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

Preventive effect of probiotics on infections following colorectal cancer surgery: An umbrella meta-analysis

BACKGROUND

Postoperative infections remain a significant source of morbidity among patients undergoing colorectal cancer (CRC) surgery. While probiotics have been proposed as a potential strategy to mitigate the risk of these infections, contemporary meta-analyses have produced conflicting findings.

AIM

To synthesize the available evidence regarding the prophylactic efficacy of probiotics in preventing infections following CRC surgery.

METHODS

A comprehensive search of PubMed and Scopus was conducted to identify relevant meta-analyses published up to February 2024. To assess the efficacy of probiotics on outcomes, relative risks (RR) and their corresponding 95%CI were pooled using a random effects model.

RESULTS

This comprehensive umbrella meta-analysis integrated eleven meta-analyses encompassing 11518 participants who fulfilled the inclusion criteria. Probiotics administration resulted in a statistically significant reduction in the incidence of total infections (RR: 0.40, 95%CI: 0.31-0.51; moderate certainty), surgical site infections (RR: 0.56, 95%CI: 0.49-0.63; high certainty), pneumonia (RR: 0.38, 95%CI: 0.30-0.48; high certainty), urinary tract infections (RR: 0.44, 95%CI: 0.31-0.61; moderate certainty), bacteremia (RR: 0.41, 95%CI: 0.30-0.56; high certainty), and sepsis (RR: 0.35, 95%CI: 0.25-0.44; high certainty). However, probiotics did not significantly affect intra-abdominal, central line, or peritoneal infections.

CONCLUSION

Probiotics have demonstrated potential in mitigating postoperative infectious complications among patients undergoing CRC surgery.

Targeting the gut microbiota: a new strategy for colorectal cancer treatment

BACKGROUND

How to reduce the high incidence rate and mortality of colorectal cancer (CRC) effectively is the focus of current research. Endoscopic treatment of early-stage CRC and colorectal adenomas (CAC) has a high success rate, but although several treatments are available for advanced CRC, such as surgery, radiotherapy, chemotherapy, and immunotherapy, the 5-year survival rate remains low. In view of the high incidence rate and mortality of CRC, early rational drug prevention for high-risk groups and exploration of alternative treatment modalities are particularly warranted. Gut microbiota is the target of and interacts with probiotics, prebiotics, aspirin, metformin, and various Chinese herbal medicines (CHMs) for the prevention of CRC. In addition, the anti-cancer mechanisms of probiotics differ widely among bacterial strains, and both bacterial strains and their derivatives and metabolites have been found to have anti-cancer effects. Gut microbiota plays a significant role in early drug prevention of CRC and treatment of CRC in its middle and late stages, targeting gut microbiota may be a new strategy for colorectal cancer treatment.

The effect of probiotics supplementation on cancer-treatment complications: a critical umbrella review of interventional meta-analyses

Cancer-related complications pose significant challenges in the management and treatment of patients with malignancies. Several meta-analyses have indicated improving effects of probiotics on cancer complications, while some studies have reported contentious findings. The purpose of the present study was to evaluate the efficacy of probiotics in addressing cancer complications, including diarrhea, mucositis, and infections, following chemotherapy, radiotherapy, and surgery. Relevant studies were searched in the PubMed, Scopus, Embase and Web of Science databases and Google Scholar up to September 2023. All meta-analyses addressing the effects of probiotics on all cancer treatments-induced complications including infection, diarrhea and oral mucositis were included. The pooled results were calculated using a random-effects model. Analyses of subgroups, sensitivity and publication bias were also conducted. The results revealed that the probiotics supplementation was effective on reduction of total cancer complications (OR:0.53; 95% CI: 0.44, 0.62, p < 0.001; I2=79.0%, p < 0.001), total infection rate (OR:0.47; 95%CI: 0.41, 0.52, p < 0.001; I2= 48.8%, p < 0.001); diarrhea (OR:0.50; 95%CI: 0.44, 0.57, p < 0.001; I2=44.4%, p = 0.023) and severe diarrhea (OR: 0.4; 95%CI: 0.27, 0.56, p < 0.001; I2=31.3%, p = 0.178), oral mucositis (OR: 0.76; 95%CI: 0.58, 0.94, p < 0.001; I2=95.5%, p < 0.001) and severe oral mucositis (OR:0.65, 95%CI: 0.58, 0.72 p < 0.001; I2=22.1%, p = 0.274). Multi strain probiotic (OR:0.49; 95%CI: 0.32, 0.65, p < 0.001; I2=90.7%, p < 0.001) were more efficacious than single strain (OR:0.73; 95%CI: 0.66, 0.81, p < 0.001; I2=0.00%, p = 0.786). The findings of the current umbrella meta-analysis provide strong evidence that probiotic supplementation can reduce cancer complications.

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.

The Role of Probiotics in Inflammation Associated with Major Surgery: A Narrative Review

Background: Gut microbiota is well-known for its ability to maintain intestinal homeostasis. However, the disruption of this homeostasis, known as dysbiosis, leads to multiple consequences, including local and systemic inflammation. Surgery-induced inflammation is a major concern for patients, as it leads to many infectious and non-infectious complications. Objective: The purpose of this review was to explore the role of probiotics and symbiotics in surgery-induced inflammation and to determine if their use is effective in combatting inflammation and its complications Methods and Materials: A literature search was conducted, and articles published only in English, until December 2022 were included. The results are reported in the form of a narrative review. Results: The perioperative use of probiotics and/or symbiotics results in lower risk of infectious complications, including reduced rates of surgical site infections, respiratory and urinary tract infections, shorter hospital stays, and fewer days of antibiotic administration. It also contributes to reducing non-infectious complications, as it mitigates systemic and local inflammation via maintenance of the intestinal barrier, improves intestinal mobility, and is associated with lower rates of postoperative pain and anastomotic leak. Conclusions: Restoring gut microbiota after disruptions caused by surgery may accelerate local healing processes, attenuate systemic inflammation, and may thus prove beneficial to certain populations.

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.

A Four-Probiotic Regime to Reduce Surgical Site Infections in Multi-Trauma Patients

Investigations that focused on the protective role of probiotics against Surgical Site Infections (SSI) in multiple-trauma (MT) patients are generally few, probably due to the complexity of the concept of trauma. We aimed to assess the efficacy of a four-probiotic regime to reduce the incidence of SSI in MT patients, with a brain injury included. MT patients, being intubated and expected to require mechanical ventilation for >10 days, were randomly allocated into placebo (n = 50) or probiotic treatment (n = 53) comprising Lactobacillus acidophilus LA-5 (1.75 × 109 cfu), Lactiplantibacillus plantarum UBLP-40 (0.5 × 109 cfu), Bifidobacterium animalis subsp. lactis BB-12 (1.75 × 109 cfu), and Saccharomycesboulardii Unique-28 (1.5 × 109 cfu) in sachets. All patients received two sachets of placebo or probiotics twice/day for 15 days and were followed-up for 30 days. The operations were classified as neurosurgical, thoracostomies, laparotomies, orthopedics, and others; then, the SSI and the isolated pathogen were registered. A total of 23 (46.0%) and 13 (24.5%) infectious insults in 89 (50 placebo patients) and 88 (53 probiotics-treated) operations (p = 0.022) were recorded, the majority of them relating to osteosynthesis—17 and 8, respectively. The most commonly identified pathogens were Staphylococcus aureus and Acinetobacter baumannii. Our results support published evidence that the prophylactic administration of probiotics in MT patients exerts a positive effect on the incidence of SSI.

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.