Dietary spinach reshapes the gut microbiome in an Apc-mutant genetic background: mechanistic insights from integrated multi-omics

Augmentation of Fermentability and Bioavailability Characteristics of Wheat Bran via the Synergistic Interaction between Arabinoxylan-Specific Degrading Enzymes and Lactic Acid Bacteria

To enhance the use of wheat bran in chicken feed, a solid-state fermentation approach was used with Lactobacillus paracasei LAC28 and Pediococcus acidilactici BCC-1, along with arabinoxylan-specific degrading enzymes (xylanase, arabinofuranosidase, feruloyl esterase, XAF). The effects of the fermentation process were evaluated both in vitro and in vivo. In the in vitro study, XAF supplementation demonstrated superior performance, significantly reducing the pH of the fermented wheat bran (FWB) and increasing lactic, acetic, and butyric acid levels, total phenol content, and free radical scavenging capacity (P < 0.05) compared to the XAF-free group. In the in vivo study, broilers were fed diets containing either unfermented wheat bran (UFWB) or FWB (fermented individually with LAC28 or BCC-1). Broilers fed FWB with BCC-1 exhibited significant improvements in body weight gain, intestinal morphology, and nutrient digestibility (P < 0.05) compared to the control group. Moreover, the FWB established a healthier microbial community in the avian gastrointestinal tract. Overall, this study demonstrated the potential of combining XAF and bacteria to enhance wheat bran fermentation, benefiting broiler intestinal health and growth. This innovative approach holds promise as a cost-efficient and sustainable strategy to improve the nutritional quality of wheat bran for animal feed applications.

Gut microbiota drives colon cancer risk associated with diet: a comparative analysis of meat-based and pesco-vegetarian diets

BACKGROUND

Colorectal cancer (CRC) risk is strongly affected by dietary habits with red and processed meat increasing risk, and foods rich in dietary fibres considered protective. Dietary habits also shape gut microbiota, but the role of the combination between diet, the gut microbiota, and the metabolite profile on CRC risk is still missing an unequivocal characterisation.

METHODS

To investigate how gut microbiota affects diet-associated CRC risk, we fed Apc-mutated PIRC rats and azoxymethane (AOM)-induced rats the following diets: a high-risk red/processed meat-based diet (MBD), a normalised risk diet (MBD with α-tocopherol, MBDT), a low-risk pesco-vegetarian diet (PVD), and control diet. We then conducted faecal microbiota transplantation (FMT) from PIRC rats to germ-free rats treated with AOM and fed a standard diet for 3 months. We analysed multiple tumour markers and assessed the variations in the faecal microbiota using 16S rRNA gene sequencing together with targeted- and untargeted-metabolomics analyses.

RESULTS

In both animal models, the PVD group exhibited significantly lower colon tumorigenesis than the MBD ones, consistent with various CRC biomarkers. Faecal microbiota and its metabolites also revealed significant diet-dependent profiles. Intriguingly, when faeces from PIRC rats fed these diets were transplanted into germ-free rats, those transplanted with MBD faeces developed a higher number of preneoplastic lesions together with distinctive diet-related bacterial and metabolic profiles. PVD determines a selection of nine taxonomic markers mainly belonging to Lachnospiraceae and Prevotellaceae families exclusively associated with at least two different animal models, and within these, four taxonomic markers were shared across all the three animal models. An inverse correlation between nonconjugated bile acids and bacterial genera mainly belonging to the Lachnospiraceae and Prevotellaceae families (representative of the PVD group) was present, suggesting a potential mechanism of action for the protective effect of these genera against CRC.

CONCLUSIONS

These results highlight the protective effects of PVD while reaffirming the carcinogenic properties of MBD diets. In germ-free rats, FMT induced changes reminiscent of dietary effects, including heightened preneoplastic lesions in MBD rats and the transmission of specific diet-related bacterial and metabolic profiles. Importantly, to the best of our knowledge, this is the first study showing that diet-associated cancer risk can be transferred with faeces, establishing gut microbiota as a determinant of diet-associated CRC risk. Therefore, this study marks the pioneering demonstration of faecal transfer as a means of conveying diet-related cancer risk, firmly establishing the gut microbiota as a pivotal factor in diet-associated CRC susceptibility. Video Abstract.

Role of Gut Microbiota in Predisposition to Colon Cancer: A Narrative Review

Globally, colorectal cancer (CRC) is a leading cause of cancer-related mortality. Dietary habits, inflammation, hereditary characteristics, and gut microbiota are some of its causes. The gut microbiota, a diverse population of bacteria living in the digestive system, has an impact on a variety of parameters, including inflammation, DNA damage, and immune response. The gut microbiome has a significant role in colon cancer susceptibility. Many studies have highlighted dysbiosis, an imbalance in the gut microbiota's makeup, as a major factor in colon cancer susceptibility. Dysbiosis has the potential to produce toxic metabolites and pro-inflammatory substances, which can hasten the growth of tumours. The ability of the gut microbiota to affect the host's immune system can also influence whether cancer develops or not. By better comprehending these complex interactions between colon cancer predisposition and gut flora, new preventive and therapeutic techniques might be developed. Targeting the gut microbiome with dietary modifications, probiotics, or faecal microbiota transplantation may offer cutting-edge approaches to reducing the risk of colon cancer and improving patient outcomes. The complex connection between the makeup of the gut microbiota and the emergence of colorectal cancer is explored in this narrative review.

Current advances in cancer energy metabolism under dietary restriction: a mini review

The manipulation of the energy or source of food for cancer cells has attracted significant attention in oncology research. Metabolic reprogramming of the immune system allows for a deeper understanding of cancer cell mechanisms, thereby impeding their progression. A more targeted approach is the restriction of cancer cells through dietary restriction (CR), which deprives cancer cells of the preferred energy sources within the tumor microenvironment, thereby enhancing immune cell efficacy. Although there is a plethora of CR strategies that can be employed to impede cancer progression, there is currently no comprehensive review that delineates the specific dietary restrictions that target the diverse metabolic pathways of cancer cells. This mini-review introduces amino acids as anti-cancer agents and discusses the role of dietary interventions in cancer prevention and treatment. It highlights the potential of a ketogenic diet as a therapeutic approach for cancer, elucidating its distinct mechanisms of action in tumor progression. Additionally, the potential of plant-based diets as anti-cancer agents and the role of polyphenols and vitamins in anti-cancer therapy were also discussed, along with some prospective interventions for CR as anti-tumor progression.

Histone Acyl Code in Precision Oncology: Mechanistic Insights from Dietary and Metabolic Factors

Cancer etiology involves complex interactions between genetic and non-genetic factors, with epigenetic mechanisms serving as key regulators at multiple stages of pathogenesis. Poor dietary habits contribute to cancer predisposition by impacting DNA methylation patterns, non-coding RNA expression, and histone epigenetic landscapes. Histone post-translational modifications (PTMs), including acyl marks, act as a molecular code and play a crucial role in translating changes in cellular metabolism into enduring patterns of gene expression. As cancer cells undergo metabolic reprogramming to support rapid growth and proliferation, nuanced roles have emerged for dietary- and metabolism-derived histone acylation changes in cancer progression. Specific types and mechanisms of histone acylation, beyond the standard acetylation marks, shed light on how dietary metabolites reshape the gut microbiome, influencing the dynamics of histone acyl repertoires. Given the reversible nature of histone PTMs, the corresponding acyl readers, writers, and erasers are discussed in this review in the context of cancer prevention and treatment. The evolving 'acyl code' provides for improved biomarker assessment and clinical validation in cancer diagnosis and prognosis.

Role of the Gut Microbiota and Its Metabolites in Tumorigenesis or Development of Colorectal Cancer

Colorectal cancer (CRC) is the most common cancer of the digestive system with high mortality and morbidity rates. Gut microbiota is found in the intestines, especially the colorectum, and has structured crosstalk interactions with the host that affect several physiological processes. The gut microbiota include CRC-promoting bacterial species, such as Fusobacterium nucleatum, Escherichia coli, and Bacteroides fragilis, and CRC-protecting bacterial species, such as Clostridium butyricum, Streptococcus thermophilus, and Lacticaseibacillus paracasei, which along with other microorganisms, such as viruses and fungi, play critical roles in the development of CRC. Different bacterial features are identified in patients with early-onset CRC, combined with different patterns between fecal and intratumoral microbiota. The gut microbiota may be beneficial in the diagnosis and treatment of CRC; some bacteria may serve as biomarkers while others as regulators of chemotherapy and immunotherapy. Furthermore, metabolites produced by the gut microbiota play essential roles in the crosstalk with CRC cells. Harmful metabolites include some primary bile acids and short-chain fatty acids, whereas others, including ursodeoxycholic acid and butyrate, are beneficial and impede tumor development and progression. This review focuses on the gut microbiota and its metabolites, and their potential roles in the development, diagnosis, and treatment of CRC.

A Review of Gut Microbiota-Derived Metabolites in Tumor Progression and Cancer Therapy

Gut microbiota-derived metabolites are key hubs connecting the gut microbiome and cancer progression, primarily by remodeling the tumor microenvironment and regulating key signaling pathways in cancer cells and multiple immune cells. The use of microbial metabolites in radiotherapy and chemotherapy mitigates the severe side effects from treatment and improves the efficacy of treatment. Immunotherapy combined with microbial metabolites effectively activates the immune system to kill tumors and overcomes drug resistance. Consequently, various novel strategies have been developed to modulate microbial metabolites. Manipulation of genes involved in microbial metabolism using synthetic biology approaches directly affects levels of microbial metabolites, while fecal microbial transplantation and phage strategies affect levels of microbial metabolites by altering the composition of the microbiome. However, some microbial metabolites harbor paradoxical functions depending on the context (e.g., type of cancer). Furthermore, the metabolic effects of microorganisms on certain anticancer drugs such as irinotecan and gemcitabine, render the drugs ineffective or exacerbate their adverse effects. Therefore, a personalized and comprehensive consideration of the patient's condition is required when employing microbial metabolites to treat cancer. The purpose of this review is to summarize the correlation between gut microbiota-derived metabolites and cancer, and to provide fresh ideas for future scientific research.

Protopanaxadiol manipulates gut microbiota to promote bone marrow hematopoiesis and enhance immunity in cyclophosphamide-induced immunosuppression mice

Protopanaxadiol (PPD) has potential immunomodulatory effects, but the underlying mechanism remains unclear. Here, we explored the potential roles of gut microbiota in the immunity regulation mechanisms of PPD using a cyclophosphamide (CTX)-induced immunosuppression mouse model. Our results showed that a medium dose of PPD (PPD-M, 50 mg/kg) effectively ameliorated the immunosuppression induced by CTX treatment by promoting bone marrow hematopoiesis, increasing the number of splenic T lymphocytes and regulating the secretion of serum immunoglobulins and cytokines. Meanwhile, PPD-M protected against CTX-induced gut microbiota dysbiosis by increasing the relative abundance of Lactobacillus, Oscillospirales, Turicibacter, Coldextribacter, Lachnospiraceae, Dubosiella, and Alloprevotella and reducing the relative abundance of Escherichia-Shigella. Importantly, PPD-M lost the ability to promote bone marrow hematopoiesis and enhance immunity when the gut microbiota was depleted by broad-spectrum antibiotics. Moreover, PPD-M promoted the production of microbiota-derived immune-enhancing metabolites including cucurbitacin C, l-gulonolactone, ceramide, DG, prostaglandin E2 ethanolamide, palmitoyl glucuronide, 9R,10S-epoxy-stearic acid, and 9'-carboxy-gamma-chromanol. KEGG topology analysis showed that the PPD-M treatment significantly enriched the sphingolipid metabolic pathway with ceramide as a main metabolite. Our findings reveal that PPD enhances immunity by manipulating gut microbiota and has the potential to be used as an immunomodulator in cancer chemotherapy.

Network analysis reveals miRNA crosstalk between periodontitis and oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the malignant tumors with a poor prognosis. Periodontitis (PD is considered a high-risk factor for OSCC, but the genetic mechanism is rarely studied. This study aims to link OSCC and PD by identifying common differentially expressed miRNAs (Co-DEmiRNAs), their related genes (Hub genes), transcription factors (TFs), signaling pathways, enrichment functions, and compounds, and searching for genetic commonalities.

METHODS

The miRNAs expression datasets of OSCC and PD were searched from the GEO database. The miRNA and related crosstalk mechanism between OSCC and PD was obtained through a series of analyses.

RESULTS

hsa-mir-497, hsa-mir-224, hsa-mir-210, hsa-mir-29c, hsa-mir-486-5p, and hsa-mir-31are the top miRNA nodes in Co-DEmiRNA-Target networks. The most significant candidate miRNA dysregulation genes are ZNF460, FBN1, CDK6, BTG2, and CBX6, while the most important dysregulation TF includes HIF1A, TP53, E2F1, MYCN, and JUN. 5-fluorouracil, Ginsenoside, Rh2, and Formaldehyde are the most correlated compounds. Enrichment analysis revealed cancer-related pathways and so on.

CONCLUSIONS

The comprehensive analysis reveals the interacting genetic and molecular mechanism between OSCC and PD, linking both and providing a foundation for future basic and clinical research.

Integrated Analysis of Colorectal Cancer Reveals Cross-Cohort Gut Microbial Signatures and Associated Serum Metabolites

BACKGROUND & AIMS

Studies have reported abnormal gut microbiota or circulating metabolome associated with colorectal cancer (CRC), but it remains a challenge to capture the CRC-relevant features consistent across geographic regions. This is particularly the problem for metabolic traits of CRC because the analyses generally use different platforms and laboratory methods, which poses a barrier to cross-dataset examination. In light of this, we sought to elucidate the microbial and metabolic signatures of CRC with broad population relevance.

METHODS

In this integrated metagenomic (healthy controls [HC], n = 91; colorectal adenoma [CRA], n = 63; CRC, n = 71) and metabolomic (HC, n = 34; CRA, n = 31; CRC, n = 35) analysis, CRC-associated features and microbe-metabolite correlations were first identified from a Shanghai cohort. A gut microbial panel was trained in the in-house cohort and cross-validated in 7 published metagenomic datasets of CRC. The in-house metabolic connections to the cross-cohort microbial signatures were used as evidence to infer serum metabolites with potentially external relevance. In addition, a combined microbe-metabolite panel was produced for diagnosing CRC or adenoma.

RESULTS

CRC-associated alterations were identified in the gut microbiome and serum metabolome. A composite microbe-metabolite diagnostic panel was developed and yielded an area under the curve of 0.912 for adenoma and 0.994 for CRC. We showed that many CRC-associated metabolites were linked to cross-cohort gut microbiome signatures of the disease, including CRC-enriched leucylalanine, serotonin, and imidazole propionate; and CRC-depleted perfluorooctane sulfonate, 2-linoleoylglycerol (18:2), and sphingadienine.

CONCLUSIONS

We generated cross-cohort metagenomic signatures of CRC, some of which linked to in-house CRC-associated serum metabolites. The microbial and metabolic shifts may have wide population relevance.

Global trends in research on miRNA-microbiome interaction from 2011 to 2021: A bibliometric analysis

An increasing number of research suggests that the microRNA (miRNA)-microbiome interaction plays an essential role in host health and diseases. This bibliometric analysis aimed to identify the status of global scientific output, research hotspots, and frontiers regarding the study of miRNA-microbiome interaction over the past decade. We retrieved miRNA-microbiome-related studies published from 2011 to 2021 from the Web of Science Core Collection database; the R package bibliometrix was used to analyze bibliometric indicators, and VOSviewer was used to visualize the field status, hotspots, and research trends of miRNA-microbiome interplay. In total, 590 articles and reviews were collected. A visual analysis of the results showed that significant increase in the number of publications over time. China produced the most papers, and the United States contributed the highest number of citations. Shanghai Jiaotong University and the University of California Davis were the most active institutions in the field. Most publications were published in the areas of biochemistry and molecular biology. Yu Aiming was the most prolific writer, as indicated by the h-index and m-index, and Liu Shirong was the most commonly co-cited author. A paper published in the International Journal of Molecular Sciences in 2017 had the highest number of citations. The keywords "expression" and "gut microbiota" appeared most frequently, and the top three groups of diseases that appeared among keywords were cancer (colorectal, et al.), inflammatory bowel disease (Crohn's disease and ulcerative colitis), and neurological disorders (anxiety, Parkinson's disease, et al.). This bibliometric study revealed that most studies have focused on miRNAs (e.g., miR-21, miR-155, and miR-146a), gut microbes (e.g., Escherichia coli, Bifidobacterium, and Fusobacterium nucleatum), and gut bacteria metabolites (e.g., butyric acid), which have the potential to improve the diagnosis, treatment, and prognosis of diseases. We found that therapeutic strategies targeting the miRNA-microbiome axis focus on miRNA drugs produced in vitro; however, some studies suggest that in vivo fermentation can greatly increase the stability and reduce the degradation of miRNA. Therefore, this method is worthy of further research.

Metabolomics of Acute vs. Chronic Spinach Intake in an Apc-Mutant Genetic Background: Linoleate and Butanoate Metabolites Targeting HDAC Activity and IFN-γ Signaling

There is growing interest in the crosstalk between the gut microbiome, host metabolomic features, and disease pathogenesis. The current investigation compared long-term (26 week) and acute (3 day) dietary spinach intake in a genetic model of colorectal cancer. Metabolomic analyses in the polyposis in rat colon (Pirc) model and in wild-type animals corroborated key contributions to anticancer outcomes by spinach-derived linoleate bioactives and a butanoate metabolite linked to increased α-diversity of the gut microbiome. Combining linoleate and butanoate metabolites in human colon cancer cells revealed enhanced apoptosis and reduced cell viability, paralleling the apoptosis induction in colon tumors from rats given long-term spinach treatment. Mechanistic studies in cell-based assays and in vivo implicated the linoleate and butanoate metabolites in targeting histone deacetylase (HDAC) activity and the interferon-γ (IFN-γ) signaling axis. Clinical translation of these findings to at-risk patients might provide valuable quality-of-life benefits by delaying surgical interventions and drug therapies with adverse side effects.

Lactulose Modulates the Structure of Gut Microbiota and Alleviates Colitis-Associated Tumorigenesis

Lactulose, a galactose-fructose disaccharide, is made from the milk sugar lactose by heating or isomerization processes. Lactulose is proposed to modulate gut microbiota and thus expected to be beneficial in treating inflammatory bowel disease. In the present study, we investigated the therapeutic effect of lactulose on gastrointestinal inflammation and inflammation-related tumorigenesis in a mouse model of colorectal cancer as well as its effect on gut microbiota composition. Azoxymethane (AOM)/dextran sulfate sodium (DSS) model was used in this study. Lactulose treatment was performed by feeding 2% lactulose for 14 weeks. Stool samples collected at 4 time points were used for metagenomic analysis of the microbiota. Pathological analysis was performed 21 weeks after AOM injection. AOM/DSS increased the macrophage counts, inflammatory cytokine expression, colorectal tumorigenesis, and imbalance in gut microbiota composition, as evidenced by increased pathogen abundance (e.g., Escherichia and Clostridium). Lactulose significantly inhibited the inflammatory events, and ameliorated inflammation and tumorigenesis. The composition of the intestinal microbiota was also restored upon lactulose treatment, and lactulose reduced pathogen abundance and increased the abundance of Muribaculum and Lachnospiraceae. Meanwhile, the pathways related to Crohn’s disease were downregulated after lactulose treatment. Our findings suggest that lactulose restores the structure and composition of the intestinal microbiota, mitigates inflammation, and suppresses inflammatory tumorigenesis.