Gut microbes in gastrointestinal cancers

Dysregulation of gut microbiota stimulates NETs-driven HCC intrahepatic metastasis: therapeutic implications of healthy faecal microbiota transplantation

The stringent regulation of intrahepatic metastases is essential for improving survival outcomes in patients with hepatocellular carcinoma (HCC). This study investigated the impact of gut microbiota on intrahepatic metastasis of HCC and evaluated the therapeutic potential of healthy fecal microbiota transplantation (FMT). Dysregulation of the gut microbiota, characterized by a significant reduction in the abundance of beneficial bacteria, such as Anaerotruncus colihominis and Dysosmobacter welbionis, was observed in patients with intrahepatic metastatic HCC. A human flora-associated (HFA) intrahepatic metastatic HCC mouse model was successfully established through consecutive 4 weeks of human-mouse FMT. Dysregulation of gut microbiota promoted intrahepatic metastasis in the mouse model, primarily by enhancing neutrophil-mediated inflammatory responses and lead to excessive formation of neutrophil extracellular traps (NETs). Consequently, it promoted tumor vascular growth and tissue necrosis, resulting in intrahepatic metastasis of HCC. Notably, FMT from healthy donors mitigated these pathological processes. This study elucidated the role and mechanism of dysregulated gut microbiota in promoting intrahepatic metastasis of HCC. Healthy FMT emerges as a promising novel therapeutic strategy for preventing and treating intrahepatic metastasis of HCC.

Probiotic biofilm modified scaffolds for facilitating osteomyelitis treatment through sustained release of bacteriophage and regulated macrophage polarization

Osteomyelitis has gradually become a catastrophic complication in orthopedic surgery due to the formation of bacterial biofilms on the implant surface and surrounding tissue. The therapeutic challenges of antibiotic resistance and poor postoperative osseointegration provide inspiration for the development of bioactive implants. We have strategically designed bioceramic scaffolds modified with Lactobacillus reuteri (LR) and bacteriophages (phages) to achieve both antibacterial and osteogenic effects. Leveraging the tendency of bacteria to adhere to the surface of implants, bioceramics have been modified with LR biofilm to promote bone repair. The LR biofilm, sterilized by pasteurization, prevents sepsis caused by live bacteria and is biocompatible with phages. Phages, being natural enemies of bacteria, not only effectively kill bacteria and inhibit biofilm formation but also readily adsorb onto the surface of bioceramics. Hence, this scaffold, loaded with a phage cocktail, lysates specific bacterial populations, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). More importantly, the inactivated LR biofilm stimulates macrophages RAW264.7 to polarize towards an anti-inflammatory M2 phenotype, creating an immune microenvironment favorable for inducing osteogenic differentiation of rat mesenchymal stem cells in vitro. In a rat model of infectious cranial defects, the scaffold not only effectively eliminated S. aureus and alleviated associated inflammation but also mediated macrophage-mediated immunoregulation, thus resulting in effective osteogenesis. Collectively, these multifunctional modified scaffolds offer an integrated approach to both bacterium elimination and bone repair, presenting a new strategy for bioactive implants in the clinical management of osteomyelitis.

Selenium-Enriched Lactiplantibacillus plantarum ZZU 8-12 Regulates Intestinal Microbiota and Inhibits Acute Liver Injury

Intake of certain Lactiplantibacillus strains was recognized as a potential strategy for acute liver injury (ALI) prevention. This study is aimed at developing a selenium-enriched Lactiplantibacillus strain-based ALI prevention strategy. L. plantarum ZZU 8-12 was isolated from human fecal sample and screened out based on its adaption to intestinal microenvironment, inhibitive capability against pathogenic bacteria, and in vivo anti-inflammation response in DSS-induced colitis mice model. The strain was applied as a producer of nano selenium particles to produce selenium-enriched L. plantarum ZZU 8-12. Intake of selenium-enriched L. plantarum ZZU 8-12 upregulated the abundance of short-chain fatty acid-producing genera including Lactiplantibacillus, Phascolarctobacterium, Butyricicoccus, and Clostridiales bacterium in fecal microbiota and thus inhibited ALI induced by CCL4 injection in mice. This study drew the potential for selenium-enriched L. plantarum ZZU 8-12 as an ingredient for ALI protection.

New Evidence for Cotinus coggygria Scop. Extracts Application in Gastrointestinal Ailments

BACKGROUND/OBJECTIVES

Cotinus coggygria Scop. is traditionally used for treatment of various gastrointestinal ailments. In this study, we investigated the phytochemical profile and biological activities of leaves, bark and flowers extracts of C. coggygria. Methods: Phytochemical analysis was performed using HPLC. The antimicrobial activity of water and methanolic extracts of C. coggygria leaves, bark and flowers towards various oral fungal and bacterial strains of clinical origin was tested by use of a microdilution assay. Additionally, their cytotoxic activity was determined against different gastrointestinal carcinoma cell lines (CAL27, FaDu, SW480, HCT116 and MRC-5) in concentrations ranging from 3.125 to 400 µg/mL for 48 and 72 h.

RESULTS

The presence of numerous flavonoid and phenolic compounds such as sulfuretin, gallic acid, rutin, hyperoside, and isoquercitrine was detected. Micrococcus luteus, Streptococcus parasanguinis, and Candida tropicalis were the most sensitive microbiological species, with MICs of 0.12 mg/mL for the most effective extracts. Additionally, the cytotoxic activity of the samples against different gastrointestinal carcinoma cell lines (CAL27, FaDu, SW480, HCT116, and MRC-5) was determined in concentrations ranging from 3.125 to 400 µg/mL. Among the tested samples, the methanolic leaf extract exhibited the highest cytotoxic capacity, and the possible mechanism could be related to its inhibitory effect on the release of proinflammatory cytokine in CD4+ cells.

CONCLUSIONS

The traditional use of C. coggygria for gastrointestinal diseases may be substantiated by its ability to inhibit the growth of harmful microorganisms and its promising cytotoxic properties. The methanolic leaf and flower extracts show significant potential for future clinical applications, and further studies are warranted to explore their mechanisms and applications in medical treatments.

Rosmarinic Acid: A Potential Therapeutic Agent in Gastrointestinal Cancer Management-A Review

Gastrointestinal cancers are still the leading cause of death worldwide. This is related, among other things, to the non-specific symptoms, especially in the initial stages, and also to the limited possibilities for treatment. Therefore, research is still being conducted to improve the detection of this type of cancer and increase the effectiveness of therapy. The potential application of natural compounds in cancer management deserves special attention. In the group of such products, there are polyphenolic compounds that reveal, e.g., anti-oxidative, anti-carcinogenic, anti-inflammatory, anti-diabetic, and neuroprotective properties. One of these polyphenols is rosmarinic acid, commonly found in plants such as the Boraginaceae and Nepetoideae subfamilies of the Lamiaceae (mint) family. A number of studies have considered the positive effects of rosmarinic acid in the treatment of many cancers, including gastrointestinal ones such as oral, stomach, pancreas, colon, and liver cancers. The main aim of this paper was to summarize the mechanisms of action of rosmarinic acid in gastrointestinal cancers.

Transformation of colitis and colorectal cancer: a tale of gut microbiota

Intestinal inflammation modifies host physiology to promote the occurrence of colorectal cancer (CRC), as seen in colitis-associated CRC. Gut microbiota is crucial in cancer progression, primarily by inducing intestinal chronic inflammatory microenvironment, leading to DNA damage, chromosomal mutation, and alterations in specific metabolite production. Therefore, there is an increasing interest in microbiota-based prevention and treatment strategies, such as probiotics, prebiotics, microbiota-derived metabolites, and fecal microbiota transplantation. This review aims to provide valuable insights into the potential correlations between gut microbiota and colitis-associated CRC, as well as the promising microbiota-based strategies for colitis-associated CRC.

Host-Gut Microbiota Metabolic Interactions and Their Role in Precision Diagnosis and Treatment of Gastrointestinal Cancers

The critical role of the gut microbiome in gastrointestinal cancers is becoming increasingly clear. Imbalances in the gut microbial community, referred to as dysbiosis, are linked to increased risks for various forms of gastrointestinal cancers. Pathogens like Fusobacterium and Helicobacter pylori relate to the onset of esophageal and gastric cancers, respectively, while microbes such as Porphyromonas gingivalis and Clostridium species have been associated with a higher risk of pancreatic cancer. In colorectal cancer, bacteria such as Fusobacterium nucleatum are known to stimulate the growth of tumor cells and trigger cancer-promoting pathways. On the other hand, beneficial microbes like Bifidobacteria offer a protective effect, potentially inhibiting the development of gastrointestinal cancers. The potential for therapeutic interventions that manipulate the gut microbiome is substantial, including strategies to engineer anti-tumor metabolites and employ microbiota-based treatments. Despite the progress in understanding the influence of the microbiome on gastrointestinal cancers, significant challenges remain in identifying and understanding the precise contributions of specific microbial species and their metabolic products. This knowledge is essential for leveraging the role of the gut microbiome in the development of precise diagnostics and targeted therapies for gastrointestinal cancers.

The Anti-Inflammatory and Curative Exponent of Probiotics: A Comprehensive and Authentic Ingredient for the Sustained Functioning of Major Human Organs

Several billion microorganisms reside in the gastrointestinal lumen, including viruses, bacteria, fungi, and yeast. Among them, probiotics were primarily used to cure digestive disorders such as intestinal infections and diarrhea; however, with a paradigm shift towards alleviating health through food, their importance is large. Moreover, recent studies have changed the perspective that probiotics prevent numerous ailments in the major organs. Probiotics primarily produce biologically active compounds targeting discommodious pathogens. This review demonstrates the implications of using probiotics from different genres to prevent and alleviate ailments in the primary human organs. The findings reveal that probiotics immediately activate anti-inflammatory mechanisms by producing anti-inflammatory cytokines such as interleukin (IL)-4, IL-10, IL-11, and IL-13, and hindering pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α by involving regulatory T cells (Tregs) and T helper cells (Th cells). Several strains of Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus reuteri, Bifidobacterium longum, and Bifidobacterium breve have been listed among the probiotics that are excellent in alleviating various simple to complex ailments. Therefore, the importance of probiotics necessitates robust research to unveil the implications of probiotics, including the potency of strains, the optimal dosages, the combination of probiotics, their habitat in the host, the host response, and other pertinent factors.

Aggravated hepatic fibrosis induced by phenylalanine and tyrosine was ameliorated by chitooligosaccharides supplementation

Hepatic fibrosis is a classic pathological manifestation of metabolic chronic hepatopathy. The pathological process might either gradually deteriorate into cirrhosis and ultimately liver cancer with inappropriate nutrition supply, or be slowed down by several multifunctional nutrients, alternatively. Herein, we found diet with excessive phenylalanine (Phe) and tyrosine (Tyr) exacerbated hepatic fibrosis symptoms of liver dysfunction and gut microflora dysbiosis in mice. Chitooligosaccharides (COS) could ameliorate hepatic fibrosis with the regulation of amino acid metabolism by downregulating the mTORC1 pathway, especially that of Phe and Tyr, and also with the alleviation of the dysbiosis of gut microbiota, simultaneously. Conclusively, this work presents new insight into the role of Phe and Tyr in the pathologic process of hepatic fibrosis, while revealing the effectiveness and molecular mechanism of COS in improving hepatic fibrosis from the perspective of metabolites.

The gut microbiota composition in patients with right- and left-sided colorectal cancer and after curative colectomy, as analyzed by 16S rRNA gene amplicon sequencing

Background

Gut pathological microbial imbalance or dysbiosis is closely associated with colorectal cancer. Although there are observable differences in molecular and clinical characteristics between patients with right- and left-sided colon cancer, differences in their gut microbiomes have not been thoroughly investigated. Furthermore, subsequent changes in microbiota status after partial colectomy remain unknown. We examined the human gut microbiota composition to determine its relationship with colon cancer and partial colon resection according to location.

Methods

Stool samples from forty-one subjects (10 in the control group, 10 in the right-sided colon cancer [RCC] group, 6 in the sigmoid colon cancer [SCC] group, 9 in the right colon resection [RCR] group and 6 in the sigmoid colon resection [SCR] group) were collected, and DNA was extracted. After terminal restriction fragment length polymorphism (T-RFLP) analysis, the samples were subjected to 16S rRNA gene amplicon sequencing, and the metabolic function of the microbiota was predicted using PICRUSt2.

Results

T-RFLP analysis showed a reduced ratio of clostridial cluster XIVa in the SCC patients and clostridial cluster IX in the RCC patients, although these changes were not evident in the RCR or SCR patients. 16S rRNA gene amplicon sequencing demonstrated that the diversity of the gut microbiota in the RCC group was higher than that in the control group, and the diversity in the SCR group was significantly higher than that in the RCR group. Principal coordinate analysis (PCoA) revealed significant differences according to the group. Analyses of the microbiota revealed that Firmicutes was significantly dominant in the RCC group and that the SCC group had a higher abundance of Verrucomicrobia. At the genus level, linear discriminant analysis effect size (LEfSe) revealed several bacteria, such as Ruminococcaceae, Streptococcaceae, Clostridiaceae, Gemellaceae, and Desulfovibrio, in the RCC group and several oral microbiomes in the SCC group. Metabolic function prediction revealed that cholesterol transport- and metabolism-related enzymes were specifically upregulated in the RCC group and that cobalamin metabolism-related enzymes were downregulated in the SCC group.

Conclusion

Gut microbial properties differ between RCC and SCC patients and between right hemicolectomy and sigmoidectomy patients and may contribute to clinical manifestations.

An Update on the Effects of Probiotics on Gastrointestinal Cancers

Because of their increasing prevalence, gastrointestinal (GI) cancers are regarded as an important global health challenge. Microorganisms residing in the human GI tract, termed gut microbiota, encompass a large number of living organisms. The role of the gut in the regulation of the gut-mediated immune responses, metabolism, absorption of micro- and macro-nutrients and essential vitamins, and short-chain fatty acid production, and resistance to pathogens has been extensively investigated. In the past few decades, it has been shown that microbiota imbalance is associated with the susceptibility to various chronic disorders, such as obesity, irritable bowel syndrome, inflammatory bowel disease, asthma, rheumatoid arthritis, psychiatric disorders, and various types of cancer. Emerging evidence has shown that oral administration of various strains of probiotics can protect against cancer development. Furthermore, clinical investigations suggest that probiotic administration in cancer patients decreases the incidence of postoperative inflammation. The present review addresses the efficacy and underlying mechanisms of action of probiotics against GI cancers. The safety of the most commercial probiotic strains has been confirmed, and therefore these strains can be used as adjuvant or neo-adjuvant treatments for cancer prevention and improving the efficacy of therapeutic strategies. Nevertheless, well-designed clinical studies are still needed for a better understanding of the properties and mechanisms of action of probiotic strains in mitigating GI cancer development.

Efficacy and Safety of Rifaximin Versus Placebo or Other Active Drugs in Critical ill Patients With Hepatic Encephalopathy

Objective: Rifaximin has been approved for use as a first-line therapy for secondary prophylaxis of hepatic encephalopathy (HE). This article is to update existing evidence on efficacy and safety of rifaximin treatment and prevention for HE. Methods: We systematically searched multiple databases until January 31 2021. The studies compared rifaximin vs. placebo or other active drugs (i.e., nonabsorbable disaccharides, other antibiotics, L-ornithine-L-aspartate (LOLA), and probiotics) for patients with overt HE (OHE), minimal HE (MHE), and recurrent HE. Results: Twenty-eight randomized controlled trials with a total of 2979 patients were included. Compared with the controls, rifaximin significantly reduced HE grade (OHE: RR = 1.11, 95% CI = 1.02-1.21), improved the cognitive impairments (MHE: RR = 1.82, 95% CI = 1.12-2.93) and prevented the risk of HE recurrent episodes (RR = 1.33, 95% CI = 1.18-1.49). No statistical difference was observed in mortality between rifaximin and their controls (RR = 0.82, 95% CI = 0.54-1.24). The incidence of total adverse events in rifaximin-treated groups was significantly lower than that in the controls during the treatment period (RR = 0.73, 95% CI = 0.54-0.98). In addition, rifaximin treatment was better than other active drugs in improving psychometric indicators (mental state, flapping tremor and portosystemic encephalopathy (PSE) index) and reducing the risk of rehospitalization in HE patients. Conclusion: Rifaximin therapy is effective and well-tolerated in different types of HE, which might be recommended as an alternative to conventional oral drugs in clinical settings.