Probiotics for the prevention or treatment of chemotherapy- or radiotherapy-related diarrhoea in people with cancer

Anticancer Potential of Postbiotic Derived from Lactobacillus brevis and Lactobacillus casei: In vitro Analysis of Breast Cancer Cell Line

Breast cancer has emerged as the most widespread and dangerous type of malignancy among women worldwide. Postbiotics have recently emerged as a promising novel adjunct in breast cancer therapy, due to their immunomodulatory effects and the potential to mitigate the adverse effects of conventional treatments. This study aims to investigate the therapeutic effects of postbiotics derived from Lactobacillus brevis (CSF2) and Lactobacillus casei (CFS5), specifically examining their ability to inhibit cell proliferation and induce apoptosis in MCF-7 breast cancer cells. In the current study, the anticancer activity of the cell-free supernatant of L. brevis and L. casei was investigated against MCF-7 cells using MTT assay, flow cytometry, and qRT-PCR technique. Both bacteria showed a high potential for the induction of cell death in MCF-7 cells. However, CFS2 cytotoxicity was significantly higher than CFS5. Flow cytometry results showed significant induction of early apoptosis in cells treated with both CFS2 and CFS5 within 48 h. The induction was notably higher in cells treated with CFS2 compared to CFS5. Overall, CFS2 therapy resulted in a greater increase in BAX and CASP9 gene expression, as well as an elevated BAX/BCL2 ratio within 48 h. These findings indicate that the CFS2 treatment showed a higher level of apoptotic activity than the CFS5 treatment. High biocompatibility was demonstrated following treatment with CFS2 and CFS5. These CFSs may serve as adjunctive medications for suppressing the proliferation of cancer cells. The results of the current study highlight the potential of postbiotics in cancer treatment and suggest that supernatants may serve as effective agents for suppressing cancer cell growth and viability.

Applications of Proteomics in Probiotics Having Anticancer and Chemopreventive Properties

Proteomics has grown in importance in molecular sciences because it gives vital information on protein identification, expression levels, and alteration. Cancer is one of the world's major causes of death and is the major focus of much research. Cancer risk is determined by hereditary variables as well as the body's immunological condition. Probiotics have increasing medical importance due to their therapeutic influence on the human body in the prevention and treatment of numerous chronic illnesses, including cancer, with no adverse effects. Several anticancer, anti-inflammatory, and chemopreventive probiotics are studied using different proteomic approaches like two-dimensional gel electrophoresis, liquid chromatography-mass spectrometry, and matrix-assisted laser desorption/ionization mass spectrometry. To gain relevant information about probiotic characteristics, data from the proteomic analysis are evaluated and processed using bioinformatics pipelines. Proteomic studies showed the significance of different proteomic approaches in characterization, comparing strains, and determination of oxidative stress of different probiotics. Moreover, proteomic approaches identified different proteins that are involved in glucose metabolism and the formation of cell walls or cell membranes, and the differences in the expression of critical enzymes in the HIF-1 signaling pathway, starch, and sucrose metabolism, and other critical metabolic pathways.

The effect of an exopolysaccharide probiotic molecule from Bacillus subtilis on breast cancer cells

Introduction

Many well-known risk factors for breast cancer are associated with dysbiosis (an aberrant microbiome). However, how bacterial products modulate cancer are poorly understood. In this study, we investigated the effect of an exopolysaccharide (EPS) produced by the commensal bacterium Bacillus subtilis on breast cancer phenotypes. Although B. subtilis is commonly included in probiotic preparations and its EPS protects against inflammatory diseases, it was virtually unknown whether B. subtilis-derived EPS affects cancer.

Methods

This work investigated effects of EPS on phenotypes of breast cancer cells as a cancer model. The phenotypes included proliferation, mammosphere formation, cell migration, and tumor growth in two immune compromised mouse models. RNA sequencing was performed on RNA from four breast cancer cells treated with PBS or EPS. IKKβ or STAT1 signaling was assessed using pharmacologic or RNAi-mediated knock down approaches.

Results

Short-term treatment with EPS inhibited proliferation of certain breast cancer cells (T47D, MDA-MB-468, HCC1428, MDA-MB-453) while having little effect on others (MCF-7, MDA-MB-231, BT549, ZR-75-30). EPS induced G1/G0 cell cycle arrest of T47D cells while increasing apoptosis of MDA-MB-468 cells. EPS also enhanced aggressive phenotypes in T47D cells including cell migration and cancer stem cell survival. Long-term treatment with EPS (months) led to resistance in vitro and promoted tumor growth in immunocompromised mice. RNA-sequence analysis showed that EPS increased expression of pro-inflammatory pathways including STAT1 and NF-κB. IKKβ and/or STAT1 signaling was necessary for EPS to modulate phenotypes of EPS sensitive breast cancer cells.

Discussion

These results demonstrate a multifaceted role for an EPS molecule secreted by the probiotic bacterium B. subtilis on breast cancer cell phenotypes. These results warrant future studies in immune competent mice and different cancer models to fully understand potential benefits and/or side effects of long-term use of probiotics.

Role of the gut microbiota in anticancer therapy: from molecular mechanisms to clinical applications

In the past period, due to the rapid development of next-generation sequencing technology, accumulating evidence has clarified the complex role of the human microbiota in the development of cancer and the therapeutic response. More importantly, available evidence seems to indicate that modulating the composition of the gut microbiota to improve the efficacy of anti-cancer drugs may be feasible. However, intricate complexities exist, and a deep and comprehensive understanding of how the human microbiota interacts with cancer is critical to realize its full potential in cancer treatment. The purpose of this review is to summarize the initial clues on molecular mechanisms regarding the mutual effects between the gut microbiota and cancer development, and to highlight the relationship between gut microbes and the efficacy of immunotherapy, chemotherapy, radiation therapy and cancer surgery, which may provide insights into the formulation of individualized therapeutic strategies for cancer management. In addition, the current and emerging microbial interventions for cancer therapy as well as their clinical applications are summarized. Although many challenges remain for now, the great importance and full potential of the gut microbiota cannot be overstated for the development of individualized anti-cancer strategies, and it is necessary to explore a holistic approach that incorporates microbial modulation therapy in cancer.

Orally Administered Probiotics in the Prevention of Chemotherapy (± Radiotherapy)-Induced Gastrointestinal Toxicity: A Systematic Review With Meta-Analysis of Randomized Trials

BACKGROUND

Chemoradiotherapy-induced gastrointestinal toxicity may lead to a significant impairment of the oncological patient's quality of life, as well as to reduced adherence to the treatment, which may have a negative impact on survival and mortality rates.

OBJECTIVE

The aim of this review was to investigate whether oral probiotic administration prevents chemotherapy (± radiotherapy)-induced gastrointestinal toxicity, particularly diarrhea.

METHODS

We searched the MEDLINE, Web of Science, and SCOPUS databases for randomized controlled trials in English published between 1990 and 2020. We conducted statistical data analyses expressing the treatment effect size as a risk ratio (RR) together with a 95% confidence interval (CI). Implications are based on trials rated as having a low risk of bias (RoB).

RESULTS

We included 8 trials (n = 697 participants), from which 3 studies rated as low RoB contained primary endpoint data; the risk of developing grade 3/4 diarrhea in patients receiving probiotics was reduced by 78% compared to the control group (RR = 0.22 [95% CI 0.05-1.08]; P = .06; n = 114 participants). Probiotics showed preventive effects in patients treated with chemotherapy alone (RR = 0.34 [0.12-0.94]; P = .04, n = 121 participants) and in patients with colorectal cancer (RR = 0.56 [0.34-0.92]; P = .02; n = 208 participants). The reduction in the incidence of overall diarrhea was not significant.

CONCLUSIONS

Probiotics failed to prove a preventive effect of statistical significance against the development of severe and overall diarrhea in cancer patients treated with chemotherapy (± radiotherapy). However, we cannot rule out that the effects of probiotics are clinically relevant, especially in certain subgroups of patients. This needs to be clarified in further well-performed studies.

Cancer pharmacomicrobiomics: targeting microbiota to optimise cancer therapy outcomes

Despite the promising advances in novel cancer therapy such as immune checkpoint inhibitors (ICIs), limitations including therapeutic resistance and toxicity remain. In recent years, the relationship between gut microbiota and cancer has been extensively studied. Accumulating evidence reveals the role of microbiota in defining cancer therapeutic efficacy and toxicity. Unlike host genetics, microbiota can be easily modified via multiple strategies, including faecal microbiota transplantation (FMT), probiotics and antibiotics. Preclinical studies have identified the mechanisms on how microbes influence cancer treatment outcomes. Clinical trials have also demonstrated the potential of microbiota modulation in cancer treatments. Herein, we review the mechanistic insights of gut microbial interactions with chemotherapy and ICIs, particularly focusing on the interplay between gut bacteria and the pharmacokinetics (eg, metabolism, enzymatic degradation) or pharmacodynamics (eg, immunomodulation) of cancer treatment. The translational potential of basic findings in clinical settings is then explored, including using microbes as predictive biomarkers and microbial modulation by antibiotics, probiotics, prebiotics, dietary modulations and FMT. We further discuss the current limitations of gut microbiota modulation in patients with cancer and suggest essential directions for future study. In the era of personalised medicine, it is crucial to understand the microbiota and its interactions with cancer. Manipulating the gut microbiota to augment cancer therapeutic responses can provide new insights into cancer treatment.

Influence of Probiotics in Prevention and Treatment of Patients Who Undergo Chemotherapy or/and Radiotherapy and Suffer from Mucositis, Diarrhoea, Constipation, Nausea and Vomiting

The administration of probiotics to patients treated with chemo- and/or radiotherapy is assumed to be beneficial. The aim of this study was to evaluate the effects of probiotic intake on the severity of selected gastrointestinal side effects of chemotherapy and radiotherapy. The searched databases included PubMed, Web of Science, and Scopus from which twenty-one studies were included. Most of them concerned diarrhoea, however, two of the studies examined constipation, another two nausea and vomiting, and eight of the included studies regarded mucositis. The total number of patients equalled 2621. The time of the conducted therapy, the administered species, neoplasm pathology, and adjuvant therapy varied. The outcome was assessed by gathering information about the statistical significance of the improvements. An enhancement was observed in thirteen studies, where probiotics had a significant impact on each of the included chemo- and/or radiotherapy side effects. However, the heterogeneity of the assessed data makes it impossible to state a firm conclusion.

The effect of probiotic and synbiotic consumption on the most prevalent chemotherapy-related complications: A systematic review of current literature

BACKGROUND

To date, many investigations have employed pro-/synbiotic to examine their effects on chemotherapy-related side effects; nevertheless, their findings are inconclusive. To address this issue, we carried out a systematic review to explore the effect of pro-/synbiotic consumption on chemotherapy-related side effects, including nausea, vomiting, mucositis, diarrhea, and constipation in adults using randomized controlled trials (RCTs).

METHODS

The electronic databases, including PubMed, Scopus, and ISI Web of Sciences, were searched systematically from the earliest available date to March 2021 to identify eligible studies. The quality of the enrolled studies was done based on the Cochrane Collaboration Risk of Bias tool.

RESULTS

A total of 10 studies involving 788 individuals were included in the current systematic review with a sample size ranging from 25 to 200, and the mean age ranged from 51.04 to 66.91 years. The findings of this study imply that probiotics consumption may be more effective in terms of mucositis compared to other complications.

CONCLUSION

Further good-quality RCTs with better methodology are called to determine whether and how pro-/synbiotics can prevent or treat chemotherapy-induced side effects. The current systematic review findings may help investigators for future studies regarding the selection study population and probiotic strains.

Oral Administration of Probiotics Reduces Chemotherapy-Induced Diarrhea and Oral Mucositis: A Systematic Review and Meta-Analysis

Background

Chemotherapy generally causes serious diarrhea and oral mucositis in cancer patients, and subsequently affects treatment. Oral administration of probiotics provides a therapeutic choice to address these limitations. This study aims to conduct a systematic review and meta-analysis on the efficacy of oral probiotic use in the management of the chemotherapy-induced adverse reactions, and to summarize the mechanisms underlying the action.

Methods

We searched PubMed, Embase, ClinicalTrials.gov, and Web of Science from the start of the study to its completion on Dec. 31, 2021. Risk of bias was assessed using Cochrane Collaboration's Tool. Statistical analysis of the acquired data was performed via the RevMan and the Stata Statistical Software. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO registration number: CRD42020220650).

Results

Twelve randomized controlled trials including 1,013 patients were recruited and analyzed via the standard procedure of meta-analysis. In contrast to the control group, orally taking probiotics significantly decreased the risk of chemotherapy-induced diarrhea (≥ 1 grade) (RR = 0.70; 95% Cl: 0.56, 0.88; P = 0.002) and oral mucositis (≥ 1 grade) (RR: 0.84; 95% Cl: 0.78, 0.91; P < 0.00001) at all grades. Further analysis found that severe diarrhea (≥ 2 grades) (RR: 0.50; 95% Cl: 0.32, 0.78; P = 0.002) and severe oral mucositis also significantly declined (≥ 3 grades) (RR: 0.66; 95% Cl: 0.55, 0.79; P < 0.00001) after oral probiotic use. Interestingly, the beneficial effects of probiotics displayed statistically significant only in Asian patients. Importantly, the more species of bacteria they took, the lower the incidences of the adverse reactions occurred. We used Egger's test P value to confirm that there is no publication bias.

Conclusions

This meta-analysis demonstrated that orally administrated probiotics has a potential to decrease chemotherapy-induced diarrhea and oral mucositis incidences. However, the efficacy of oral probiotic use against the adverse reactions needs to be further verified through more clinical trials, and the species and number of probiotics have to be optimized and standardized prior to clinical applications.

Systematic Review Registration

https://www.crd.york.ac.uk, identifier: 220650.

Gut microbiota-drug interactions in cancer pharmacotherapies: implications for efficacy and adverse effects

INTRODUCTION

The gut microbiota is involved in host physiology and health. Reciprocal microbiota-drug interactions are increasingly recognized as underlying some individual differences in therapy response and adverse events. Cancer pharmacotherapies are characterized by a high degree of interpatient variability in efficacy and side effect profile and recently, the microbiota has emerged as a factor that may underlie these differences.

AREAS COVERED

The effects of cancer pharmacotherapy on microbiota composition and function are reviewed with consideration of the relationship between baseline microbiota composition, microbiota modification, antibiotics exposure and cancer therapy efficacy. We assess the evidence implicating the microbiota in cancer therapy-related adverse events including impaired gut function, cognition and pain perception. Finally, potential mechanisms underlying microbiota-cancer drug interactions are described, including direct microbial metabolism, and microbial modulation of liver metabolism and immune function. This review focused on preclinical and clinical studies conducted in the last 5 years.

EXPERT OPINION

Preclinical and clinical research supports a role for baseline microbiota in cancer therapy efficacy, with emerging evidence that the microbiota modification may assist in side effect management. Future efforts should focus on exploiting this knowledge towards the development of microbiota-targeted therapies. Finally, a focus on specific drug-microbiota-cancer interactions is warranted.

The impact of pelvic radiotherapy on the gut microbiome and its role in radiation-induced diarrhoea: a systematic review

Pelvic radiotherapy is the key treatment for pelvic malignancies, usually including pelvic primary tumour lesions and lymphatic drainage areas in the pelvic region. Therefore, the intestinal tract in the radiation field is inevitably damaged, a phenomenon clinically referred to as radiation enteritis, and diarrhoea is the most common clinical symptom of radiation enteritis. Therefore, it is necessary to study the mechanism of radiation-induced diarrhoea. It has been found that the gut microbiome plays an important role in the development of diarrhoea in response to pelvic radiotherapy, and the species and distribution of intestinal microbiota are significantly altered in patients after pelvic radiotherapy. In this study, we searched for articles indexed in the Cochrane Library, Web of Science, EMBASE and PubMed databases in English and CNKI, Wanfang data and SINOMED in Chinese from their inception dates through 13 March 2020 to collect studies on the gut microbiome in pelvic radiotherapy patients. Eventually, we included eight studies: one study report on prostatic carcinoma, five studies on gynaecological carcinoma and two papers on pelvic carcinomas. All studies were designed as self-controlled studies, except for one that compared toxicity to nontoxicity. The results from all the studies showed that the diversity of intestinal flora decreased during and after pelvic radiotherapy, and the diversity of intestinal flora decreased significantly in patients with diarrhoea after radiotherapy. Five studies observed that the community composition of the gut microbiota changed at the phylum, order or genus level before, during, and after pelvic radiotherapy at different time points. In addition, the composition of the gut microbiota before radiotherapy was different between patients with postradiotherapy diarrhoea and those without diarrhoea in five studies. However, relevant studies have not reached consistent results regarding the changes in microbiota composition. Changes in the intestinal flora induced by pelvic radiotherapy and their relationship between changes in intestinal flora and the occurrence of radiation-induced diarrhoea (RID) are discussed in this study, providing a theoretical basis for the causes of RID after pelvic radiotherapy.

The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

The therapy of gastrointestinal carcinomas includes surgery, chemo- or immunotherapy, and radiation with diverse complications such as surgical-site infection and enteritis. In recent years, the microbiome’s influence on different diseases and complications has been studied in more detail using methods such as next-generation sequencing. Due to the relatively simple collectivisation, the gut microbiome is the best-studied so far. While certain bacteria are sometimes associated with one particular complication, it is often just the loss of alpha diversity linked together. Among others, a strong influence of Fusobacterium nucleatum on the effectiveness of chemotherapies is demonstrated. External factors such as diet or specific medications can also predispose to dysbiosis and lead to complications. In addition, there are attempts to treat developed dysbiosis, such as faecal microbiota transplant or probiotics. In the future, the underlying microbiome should be investigated in more detail for a better understanding of the precipitating factors of a complication with specific therapeutic options.

Microbiome as a Target for Cancer Therapy

Recently, the microbiome has been gaining traction as a major player regulating various functions that correlate with many pathological conditions, including cancer. The central gut microbiota population has the capability to regulate normal inflammatory, immune, and metabolic functions, and disturbance in the balance of the normal microbiota population can subsequently induce pathological responses that closely relate with the mechanistic development and progression of cancer in various forms and sites. As a disease with major socioeconomic burden partly due to its current therapeutic options, modulating the imbalanced gut microbiota represents a novel option not only as an adjuvant therapy to relieve cancer treatment–related symptoms but also to influence cancer progression itself. In this review, we will discuss how the microbiome, specifically the gut microbiota, could affect cancer pathogenesis and what the effect of gut microbiota–targeting treatment options have on the many aspects of cancer pathologies based on the knowledge of recent years.

The role of dietary supplements, including biotics, glutamine, polyunsaturated fatty acids and polyphenols, in reducing gastrointestinal side effects in patients undergoing pelvic radiotherapy: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Pelvic radiotherapy (RT) often results in gastrointestinal toxicity and clinical trials have demonstrated a potential benefit of dietary supplements in alleviating acute effects. However, no prophylactic agents have been approved to date for relief of gastrointestinal side-effects caused by pelvic radiation. In this systematic review, we evaluated the efficacy of dietary supplements in preventing or alleviating symptoms of gastrointestinal toxicity in patients undergoing pelvic RT.

MATERIALS AND METHODS

CENTRAL, MEDLINE, EMBASE, and ClinicalTrials.gov were searched up to June 2020 for randomised controlled trials. Interventions included four supplement categories: biotics, glutamine, poly-unsaturated fatty acids and polyphenols. Efficacy was determined with reference to outcomes based on symptoms of acute gastrointestinal toxicity, including diarrhoea, nausea, vomiting, flatulence/bloating, bowel movement frequency, tenesmus and rectal bleeding.

RESULTS

Twenty-three randomised controlled trials (1919 patients) were identified in this review. Compared with placebo, probiotics (RR = 0.71; 95% CI: 0.52 to 0.99), synbiotics (RR = 0.45; 95% CI: 0.28 to 0.73) and polyphenols (RR = 0.30; 95% CI: 0.13 to 0.70) were significantly associated with a lower risk of diarrhoea. Biotic supplements also reduced the risk of moderate to severe diarrhoea (RR = 0.49; 95% CI: 0.36 to 0.67) and the need for anti-diarrhoeal medication (RR = 0.64; 95%CI: 0.44 to 0.92). In contrast, glutamine had no effect on acute symptoms (RR = 1.05; 95% CI: 0.86 to 1.29). There was a non-significant trend for reduction in nausea and mean bowel movements per day using dietary supplements.

CONCLUSIONS

Biotic supplements, especially probiotics and synbiotics, reduce acute symptoms of gastrointestinal toxicity in patients undergoing pelvic radiotherapy.

The Effect of Perioperative Administration of Probiotics on Colorectal Cancer Surgery Outcomes

The perioperative care of colorectal cancer (CRC) patients includes antibiotics. Although antibiotics do provide a certain protection against infections, they do not eliminate them completely, and they do carry risks of microbial resistance and disruption of the microbiome. Probiotics can maintain the microbiome’s balance postoperatively by maintaining intestinal mucosal integrity and reducing bacterial translocation (BT). This review aims to assess the role of probiotics in the perioperative management of CRC patients. The outcomes were categorised into: postoperative infectious and non-infectious complications, BT rate analysis, and intestinal permeability assessment. Fifteen randomised controlled trials (RCTs) were included. There was a trend towards lower rates of postoperative infectious and non-infectious complications with probiotics versus placebo. Probiotics reduced BT, maintained intestinal mucosal permeability, and provided a better balance of beneficial to pathogenic microorganisms. Heterogeneity among RCTs was high. Factors that influence the effect of probiotics include the species used, using a combination vs. single species, the duration of administration, and the location of the bowel resection. Although this review provided evidence for how probiotics possibly operate and reported notable evidence that probiotics can lower rates of infections, heterogeneity was observed. In order to corroborate the findings, future RCTs should keep the aforementioned factors constant.

Heat-inactivated Lactobacillus plantarum nF1 promotes intestinal health in Loperamide-induced constipation rats

Constipation is a common condition that affects individuals of all ages, and prolonged constipation needs to be prevented to avoid potential complications and reduce the additional stress on individuals with pre-medical conditions. This study aimed to evaluate the effects of heat-inactivated Lactobacillus plantarum (HLp-nF1) on loperamide-induced constipation in rats. Constipation-induced male rats were treated orally with low to high doses of HLp-nF1 and an anti-constipation medication Dulcolax for five weeks. Study has 8 groups, control group; loperamide-treated group; Dulcolax-treated group; treatment with 3.2 × 10¹⁰, 8 × 10¹⁰ and 1.6 × 10¹¹, cells/mL HLp-nF1; Loperamide + Dulcolax treated group. HLp-nF1 treated rats showed improvements in fecal pellet number, weight, water content, intestinal transit length, and contractility compared to the constipation-induced rats. Also, an increase in the intestine mucosal layer thickness and the number of mucin-producing crypt epithelial cells were observed in HLp-nF1-treated groups. Further, the levels of inflammatory cytokines levels were significantly downregulated by treatment with HLp-nF1 and Dulcolax. Notably, the metagenomics sequencing analysis demonstrated a similar genus pattern to the pre-preparation group and control with HLp-nF1 treatment. In conclusion, the administration of >3.2 × 10¹⁰ cells/mL HLp-nF1 has a positive impact on the constipated rats overall health.

Lactobacillus Kefiri LKF01 (Kefibios®) for Prevention of Diarrhoea in Cancer Patients Treated with Chemotherapy: A Prospective Study

Diarrhoea is one of the main side effects that cancer patients face. The literature showsthat the incidence of chemotherapy (CT)-induced diarrhoea (grade 3–4) in treated patients is in the range of 10–20%, particularly after 5-fluorouracil (5-FU) bolus or some combination therapies of irinotecan and fluoropyrimidines. The aim of the present study was to evaluate the clinical effectiveness of Lactobacillus kefiri LKF01 (Kefibios^®) in the prevention or treatment of CT-related diarrhoea in the cancer population. We conducted a prospective observational study. Patients enrolled were adults treated for at least four months with 5-FU-based CT. Kefibios^® was administered to patients every day. The primary outcome was the evaluation of the incidence of grade 3–4 CT-induced diarrhoea. We included 76 patients in the final analysis. A 6.6% incidence of high-grade diarrhoea was found in the evaluated population (4.7% of patients treated with 5-FU-based therapy and 8.5% of patients treated with capecitabine-based CT). The overall incidence of high-grade diarrhoea observed was higher in the 1st and 2nd cycles (3.9%), with a subsequent sharp reduction from the 3rd cycle (1.3%) and negativisation from the 5th cycle. Lactobacillus kefiri LKF01 (Kefibios^®) is safe and effective in preventing severe diarrhoea in cancer patients receiving 5-FU or capecitabine-based treatment.

Gastrointestinal side effects of cancer treatments

Cancer survival rates have significantly improved over the last number of years due to advancements in cancer therapies. Unfortunately this has come at a cost. Therapeutic side effects are feared complications of therapy that may result in decreased quality of life and early cessation of the therapy, which can have knock-on effects on outcomes. This article outlines the main gastrointestinal side effects seen with radiation therapy, chemotherapy and immunotherapy, and discusses appropriate investigation and management.

Milk fermented by Lactobacillus casei CRL431 administered as an immune adjuvant in models of breast cancer and metastasis under chemotherapy

Chemotherapy is the most common treatment for breast cancer and its metastasis; however, it affects the patients' quality of life. Previously, it was demonstrated that milk fermented by Lactobacillus casei CRL431 (probiotic fermented milk (PFM)) exerted benefits against breast cancer metastasis by modulating the immune response in a mouse model. The aim of this work was to evaluate PFM administration on the side effects of capecitabine and on its anti-tumour/anti-metastatic effects. In vitro, 4T1 breast cancer cells were treated with capecitabine in the presence of immune cells' conditioned media from mice administered with PFM. Cell viability was evaluated by MTT assay. In vivo, BALB/c mice (healthy, bearing breast cancer or with potential metastasis) were treated or not with capecitabine and administered with PFM. Blood cell counts, intestinal damages, lung histology and serum cytokines were evaluated. Results showed that capecitabine's toxicity on 4T1 cells was improved by the immune cells from mice that received PFM when the lower dose of capecitabine was evaluated. PFM reduced capecitabine side effects in all the mouse models and decreased intestinal mucositis and mortality. PFM administration to mice under chemotherapy maintained the anti-cancer/anti-metastasis effect of capecitabine with similar or decreased values for serum IL-10 and TNF-α and decreased IL-6, a cytokine related to poor prognosis in advanced cancer patients. In addition, PFM by itself reduced metastasis without side effects and improved the host's immune response. PFM has a potential to be administered as an immune adjuvant in patients under chemotherapy without affecting the treatment. KEY POINTS: • Milk fermented by L. casei CRL431 (PFM) diminished capecitabine side effects. • Capecitabine's toxicity on 4T1 cells was improved by the PFM-stimulated immune cells. • PFM maintained anti-cancer/anti-metastasis effect of capecitabine in mouse models. Graphical abstract.

Dietary restriction increases protective gut bacteria to rescue lethal methotrexate-induced intestinal toxicity

Methotrexate (MTX) is a typical chemotherapeutic drug that is widely used in the treatment of various malignant diseases as well as autoimmune diseases, with gastrointestinal toxicity being its most prominent complication which could have a significant effect on the prognosis of patients. Yet effective ways to alleviate such complications remains to be explored. Here we show that 30% dietary restriction (DR) for 2 weeks dramatically increased the survival rate of 2-month-old female mice after lethal-dose MTX exposure. DR significantly reduced intestinal inflammation, preserved the number of basal crypt PCNA-positive cells, and protected the function of intestinal stem cells (ISCs) after MTX treatment. Furthermore, ablating intestinal microbiota by broad-spectrum antibiotics completely eliminated the protective effect achieved by DR. 16S rRNA gene deep-sequencing analysis revealed that short-term DR significantly increased the Lactobacillus genus, with Lactobacillus rhamnosus GG gavage partially mimicking the rescue effect of DR on the intestines of ad libitum fed mice exposed to lethal-dose MTX. Together, the current study reveals that DR could be a highly effective way to alleviate the lethal injury in the intestine after high-dose MTX treatment, which is functionally mediated by increasing the protective intestinal microbiota taxa in mice. Keywords: Dietary restriction, Methotrexate, Gut microbiota, Intestinal stem cells, intestinal toxicity.

Gut microbiome, big data and machine learning to promote precision medicine for cancer

The gut microbiome has been implicated in cancer in several ways, as specific microbial signatures are known to promote cancer development and influence safety, tolerability and efficacy of therapies. The 'omics' technologies used for microbiome analysis continuously evolve and, although much of the research is still at an early stage, large-scale datasets of ever increasing size and complexity are being produced. However, there are varying levels of difficulty in realizing the full potential of these new tools, which limit our ability to critically analyse much of the available data. In this Perspective, we provide a brief overview on the role of gut microbiome in cancer and focus on the need, role and limitations of a machine learning-driven approach to analyse large amounts of complex health-care information in the era of big data. We also discuss the potential application of microbiome-based big data aimed at promoting precision medicine in cancer.

Effects of 10.6-μm laser moxibustion and electroacupuncture at ST36 in a 5-Fu-induced diarrhea rat model

OBJECTIVE

The aim of this study was to investigate the effect of 10.6-μm laser moxibustion and electroacupuncture in 5-fluorouracil (5-Fu)-induced diarrhea model rats.

METHODS

Forty-eight Sprague Dawley rats were randomly divided into 4 groups: a normal group, model group, 10.6-μm laser moxibustion (LM) group, and electroacupuncture (EA) group. Diarrhea was induced by 5-Fu (50 mg/kg) injection in 36 rats; the LM and EA groups received treatment at acupoint ST36 (Zusanli) on hind limbs once a day for 6 days.

RESULTS

5-Fu injection caused body weight decline and diarrhea. From the 5th to 7th day, the LM group showed higher body weights than the model group (P < 0.05). On the 6th day, diarrhea score of the LM group was better than that of the EA group (P < 0.05). Both scores of the LM group and EA group were better than that of model group (P < 0.05). The LM group and EA group both had better intestine pathological scores and lower endotoxin (ET) and diamine oxide (DAO) activity than the model group (P < 0.01). The LM group got better pathological scores than the EA group (P < 0.01). Ultramicroscopic structures of the model group showed severe damage while the LM group and EA group remained good in their small intestines. The model group had obviously decreased occludin protein in intestine tissues than the control group (P < 0.01), while occludin expressions in the LM group and EA group were both obviously increased compared with the model group (P < 0.01).

CONCLUSION

LM and EA treatment on ST36 could alleviate damage to intestinal barrier function and alleviate diarrhea caused by 5-Fu.

Microbiota modification in hematology: still at the bench or ready for the bedside?

Growing evidence suggests that human microbiota likely influence diverse processes including hematopoiesis, chemotherapy metabolism, and efficacy, as well as overall survival in patients with hematologic malignancies and other cancers. Both host genetic susceptibility and host-microbiota interactions may impact cancer risk and response to treatment; however, microbiota have the potential to be uniquely modifiable and accessible targets for treatment. Here, we focus on strategies to modify microbiota composition and function in patients with cancer. First, we evaluate the use of fecal microbiota transplant to restore microbial equilibrium following perturbation by antibiotics and chemotherapy, and as a treatment of complications of hematopoietic stem cell transplantation (HSCT), such as graft-versus-host disease and colonization with multidrug-resistant organisms. We then address the potential use of both probiotics and dietary prebiotic compounds in targeted modulation of the microbiota intended to improve outcomes in hematologic diseases. With each type of therapy, we highlight the role that abnormal, or dysbiotic, microbiota play in disease, treatment efficacy, and toxicity and evaluate their potential promise as emerging strategies for microbiota manipulation in patients with hematologic malignancies and in those undergoing HSCT.

Faecal microbiota transplantation for the treatment of diarrhoea induced by tyrosine-kinase inhibitors in patients with metastatic renal cell carcinoma

Diarrhoea is one of the most burdensome and common adverse events of chemotherapeutics, and has no standardised therapy to date. Increasing evidence suggests that the gut microbiome can influence the development of chemotherapy-induced diarrhoea. Here we report findings from a randomised clinical trial of faecal microbiota transplantation (FMT) to treat diarrhoea induced by tyrosine kinase inhibitors (TKI) in patients with metastatic renal cell carcinoma (ClinicalTrials.gov number: NCT04040712). The primary outcome is the resolution of diarrhoea four weeks after the end of treatments. Twenty patients are randomised to receive FMT from healthy donors or placebo FMT (vehicle only). Donor FMT is more effective than placebo FMT in treating TKI-induced diarrhoea, and a successful engraftment is observed in subjects receiving donor faeces. No serious adverse events are observed in both treatment arms. The trial meets pre-specified endpoints. Our findings suggest that the therapeutic manipulation of gut microbiota may become a promising treatment option to manage TKI-dependent diarrhoea.

The Butyrogenic and Lactic Bacteria of the Gut Microbiota Determine the Outcome of Allogenic Hematopoietic Cell Transplant

Graft versus host disease (GVHD) is a post-transplant pathology in which donor-derived T cells present in the Peyer's patches target the cell-surface alloantigens of the recipient, causing host tissue damages. Therefore, the GVHD has long been considered only a purely immunological process whose prevention requires an immunosuppressive treatment. However, since the early 2010s, the impact of gut microbiota on GVHD has received increased attention. Both a surprising fall in gut microbiota diversity and a shift toward Enterobacteriaceae were described in this disease. Recently, unexpected results were reported that further link GVHD with changes in bacterial composition in the gut and disruption of intestinal epithelial tight junctions leading to abnormal intestinal barrier permeability. Patients receiving allogenic hematopoietic stem cell transplant (allo-HCT) as treatment of hematologic malignancies showed a decrease of the overall diversity of the gut microbiota that affects Clostridia and Blautia spp. and a predominance of lactic acid bacteria (LAB) of the Enterococcus genus, in particular the lactose auxotroph Enterococcus faecium. The reduced microbiota diversity (likely including Actinobacteria, such as Bifidobacterium adolescentis that cross feed butyrogenic bacteria) deprives the butyrogenic bacteria (such as Roseburia intestinalis or Eubacterium) of their capacity to metabolize acetate to butyrate. Indeed, administration of butyrate protects against the GVHD. Here, we review the data highlighting the possible link between GVHD and lactase defect, accumulation of lactose in the gut lumen, reduction of Reg3 antimicrobial peptides, narrower enzyme equipment of bacteria that predominate post-transplant, proliferation of En. faecium that use lactose as metabolic fuels, induction of innate and adaptive immune response against these bacteria which maintains an inflammatory process, elevated expression of myosin light chain kinase 210 (MLCK210) and subsequent disruption of intestinal barrier, and translocation of microbial products (lactate) or transmigration of LAB within the liver. The analysis of data from the literature confirms that the gut microbiota plays a major role in the GVHD. Moreover, the most recent publications uncover that the LAB, butyrogenic bacteria and bacterial cross feeding were the missing pieces in the puzzle. This opens new bacteria-based strategies in the treatment of GVHD.

Gut Microbiota, Antibiotic Therapy and Antimicrobial Resistance: A Narrative Review

Antimicrobial resistance is a major concern. Epidemiological studies have demonstrated direct relationships between antibiotic consumption and emergence/dissemination of resistant strains. Within the last decade, authors confounded spectrum activity and ecological effects and did not take into account several other factors playing important roles, such as impact on anaerobic flora, biliary elimination and sub-inhibitory concentration. The ecological impact of antibiotics on the gut microbiota by direct or indirect mechanisms reflects the breaking of the resistance barrier to colonization. To limit the impact of antibiotic therapy on gut microbiota, consideration of the spectrum of activity and route of elimination must be integrated into the decision. Various strategies to prevent (antimicrobial stewardship, action on residual antibiotics at colonic level) or cure dysbiosis (prebiotic, probiotic and fecal microbiota transplantation) have been introduced or are currently being developed.

Microbiota modification in hematology: still at the bench or ready for the bedside?

Growing evidence suggests that human microbiota likely influence diverse processes including hematopoiesis, chemotherapy metabolism, and efficacy, as well as overall survival in patients with hematologic malignancies and other cancers. Both host genetic susceptibility and host-microbiota interactions may impact cancer risk and response to treatment; however, microbiota have the potential to be uniquely modifiable and accessible targets for treatment. Here, we focus on strategies to modify microbiota composition and function in patients with cancer. First, we evaluate the use of fecal microbiota transplant to restore microbial equilibrium following perturbation by antibiotics and chemotherapy, and as a treatment of complications of hematopoietic stem cell transplantation (HSCT), such as graft-versus-host disease and colonization with multidrug-resistant organisms. We then address the potential use of both probiotics and dietary prebiotic compounds in targeted modulation of the microbiota intended to improve outcomes in hematologic diseases. With each type of therapy, we highlight the role that abnormal, or dysbiotic, microbiota play in disease, treatment efficacy, and toxicity and evaluate their potential promise as emerging strategies for microbiota manipulation in patients with hematologic malignancies and in those undergoing HSCT.

The Effects of Probiotic Supplementation on the Incidence of Diarrhea in Cancer Patients Receiving Radiation Therapy: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

The protective effects of probiotic supplementation against radiation-induced diarrhea (RID) have been reported in previous systematic reviews; however so far, only non-conclusive results have been obtained. The objective of this study was to systematically update and evaluate the available evidence for probiotic supplementation. The protocol of this systematic review has been registered (CRD42018106059) with the International Prospective Register of Systematic Reviews (PROSPERO). The primary efficacy outcome was the incidence of RID. Secondary outcomes were the incidence of watery stool, soft stool, and antidiarrheal medication use. There were eight trials, and a total of 1116 participants were included in the primary analysis. Compared with placebo, probiotics were associated with a lower risk of RID [risk ratio (RR) = 0.62, 95% CI = 0.46, 0.83]. A requisite heterogeneity-adjusted trial sequential analysis indicated conclusive evidence for this beneficial effect. No statistically significant reduction in RID (RR = 0.52, 95% CI = 0.14, 1.91) was observed on subgroup analysis in patients receiving both radiation therapy and chemotherapy. However, those patients receiving only radiation therapy (RT) demonstrated significant benefit (RR = 0.61, 95% CI = 0.48, 0.78). There was a significant difference in the antidiarrheal medication use (RR = 0.54, 95% CI = 0.35, 0.84) observed with the use of probiotics. However, no significant difference was observed for the incidence of soft and watery stool. The use of probiotics is beneficial in preventing RID in patients receiving RT.

Cepharanthine Hydrochloride Improves Cisplatin Chemotherapy and Enhances Immunity by Regulating Intestinal Microbes in Mice

Chemotherapy is one of the major treatment strategies for esophageal squamous cell carcinoma (ESCC). Unfortunately, most chemotherapeutic drugs have significant impacts on the intestinal microbes, resulting in side effects and reduced efficiency. Therefore, new strategies capable of overcoming these disadvantages of current chemotherapies are in urgent need. The natural product, Cepharanthine hydrochloride (CEH), is known for its anticancer and immunoregulatory properties. By sequencing the V4 region of 16S rDNA, we characterized the microbes of tumor-bearing mice treated with different chemotherapy strategies, including with CEH. We found that CEH improved the therapeutic effect of CDDP by manipulating the gut microbiota. Through metagenomic analyses of the microbes community, we identified a severe compositional and functional imbalance in the gut microbes community after CDDP treatment. However, CEH improved the effect of chemotherapy and ameliorated CDDP treatment-induced imbalance in the intestinal microbes. Mechanically, CEH activated TLR4 and MYD88 innate immune signaling, which is advantageous for the activation of the host's innate immunity to exert a balanced intestinal environment as well as to trigger a better chemotherapeutic response to esophageal cancer. In addition, TNFR death receptors were activated to induce apoptosis. In summary, our findings suggest that chemotherapy of CDDP combined with CEH increased the effect of chemotherapy and reduced the side effects on the microbes and intestinal mucosal immunity. We believe that these findings provide a theoretical basis for new clinical treatment strategies.

Therapeutic bacteria to combat cancer; current advances, challenges, and opportunities

Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria-assisted tumor-targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.

Management of sepsis in neutropenic cancer patients: 2018 guidelines from the Infectious Diseases Working Party (AGIHO) and Intensive Care Working Party (iCHOP) of the German Society of Hematology and Medical Oncology (DGHO)

Sepsis and septic shock are major causes of mortality during chemotherapy-induced neutropenia for malignancies requiring urgent treatment. Thus, awareness of the presenting characteristics and prompt management is most important. Improved management of sepsis during neutropenia may reduce the mortality of cancer therapies. However, optimal management may differ between neutropenic and non-neutropenic patients. The aim of the current guideline is to give evidence-based recommendations for hematologists, oncologists, and intensive care physicians on how to manage adult patients with neutropenia and sepsis.