Role of gut microbiota-immunity axis in patients undergoing surgery for colorectal cancer: Focus on short and long-term outcomes

Berberine improved the microbiota in lung tissue of colon cancer and reversed the bronchial epithelial cell changes caused by cancer cells

Objective

The lung is a common organ for colon cancer metastasis, and the objective of this experiment was to explore the protective effect of berberine on lung tissue or alveolar epithelial cells induced by colon cancer.

Methods

Thirty-six BALB/c nude mice were used to establish a xenograft model of colon cancer with the HT29 cell line and were treated with berberine and probiotics. Human bronchial epithelial BEAS-2B cells were induced by conditioned medium (CM) from the colon cancer cell lines HT29 and RKO and were treated with berberine. Lung tissues were collected to detect the changes in the microbiota using 16S rDNA sequencing and the expression of inflammatory cytokines. The expression of E-cadherin and N-cadherin in BEAS-2B cells was detected by cellular immunofluorescence. The changes in cell proliferation were detected by the CCK-8 assay. Western blotting was used to detect E-cadherin, N-cadherin, collagen I, fibronectin, PDGF-β, and RAD51 expression in BEAS-2B cells.

Results

The richness and evenness of the microbiota in the lung tissues of mice with colon cancer were significantly lower than those of the control group. Berberine significantly increased the abundances of Bacteroidetes, Bacteroidia, Bacteroidales, Lactobacillaceae, Lactobacillus and Acinetobacter in the lung tissue of mice with colon cancer, with reduced abundances of Actinobacteria, Bacillales, Staphylococcaceae and Staphylococcus. Berberine or probiotics significantly increased the alpha diversity of the lung microbiota. Compared with probiotics, berberine significantly enhanced the abundance of microbiota involved in the metabolism of lysosomes, flavone and flavonol biosynthesis, glycosaminoglycan degradation, and glycosphingolipid biosynthesis-ganglio. Berberine increased IL-6 and IL-10 and decreased IL-17 and IFN-γ expression in lung tissue (P > 0.05), but berberine-probiotics significantly decreased IL-17 and IFN-γ and increased IL-10 expression (P < 0.05). Colon cancer cells could not induce BEAS-2B proliferation but decreased the expression of the epithelial marker E-cadherin and altered the expression of extracellular matrix-related proteins (collagen I, fibronectin, and PDGF-β), which were reversed by berberine. Berberine increased RAD51 expression in BEAS-2B cells, which had been decreased by HT29 and RKO CM treatment.

Conclusion

Berberine can selectively regulate the abundance of some microbiomes of lung tissue in colon cancer, improve the inflammatory response in lung tissue, and antagonize the cancerous stimulation of colon cancer cells to lung tissue cells by regulating the bronchial epithelial cell phenotype, extracellular matrix remodelling and the expression of the repair gene RAD51.

Collagenase-producing bacteria are common in anastomotic leakage after colorectal surgery: a systematic review

PURPOSE

Some gut bacteria can produce enzymes (collagenases) that can break down collagen in the intestinal wall. This could be a part of the pathophysiology of anastomotic leakage (AL). This systematic review aimed to investigate if such bacteria were present more frequently in AL patients versus non-AL patients following colorectal surgery.

METHODS

This systematic review was reported according to the PRISMA and AMSTAR guidelines. Before the literature search, a study protocol was registered at PROSPERO (CRD42022363454). We searched PubMed, EMBASE, Google Scholar, and Cochrane CENTRAL on April 9th, 2023, for randomized and observational human studies of AL following colorectal surgery with information on gastrointestinal bacteria. The primary outcome was bacteria with the potential to produce collagenase. The risk of bias was assessed with the Newcastle-Ottawa Scale, as all studies were observational.

RESULTS

We included 15 studies, with a total of 52,945 patients, of which 1,747 had AL, and bacteriological information from feces, mucosa, the resected specimen, or drain fluid was presented. In 10 of the 15 studies, one or more collagenase-producing bacteria were identified in the patients with AL. Neither the bacteria nor the collagenase production were quantified in any of the studies. The studies varied greatly in terms of sample material, analytical method, and time of collection. Studies using DNA sequencing methods did not report findings of collagenase-producing bacteria.

CONCLUSION

Collagenase-producing bacteria are more common in patients with AL following colorectal surgery than in patients without AL, but the significance is unclear. From the current studies, it is not possible to determine the pathogenicity of the individual gut bacteria.

Molecular mechanism of colorectal cancer and screening of molecular markers based on bioinformatics analysis

Genomics and bioinformatics methods were used to screen genes and molecular markers correlated with colorectal cancer incidence and progression, and their biological functions were analyzed. Differentially expressed genes were obtained using the GEO2R program following colorectal cancer chip data GSE44076 retrieval from the Gene Expression Omnibus gene expression comprehensive database. An online database (David) that combines annotation, visualization, and gene discovery was utilized for investigating genes. Pathway and protein analyses were performed via resources from the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Visual analysis of the KEGG pathway was carried out according to ClueGO and CluePedia to establish the PPI network of gene interaction between pathways; the genes with the highest connectivity were screened by the molecular complex detection analysis method as Hub genes in this study; gene expression was verified by GEPIA online analysis tool, and Kaplan-Meier survival curve was drawn for prognosis analysis. By analyzing GSE44076 microarray data, 86 genes were selected, and colorectal cancer tissues' upregulation was observed in 27 genes and downregulation in 59 ones. GO assessment revealed that the differentially expressed genes were basically correlated with retinol dehydrogenase activity, carbon dehydrogenase activity, collagen-containing extracellular matrix, anchored component of memory, and cellular hormone metabolic process. Moreover, the KEGG assessment revealed that the differential genes contained various signal pathways such as retinol metabolism, chemical carotenogenesis, and nitrogen metabolism. Through further analysis of the PPI protein network, 4 clusters were obtained, and 16 Hub genes were screened out by combining the degree of each gene. Through the analysis of each gene on the prognosis of colon cancer through the GEPIA online analysis website, it was found that the expression levels of AQP8, CXCL8, and ZG16 genes were remarkably associated with colon cancer prognosis (P < 0.05). Genomics and bioinformatics methods can effectively analyze the genes and molecular markers correlated with colorectal cancer incidence and progression, help to systematically clarify the molecular mechanism of 16 key genes in colorectal cancer development and progression, and provide a theoretically valid insight for the screening of diagnostic markers of colorectal cancer and the selection of accurate targets for drug therapy.

Gut Microbiota in Diagnosis, Therapy and Prognosis of Cholangiocarcinoma and Gallbladder Carcinoma-A Scoping Review

Cancers of the biliary tract are more common in Asia than in Europe, but are highly lethal due to delayed diagnosis and aggressive tumor biology. Since the biliary tract is in direct contact with the gut via the enterohepatic circulation, this suggests a potential role of gut microbiota, but to date, the role of gut microbiota in biliary tract cancers has not been elucidated. This scoping review compiles recent data on the associations between the gut microbiota and diagnosis, progression and prognosis of biliary tract cancer patients. Systematic review of the literature yielded 154 results, of which 12 studies and one systematic review were eligible for evaluation. The analyses of microbiota diversity indices were inconsistent across the included studies. In-depth analyses revealed differences between gut microbiota of biliary tract cancer patients and healthy controls, but without a clear tendency towards particular species in the studies. Additionally, most of the studies showed methodological flaws, for example non-controlling of factors that affect gut microbiota. At the current stage, there is a lack of evidence to support a general utility of gut microbiota diagnostics in biliary tract cancers. Therefore, no recommendation can be made at this time to include gut microbiota analyses in the management of biliary tract cancer patients.

Alterations of gut microbiome following gastrointestinal surgical procedures and their potential complications

Intestinal microorganisms play a crucial role in shaping the host immunity and maintaining homeostasis. Nevertheless, alterations in gut bacterial composition may occur and these alterations have been linked with the pathogenesis of several diseases. In surgical practice, studies revealed that the microbiome of patients undergoing surgery changes and several post-operative complications seem to be associated with the gut microbiota composition. In this review, we aim to provide an overview of gut microbiota (GM) in surgical disease. We refer to several studies which describe alterations of GM in patients undergoing different types of surgery, we focus on the impacts of peri-operative interventions on GM and the role of GM in development of post-operative complications, such as anastomotic leak. The review aims to enhance comprehension regarding the correlation between GM and surgical procedures based in the current knowledge. However, preoperative and postoperative synthesis of GM needs to be further examined in future studies, so that GM-targeted measures could be assessed and the different surgery complications could be reduced.

Preparing the Bowel (Microbiome) for Surgery: Surgical Bioresilience

The preparation of the bowel for radical surgery is a corner stone of elective colorectal practice. The evidence for this intervention is of variable quality and it is often contradictory, yet there is now a global move toward the adoption of oral antibiotic therapy for the reduction of perioperative infective complications, such as surgical site infections. The gut microbiome is a critical mediator of the systemic inflammatory response to surgical injury, wound healing, and perioperative gut function. The loss of critical microbial symbiotic functions caused by bowel preparation and surgery has an adverse impact on surgical outcomes, yet the mechanisms through which this occurs are poorly defined. In this review, the evidence for bowel preparation strategies is critically appraised in the context of the gut microbiome. The impact of antibiotic therapy on the surgical gut microbiome and the importance of the intestinal "resistome" to surgical recovery is described. Data to support the augmentation of the microbiome through diet, probiotic and symbiotic approaches, as well as fecal transplantation are also appraised. Finally, we propose a novel strategy of bowel preparation defined as " surgical bioresilience " and define areas or prioritization in this emerging field. This describes the optimization of surgical intestinal homeostasis and core surgical exposome-microbiome interactions that regulate the wound immune microenvironment, the systemic inflammatory response to surgical injury, and gut function across the perioperative time course.

A study on the method and effect of the construction of a humanized mouse model of fecal microbiota transplantation

The gestation period is critical for the health of the mother and fetus. Malnutrition or over nutrition during pregnancy may cause gestational diseases that can result in adverse pregnancy outcomes. Fecal microbiota transplantation (FMT) can be used to re-establish new gut microbiota to treat a variety of diseases and construct a model to investigate the nutritional health during pregnancy. Therefore, this study investigated whether human-derived gut microbiota during pregnancy could colonize the intestines of mice. Moreover, we determined the time and method of intervention for FMT. Based on this information, a humanized mouse model of FMT was constructed to simulate the human intestinal microecology during pregnancy, and serve as a useful animal model for the study of nutritional health and disease during pregnancy. Germ-free (GF) and specific pathogen free (SPF) C57BL/6J mice were selected for humanized gestational FMT and the transplantation outcomes were evaluated. The results demonstrated that the gestational intestinal microbiota colonized the intestines of mice, allowing researchers to construct a humanized mouse model of gestational FMT. The main intestinal flora of the gestational period were transplanted into GF mice, with the gestational flora being similar to the flora of GF mice after transplantation. However, antibiotics could not eliminate the original microbial flora in SPF mice, and the flora was complex and variable after FMT with little increase in abundance. Background flora had a significant impact on the outcomes assessment. The results were better in GF mice than in SPF mice, and after microbiota transplantation, a superior effect was observed on day 21 compared to days 7 and 14.

The effect of probiotics on postsurgical complications in patients with colorectal cancer: a systematic review and meta-analysis

Context

Clinical trials have investigated the effect of probiotics on postsurgical complications in colorectal cancer (CRC). However, so far, there are no systematic reviews evaluating the effect of probiotics and synbiotics on the clinical or infectious postsurgical complications of colorectal cancer.

Objective

The objective of this review was to synthesize the best available evidence on the effects of the use of probiotics or synbiotics on pre-, peri-, and post-operative complications of CRC surgical resection.

Data Sources

A search of the PubMed, Embase, LILACS, Scopus, Cochrane, Web of Science, ProQuest, and Google Scholar databases was conducted for clinical trials published up until January 2022.

Data Extraction

The population characteristics, period and protocol of supplementation, and postoperative complications were extracted and reported. A random-effects model was used to estimate the effect of probiotic and synbiotic treatment on these variables.

Data Synthesis

In total, 2518 studies were identified, of which 16 were included in the qualitative synthesis and 13 in the meta-analysis. Overall, probiotic supplementation reduced the incidence of ileus (odds ratio [OR] = .13, 95% confidence interval [CI]: .02, .78), diarrhea (OR = .32, 95% CI: .15, .69), abdominal collection (OR: .35, 95% CI: .13, .92), sepsis (OR = .41, 95% CI: .22, .80), pneumonia (OR = .39, 95% CI: .19, .83), and surgical site infection (OR = .53, 95% CI: .36, .78). The results of the subgroup analysis indicated that lower dose (&lt;109 colony-forming units), higher duration of supplementation (&gt;14 days), and being administrated ≤5 days before and &gt;10 days after surgery was more effective at reducing the incidence of surgical site infection.

Conclusion

Probiotics and synbiotics seem to be a promising strategy for the prevention of postoperative complications after CRC surgery. Larger, high-quality randomized controlled trials are needed to establish the optimal treatment protocol for the use of probiotics and synbiotics in preventing postoperative complications for CRC surgery.

Probiotics and synbiotics for preventing postoperative infectious complications in colorectal cancer patients: a systematic review and meta-analysis

BACKGROUND

The health benefits of probiotics and synbiotics in healthy adults are well established, but their role in preventing infectious complications after surgery for colorectal cancer remains controversial. The aim of this meta-analysis was to assess the impact of probiotics/synbiotics on the incidence of infectious complications in patients who had surgery for colorectal cancer.

METHODS

A comprehensive literature search of all randomized control trials (RCTs) was conducted using PubMed, Embase, World Health Organization (WHO) Global Index Medicus, WHO clinical trial registry, and Clinicaltrials.gov. Inclusion criteria included RCTs comparing the use of any strain or dose of a specified probiotic/synbiotic with placebo or a "standard care" control group. The incidence of postoperative infectious complications was analyzed.

RESULTS

Fourteen RCTs involving 1566 patients (502 receiving probiotics, 273 receiving synbiotics, and 791 receiving placebo) were analyzed. Overall, probiotic or synbiotic administration significantly reduced the risk of developing postoperative infectious complications by 37% (relative risk (RR) = 0.63, 95% confidence interval (CI) 0.54-0.74, p < 0.001). Furthermore, when considering the six different types of postoperative infectious complications (septicemia, incision infection, central line infection, pneumonia infection, urinary infection, and incidence of diarrhea), probiotic or synbiotic administration was beneficial in reducing the incidence of each one of them. The quality of evidence was listed below: incidence of diarrhea (high), septicemia (moderate), incision infection (moderate), pneumonia infection (moderate), urinary infection (moderate), and central line infection (low). However, for the main outcome of infectious complications, we found evidence of possible publication bias, although estimates still showed a reduction following trim-and-fill analysis (RR = 0.72, 95% CI 0.62-0.84, p < 0.001).

CONCLUSIONS

The use of probiotic/synbiotic supplementation is associated with a significant reduction in the risk of developing postoperative infectious complications in patients who had surgery for colorectal cancer. Additional studies are needed to confirm the findings due to publication bias and low quality of evidence.

Microbiota, Bacterial Carbonic Anhydrases, and Modulators of Their Activity: Links to Human Diseases?

The involvement of the human microbiome is crucial for different host functions such as protection, metabolism, reproduction, and especially immunity. However, both endogenous and exogenous factors can affect the balance of the microbiota, creating a state of dysbiosis, which can start various gastrointestinal or systemic diseases. The challenge of future medicine is to remodel the intestinal microbiota to bring it back to healthy equilibrium (eubiosis) and, thus, counteract its negative role in the diseases' onset. The shaping of the microbiota is currently practiced in different ways ranging from diet (or use of prebiotics, probiotics, and synbiotics) to phage therapy and antibiotics, including microbiota fecal transplantation. Furthermore, because microbiota modulation is a capillary process, and because many microbiota bacteria (both beneficial and pathogenic) have carbonic anhydrases (specifically the four classes α, β, γ, and ι), we believe that the use of CA inhibitors and activators can open up new therapeutic strategies for many diseases associated with microbial dysbiosis, such as the various gastrointestinal disorders and the same colorectal cancer.

The role of the bacterial microbiome in the treatment of cancer

The human microbiome is defined as the microorganisms that reside in or on the human body, such as bacteria, viruses, fungi, and protozoa, and their genomes. The human microbiome participates in the modulation of human metabolism by influencing several intricate pathways. The association between specific bacteria or viruses and the efficacy of cancer treatments and the occurrence of treatment-related toxicity in cancer patients has been reported. However, the understanding of the interaction between the host microbiome and the cancer treatment response is limited, and the microbiome potentially plays a greater role in the treatment of cancer than reported to date. Here, we provide a thorough review of the potential role of the gut and locally resident bacterial microbiota in modulating responses to different cancer therapeutics to demonstrate the association between the gut or locally resident bacterial microbiota and cancer therapy. Probable mechanisms, such as metabolism, the immune response and the translocation of microbiome constituents, are discussed to promote future research into the association between the microbiome and other types of cancer. We conclude that the interaction between the host immune system and the microbiome may be the basis of the role of the microbiome in cancer therapies. Future research on the association between host immunity and the microbiome may improve the efficacy of several cancer treatments and provide insights into the cause of treatment-related side effects.

Role of Intestinal Microbiota on Gut Homeostasis and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that is immune mediated. Patients typically present with synovial inflammation, which gradually deteriorates to investigate severe cartilage and bone damage, affecting an individual's ability to perform basic tasks and impairing the quality of life. When evaluated against healthy controls, patients with RA have notable variations within the constituents of the gut microbiota. The human gastrointestinal tract mucosa is colonized by trillions of commensal microbacteria, which are key actors in the initiation, upkeep, and operation of the host immune system. Gut microbiota dysbiosis can adversely influence the immune system both locally and throughout the host, thus predisposing the host to a number of pathologies, including RA. Proximal intestinal immunomodulatory cells, situated in specific locales within the intestine, are a promising intermediary through which the gastrointestinal microbiota can influence the pathogenesis and progression of RA. In the early stages of the disease, the microbiota appear to differ from those present in healthy controls. This difference may reflect potential autoimmune mechanisms. Research studies evaluating intestinal microbiota have demonstrated that RA is associated with a bacterial population growth or with a decline when judged against control groups. The aim of this review is to examine the studies that connect intestinal dysbiosis with the autoimmune pathways implicated in the pathogenesis of RA.

Gut Microbiota as Potential Biomarker and/or Therapeutic Target to Improve the Management of Cancer: Focus on Colibactin-Producing Escherichia coli in Colorectal Cancer

Simple Summary

Gut microbiota is emerging as new diagnostic and prognostic marker and/or therapeutic target to improve the management of cancer. This review aims to summarize microbial signatures that have been associated with digestive and other cancers. We report the clinical relevance of these microbial markers to predict the response to cancer therapy. Among these biomarkers, colibactin-producing E. coli are prevalent in the colonic mucosa of patients with colorectal cancer and they promote colorectal carcinogenesis in several pre-clinical models. Here we discuss the promising use of colibactin-producing E. coli as a new predictive factor and a therapeutic target in colon cancer management.

Abstract

The gut microbiota is crucial for physiological development and immunological homeostasis. Alterations of this microbial community called dysbiosis, have been associated with cancers such colorectal cancers (CRC). The pro-carcinogenic potential of this dysbiotic microbiota has been demonstrated in the colon. Recently the role of the microbiota in the efficacy of anti-tumor therapeutic strategies has been described in digestive cancers and in other cancers (e.g., melanoma and sarcoma). Different bacterial species seem to be implicated in these mechanisms: F. nucleatum, B. fragilis, and colibactin-associated E. coli (CoPEC). CoPEC bacteria are prevalent in the colonic mucosa of patients with CRC and they promote colorectal carcinogenesis in susceptible mouse models of CRC. In this review, we report preclinical and clinical data that suggest that CoPEC could be a new factor predictive of poor outcomes that could be used to improve cancer management. Moreover, we describe the possibility of using these bacteria as new therapeutic targets.

Postoperative Complications Are Associated with Long-Term Changes in the Gut Microbiota Following Colorectal Cancer Surgery

Changes in the gut microbiome have already been associated with postoperative complications in major abdominal surgery. However, it is still unclear whether these changes are transient or a long-lasting effect. Therefore, the aim of this prospective clinical pilot study was to examine long-term changes in the gut microbiota and to correlate these changes with the clinical course of the patient. Methods: In total, stool samples of 62 newly diagnosed colorectal cancer patients undergoing primary tumor resection were analyzed by 16S-rDNA next-generation sequencing. Stool samples were collected preoperatively in order to determine the gut microbiome at baseline as well as at 6, 12, and 24 months thereafter to observe longitudinal changes. Postoperatively, the study patients were separated into two groups-patients who suffered from postoperative complications (n = 30) and those without complication (n = 32). Patients with postoperative complications showed a significantly stronger reduction in the alpha diversity starting 6 months after operation, which does not resolve, even after 24 months. The structure of the microbiome was also significantly altered from baseline at six-month follow-up in patients with complications (p = 0.006). This was associated with a long-lasting decrease of a large number of species in the gut microbiota indicating an impact in the commensal microbiota and a long-lasting increase of Fusobacterium ulcerans. The microbial composition of the gut microbiome shows significant changes in patients with postoperative complications up to 24 months after surgery.

Evaluation of prognostic factors and clinicopathological patterns of recurrence after curative surgery for colorectal cancer

BACKGROUND

Colorectal cancer is a common tumor with a quite high-related mortality. Despite the used curative treatments, patients will develop cancer recurrence in up to 50% of the cases and/or other primary neoplasms. Although most of the recurrences are discovered within 3 years from the first treatment, a small percentage is found after 5 years. The early detection of recurrence is crucial to allow further therapies improving patients’ survival. Several follow-up programs have been developed but the optimal one is far from being established.

AIM

To evaluation of potential prognostic factors for timing and patterns of recurrence in order to plan tailored follow-up programs.

METHODS

Perioperative and long-term data of all consecutive patients surgically treated with curative intent, from January 2006 to June 2009, for colorectal adenocar-cinoma, were retrospectively reviewed to find potential prognostic factors associated with: (1) Recurrence incidence; (2) Incidence of an early (within 3 years from surgery) or late recurrence; and (3) Different sites of recurrence. In addition, the incidence of other primary neoplasms has been evaluated in a cohort of patients with a minimum potential follow-up of 10 years.

RESULTS

Our study included 234 patients. The median follow-up period has been 119 ± 46.2 mo. The recurrence rate has been 25.6%. Patients with a higher chance to develop recurrence had also the following characteristics: Higher levels of preoperative glycemia and carcinoembryonic antigen, highest anaesthesiologists Score score, occlusion, received a complex operation performed with an open technique, after a longer hospital stay, and showed advanced tumors. The independent prognostic factors for recurrence were the hospital stay, N stage 2, and M stage 1 (multivariate analysis). Younger ages were significantly associated with an early recurrence onset. Patients that received intermediate colectomies or segmental resections, having an N stage 2 or American Joint Committee on Cancer stage 3 tumors were also associated with a higher risk of liver recurrence, while metastatic diseases at diagnosis were linked with local recurrence. Neoadjuvant treatments showed lung recurrence. Finally, bigger tumors and higher lymph node ratio were associated with peritoneal recurrence (marginally significant). Thirty patients developed a second malignancy during the follow-up time.

CONCLUSION

Several prognostic factors should be considered for tailored follow-up programs, eventually, beyond 5 years from the first treatment.

Role of gut microbiome in regulating the effectiveness of metformin in reducing colorectal cancer in type 2 diabetes

The prevalence of colorectal cancer (CRC) and type 2 diabetes mellitus (T2DM) is increasing globally. It is rarely noticed that the incidence of CRC is higher in patients with T2DM. What needs to be mentioned is that metformin, a commonly used clinical drug for T2DM, attracts scholars’ attention because of its benefits in lowering the risk of developing CRC. Hence, we try to find the common grounds of initiation of T2DM and CRC and the reason why metformin reduces the risk of CRC in patients with T2DM. We noticed consistent changes of gut microbiota, such as elevated Bacteroides, Prevotella and Bifidobacterium and depressed Firmicutes and Lactobacillus. Furthermore, many studies in recent years have proved that the efficacy of metformin, such as improving blood glucose, depends on the gut microbiota. Coincidentally, the progression of CRC is inseparable from the contributions of gut microbiota. Therefore, we first proposed the concept of the metformin-gut microbiota–CRC (in T2DM) axis to explain the effect of metformin in reducing CRC in patients with T2DM. In this review, we elaborated the new concept and its potential clinical application value.