Perioperative synbiotics administration decreases postoperative infections in patients with colorectal cancer: a randomized, double-blind clinical trial

It Is All about Probiotics to Control Cervical Cancer

Cervical cancer (CC) is the fourth most common malignancy in female patients. "Human papillomavirus" (HPV) contamination is a leading cause of all forms of cervical cancer, accounting for an expected 570,000 reported incidents in 2018. Two HPV strains (16 and 18) are responsible for 70% of CC and pre-cancerous cervical abnormalities. CC is one of the foremost reasons for the malignancy death rate in India among women ranging from 30 to 69 years of age in India, responsible for 17% of all cancer deaths. Currently approved cervical cancer treatments are associated with adverse reactions that might harm the lives of women affected by this disease. Consequently, probiotics can play a vital role in the treatment of CC. It is reflected from various studies regarding the role of probiotics in the diagnosis, prevention or treatment of cancer. In this review article, we have discussed the rationale of probiotics for treatment of CC, the role of probiotics as effective adjuvants in anti-cancer therapy and the combined effect of the anti-cancer drug along with probiotics to minimize the side effects due to chemotherapy.

The impact of pre-, pro- and synbiotics supplementation in colorectal cancer treatment: a systematic review

Introduction

The effectiveness of the supplementation of prebiotics, probiotics and synbiotics as a therapeutic approach in colorectal cancer (CRC) remains unclear. The aim of this systematic review is to critically examine the current scientific evidence on the impact of modulating the microbiota, through the use of prebiotics, probiotics and synbiotics, in patients diagnosed with CRC undergoing treatment, to determine the potential therapeutic use of this approach.

Methods

This systematic review was made according to the PRISMA 2020 guidelines. Inclusion criteria were randomized controlled trials (RCT) comparing the impact of pre-, pro-, or synbiotic supplementation with placebo or standard care in patients with CRC undergoing treatment. Exclusion criteria were non-human studies, non-RCTs, and studies in languages other than English or Portuguese. Six databases were consulted, namely, Cochrane Library, Pubmed, Scopus, Cinahl, MedicLatina and Web of Science until May of 2023. RAYYAN software was used to manage the search results and risk of bias was assessed according to the guidelines of the Cochrane Collaboration using the Rob 2.0 tool.

Results

Twenty-four RCTs met the inclusion criteria and were included in this review. Administration of pre-, pro-, or synbiotics improved surgical outcomes such as the incidence of infectious and non-infectious postoperative complications, return to normal gut function, hospital length of stay, and antibiotic usage. The supplementation of these microorganisms also alleviated some symptoms from chemotherapy and radiotherapy, mainly diarrhea. Evidence on the best approach in terms of types of strains, dosage and duration of intervention is still scarce.

Conclusions

Pre-, pro-, and synbiotics supplementation appears to be a beneficial therapeutic approach in CRC treatment to improve surgical outcomes and to alleviate side-effects such as treatment toxicity. More RCTs with larger sample sizes and less heterogeneity are needed to confirm these potential benefits and to determine the best strains, dosage, and duration of administration in each situation.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023413958.

Effect of probiotics and synbiotics on complications of wound infection after colorectal surgery: A meta-analysis

Wound infection is a serious complication that impacts the prognosis of patients after colorectal surgery (CS). Probiotics and synbiotics (Pro and Syn) are live bacteria that produce bacteriostatic agents in the intestinal system and have a positive effect on postoperative wound infections. The purpose of this study was to evaluate the effect of Pro and Syn on complications of wound infection after CS. In November 2023, we searched relevant clinical trial reports from Pubmed, Cochrane Library, and Embase databases and screened the retrieved reports, extracted data, and finally analysed the data by using RevMan 5.3. A total of 12 studies with 1567 patients were included in the study. Pro and Syn significantly reduced total infection (OR, 0.44; 95% CI, 0.35, 0.56; p < 0.00001), surgical incision site infection (SSI) (OR, 0.61; 95% CI, 0.45, 0.81; p = 0.002), pneumonia (OR, 0.43; 95% CI, 0.25, 0.72; p = 0.001), urinary tract infection (OR, 0.28; 95% CI, 0.14, 0.56; p = 0.0003), and Pro and Syn did not reduce anastomotic leakage after colorectal surgery (OR, 0.84; 95% CI, 0.50, 1.41; p = 0.51). Pro and Syn can reduce postoperative wound infections in patients with colorectal cancer, which benefits patients' postoperative recovery.

Modulating the gut microbiota by probiotics, prebiotics, postbiotics, and fecal microbiota transplantation: An emerging trend in cancer patient care

Treatment resistance, together with acute and late adverse effects, represents critical issues in the management of cancer patients. Promising results from preclinical and clinical research underline the emerging trend of a microbiome-based approach in oncology. Favorable bacterial species and higher gut diversity are associated with increased treatment efficacy, mainly in chemo- and immunotherapy. On the other hand, alterations in the composition and activity of gut microbial communities are linked to intestinal dysbiosis and contribute to high treatment-induced toxicity. In this Review, we provide an overview of studies concerning gut microbiota modulation in patients with solid and hematologic malignancies with a focus on probiotics, prebiotics, postbiotics, and fecal microbiota transplantation. Targeting the gut microbiome might bring clinical benefits and improve patient outcomes. However, a deeper understanding of mechanisms and large clinical trials concerning microbiome and immunological profiling is warranted to identify safe and effective ways to incorporate microbiota-based interventions in routine clinical practice.

Expanding CYLD protein in NF-κβ/TNF-α signaling pathway in response to Lactobacillus acidophilus in non-metastatic rectal cancer patients

The CYLD gene is a tumor suppressor, reduced in many cancers. Here, we aimed to investigate CYLD protein level and NF-κβ/TNF-α signaling pathway in rectal cancer patients with Lactobacillus acidophilus (L. acidophilus) consumption. One hundred ten patients with non-metastatic rectal cancer were randomly divided into L. acidophilus probiotic (500 mg, three times daily) and placebo groups for 13 weeks. The expression of CYLD, TNF-α, and NF-κB proteins and the genes involved in the NF-κβ/TNF-α pathway were evaluated using ELISA and qPCR techniques. The survival rate was measured after five years. Unlike the placebo group, the results showed a significant increase in the expression of CYLD protein and tumor suppressor genes, including FOXP3, ROR-γ, Caspase3, GATA3, T-bet, and a considerable decrease in the expression of NF-ҝβ and TNF-α proteins and oncogenes, including STAT3, 4, 5, 6, and SMAD 3, in the probiotic group. A higher overall survival rate was seen after L. acidophilus consumption compared to the placebo group (P < 0.05). L. acidophilus consumption can reduce inflammation factors by affecting CYLD protein and its downstream signaling pathways. A schematic plot of probiotic consumption Effects on the CYLD protein in regulating the NF-ĸβ signaling pathway in colorectal cancer. NF-ĸβ can be activated by canonical and noncanonical pathways, which rely on IκB degradation and p100 processing, respectively. In the canonical NF-κβ pathway, dimmers, such as p65/p50, are maintained in the cytoplasm by interacting with an IκBα protein. The binding of a ligand to a cell-surface receptor activates TRAF2, which triggers an IKK complex, containing -α, -β, -g, which phosphorylates IKK-β. It then phosphorylates IκB-α, leading to K48-ubiquitination and degradation of this protein. The p65/p50 protein freely enters the nucleus to turn on target genes. The non-canonical pathway is primarily involved in p100/RelB activation. It differs from the classical pathway in that only certain receptor signals activate this pathway. It proceeds through an IKK complex that contains two IKK-α subunits but not NEMO. Several materials including peptidoglycan, phorbol, myristate, acetate, and gram-positive bacteria such as probiotics inhibit NF-κB by inducing CYLD. This protein can block the canonical and noncanonical NF-κβ pathways by removing Lys-63 ubiquitinated chains from activated TRAFs, RIP, NEMO, and IKK (α, β, and γ). Moreover, TNF-α induces apoptosis by binding caspase-3 to FADD.

The Efficacy of Probiotics, Prebiotics, and Synbiotics in Patients Who Have Undergone Abdominal Operation, in Terms of Bowel Function Post-Operatively: A Network Meta-Analysis

BACKGROUND

Abdominal operations may lead to post-operative bowel dysfunction, while administration of probiotics, prebiotics and synbiotics may limit its manifestation. Τhe study aimed to assess the efficacy of probiotics, prebiotics and synbiotics in patients who undergone abdominal operation, in terms of bowel function post-operatively.

METHODS

PubMed, Scopus, Cochrane Central Register of Controlled Trials (Central), Embase, US Registry of clinical trials, and sources of grey literature were searched. The relative effect sizes were estimated, and we obtained the relative ranking of the interventions using cumulative ranking curves.

RESULTS

In total, 30 studies were included in the analysis. For the outcome of post-operative ileus, probiotics was superior to placebo/no intervention (relative risk, RR: 0.38; 95%CI: 0.14-0.98) with the highest SUCRA (surface under the cumulative ranking) value (92.1%). For time to first flatus, probiotics (MD: -0.47; 95%CI: -0.78 to -0.17) and synbiotics (MD: -0.53; 95%CI: -0.96 to -0.09) were superior to placebo/no intervention. For time to first defecation and for post-operative abdominal distension probiotics were superior to placebo/no intervention. For post-operative hospitalization days, synbiotics were superior to placebo/no intervention (MD: -3.07; 95%CI: -4.80 to -1.34).

CONCLUSIONS

Administration of probiotics in patients who had undergone abdominal surgery reduced the prevalence of post-operative ileus, time to first flatus, time to first defecation, and prevalence of post-operative abdominal distension. Synbiotics reduce time to first flatus and post-operative hospitalization days.

Comparative Effects of Different Nutritional Supplements on Inflammation, Nutritional Status, and Clinical Outcomes in Colorectal Cancer Patients: A Systematic Review and Network Meta-Analysis

Nutritional supplements have been widely used in colorectal cancer (CRC) patients. The aim of this network meta-analysis (NMA) was to compare the effects of different nutritional supplements on inflammation, nutritional status, and clinical outcomes in CRC patients. Four electronic databases were searched until December 2022. Randomized controlled trials (RCTs) comparing nutritional supplements of omega-3 fatty acids (omega-3), arginine, vitamin D, glutamine, probiotics, or their combinations with placebo or standard treatment were selected. The outcomes were inflammatory indicators, nutritional indicators, and clinical outcomes. A random-effects Bayesian NMA was performed to rank the effect of each supplement. In total, 34 studies involving 2841 participants were included. Glutamine was superior in decreasing tumor necrosis factor-α (MD -25.2; 95% CrI [-32.62, -17.95]), whereas combined omega-3 and arginine supplementation was more effective in decreasing interleukin-6 (MD -61.41; 95% CrI [-97.85, -24.85]). No nutritional supplements significantly maintained nutritional indicators in CRC patients. Regarding clinical outcomes, glutamine ranked highest in reducing the length of hospital stay (MD -3.71; 95% CrI [-5.89, -1.72]) and the incidence of wound infections (RR 0.12; 95% CrI [0, 0.85]), and probiotics were rated as best in reducing the incidence of pneumonia (RR 0.38; 95% CrI [0.15, 0.81]). Future well-designed RCTs are needed to further confirm these findings.

Synbiotics as Supplemental Therapy for the Alleviation of Chemotherapy-Associated Symptoms in Patients with Solid Tumours

Chemotherapy is still the first line of treatment for most cancer patients. Patients receiving chemotherapy are generally prone to infections, which result in complications, such as sepsis, mucositis, colitis, and diarrhoea. Several nutritional approaches have been trialled to counter the chemotherapy-associated side effects in cancer patients, but none have yet been approved for routine clinical use. One of the approaches to reduce or avoid chemotherapy-associated complications is to restore the gut microbiota. Gut microbiota is essential for the healthy functioning of the immune system, metabolism, and the regulation of other molecular responses in the body. Chemotherapy erodes the mucosal layer of the gastrointestinal tract and results in the loss of gut microbiota. One of the ways to restore the gut microbiota is through the use of probiotics. Probiotics are the ‘good’ bacteria that may provide health benefits if consumed in appropriate amounts. Some studies have highlighted that the consumption of probiotics in combination with prebiotics, known as synbiotics, may provide better health benefits when compared to probiotics alone. This review discusses the different nutritional approaches that have been studied in an attempt to combat chemotherapy-associated side effects in cancer patients with a particular focus on the use of pre-, pro- and synbiotics.

Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

Examining the Role of Microbiota-Centered Interventions in Cancer Therapeutics: Applications for Urothelial Carcinoma

Modern advances in genomic and molecular technologies have sparked substantial research on the human intestinal microbiome over the past decade. A deeper understanding of the microbiome has illuminated that dysbiosis, or a disruption in the microbiome, is associated with inflammatory disease states and carcinogenesis. Novel therapies that target the microbiome and restore healthy flora may have value in dampening the immunopathologic state induced by dysbiosis. A narrative review of the literature on the use of microbiota-centered interventions (MCIs) was conducted. Several randomized clinical trials show that MCIs can augment response to immune checkpoint inhibitor (ICI) therapy in patients with metastatic cancer. Clinical trials have also demonstrated that modulation of the intestinal microbiome can enhance recovery and reduce infectious complications in the surgical management of colorectal adenocarcinoma. Overall, these major discoveries suggest future clinical applications of MCIs for a wide range of immune-mediated conditions. These results may also translate to improved patient outcomes in systemic immunotherapy for urothelial carcinoma as well as in patients recovering from radical cystectomy (RC), which is complicated by high infection rates. Further research is needed to evaluate the optimal bacterial composition of microbiota-centered therapies and the specific cellular changes that lead to improved tumor antigen recognition after microbiota-centered therapies.

The implication of gut microbiota in recovery from gastrointestinal surgery

Recovery from gastrointestinal (GI) surgery is often interrupted by the unpredictable occurrence of postoperative complications, including infections, anastomotic leak, GI dysmotility, malabsorption, cancer development, and cancer recurrence, in which the implication of gut microbiota is beginning to emerge. Gut microbiota can be imbalanced before surgery due to the underlying disease and its treatment. The immediate preparations for GI surgery, including fasting, mechanical bowel cleaning, and antibiotic intervention, disrupt gut microbiota. Surgical removal of GI segments also perturbs gut microbiota due to GI tract reconstruction and epithelial barrier destruction. In return, the altered gut microbiota contributes to the occurrence of postoperative complications. Therefore, understanding how to balance the gut microbiota during the perioperative period is important for surgeons. We aim to overview the current knowledge to investigate the role of gut microbiota in recovery from GI surgery, focusing on the crosstalk between gut microbiota and host in the pathogenesis of postoperative complications. A comprehensive understanding of the postoperative response of the GI tract to the altered gut microbiota provides valuable cues for surgeons to preserve the beneficial functions and suppress the adverse effects of gut microbiota, which will help to enhance recovery from GI surgery.

Soluble peptidoglycan fragments produced by Limosilactobacillus fermentum with antiproliferative activity are suitable for potential therapeutic development: A preliminary report

Currently, the use of probiotic strains and their products represents a promising innovative approach as an antagonist treatment against many human diseases. Previous studies showed that a strain of Limosilactobacillus fermentum (LAC92), previously defined as Lactobacillus fermentum, exhibited a suitable amensalistic property. The present study aimed to purify the active components from LAC92 to evaluate the biological properties of soluble peptidoglycan fragments (SPFs). The cell-free supernatant (CFS) and bacterial cells were separated after 48 h of growth in MRS medium broth and treated for isolation of SPFs. Antimicrobial activity and proliferation analysis on the human cell line HTC116 were performed using technologies such as xCELLigence, count and viability, and clonogenic analysis. MALDI-MS investigation and docking analysis were performed to determine the molecular structure and hypothetical mode of action, respectively. Our results showed that the antimicrobial activity was mainly due to SPFs. Moreover, the results obtained when investigating the SPF effect on the cell line HCT116 showed substantial preliminary evidence, suggesting their significant cytostatic and quite antiproliferative properties. Although MALDI was unable to identify the molecular structure, it was subsequently revealed by analysis of the bacterial genome. The amino acid structure is called peptide 92. Furthermore, we confirmed by molecular docking studies the interaction of peptide 92 with MDM2 protein, the negative regulator of p53. This study showed that SPFs from the LAC92 strain exerted anticancer effects on the human colon cancer HCT116 cell line via antiproliferation and inducing apoptosis. These findings indicated that this probiotic strain might be a potential candidate for applications in functional products in the future. Further examination is needed to understand the specific advantages of this probiotic strain and improve its functional features to confirm these data. Moreover, deeper research on peptide 92 could increase our knowledge and help us understand if it will be possible to apply to specific diseases such as CRC.

Perioperative Probiotics Application for Preventing Postoperative Complications in Patients with Colorectal Cancer: A Systematic Review and Meta-Analysis

Background and Objectives: Perioperative probiotic administration in patients who undergo gastrointestinal surgery can reduce postoperative infectious complications. This systematic review and meta-analysis aimed to evaluate the effect of probiotics on postoperative outcomes in patients who underwent colorectal cancer surgery. Materials and Methods: For this study, we followed the protocol published by PROSPERO (registration number: CRD42021247277). We included studies on patients undergoing open, laparoscopic, or robotic colorectal cancer surgery for curative intent. We conducted a comprehensive search with online databases (trial registries and ClinicalTrials.gov), other literature sources, and conference proceedings, with no language restriction, up until 12 August 2022. We assessed risk of bias, extracted data, and conducted statistical analyses by using a random-effects model and interpreted the results based on the Cochrane Handbook for Systematic Reviews of Interventions. We rated the certainty of evidence (CoR) according to the GRADE approach. Results: We identified 20 published full-text studies. The use of probiotics probably results in little to no difference in perioperative mortality (risk ratio (RR): 0.17, 95% CI: 0.02 to 1.38; I2 = 0%; moderate CoE) and may result in reducing the overall postoperative infectious complications (RR: 0.45, 95% CI: 0.27 to 0.76; I2 = 38%; low CoE) after colorectal cancer surgery. Probiotics may result in little to no difference in probiotics-related adverse events (RR: 0.73, 95% CI: 0.45 to 1.19; I2 = 0%; low CoE). While probiotics may result in reducing the overall postoperative complications (RR: 0.47, 95% CI: 0.30 to 0.74; I2 = 8%; low CoE), it may result in little to no difference in hospital length of stay (LOS) (MD: -1.06, 95% CI: -1.64 to -0.47; I2 = 8%; low CoE) and postoperative quality of life (QOL) (MD: +5.64, 95% CI: 0.98 to 10.3; low CoE). Conclusions: Perioperative probiotic administration may reduce complications, including overall infectious complications, in patients undergoing colorectal cancer surgery without any additional adverse effects. In addition, probiotics may have similar effects on perioperative mortality; procedure-related complications such as anastomotic leakage, and hospital LOS; or improve the QOL. Thus, probiotics may be considered a beneficial supplement to routine perioperative care for colorectal cancer surgery.

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/Synbiotics to Reduce Infectious Complications after Colorectal Surgery: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Aim: The aims of this systematic review and meta-analysis were to assess to what extent probiotics/synbiotics reduce infectious complications after colorectal surgery and whether probiotics or synbiotics should be considered as perioperative measures preventing or reducing infectious complications after CRS and should be included in enhanced recovery programmes (ERP). Secondary aims were to answer practical questions precisely on the best formulation and the type and timing of probiotics or synbiotics in CRS. Method: This systematic review and quantitative meta-analysis were conducted in accordance with PRISMA 2020 guidelines. Inclusion criteria were randomised trials comparing perioperative probiotics/synbiotics with a placebo or standard care in elective colorectal surgery. Exclusion criteria were non-randomised trials. Overall infectious complications and surgical site infections (SSIs including both deep abdominal infections and wound (skin or under the skin) infections) were the primary outcomes. Secondary outcomes were pulmonary and urinary infections, wound infections, and anastomotic leaks. The databases consulted were Medline, Cochrane Database of Systematic Reviews, Scopus, and Clinical Trials Register. Risk of bias was assessed according to the GRADE approach. The analysis calculated the random effects estimates risk ratio (RR) for each outcome. Results: 21 trials were included; 15 evaluated probiotics, and 6 evaluated synbiotics. There were significantly fewer infectious complications (risk ratio (RR) 0.59 [0.47–0.75], I² = 15%) and fewer SSI (RR 0.70 [0.52–0.95], I² = 0%) in the probiotic or synbiotic group. There were also significantly fewer pulmonary infections (RR 0.35 [0.20–0.63]) and urinary infections RR 0.41 [0.19–0.87]) as opposed to anastomotic leaks (RR 0.83 [0.47–1.48]) and wound infections (RR 0.74 [0.53–1.03]). Sensitivity analyses showed no significant difference between probiotics and synbiotics in reducing postoperative infections (RR 0.55 [0.42–0.73] versus RR 0.69 [0.42–1.13], p = 0.46). Conclusions: Based on the finding of this study, probiotics/synbiotics reduce infectious complications after colorectal surgery. The effect size was more pronounced for pulmonary and urinary infections. From a practical aspect, some of the questions related to formulations and duration of probiotics or synbiotics need to be answered before including them definitively in enhanced recovery after colorectal surgery programmes.

Dietary modulation of gut microbiota in patients with colorectal cancer undergoing surgery: A review

Colorectal cancer (CRC) is the third most frequent malignancy and the second cause of cancer death worldwide. Several factors have been postulated to be involved in CRC pathophysiology, including physical inactivity, unhealthy dietary habits, obesity, and the gut microbiota. Emerging data suggest that the microbiome may play a key role in CRC prognosis and derived complications in patients undergoing colorectal surgery. On the other hand, dietary intervention has been demonstrated to be able to induce significant changes in the gut microbiota and related metabolites in different conditions; therefore, the manipulation of gut microbiota through dietary intervention may constitute a useful approach to improve perioperative dysbiosis and post-surgical outcomes in patients with CRC. In this article, we review the role of the gut microbiota in CRC surgery complications and the potential therapeutic modulation of gut microbiome through nutritional intervention in patients with CRC undergoing surgery.

Probiotics or Synbiotics for Preventing Postoperative Infection in Hepatopancreatobiliary Cancer Patients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Postoperative infection of hepatopancreatobiliary cancer (HPBC) is a major cause of morbidity and mortality. Probiotics and synbiotics are potential prevention strategies, but evidence on the efficacy of probiotics or synbiotics in the prevention of postoperative infection for HPBC remains controversial. This study aimed to define the impact of probiotics or synbiotics on the incidence of postoperative infection in HPBC patients.

METHODS

A systematic search of the Cochrane Library, PubMed, Embase, and Web of Science databases was conducted from inception to February 2, 2021 to identify randomized controlled trials (RCTs) evaluating the efficacy of probiotics or synbiotics in HPBC. Data were pooled and expressed as the risk ratio (RR) and mean difference (MD) with 95% confidence intervals.

RESULTS

Eight RCTs involving 445 participants were included. Supplementation with probiotics or synbiotics significantly reduced the incidence of postoperative infection (RR 0.55) in HPBC patients, and both probiotics (RR 0.68) and synbiotics (RR 0.41) were effective in reducing the incidence of postoperative infection. In addition, probiotics or synbiotics can reduce duration of antibiotic use (MD -3.52) and length of hospital stay (MD -4.21).

CONCLUSION

Probiotics or synbiotics are effective strategies for the prevention of postoperative infection in HPBC patients.

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.

Effects of Probiotics at the Interface of Metabolism and Immunity to Prevent Colorectal Cancer-Associated Gut Inflammation: A Systematic Network and Meta-Analysis With Molecular Docking Studies

Background

Dysbiosis/imbalance in the gut microbial composition triggers chronic inflammation and promotes colorectal cancer (CRC). Modulation of the gut microbiome by the administration of probiotics is a promising strategy to reduce carcinogenic inflammation. However, the mechanism remains unclear.

Methods

In this study, we presented a systematic network, meta-analysis, and molecular docking studies to determine the plausible mechanism of probiotic intervention in diminishing CRC-causing inflammations.

Results

We selected 77 clinical, preclinical, in vitro, and in vivo articles (PRISMA guidelines) and identified 36 probiotics and 135 training genes connected to patients with CRC with probiotic application. The meta-analysis rationalizes the application of probiotics in the prevention and treatment of CRC. An association network is generated with 540 nodes and 1,423 edges. MCODE cluster analysis identifies 43 densely interconnected modules from the network. Gene ontology (GO) and pathway enrichment analysis of the top scoring and functionally significant modules reveal stress-induced metabolic pathways (JNK, MAPK), immunomodulatory pathways, intrinsic apoptotic pathways, and autophagy as contributors for CRC where probiotics could offer major benefits. Based on the enrichment analyses, 23 CRC-associated proteins and 7 probiotic-derived bacteriocins were selected for molecular docking studies. Results indicate that the key CRC-associated proteins (e.g., COX-2, CASP9, PI3K, and IL18R) significantly interact with the probiotic-derived bacteriocins (e.g., plantaricin JLA-9, lactococcin A, and lactococcin mmfii). Finally, a model for probiotic intervention to reduce CRC-associated inflammation has been proposed.

Conclusion

Probiotics and/or probiotic-derived bacteriocins could directly interact with CRC-promoting COX2. They could modulate inflammatory NLRP3 and NFkB pathways to reduce CRC-associated inflammation. Probiotics could also activate autophagy and apoptosis by regulating PI3K/AKT and caspase pathways in CRC. In summary, the potential mechanisms of probiotic-mediated CRC prevention include multiple signaling cascades, yet pathways related to metabolism and immunity are the crucial ones.

How to Improve Health with Biological Agents-Narrative Review

The proper functioning of the human organism is dependent on a number of factors. The health condition of the organism can be often enhanced through appropriate supplementation, as well as the application of certain biological agents. Probiotics, i.e., live microorganisms that exert a beneficial effect on the health of the host when administered in adequate amounts, are often used in commonly available dietary supplements or functional foods, such as yoghurts. Specific strains of microorganisms, administered in appropriate amounts, may find application in the treatment of conditions such as various types of diarrhoea (viral, antibiotic-related, caused by Clostridioides difficile), irritable bowel syndrome, ulcerative colitis, Crohn’s disease, or allergic disorders. In contrast, live microorganisms capable of exerting influence on the nervous system and mental health through interactions with the gut microbiome are referred to as psychobiotics. Live microbes are often used in combination with prebiotics to form synbiotics, which stimulate growth and/or activate the metabolism of the healthy gut microbiome. Prebiotics may serve as a substrate for the growth of probiotic strains or fermentation processes. Compared to prebiotic substances, probiotic microorganisms are more tolerant of environmental conditions, such as oxygenation, pH, or temperature in a given organism. It is also worth emphasizing that the health of the host may be influenced not only by live microorganisms, but also by their metabolites or cell components, which are referred to as postbiotics and paraprobiotics. This work presents the mechanisms of action employed by probiotics, prebiotics, synbiotics, postbiotics, paraprobiotics, and psychobiotics, together with the results of studies confirming their effectiveness and impact on consumer health.

Lactobacillus kefiranofaciens ZW18 from Kefir enhances the anti-tumor effect of anti-programmed cell death 1 (PD-1) immunotherapy by modulating gut microbiota

The research of probiotics assisting PD-1 inhibitors in anti-tumor has attracted widespread attention. Therefore, it is significative to find new probiotic strains with PD-1 inhibitors promoting effect. This study aims...

Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review

Optimal gut motility is central to bowel function and gut health. The link between the gut dysmotility related disorders and dysfunctional-intestinal barriers has led to a hypothesis that certain probiotics could help in normalizing gut motility and maintain gut health. This review investigates the roles of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019™) on gut health, and its mechanisms of action in various pre-clinical and clinical studies. Research supports the hypothesis that B. lactis HN019™ has a beneficial role in maintaining intestinal barrier function during gastrointestinal infections by competing and excluding potential pathogens via different mechanisms; maintaining normal tight junction function in vitro; and regulating host immune defense toward pathogens in both in vitro and human studies. This has been observed to lead to reduced incidence of diarrhea. Interestingly, B. lactis HN019™ also supports normal physiological function in immunosenescent elderly and competes and excludes potential pathogens. Furthermore, B. lactis HN019™ reduced intestinal transit time and increased bowel movement frequency in functional constipation, potentially by modulating gut–brain–microbiota axis, mainly via serotonin signaling pathway, through short chain fatty acids derived from microbial fermentation. B. lactis HN019™ is thus a probiotic that can contribute to relieving gut dysmotility related disorders.

Molecular Immune Mechanism of Intestinal Microbiota and Their Metabolites in the Occurrence and Development of Liver Cancer

Intestinal microorganisms are closely associated with immunity, metabolism, and inflammation, and play an important role in health and diseases such as inflammatory bowel disease, diabetes, cardiovascular disease, Parkinson’s disease, and cancer. Liver cancer is one of the most fatal cancers in humans. Most of liver cancers are slowly transformed from viral hepatitis, alcoholic liver disease, and non-alcoholic fatty liver disease. However, the relationship between intestinal microbiota and their metabolites, including short-chain fatty acids, bile acids, indoles, and ethanol, and liver cancer remains unclear. Here, we summarize the molecular immune mechanism of intestinal microbiota and their metabolites in the occurrence and development of liver cancer and reveal the important role of the microbiota-gut-liver axis in liver cancer. In addition, we describe how the intestinal flora can be balanced by antibiotics, probiotics, postbiotics, and fecal bacteria transplantation to improve the treatment of liver cancer. This review describes the immunomolecular mechanism of intestinal microbiota and their metabolites in the occurrence and development of hepatic cancer and provides theoretical evidence support for future clinical practice.

Antituberculosis Therapy and Gut Microbiota: Review of Potential Host Microbiota Directed-Therapies

Tuberculosis (TB) remains a major public health concern with millions of deaths every year. The overlap with HIV infections, long treatment duration, and the emergence of drug resistance are significant obstacles to the control of the disease. Indeed, the standard first-line regimen TB treatment takes at least six months and even longer for the second-line therapy, resulting in relapses, drug resistance and re-infections. Many recent reports have also shown prolonged and significant damage of the gut microbial community (dysbiosis) from anti-TB drugs that can detrimentally persist several months after the cessation of treatment and could lead to the impairment of the immune response, and thus re-infections and drug resistance. A proposed strategy for shortening the treatment duration is thus to apply corrective measures to the dysbiosis for a faster bacterial clearance and a better treatment outcome. In this review, we will study the role of the gut microbiota in both TB infection and treatment, and its potential link with treatment duration. We will also discuss, the new concept of "Host Microbiota Directed-Therapies (HMDT)" as a potential adjunctive strategy to improve the treatment effectiveness, reduce its duration and or prevent relapses. These strategies include the use of probiotics, prebiotics, gut microbiota transfer, and other strategies. Application of this innovative solution could lead to HMDT as an adjunctive tool to shorten TB treatment, which will have enormous public health impacts for the End TB Strategy worldwide.

Strategies for the treatment of colorectal cancer caused by gut microbiota

Colorectal cancer (CRC), also named as colon and rectal or bowel cancer, is one of the leading neoplasia diagnosed in the world. Genetic sequencing studies of microorganisms from the intestinal microbiota of patients with CRC revealed that changes in its composition occur with the development of the disease, which can play a fundamental role in its development, being mediated by the production of metabolites and toxins that damage enterocytes. Some microorganisms are frequently reported in the literature as the main agents of this process, such as the bacteria Fusobacterium nucleatum, Escherichia coli and Bacteroides fragilis. Thus, understanding the mechanisms and function of each microorganism in CRC is essential for the development of treatment tools that focus on the gut microbiota. This review verifies current research aimed at evaluating the microorganisms present in the microbiota that can influence the development of CRC, as well as possible forms of treatment that can prevent the initiation and/or spread of this disease. Due to the incidence of CRC, alternatives have been launched considering factors beyond those already known in the disease development, such as diet, fecal microbiota transplantation, use of probiotics and antibiotics, which have been widely studied for this purpose. However, despite being promising, the studies that focus on the development of new therapeutic approaches targeting the microorganisms that cause CRC still need to be improved and better developed, involving new techniques to elucidate the effectiveness and safety of these new methods.

Probiotics Evaluation in Oncological Surgery: A Systematic Review of 36 Randomized Controlled Trials Assessing 21 Diverse Formulations

BACKGROUND

Objectives were to evaluate probiotics safety and efficacy in oncological surgery.

METHODS

Systematic review methodology guided by Cochrane, PRISMA, SWiM, and CIOMS. Protocol registered on PROSPERO (CRD42018086168).

RESULTS

36 RCTs (on 3305 participants) and 6 nonrandomized/observational studies were included, mainly on digestive system cancers. There was evidence of a beneficial effect on preventing infections, with 70% of RCTs' (21/30) direction of effect favoring probiotics. However, five RCTs (17%) favored controls for infections, including one trial with RR 1.57 (95% CI: 0.79, 3.12). One RCT that changed (balanced) its antibiotics protocol after enrolling some participants had mortality risk RR 3.55 (95% CI: 0.77, 16.47; 7/64 vs. 2/65 deaths). The RCT identified with the most promising results overall administered an oral formulation of Lactobacillus acidophilus LA-5 + Lactobacillus plantarum + Bifidobacterium lactis BB-12 + Saccharomyces boulardii. Methodological quality appraisals revealed an overall substantial risk-of-bias, with only five RCTs judged as low risk-of-bias.

CONCLUSIONS

This large evidence synthesis found encouraging results from most formulations, though this was contrasted by potential harms from a few others, thus validating the literature that "probiotics" are not homogeneous microorganisms. Given microbiome developments and infections morbidity, further high-quality research is warranted using those promising probiotics identified herein.

Probiotic/Synbiotic Treatment and Postoperative Complications in Colorectal Cancer Patients: Systematic Review and Meta-analysis of Randomized Controlled Trials

Colorectal cancer (CRC) is a leading cause of morbidity and mortality. Post-CRC resection complications and lower quality of life (QoL) are associated with a lower long-term survival. Perioperative administration of probiotics/synbiotics might lower prevalence of side effects and improve QoL and survival among CRC patients. Medline, Web of Science, Cochrane database, Embase, and clinical trials registries were searched in January 2020. Altogether, 16 randomized placebo-controlled probiotic/synbiotic clinical trials that included patients undergoing CRC surgery and investigated postoperative complications and QoL side effects were found. Meta-analyses using random-effects model were performed on data from 11 studies to calculate the effects of probiotics/synbiotics on common CRC resection postoperative side effects and complications. Perioperative probiotics/synbiotics administration was associated with lower infection incidence (odds ratio [OR] = 0.34, P < 0.001), lower diarrheal incidence (OR = 0.38, P < 0.001), faster return to normal gut function (mean difference [MD] −0.66 days, P < 0.001), shorter postoperative antibiotics use (MD −0.64 days, P < 0.001), lower incidence of septicemia (OR = 0.31, P < 0.001), and shorter length of hospital stay (MD −0.41 days, P = 0.110). The results support the hypothesis that short-term perioperative administration of probiotics/synbiotics, which are easy to administer, have few side-effects, and are low cost compared with alternatives, might help to alleviate gastrointestinal symptoms and postoperative complications among CRC patients.

Accomplishment of probiotics in human health pertaining to immunoregulation and disease control

It is a well-established fact that the microbiome harboring the human body plays a critical role in maintaining human health and can influence treatments against various ailments. Human microbiome-based research contemplates the possibility of selecting and administering specific commensal bacterial strains to modulate the gut microbiota to attain favorable outcomes to the therapies. Consumption of probiotics and probiotic-based dietary supplements as functional foods has been a promising treatment strategy against various diseases. Clinical studies demonstrate that probiotic administration alters gut microbiota composition and instigates immune modulation in the host. The benefits of probiotics are reported to be strain-specific and depend on the host's baseline immune competence. This review explores the role of probiotics in alleviating symptoms of allergy, cancer, cardio vascular (CV) diseases, diabetes mellitus (DM), bowel diseases (IBD and IBS), periodontal disease, diseases affecting liver and kidney, neuroinflammatory diseases, and viral infections. Also, it surveyed the broad spectrum bioactive compounds produced by probiotics and possible mechanisms that trigger the immune system.

Probiotics supplementation in patients with colorectal cancer: a systematic review of randomized controlled trials

CONTEXT

Colorectal cancer (CRC) is a leading cause of cancer deaths. Recently, much attention has been given to the microbiome and probiotics as preventive and therapeutic approaches to CRC and the mechanisms involved.

OBJECTIVES

To interpret the findings of randomized controlled trials (RCTs) of probiotics relative to patients with CRC and to outline challenges of and future directions for using probiotics in the management and prevention of CRC.

DATA SOURCES

Web of Science, PubMed, ProQuest, Wile, y and Scopus databases were searched systematically from January 17-20, 2020, in accordance with PRISMA guidelines.

STUDY SELECTION

Primacy RCTs that reported the effects of administration to patients with CRC of a probiotic vs a placebo were eligible to be included.

DATA EXTRACTION

The studies were screened and selected independently by 2 authors on the basis of prespecified inclusion and exclusion criteria. The data extraction and risk-of-bias assessment were also performed independently by 2 authors.

RESULTS

A total of 23 RCTs were eligible for inclusion. Probiotics supplementation in patients with CRC improved their quality of life, enhanced gut microbiota diversity, reduced postoperative infection complications, and inhibited pro-inflammatory cytokine production. The use of certain probiotics in patients with CRC also reduced the side effects of chemotherapy, improved the outcomes of surgery, shortened hospital stays, and decreased the risk of death. Bifidobacteria and Lactobacillus were the common probiotics used across all studies.

CONCLUSION

Probiotics have beneficial effects in patients with CRC regardless of the stage of cancer. There is an opportunity for probiotics to be used in mainstream health care as a therapy in the fight against CRC, especially in early stages; however, larger clinical trialsof selected or a cocktail of probiotics are needed to confirm the efficacy, dosage, and interactions with chemotherapeutics agents.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020166865.

The effect of pro/synbiotics on postoperative infections in colorectal cancer patients: A systematic review and meta-analysis

In 1954, the term "probiotics" was coined by Ferdinand Vergin in his article. Although there are many clinical reports on the use of pro/synbiotics and other microbial preparations to prevent postoperative infections and related complications in patients with Colorectal cancer (CRC), their effectiveness remains divided. Therefore, we collected relevant high-quality randomized controlled trial (RCT) studies and conducted systematic review and meta-analysis. We electronically searched online databases (the PubMed, EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Allied and Alternative Medieine (AMED), China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu) for literature published until December 2020. These reports were rigorously screened, and the data extracted, assessed for risk of bias (ROB), and subjected to meta-analysis and subgroup analysis. Postoperative infections were the main criteria for outcomes. Nineteen high-quality articles were included, involving 1975 patients. Compared with the control group, the pro/synbiotics group had reduced total postoperative infections ((odds ratio)OR = 0.28, 95% (confidence interval)CI: 0.20; 0.39, p < 0.0001), which included surgical site infections (SSI) (OR = 0.43, 95% CI: 0.31; 0.58, p < 0.0001) and non-surgical site infections (non-SSI) (OR = 0.28 95% CI: 0.20; 0.39, p < 0.0001).What is more, in aspects of inflammatory factors, intestinal dysbiosis, non-infectious complications, and systemic symptoms, the treatment group was better than the control group. However, there were no differences in perineal infections (OR = 0.45, 95% CI: 0.13; 1.50, p = 0.1933), celiac infections (OR = 0.54, 95% CI: 0.11; 2.66, p = 0.4471), or systemic inflammatory response syndrome (SIRS) incidence (OR = 0.63, 95% CI: 0.31; 1.30, p = 0.2139), etc. There were no differences in intervention (probiotics or synbiotics), strain type (multistrain or non-multistrain probiotics), and intervention time (administration preoperatively or pre-and-postoperatively). Pro/synbiotics can effectively prevent postoperative infections and related complications in patients with CRC. The strain type and intervention time did not affect the treatment effects.

The Roles of Lactobacillus Acidophilus and Pectin in Preventing Postoperative Sepsis and Intestinal Adaptation in a Rat Model of Short Bowel Syndrome

One of the primary causes of morbidity and mortality in those with short bowel syndrome (SBS) is sepsis, caused by bacterial translocation (BT). Since synbiotics can cease gut-related bacterial overgrowth, they may serve as a supportive dietary supplement-based strategy after gastrointestinal surgery. This study was conducted to determine the effects of Lactobacillus acidophilus and pectin on BT and gut adaptation after extensive small bowel resection in the rat. Forty rats were distributed in four groups. Group A suffered laparotomy, group B suffered gut transection and reanastomosis, SBS rats (group C) suffered 75% small gut resection, and finally, Group D suffered gut resection and treated with a synbiotic cocktail from day 7 before the surgery to day 14 after it. Intestinal structural changes and BT to mesenteric lymph nodes, liver, portal blood, and peripheral blood were detected on day 15 post-surgery. Treatment with a synbiotic cocktail led to a considerable reduction in bacterial translocation to liver and portal vein (degree II) compared with SBS untreated rats. Also, synbiotic administration significantly increased jejunum and ileum villus height and crypt depth, ileum villus width, and percentage of goblet cells in jejunum and ileum compared with SBS rats. In the rat model of short bowel syndrome, L. acidophilus, and pectin, as a potential synbiotic compound, could decrease the BT from the gut and improve the bowel adaptation.

The Intestinal Microbiota and Colorectal Cancer

The intestinal microbiota, composed of a large population of microorganisms, is often considered a “forgotten organ” in human health and diseases. Increasing evidence indicates that dysbiosis of the intestinal microbiota is closely related to colorectal cancer (CRC). The roles for intestinal microorganisms that initiated and facilitated the CRC process are becoming increasingly clear. Hypothesis models have been proposed to illustrate the complex relationship between the intestinal microbiota and CRC. Recent studies have identified Streptococcus bovis, enterotoxigenic Bacteroides fragilis, Fusobacterium nucleatum, Enterococcus faecalis, Escherichia coli, and Peptostreptococcus anaerobius as CRC candidate pathogens. In this review, we summarized the mechanisms involved in microbiota-related colorectal carcinogenesis, including inflammation, pathogenic bacteria, and their virulence factors, genotoxins, oxidative stress, bacterial metabolites, and biofilm. We also described the clinical values of intestinal microbiota and novel strategies for preventing and treating CRC.

The Inhibitory Effect of Gut Microbiota and Its Metabolites on Colorectal Cancer

Colorectal cancer (CRC) is regarded as one of the most common and deadly forms of cancer. Gut microbiota is vital to retain and promote several functions of intestinal. Although previous researches have shown that some gut microbiota have the abilities to inhibit tumorigenesis and prevent cancer from progressing, they have not yet clearly identified associative mechanisms. This review not only concentrates on the antitumor effects of metabolites produced by gut microbiota, for example, SCFA, ferrichrome, urolithins, equol and conjugated linoleic acids, but also the molecules which constituted the bacterial cell wall have the antitumor effect in the host, including lipopolysaccharide, lipoteichoic acid, β-glucans and peptidoglycan. The aim of our review is to develop a possible therapeutic method, which use the products of gut microbiota metabolism or gut microbiota constituents to help treat or prevent colorectal cancer.

Therapeutic methods of gut microbiota modification in colorectal cancer management - fecal microbiota transplantation, prebiotics, probiotics, and synbiotics

The link between gut microbiota and the development of colorectal cancer has been investigated. An imbalance in the gut microbiota promotes the progress of colorectal carcinogenesis via multiple mechanisms, including inflammation, activation of carcinogens, and tumorigenic pathways as well as damaging host DNA. Several therapeutic methods are available with which to alter the composition and the activity of gut microbiota, such as administration of prebiotics, probiotics, and synbiotics; these can confer various benefits for colorectal cancer patients. Nowadays, fecal microbiota transplantation is the most modern way of modulating the gut microbiota. Even though data regarding fecal microbiota transplantation in colorectal cancer patients are still rather limited, it has been approved as a clinical method of treatment-recurrent Clostridium difficile infection, which may also occur in these patients. The major benefits of fecal microbiota transplantation include modulation of immunotherapy efficacy, amelioration of bile acid metabolism, and restoration of intestinal microbial diversity. Nonetheless, more studies are needed to assess the long-term effects of fecal microbiota transplantation. In this review, the impact of gut microbiota on the efficiency of anti-cancer therapy and colorectal cancer patients' overall survival is also discussed.

The role of pro-, pre- and symbiotics in cancer: A systematic review

WHAT IS KNOWN AND OBJECTIVE

Cancer is one of the most important causes of morbidity and mortality worldwide. Pro-, pre- and symbiotics can modulate host metabolism and gut microbiota and potentially help prevent cancer and modulate the adverse effects (AEs) of treatments. Numerous studies on this role for pro-, pre- and symbiotics have reported inconsistent results. The purpose of this review was to examine current scientific evidence from randomized controlled trials (RCTs) on the effects of pro-, pre- and symbiotics on the incidence of complications and AEs, especially diarrhoea, in cancer management.

METHODS

A systematic literature search was implemented in MEDLINE using the MeSH terms "probiotics", "prebiotics", "symbiotics" and "neoplasms", according to PRISMA guidelines. Reference lists were also handsearched to identify additional eligible RCTs. Three reviewers independently assessed the eligibility of each RCT. Of 714 retrieved abstracts, 22 articles with 2287 participants were included in the analysis.

RESULTS AND DISCUSSION

The most studied bacteriotherapies were probiotics and symbiotics, in 10 and 7 studies, respectively. Both Lactobacillus and Bifidobacterium strains were used in 18 studies, while Lactobacillus and Bifidobacterium strains were individually used in 9 and 2 studies, respectively. Diarrhoea incidence rates were 3.2%-39.1% in intervention groups and 6.7%-60.9% in control groups, while infection incidence rates were 11.1%-22.7% in intervention groups and 17.3%-28.7% in control groups.

WHAT IS NEW AND CONCLUSIONS

Pro-, pre- and symbiotics may potentially be efficacious in reducing complications associated with chemotherapy, radiotherapy and surgery in patients with cancer.

An Overview of Gut Microbiota and Colon Diseases with a Focus on Adenomatous Colon Polyps

It is known and accepted that the gut microbiota composition of an organism has an impact on its health. Many studies deal with this topic, the majority discussing gastrointestinal health. Adenomatous colon polyps have a high prevalence as colon cancer precursors, but in many cases, they are hard to diagnose in their early stages. Gut microbiota composition correlated with the presence of adenomatous colon polyps may be a noninvasive and efficient tool for diagnosis with a high impact on human wellbeing and favorable health care costs. This review is meant to analyze the gut microbiota correlated with the presence of adenomatous colon polyps as the first step for early diagnosis, prophylaxis, and treatment.

The role of gut microbiota in cancer treatment: friend or foe?

The gut microbiota has been implicated in cancer and shown to modulate anticancer drug efficacy. Altered gut microbiota is associated with resistance to chemo drugs or immune checkpoint inhibitors (ICIs), whereas supplementation of distinct bacterial species restores responses to the anticancer drugs. Accumulating evidence has revealed the potential of modulating the gut microbiota to enhance the efficacy of anticancer drugs. Regardless of the valuable findings by preclinical models and clinical data of patients with cancer, a more thorough understanding of the interactions of the microbiota with cancer therapy helps researchers identify novel strategy for cancer prevention, stratify patients for more effective treatment and reduce treatment complication. In this review, we discuss the scientific evidence on the role of gut microbiota in cancer treatment, and highlight the latest knowledge and technologies leveraged to target specific bacteria that contribute to tumourigenesis. First, we provide an overview of the role of the gut microbiota in cancer, establishing the links between bacteria, inflammation and cancer treatment. Second, we highlight the mechanisms used by distinct bacterial species to modulate cancer growth, immune responses, as well as the efficacy of chemotherapeutic drugs and ICIs. Third, we demonstrate various approaches to modulate the gut microbiota and their potential in translational research. Finally, we discuss the limitations of current microbiome research in the context of cancer treatment, ongoing efforts to overcome these challenges and future perspectives.

Perioperative Probiotics or Synbiotics in Adults Undergoing Elective Abdominal Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To define the impact of perioperative treatment with probiotics or synbiotics on postoperative outcome in patients undergoing abdominal surgery.

BACKGROUND

Postoperative surgical infection accounts for a third of all cases of sepsis, and is a leading cause of morbidity and mortality. Probiotics, prebiotics, and synbiotics (preparations that combine probiotics and prebiotics) are nutritional adjuncts that are emerging as novel therapeutic modalities for preventing surgical infections. However, current evidence on their effects is conflicting.

METHODS

A comprehensive search of the PubMed, Embase, and WHO Global Index Medicus electronic databases was performed to identify randomized controlled trials evaluating probiotics or synbiotics in adult patients undergoing elective colorectal, upper gastrointestinal, transplant, or hepatopancreaticobiliary surgery. Bibliographies of studies were also searched. The primary outcome measure was incidence of postoperative infectious complications. Secondary outcomes included incidence of noninfectious complications, mortality, length of hospital stay, and any treatment-related adverse events. Quantitative pooling of the data was undertaken using a random effects model.

RESULTS

A total of 34 randomized controlled trials reporting on 2723 participants were included. In the intervention arm, 1354 patients received prebiotic or symbiotic preparations, whereas 1369 patients in the control arm received placebo or standard care. Perioperative administration of either probiotics or synbiotics significantly reduced the risk of infectious complications following abdominal surgery [relative risk (RR) 0.56; 95% confidence interval (CI) 0.46-0.69; P < 0.00001, n = 2723, I = 42%]. Synbiotics showed greater effect on postoperative infections compared with probiotics alone (synbiotics RR: 0.46; 95% CI: 0.33-0.66; P < 0.0001, n = 1399, I = 53% probiotics RR: 0.65; 95% CI: 0.53-0.80; P < 0.0001, n = 1324, I = 18%). Synbiotics but not probiotics also led to a reduction in total length of stay (synbiotics weighted mean difference: -3.89; 95% CI: -6.60 to -1.18 days; P = 0.005, n = 535, I = 91% probiotics RR: -0.65; 95% CI: -2.03-0.72; P = 0.35, n = 294, I = 65%). There were no significant differences in mortality (RR: 0.98; 95% CI: 0.54-1.80; P = 0.96, n = 1729, I = 0%) or noninfectious complications between the intervention and control groups. The preparations were well tolerated with no significant adverse events reported.

CONCLUSIONS

Probiotics and synbiotics are safe and effective nutritional adjuncts in reducing postoperative infective complications in elective abdominal surgery. The treatment effects are greatest with synbiotics.

Gut Microbiota and Cancer: From Pathogenesis to Therapy

Cancer is a multifactorial pathology and it represents the second leading cause of death worldwide. In the recent years, numerous studies highlighted the dual role of the gut microbiota in preserving host’s health. Gut resident bacteria are able to produce a number of metabolites and bioproducts necessary to protect host’s and gut’s homeostasis. Conversely, several microbiota subpopulations may expand during pathological dysbiosis and therefore produce high levels of toxins capable, in turn, to trigger both inflammation and tumorigenesis. Importantly, gut microbiota can interact with the host either modulating directly the gut epithelium or the immune system. Numerous gut populating bacteria, called probiotics, have been identified as protective against the genesis of tumors. Given their capability of preserving gut homeostasis, probiotics are currently tested to help to fight dysbiosis in cancer patients subjected to chemotherapy and radiotherapy. Most recently, three independent studies show that specific gut resident species may potentiate the positive outcome of anti-cancer immunotherapy. The highly significant studies, uncovering the tight association between gut microbiota and tumorigenesis, as well as gut microbiota and anti-cancer therapy, are here described. The role of the Lactobacillus rhamnosus GG (LGG), as the most studied probiotic model in cancer, is also reported. Overall, according to the findings here summarized, novel strategies integrating probiotics, such as LGG, with conventional anti-cancer therapies are strongly encouraged.

A Systematic Review, Meta-Analysis, and Meta-Regression Evaluating the Efficacy and Mechanisms of Action of Probiotics and Synbiotics in the Prevention of Surgical Site Infections and Surgery-Related Complications

Intestinal microbiota play an important role in the pathogenesis of surgical site infections (SSIs) and other surgery-related complications (SRCs). Probiotics and synbiotics were found to lower the risk of surgical infections and other surgery-related adverse events. We systematically reviewed the approach based on the administration of probiotics and synbiotics to diminish SSIs/SRCs rates in patients undergoing various surgical treatments and to determine the mechanisms responsible for their effectiveness. A systematic literature search in PubMed/MEDLINE/Cochrane Central Register of Controlled Trials from the inception of databases to June 2018 for trials in patients undergoing surgery supplemented with pre/pro/synbiotics and randomized to the intervention versus placebo/no treatment and reporting on primarily: (i) putative mechanisms of probiotic/symbiotic action, and secondarily (ii) SSIs and SRCs outcomes. Random-effect model meta-analysis and meta-regression analysis of outcomes was done. Thirty-five trials comprising 3028 adult patients were included; interventions were probiotics (n = 16) and synbiotics (n = 19 trials). We found that C-reactive protein (CRP) and Interleukin-6 (IL-6) were significantly decreased (SMD: -0.40, 95% CI [-0.79, -0.02], p = 0.041; SMD: -0.41, 95% CI [-0.70, -0.02], p = 0.006, respectively) while concentration of acetic, butyric, and propionic acids were elevated in patients supplemented with probiotics (SMD: 1.78, 95% CI [0.80, 2.76], p = 0.0004; SMD: 0.67, 95% CI [0.37, -0.97], p = 0.00001; SMD: 0.46, 95% CI [0.18, 0.73], p = 0.001, respectively). Meta-analysis confirmed that pro- and synbiotics supplementation was associated with significant reduction in the incidence of SRCs including abdominal distention, diarrhea, pneumonia, sepsis, surgery site infection (including superficial incisional), and urinary tract infection, as well as the duration of antibiotic therapy, duration of postoperative pyrexia, time of fluid introduction, solid diet, and duration of hospital stay (p < 0.05). Probiotics and synbiotics administration counteract SSIs/SRCs via modulating gut-immune response and production of short chain fatty acids.