A randomised trial of probiotics to reduce severity of physiological and microbial disorders induced by partial gastrectomy for patients with gastric cancer

Effects of probiotics on bowel function restoration following ileostomy closure in rectal cancer patients: a randomized controlled trial

AIM

The aim was to determine the efficacy of probiotics in restoring bowel function following ileostomy reversal in patients with rectal cancer.

METHOD

This was a pilot, randomized, double-blind, placebo-controlled trial. The probiotic used in this study, Lactobacillus plantarum CJLP243, was derived from kimchi. Patients were randomly allocated to a probiotic or placebo group and medication was taken once daily from preoperative day 1 to day 21. Primary outcomes were the Memorial Sloan Kettering Cancer Centre Bowel Function Index (MSKCC BFI) instrument and the low anterior resection syndrome score. The secondary outcomes were the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and CR29 questionnaire responses.

RESULTS

Forty patients were enrolled, and 36 patients (probiotics, n = 17; placebo, n = 19) completed the primary outcomes. Total scores for the MSKCC questionnaire (56.2 ± 12.0 vs. 55.0 ± 10.7, P = 0.356) and low anterior resection syndrome scores (33.3 ± 7.6 vs. 36.0 ± 5.3, P = 0.257) were not significantly different between the probiotic and placebo groups, respectively. In the MSKCC BFI, the postoperative dietary scale score at week 1 was significantly higher in the probiotic group (13.1 ± 3.8 vs. 9.0 ± 3.0, P < 0.001). There were no other significant differences between the two groups for any other questionnaire scores.

CONCLUSION

There were no significant effects supporting the use of a probiotic for improved bowel function in patients following ileostomy reversal. Nevertheless, the administration of probiotics showed trends toward improvements in some subscale bowel function measures, suggesting further studies may be warranted.

Role of the Gastric Microbiome in Gastric Cancer: From Carcinogenesis to Treatment

The development of sequencing technology has expanded our knowledge of the human gastric microbiome, which is now known to play a critical role in the maintenance of homeostasis, while alterations in microbial community composition can promote the development of gastric diseases. Recently, carcinogenic effects of gastric microbiome have received increased attention. Gastric cancer (GC) is one of the most common malignancies worldwide with a high mortality rate. Helicobacter pylori is a well-recognized risk factor for GC. More than half of the global population is infected with H. pylori, which can modulate the acidity of the stomach to alter the gastric microbiome profile, leading to H. pylori-associated diseases. Moreover, there is increasing evidence that bacteria other than H. pylori and their metabolites also contribute to gastric carcinogenesis. Therefore, clarifying the contribution of the gastric microbiome to the development and progression of GC can lead to improvements in prevention, diagnosis, and treatment. In this review, we discuss the current state of knowledge regarding changes in the microbial composition of the stomach caused by H. pylori infection, the carcinogenic effects of H. pylori and non-H. pylori bacteria in GC, as well as the potential therapeutic role of gastric microbiome in H. pylori infection and GC.

Gastric Cancer Microbiome

Identifying a microbiome pattern in gastric cancer (GC) is hugely debatable due to the variation resulting from the diversity of the studied populations, clinical scenarios, and metagenomic approach. H. pylori remains the main microorganism impacting gastric carcinogenesis and seems necessary for the initial steps of the process. Nevertheless, an additional non-H. pylori microbiome pattern is also described, mainly at the final steps of the carcinogenesis. Unfortunately, most of the presented results are not reproducible, and there are no consensual candidates to share the H. pylori protagonists. Limitations to reach a consistent interpretation of metagenomic data include contamination along every step of the process, which might cause relevant misinterpretations. In addition, the functional consequences of an altered microbiome might be addressed. Aiming to minimize methodological bias and limitations due to small sample size and the lack of standardization of bioinformatics assessment and interpretation, we carried out a comprehensive analysis of the publicly available metagenomic data from various conditions relevant to gastric carcinogenesis. Mainly, instead of just analyzing the results of each available publication, a new approach was launched, allowing the comprehensive analysis of the total sample amount, aiming to produce a reliable interpretation due to using a significant number of samples, from different origins, in a standard protocol. Among the main results, Helicobacter and Prevotella figured in the "top 6" genera of every group. Helicobacter was the first one in chronic gastritis (CG), gastric cancer (GC), and adjacent (ADJ) groups, while Prevotella was the leader among healthy control (HC) samples. Groups of bacteria are differently abundant in each clinical situation, and bacterial metabolic pathways also diverge along the carcinogenesis cascade. This information may support future microbiome interventions aiming to face the carcinogenesis process and/or reduce GC risk.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs. Video Abstract.

Revealing the Disturbed Vaginal Micobiota Caused by Cervical Cancer Using High-Throughput Sequencing Technology

Cervical cancer is the fourth most prevalent cancer type among all malignancies, so it is of great significance to find its actual pathogenesis mechanisms. In the present study, 90 women were enrolled, and high-throughput sequencing technology was firstly used to analyze the vaginal microbiota of healthy women (C group), cervical intraepithelial neoplasia patients (CIN group) and cervical cancer patients (CER group). Our results indicates that compared with C group, a higher HPV infection rate as well as increased Neutrophil ratio and tumor marker squamous cell carcinoma antigen (SCCA) were obtained, and a decrease in Lymphocyte ratio and Hemoglobin were also present. In addition, the cervical cancer showed a strong association with reduced probiotics Lactobacillus, increased pathogens Prevotella spp., Sneathia spp. and Pseudomonas spp. These results prove that the immunological changes generated by the cervical cancer and the vaginal microbiota can interact with each other. However, further study investigating the key bacteria for cervical cancer is still needed, which can be a clue for the diagnosis or treatment of cervical cancer.

Xiaoyaosan slows cancer progression and ameliorates gut dysbiosis in mice with chronic restraint stress and colorectal cancer xenografts

Depression is a risk factor for colorectal cancer (CRC) progression. Xiaoyaosan (XYS) is a traditional Chinese medicine prescription for treating depression. Our present study aimed to investigate the effect of XYS on chronic restraint stress (CRS) in mice with CRC xenografts and explore its underlying mechanisms. XYS treatment for 21 consecutive days successfully reduced the tumour volume and tumour weight in mice and prolonged the overall survival time. In addition, the intestinal permeability in the XYS group was significantly improved after administration. The 16S rRNA high-throughput sequencing method was used to sequence stool samples to check the structure and changes of gut bacteria. XYS mainly regulated the abundance of Bacteroides, Lactobacillus, Desulfovibrio and Rikenellaceae. Taken together, these results provide direct strong evidence that XYS effectively improves the progression of CRC in CRS-handled mice, and its efficacy is associated with the modulation of gut dysbiosis. The application of XYS can be a novel therapeutic strategy for CRC patients with depression.

Intestinal microbiota regulates anti-tumor effect of disulfiram combined with Cu2+ in a mice model

Background

A growing number of studies show that intestinal microbiota affect the therapeutic effects of antineoplastic agents. Disulfiram (tetraethylthiuram disulfide, DSF) is an old alcohol‐aversion drug that has been shown to be effective against various types of cancers in preclinical studies, while few studies are carried out to explore its mechanism.

Methods

A mice model of melanoma xenograft was generated and treated with antibiotics (Abx), disulfiram/copper (DSF/Cu²⁺), Abx + DSF/Cu²⁺, and the tumor volume and survival curve were observed. Hematoxylin‐eosin (HE) staining and western blotting (WB) were used to observe the protein changes related to cell morphology, inflammation, and apoptosis in tumor tissues. Quantitative real time polymerase chain reaction (qPCR) was used to detect the expression of pro‐inflammatory cytokines in tumors. High‐throughput sequencing was used to detect the effects of Abx and DSF/Cu²⁺ on intestinal microbiota.

Results

The DSF/Cu²⁺ and Abx + DSF/Cu²⁺ markedly delayed tumor progression and prolonged mice survival, of which the combination of Abx and DSF/Cu²⁺ possessed the best anti‐tumor effect. Abx + DSF/Cu²⁺ significantly reduced the pro‐inflammatory cytokines Interleukin‐1β (IL‐1β), IL‐6 and tumor necrosis factor α (TNF‐α) in tumors, and significantly reduced the expression of phosphorylated‐protein kinase B (p‐AKT)/protein kinase B (AKT), toll‐like receptors 4 (TLR‐4), and phosphorylated‐ nuclear factor kappa‐B (p‐NFκB)/NFκB in tumors. Moreover our high‐throughput sequencing first indicated that the sound anti‐cancer effect of Abx + DSF/Cu²⁺ had a strong connection with the increased abundance of intestinal beneficial bacteria Akkermansia, as well as the reduced abundance of opportunistic pathogenic bacteria Campylobacterales, Helicobacteraceae, and Coriobacteriaceae.

Conclusions

The disturbed intestinal microbiota (increased abundance of opportunistic pathogens Campylobacterales, Helicobacteraceae, and Coriobacteriaceae) and the over‐activated TLR4/NF‐κB signaling pathway in tumor tissues deteriorated the cancer development, and the using of antibiotics is benefit to enhance the therapeutic effect of DSF on tumors via inhibiting the growth of opportunistic pathogenic bacteria.

Antibiotics for cancer treatment: A double-edged sword

Various antibiotics have been used in the treatment of cancers, via their anti-proliferative, pro-apoptotic and anti-epithelial-mesenchymal-transition (EMT) capabilities. However, increasingly studies have indicated that antibiotics may also induce cancer generation by disrupting intestinal microbiota, which further promotes chronic inflammation, alters normal tissue metabolism, leads to genotoxicity and weakens the immune response to bacterial malnutrition, thereby adversely impacting cancer treatment. Despite the advent of high-throughput sequencing technology in recent years, the potential adverse effects of antibiotics on cancer treatments via causing microbial imbalance has been largely ignored. In this review, we discuss the double-edged sword of antibiotics in the field of cancer treatments, explore their potential mechanisms and provide solutions to reduce the potential negative effects of antibiotics.

The effect of acupuncture on tumor growth and gut microbiota in mice inoculated with osteosarcoma cells

BACKGROUND

Cancer is a complex systemic disease. As a key component of traditional Chinese medicine, acupuncture is a clinically proven medical treatment for many diseases, and it also has preventative effects as it balances the body, allowing it to self-regulate. For cancer patients, acupuncture is widely used as complementary therapy to boost the immune system and reduce the side effects of radiotherapy and chemotherapy. However, few studies have determined how acupuncture against cancer, especially in regulating the intestinal flora of the tumor-burdened mice.

METHODS

We treated osteosarcoma tumor-burdened mice by using needling on different acupoints and acupoints combination, thereafter determined the effects of acupuncture on tumor growth by using imaging technology in vitro. In addition, intestinal bacteria were analyzed for further understanding the holistic and systemic treatment effects of acupuncture in osteosarcoma tumor-burdened mice.

RESULTS

Acupuncture treatment can delay tumor growth and changes of intestinal bacteria in osteosarcoma tumor-burdened mice. In detail, the loss of body weight and the development of tumor volume of mice have been postposed by needling specific acupoints. In addition, acupuncture treatment has delayed the changes of the relative abundance of Bacteroidetes, Firmicutes and Candidatus Saccharibacteria at the phylum level. Moreover, the relative abundance of many bacteria (e.g., Catabacter, Acetatifactor and Aestuariispira) has been regulated by using acupuncture treatment, and the trend of structural changes of these bacteria at the genus level has also been postposed compared to that of the tumor-burdened mice model group.

CONCLUSION

Our results suggest that acupuncture may provide a systemic treatment for cancer. Our findings encourage new and extensive research into the effects of acupuncture on changes of the intestinal microbiome associated with the development of cancer.

Oral Probiotics Alleviate Intestinal Dysbacteriosis for People Receiving Bowel Preparation

Background: Bowel preparation is necessary for successful colonoscopy, while it can seriously affect intestinal microbial composition and damage the intestinal mucosal barriers in humans.

Methods: To figure out whether probiotics can sustain intestinal homeostasis and guard people's health, the probiotic drug of Bifidobacterium Tetragenous viable Bacteria Tablets (P group, n = 16) or placebo (C group, n = 16) was used for volunteers receiving bowel preparation, and high-throughput sequencing method was applied to monitor their intestinal microbial changes.

Results: The present results suggested that bowel preparation obviously reduced the intestinal microbial diversity, while taking probiotics significantly restored it to normal level. In addition, probiotics sharply reduced the abundance of pathogenic Proteobacteria, and obviously lowered the ratio of Firmicutes/Bacteroidetes compared with control group at phylum level (P < 0.05). And probiotics markedly decreased the abundance of pathogenic Acinetobacter and Streptococcus, while greatly enriched the relative abundance of beneficial bacteria Bacteroides, Roseburia, Faecalibacterium, and Parabacteroides at genus level (P < 0.05).

Conclusion: Probiotic drugs, e.g., Bifidobacterium Tetragenous viable Bacteria Tablets, can be used to restore intestinal dysbacteriosis caused by bowel preparation, and reduce side effects during colonoscopy.

Novel cancer therapy targeting microbiome

In the human intestinal tract, there are more than 100 trillion symbiotic bacteria, which form the gut microbiota. Approximately 70% of the human immune system is in the intestinal tract, which prevents infection by pathogenic bacteria. When the intestinal microbiota is disturbed, causing dysbiosis, it can lead to obesity, diabetes mellitus, inflammatory bowel disease, rheumatoid arthritis, multiple sclerosis, autism spectrum disorder and cancer. Recent metabolomics analyses have also made the association between the microbiota and carcinogenesis clear. Here, we review the current evidence on the association between the microbiota and gastric, bladder, hepatobiliary, pancreatic, lung and colorectal cancer. Moreover, several animal studies have revealed that probiotics seem to be effective for the prevention of carcinogenesis to some extent. In this review, we focused on this relationship between the microbiota and cancer, and considered how to prevent cancer using strategies involving the gut microbiota.