regulation of GI physiology, particularly GI motility. The GI tract expresses an array of receptors, such as toll-like receptors (TLRs), G-protein coupled receptors, aryl hydrocarbon receptor (AhR), and ligand-gated ion channels, that sense different gut microbiota-derived bioactive substances. Specifically, microbial cell wall components and metabolites, including lipopeptides, peptidoglycan, lipopolysaccharides (LPS), bile acids (BAs), short-chain fatty acids (SCFAs), and tryptophan metabolites, mediate the effect of gut microbiota on GI motility through their close interactions with the enteroendocrine system, enteric nervous system, intestinal smooth muscle, and immune system. In turn, GI motility affects the colonization within the gut microbiota. However, the mechanisms by which gut microbiota interacts with GI motility remain to be elucidated. Deciphering the underlying mechanisms is greatly important for the prevention or treatment of GI dysmotility, which is a complication associated with many GI diseases, such as irritable bowel syndrome (IBS) and constipation. In this perspective, we overview the current knowledge on the role of gut microbiota and its metabolites in the regulation of GI motility, highlighting the potential mechanisms, in an attempt to provide valuable clues for the development of gut microbiota-dependent therapy to improve GI motility.

Role of gut microbiota in postoperative complications and prognosis of gastrointestinal surgery: A narrative review

Gastrointestinal surgery is often challenging because of unexpected postoperative complications such as pouchitis, malabsorption, anastomotic leak, diarrhea, inflammatory responses, and life-threatening infections. Moreover, the gut microbiota has been shown to be associated with the complications described above. Major intestinal reconstruction, such as Roux-en-Y gastric bypass (RYGB) and ileal pouch-anal anastomosis surgery, could result in altered gut microbiota, which might lead to some of the benefits of these procedures but could also contribute to the development of postsurgical complications. Moreover, postsurgical reestablishment of the gut microbiota population is still poorly understood. Here, we review evidence outlining the role of gut microbiota in complications of gastrointestinal surgery, especially malabsorption, anastomotic leak, pouchitis, and infections. In addition, this review will evaluate the risks and benefits of live biotherapeutics in the complications of gastrointestinal surgery.

Effectiveness and safety of acupuncture for postoperative ileus following gastrointestinal surgery: A systematic review and meta-analysis

Background

Postoperative ileus (POI) is an important complication of gastrointestinal (GI) surgery. Acupuncture has been increasingly used in treating POI. This study aimed to assess the effectiveness and safety of acupuncture for POI following GI surgery.

Methods

Seven databases (PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, Wan fang Data, VIP Database for Chinese Technical Periodicals, and Chinese Biomedical Literature Database) and related resources were searched from inception to May 30, 2021. Randomized controlled trials (RCTs) reporting the acupuncture for POI in GI were included. The quality of RCTs was assessed by the Cochrane Collaboration Risk of Bias tool, and the certainty of the evidence was evaluated by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. A meta-analysis was performed by using RevMan 5.4 software.

Results

Eighteen RCTs involving 1413 participants were included. The meta-analysis showed that acupuncture could reduce the time to first flatus (TFF) (standardized mean difference [SMD] = −1.14, 95% confidence interval [CI]: −1.54 to −0.73, P < 0.00001), time to first defecation (TFD) (SMD = −1.31, 95% CI: −1.88 to −0.74, P < 0.00001), time to bowel sounds recovery (TBSR) (SMD = −1.57, 95% CI: −2.14 to −1.01, P < 0.00001), and length of hospital stay (LOS) (mean difference [MD] = −1.68, 95% CI: −2.55 to −0.80, P = 0.0002) compared with usual care. A subgroup analysis found that acupuncture at distal acupoints once daily after surgery had superior effects on reducing TFF and TFD. A sensitivity analysis supported the validity of the finding. Acupuncture also manifested an effect of reducing TFF, TFD and TBSR compared with sham acupuncture but the result was not stable. Relatively few trials have reported whether adverse events have occurred.

Conclusions

Acupuncture showed a certain effect in reducing POI following GI surgery with very low-to-moderate quality of evidence. The overall safety of acupuncture should be further validated. More high-quality, large-scale, and multicenter original trials are needed in the future.