Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Methyl-esterification, degree of polymerization and ∆4,5-unsaturation of galacturonic acid oligosaccharides as determinants of immunomodulation

In recent years, immunomodulation by pectin and pectin-derived galacturonic acid oligosaccharides has been the subject of wide-spread scientific research due to the potential of different pectin structures as bioactive biomolecules. Yet, gaps remain in understanding the structure-dependent immunomodulation of galacturonic acid. This study describes in vitro immunomodulatory effects of well-characterized galacturonic acid oligosaccharides. Both methyl-esterified and non-methyl-esterified galacturonic acid oligosaccharides with a saturated non-reducing end (degree of polymerization 1-10) significantly induced cytokine production by THP-1 macrophages and directly activated TLR2 and TLR4 in transfected HEK-293 cells, even when accounting for minor endotoxin contamination. In contrast, both methyl-esterified and non-methyl-esterified galacturonic acid oligosaccharides with a Δ4,5-unsaturated non-reducing end (degree of polymerization 1-7) did not activate TLR2 and TLR4 and led to significantly reduced cytokine production (p < 0.05), suggesting Δ4,5-(un)saturation as a pivotal factor for immunomodulation by galacturonic acid oligosaccharides. Exposure to non-methyl-esterified saturated galacturonic acid oligosaccharides resulted in significantly lower TNF-α production, IL-1β production and TLR4 activation (p < 0.05) compared to methyl-esterified saturated galacturonic acid oligosaccharides, while IL-10 production and TLR2 activation remained unchanged. These findings establish galacturonic acid oligosaccharides as versatile immunomodulators with TLR2 and TLR4 binding capacity, fit for different immunomodulatory applications depending on their structural characteristics.

Dietary counselling to increase soluble fibre in patients with gynaecological cancers undergoing pelvic radiotherapy: A feasibility study

BACKGROUND

This study aimed to determine the feasibility of increasing soluble fibre intake via dietary counselling to improve gastrointestinal toxicity and quality of life in patients with gynaecological cancers undergoing pelvic radiotherapy without adverse consequences on radiation treatment (RT) delivery accuracy.

METHODS

A single-arm, single-centre intervention feasibility trial included patients with gynaecological cancers undergoing pelvic RT ± chemotherapy at a tertiary hospital. Participants were provided weekly dietary counselling over the duration of their RT (5-6 weeks) to increase soluble fibre intake incrementally each week. Stakeholder surveys were also completed.

RESULTS

In total, 9 of 14 eligible patients participated (55 years old [SD 13.2], diagnosis: cervical [n = 3], endometrial/uterine [n = 5] and vaginal [n = 1]), with the majority categorised as low fibre consumers at baseline (n = 6). On average, soluble fibre intake increased by 150% throughout treatment. There were no adverse events or major adjustments required for RT delivery. There were improving trends in the functional subset identified. Results may be confounded by the sample size resulting from limited eligibility (n = 14) and a high attrition rate (n = 4).

CONCLUSIONS

Most participants successfully increased their soluble fibre intake throughout treatment, without significant adverse events noted for RT delivery accuracy. These results provide preliminary data to calculate the sample size required to produce meaningful effect sizes. However, this study highlighted challenges in participant recruitment and retention, with limited organisational support and perceived compatibility.

Baseline colitogenicity and acute perturbations of gut microbiota in immunotherapy-related colitis

Immunotherapy-related colitis (irC) frequently emerges as an immune-related adverse event during immune checkpoint inhibitor therapy and is presumably influenced by the gut microbiota. We longitudinally studied microbiomes from 38 ICI-treated cancer patients. We compared 13 ICI-treated subjects who developed irC against 25 ICI-treated subjects who remained irC-free, along with a validation cohort. Leveraging a preclinical mouse model, predisease stools from irC subjects induced greater colitigenicity upon transfer to mice. The microbiota during the first 10 days of irC closely resembled inflammatory bowel disease microbiomes, with reduced diversity, increased Proteobacteria and Veillonella, and decreased Faecalibacterium, which normalized before irC remission. These findings highlight the irC gut microbiota as functionally distinct but phylogenetically similar to non-irC and healthy microbiomes, with the exception of an acute, transient disruption early in irC. We underscore the significance of longitudinal microbiome profiling in developing clinical avenues to detect, monitor, and mitigate irC in ICI therapy cancer patients.

The critical role of tumor microbiome in cancer immunotherapy

In recent years, the microbiome has shown an integral role in cancer immunotherapy and has become a prominent and widely studied topic. A full understanding of the interactions between the tumor microbiome and various immunotherapies offers opportunities for immunotherapy of cancer. This review scrutinizes the composition of the tumor microbiome, the mechanism of microbial immune regulation, the influence of tumor microorganisms on tumor metastasis, and the interaction between tumor microorganisms and immunotherapy. In addition, this review also summarizes the challenges and opportunities of immunotherapy through tumor microbes, as well as the prospects and directions for future related research. In conclusion, the potential of microbial immunotherapy to enhance treatment outcomes for cancer patients should not be underestimated. Through this review, it is hoped that more research on tumor microbial immunotherapy will be done to better solve the treatment problems of cancer patients.

A whole food, plant-based diet reduces amino acid levels in patients with metastatic breast cancer

BACKGROUND

Amino acids are critical to tumor survival. Tumors can acquire amino acids from the surrounding microenvironment, including the serum. Limiting dietary amino acids is suggested to influence their serum levels. Further, a plant-based diet is reported to contain fewer amino acids than an animal-based diet. The extent to which a plant-based diet lowers the serum levels of amino acids in patients with cancer is unclear.

METHODS

Patients with metastatic breast cancer (n = 17) were enrolled in a clinical trial with an ad libitum whole food, plant-based diet for 8 weeks without calorie or portion restriction. Dietary changes by participants were monitored using a three-day food record. Serum was collected from participants at baseline and 8 weeks. Food records and serum were analyzed for metabolic changes.

RESULTS

We found that a whole food, plant-based diet resulted in a lower intake of calories, fat, and amino acids and higher levels of fiber. Additionally, body weight, serum insulin, and IGF were reduced in participants. The diet contained lower levels of essential and non-essential amino acids, except for arginine (glutamine and asparagine were not measured). Importantly, the lowered dietary intake of amino acids translated to reduced serum levels of amino acids in participants (5/9 essential amino acids; 4/11 non-essential amino acids).

CONCLUSIONS

These findings provide a tractable approach to limiting amino acid levels in persons with cancer. This data lays a foundation for studying the relationship between amino acids in patients and tumor progression. Further, a whole-food, plant-based diet has the potential to synergize with cancer therapies that exploit metabolic vulnerabilities.

TRIAL REGISTRATION

The clinical trial was registered with ClinicalTrials.gov identifier NCT03045289 on 2017-02-07.

Static and dynamic in vitro colonic models reveal the spatiotemporal production of flavan-3-ol catabolites

Flavan-3-ols are the most found flavonoid compounds in the human diet. Polymeric and monomeric flavan-3-ols reach the colonic region intact, where the gut microbiota utilizes them as substrates. In this research work, we investigated the pattern of colonic metabolites associated with flavan-3-ols, conducting a comprehensive analysis that combined (un)targeted metabolomics and in vitro colonic models. Firstly, the proposed flavan-3-ol metabolic pathway was investigated in-depth using a static in vitro model inoculated with different fecal donors. An apple, (-)-epicatechin, and procyanidin C1 were employed as feeding conditions. Small phenolic acids, such as phenylpropanoic acid and 3,4-dihydroxybenzoic acid, were positively associated with the apple feeding condition. In contrast, 5-(3',4'-dihydroxyphenyl)-γ-valerolactone and other specific early intermediates like phenylvaleric acids were positively associated with (-)-epicatechin. Secondly, by employing a dynamic in vitro simulator model of the human digestion system (SHIME), we reconstructed the flavan-3-ol metabolic pathway regionally. In the proximal colon region, we localized catabolites, such as 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, while in the distal region, we identified mainly small phenolics. Combining static and dynamic in vitro models, we observed differences in the release of flavan-3-ol catabolites, influenced by both the food structure (isolated compounds and a food matrix) and the colonic region. This study sheds light on the colonic catabolism of one of the main dietary (poly)phenols and localizes microbial metabolites.

Tumor Microenvironment-Responsive Nanoparticles Enhance IDO1 Blockade Immunotherapy by Remodeling Metabolic Immunosuppression

The clinical efficacy of immune checkpoint blockade (ICB) therapy is significantly compromised in the metabolically disordered tumor microenvironment (TME), posing a formidable challenge that cannot be ignored in current antitumor strategies. In this study, TME-responsive nanoparticles (HMP1G NPs) loaded with 1-methyltryptophan (1-MT; an indoleamine 2,3-dioxygenase 1 [IDO1] inhibitor,) and S-nitrosoglutathione (GSNO; a nitric oxide donor) is developed to enhance the therapeutic efficacy of 1-MT-mediated ICB. The HMP1G NPs responded to H+ and glutathione in the TME, releasing Mn2+, GSNO, and 1-MT. The released Mn2+ catalyzed the production of abundant reactive oxygen species and nitric oxide from hydrogen peroxide and GSNO, and the generated nitric oxide, synergistically with 1-MT, inhibited the accumulation of kynurenine mediated by IDO1 in the tumor. Mechanistically, HMP1G NPs downregulated tumor cell-derived IDO1 via the aryl hydrocarbon receptor/signal transducer and activator of transcription 3/interleukin signaling axis to improve kynurenine/tryptophan metabolism and immunosuppression. In a murine breast cancer model, treatment with HMP1G NPs elicited effective antitumor immunity and enhanced survival outcomes. This study highlights a novel nano-platform that simultaneously improves metabolism and enhances ICB efficacy to achieve a new and efficient antitumor strategy.

Guilds as guides for health vs. disease

In a recent Cell paper, Wu et al. identified microbiome guilds based on bacterial co-occurrence among type 2 diabetes patients. Two competing guilds, associated with high-fiber vs. control diets, correlated with healthy biomarkers. The potential of this approach was further verified across 15 diseases in 26 studies.

Diet and Immune Effects Trial (DIET)- a randomized, double-blinded dietary intervention study in patients with melanoma receiving immunotherapy

BACKGROUND

Gut microbiome modulation is a promising strategy for enhancing the response to immune checkpoint blockade (ICB). Fecal microbiota transplant studies have shown positive signals of improved outcomes in both ICB-naïve and refractory melanoma patients; however, this strategy is challenging to scale. Diet is a key determinant of the gut microbiota, and we have previously shown that (a) habitual high dietary fiber intake is associated with an improved response to ICB and (b) fiber manipulation in mice impacts antitumor immunity. We recently demonstrated the feasibility of a controlled high-fiber dietary intervention (HFDI) conducted in melanoma survivors with excellent compliance and tolerance. Building on this, we are now conducting a phase II randomized trial of HFDI versus a healthy control diet in melanoma patients receiving ICB.

METHODS

This is a randomized, double-blind, fully controlled feeding study that will enroll 45 melanoma patients starting standard-of-care (SOC) ICB in three settings: adjuvant, neoadjuvant, and unresectable. Patients are randomized 2:1 to the HFDI (target fiber 50 g/day from whole foods) or healthy control diet (target fiber 20 g/day) stratified by BMI and cohort. All meals are prepared by the MD Anderson Bionutrition Core and are isocaloric and macronutrient-controlled. The intervention includes a 1-week equilibration period and then up to 11 weeks of diet intervention. Longitudinal blood, stool and tumor tissue (if available) are collected throughout the trial and at 12 weeks post intervention.

DISCUSSION

This DIET study is the first fully controlled feeding study among cancer patients who are actively receiving immunotherapy. The goal of the current study is to establish the effects of dietary intervention on the structure and function of the gut microbiome in patients with melanoma treated with SOC immunotherapies. The secondary endpoints include changes in systemic and tumor immunity, changes in the metabolic profile, quality of life, symptoms, disease response and immunotherapy toxicity.

TRIAL REGISTRATION

This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT04645680. First posted 2020-11-27; last verified 2024-06.

Diet and Cancer Metabolism

Diet and exercise are modifiable lifestyle factors known to have a major influence on metabolism. Clinical practice addresses diseases of altered metabolism such as diabetes or hypertension by altering these factors. Despite enormous public interest, there are limited defined diet and exercise regimens for cancer patients. Nevertheless, the molecular basis of cancer has converged over the past 15 years on an essential role for altered metabolism in cancer. However, our understanding of the molecular mechanisms that underlie the impact of diet and exercise on cancer metabolism is in its very early stages. In this work, we propose conceptual frameworks for understanding the consequences of diet and exercise on cancer cell metabolism and tumor biology and also highlight recent developments. By advancing our mechanistic understanding, we also discuss actionable ways that such interventions could eventually reach the mainstay of both medical oncology and cancer control and prevention.

The role of the gut microbiome in modulating immunotherapy efficacy in colorectal cancer

This systematic literature review and meta-analysis provide an overview of the critical role of gut microbiota in modulating the efficacy of immunotherapy for colorectal cancer. Gut microbes influence host immune responses through multiple mechanisms including modulation of immune cell activity, metabolite action, and immune tolerance. The ability of specific gut microbes to improve the efficacy of immune checkpoint inhibitors has been linked to their ability to improve gut barrier function, modulate immune cell activity, and produce key immunomodulatory metabolites such as short-chain fatty acids. In addition, the composition and diversity of the gut microbiota are strongly associated with the efficacy of immunotherapies, demonstrating the potential to improve therapeutic response by modifying the gut microbiota. This paper also discusses the prospect of manipulating the gut microbiota through strategies such as fecal microbial transplantation, probiotic supplementation, and dietary modifications to optimize the efficacy of immunotherapy.

Frequent intake of high fiber and probiotic diets lowers risks associated with atopic dermatitis and house dust mite allergy: a cross-sequential study of young Chinese adults from Singapore and Malaysia

PURPOSE

Dietary fiber intake may influence the risk and severity of atopic dermatitis (AD), a common chronic allergic skin condition. This cross-sequential study investigated the association between dietary fiber intake and various characteristics of AD, including house dust mites (HDM) allergy and dry skin, in 13,561 young Chinese adults (mean years = 22.51, SD ± 5.90) from Singapore and Malaysia.

METHODS

Dietary habits were assessed using a validated semi-quantitative, investigator-administered food frequency questionnaire from the International Study of Asthma and Allergies in Childhood. We derived an amount-based dietary index to estimate fiber intake while studying its correlation with probiotic drinks intake. AD status was determined by skin prick tests for HDM and symptomatic histories of eczema. Multivariable logistic regression analysis, adjusting for demographic, genetic predisposition, body mass index and lifestyle factors, and synergy factor analysis were used to explore the association and interaction of dietary factors on disease outcomes.

RESULTS

High fiber intake (approximately 98.25 g/serving/week) significantly lowered the associated risks for HDM allergy (Adjusted Odds Ratio [AOR]: 0.895; 95% Confidence Intervals [CI]: 0.810-0.989; adjusted p-value < 0.05) and AD (AOR: 0.831; 95% CI: 0.717-0.963; adjusted p-value < 0.05), but not dry skin. While probiotic intake was not associated with AD, it was significantly correlated with fiber intake (R2 = 0.324, p-value < 0.0001). Among those frequently consuming probiotics, moderate fiber intake sufficiently lowered the AD risk (AOR: 0.717; 95% CI: 0.584-0.881; adjusted p-value < 0.01). Moreover, a fibre-rich diet independently mitigated risks associated with high intake of fats, saturated fats, and protein.

CONCLUSION

A high-fiber diet is associated with AD and HDM allergy. Moderate-to-high fiber intake, particularly in conjunction with probiotics, may further mitigate AD risks.

Gut microbiota as a biomarker and modulator of anti-tumor immunotherapy outcomes

Although immune-checkpoint inhibitors (ICIs) have significantly improved cancer treatment, their effectiveness is limited by primary or acquired resistance in many patients. The gut microbiota, through its production of metabolites and regulation of immune cell functions, plays a vital role in maintaining immune balance and influencing the response to cancer immunotherapies. This review highlights evidence linking specific gut microbial characteristics to increased therapeutic efficacy in a variety of cancers, such as gastrointestinal cancers, melanoma, lung cancer, urinary system cancers, and reproductive system cancers, suggesting the gut microbiota's potential as a predictive biomarker for ICI responsiveness. It also explores the possibility of enhancing ICI effectiveness through fecal microbiota transplantation, probiotics, prebiotics, synbiotics, postbiotics, and dietary modifications. Moreover, the review underscores the need for extensive randomized controlled trials to confirm the gut microbiota's predictive value and to establish guidelines for microbiota-targeted interventions in immunotherapy. In summary, the article suggests that a balanced gut microbiota is key to maximizing immunotherapy benefits and calls for further research to optimize microbiota modulation strategies for cancer treatment. It advocates for a deeper comprehension of the complex interactions between gut microbiota, host immunity, and cancer therapy, aiming for more personalized and effective treatment options.

Prevotellaceae Modulates Colorectal Cancer Immune Microenvironment to Assist Anti-PD-L1 Immunotherapy

Background/Aims

Colorectal cancer (CRC) stands as the third most prevalent cancer on a global scale. In recent years, immunotherapy, such as anti-PD-L1 treatment, has demonstrated promising therapeutic outcomes in CRC. However, studies have suggested that intestinal microbiota may influence the efficacy of anti-PD-L1 immunotherapy. This study aimed to investigate the linkage between intestinal bacteria and anti-PD-L1 therapy.

Materials and Methods

Bioinformatics analysis was employed to study the correlation between the intestinal microbiota of CRC patients and immune infiltration. The study delved into the relationship between Prevotellaceae and immune-related genes in CRC. Mouse experiments were conducted to validate the association between Prevotellaceae abundance and the efficacy of anti-PD-L1 tumor treatment. Prevotellaceae abundance in mouse feces was assayed by 16S sequencing. Flow cytometry was utilized to assay immune cell infiltration in patient tumor tissues, while western blot and quantitative polymerase chain reaction (qPCR) assays measured IFN-γ, IL-2, and PD-L1 levels in tumor tissues.

Results

The high immune cell infiltration group demonstrated reduced tumor purity when compared with the group displaying low immune cell infiltration. Substantial variances were discerned in the Stromal Score, Immune Score, ESTIMATE Score, and Tumor Purity among the 3 distinct subtypes. The community evenness in the gut microbiota of CRC patients from cluster 2 and cluster 3 subtypes displayed significant differences. Members of the Prevotellaceae family were significantly enriched in the gut microbiota of cluster 3 subtype patients. In vivo experiments ascertained the supportive role of Prevotellaceae in anti-PD-L1 immunotherapy.

Conclusion

The facilitating effect of Prevotellaceae on anti-PD-L1 treatment was demonstrated in CRC. The findings suggest that elevating Prevotellaceae abundance may offer a new direction for assisting in CRC immunotherapy and provide a foundation for devising more effective CRC immunotherapeutic strategies.

asmbPLS: biomarker identification and patient survival prediction with multi-omics data

Introduction

With the advancement of high-throughput studies, an increasing wealth of high-dimensional multi-omics data is being collected from the same patient cohort. However, leveraging this multi-omics data to predict survival outcomes poses a significant challenge due to its complex structure.

Methods

In this article, we present a novel approach, the Adaptive Sparse Multi-Block Partial Least Squares (asmbPLS) Regression model, which introduces a dynamic assignment of penalty factors to distinct blocks within various PLS components, facilitating effective feature selection and prediction.

Results

We compared the proposed method with several state-of-the-art algorithms encompassing prediction performance, feature selection and computation efficiency. We conducted comprehensive evaluations using both simulated data with various scenarios and a real dataset from the melanoma patients to validate the effectiveness and efficiency of the asmbPLS method. Additionally, we applied the lung squamous cell carcinoma (LUSC) dataset from The Cancer Genome Atlas (TCGA) to further assess the feature selection capability of asmbPLS.

Discussion

The inherent nature of asmbPLS imparts it with higher sensitivity in feature selection compared to other methods. Furthermore, an R package called asmbPLS implementing this method is made publicly available.

The impact of fibre and prebiotic interventions on outcomes in cancer and haematopoietic stem cell transplantation: A systematic review

BACKGROUND & AIMS

Cancer therapy is associated with a range of toxicities that severely impact patient well-being and a range of clinical outcomes. Dietary fibre/prebiotics characteristically improve the gastrointestinal microenvironment, which consequently elicits beneficial downstream effects that could be relevant to the prevention and management of treatment-related toxicities. Despite the compelling theoretical scientific rationale there has been limited effort to synthesise the available evidence to conclude such scientific underpinning to the clinical use of fibre/prebiotics in cancer patients. Therefore, this systematic review aimed to evaluate the clinical impact of fibre/prebiotic-based interventions on gastrointestinal-side effects; gastrointestinal-microbiome; clinical outcomes; nutrition status and body composition; and quality-of-life in children and adults being treated for cancer or undergoing a haematopoietic stem cell transplant (HSCT).

METHODS

This study was conducted in adherence to PRISMA guidelines, and the protocol was published prospectively with PROSPERO (CRD42022299428). Three databases (MEDLINE (Ovid), CINHAL, EMBASE) were searched from inception to December 2023. All articles were assessed for bias using the Cochrane risk-of-bias tool RoB 2.0 (for RCTs) and ROBINS-I (for non-RCTs).

RESULTS

A total of 9989 de-duplicated records were identified, of these, 14 (paediatrics [n = 1], adults [n = 13]) met the inclusion criteria (randomised controlled trials (RCT) [n = 11], observational or non-RCTs [n = 3]). The risk-of-bias was graded to be serious/high (n = 6); moderate/some concerns (n = 7); low (n = 1). Interventions included prebiotic supplement (n = 8), nutrition supplement/formula with added fibre/prebiotic (n = 3) and dietary modification (n = 3). The dose of fibre intervention ranged from 2.4g to 30g per day. Substantial heterogeneity of target parameters was identified across a range all outcome categories, precluding definitive conclusions.

CONCLUSION

The scientific rationale for fibre/prebiotics-based interventions for the prevention or management of cancer treatment-related toxicities is compelling. However, it is clear that the scientific and clinical field remains disconnected in how to effectively translate this approach to improve cancer outcomes. High-quality intervention studies translatable to clinical practice are now evidently crucial to determine if and how fibre/prebiotics should be used to support people undergoing cancer or HSCT therapy.

A yeast-based oral therapeutic delivers immune checkpoint inhibitors to reduce intestinal tumor burden

Engineered probiotics are an emerging platform for in situ delivery of therapeutics to the gut. Herein, we developed an orally administered, yeast-based therapeutic delivery system to deliver next-generation immune checkpoint inhibitor (ICI) proteins directly to gastrointestinal tumors. We engineered Saccharomyces cerevisiae var. boulardii (Sb), a probiotic yeast with high genetic tractability and innate anticancer activity, to secrete "miniature" antibody variants that target programmed death ligand 1 (Sb_haPD-1). When tested in an ICI-refractory colorectal cancer (CRC) mouse model, Sb_haPD-1 significantly reduced intestinal tumor burden and resulted in significant shifts to the immune cell profile and microbiome composition. This oral therapeutic platform is modular and highly customizable, opening new avenues of targeted drug delivery that can be applied to treat a myriad of gastrointestinal malignancies.

Oncolytic Virotherapies and Adjuvant Gut Microbiome Therapeutics to Enhance Efficacy Against Malignant Gliomas

Glioblastoma (GBM) is the most prevalent malignant brain tumor. Current standard-of-care treatments offer limited benefits for patient survival. Virotherapy is emerging as a novel strategy to use oncolytic viruses (OVs) for the treatment of GBM. These engineered and non-engineered viruses infect and lyse cancer cells, causing tumor destruction without harming healthy cells. Recent advances in genetic modifications to OVs have helped improve their targeting capabilities and introduce therapeutic genes, broadening the therapeutic window and minimizing potential side effects. The efficacy of oncolytic virotherapy can be enhanced by combining it with other treatments such as immunotherapy, chemotherapy, or radiation. Recent studies suggest that manipulating the gut microbiome to enhance immune responses helps improve the therapeutic efficacy of the OVs. This narrative review intends to explore OVs and their role against solid tumors, especially GBM while emphasizing the latest technologies used to enhance and improve its therapeutic and clinical responses.

Dietary pattern and the corresponding gut microbiome in response to immunotherapy in Thai patients with advanced non-small cell lung cancer (NSCLC)

Gut microbiota is considered a key player modulating the response to immune checkpoint inhibitors (ICI) in cancer. The effects of dietary pattern on this interaction is not well-studied. A prospective multicenter cohort of 95 patients with advanced non-small cell lung cancer (NSCLC) undergoing ICI therapy were enrolled. Stool shotgun metagenomic sequencing was performed. Three-day dietary patterns before ICI were assessed. Patients were categorized as hyperprogressive disease (HPD) if they exhibited a time to treatment failure of less than 2 months. All others were categorized as non-hyperprogressive disease (non-HPD). The correlation between dietary patterns, gut microbiome, and response to ICI therapy was analyzed. In the multivariate analysis, a high abundance of Firmicutes unclassified and the Ruminococcaceae family correlated with a significantly diminished progression-free survival (PFS) with an HR of 2.40 [P = 0.006] and 4.30 [P = 0.005], respectively. More specifically, within the subset of NSCLC patients treated solely with ICI therapy, a high abundance of Intestinimonas and the Enterobacteriaceae family were associated with substantially reduced PFS with an HR of 2.61 [P = 0.02] and HR 3.34 [P = 0.005], respectively. In our comprehensive dietary pattern analysis, the HPD group showed increased consumption of cholesterol, sodium, and fats beyond recommended levels compared to the non-HPD group. This group also displayed a tendency towards higher food pattern scores characterized by a high intake of fat and dairy products. Our study revealed a distinct association between the gut microbiome composition and treatment outcomes. The overall composition of diet might be related to ICI therapeutic outcomes.

Longitudinal analysis of the gut microbiota during anti-PD-1 therapy reveals stable microbial features of response in melanoma patients

Immune checkpoint inhibitors (ICIs) improve outcomes in advanced melanoma, but many patients are refractory or experience relapse. The gut microbiota modulates antitumor responses. However, inconsistent baseline predictors point to heterogeneity in responses and inadequacy of cross-sectional data. We followed patients with unresectable melanoma from baseline and during anti-PD-1 therapy, collecting fecal and blood samples that were surveyed for changes in the gut microbiota and immune markers. Varying patient responses were linked to different gut microbiota dynamics during ICI treatment. We select complete responders by their stable microbiota functions and validate them using multiple external cohorts and experimentally. We identify major histocompatibility complex class I (MHC class I)-restricted peptides derived from flagellin-related genes of Lachnospiraceae (FLach) as structural homologs of tumor-associated antigens, detect FLach-reactive CD8+ T cells in complete responders before ICI therapy, and demonstrate that FLach peptides improve antitumor immunity. These findings highlight the prognostic value of microbial functions and therapeutic potential of tumor-mimicking microbial peptides.

Dietary auxin may help patients to fight cancer

The phytohormone auxin (indole-3-acetic acid; IAA) increases the efficacy of cancer treatment. IAA is a universal molecule, being produced by bacteria, fungi, and plants. Therefore, incorporating IAA-rich products derived from microbes or plants, such as yoghurt, probiotics, microgreens, and fresh carrots into the diet may be promising for disease management.

Structural elucidation of a capsular polysaccharide from Bacteroides uniformis and its ameliorative impact on DSS-induced colitis in mice

Capsular polysaccharides derived from Bacteroides species have emerged as potential mitigators of intestinal inflammation in murine models. However, research on capsular polysaccharides from B. uniformis, a Bacteroides species with reduced abundance in colons of patients with ulcerative colitis, remains scarce. In this study, we extracted a neutral polysaccharide component from B. uniformis ATCC8492, termed BUCPS1B, using ultrasonic disruption, ethanol precipitation, and anion exchange chromatography. Structural characterization revealed BUCPS1B as a water-soluble polysaccharide with an α-1,4-glucan main chain adorned with minor substituent sugar residues. BUCPS1B alleviated intestinal inflammation in a mouse model of colitis and induced polarization of macrophages into M2-type. Furthermore, BUCPS1B modulated the gut microbiota composition, increased the abundance of the probiotic Akkermansia muciniphila and altered the gut metabolic profile to promote phenylalanine and short chain fatty acids metabolism. BUCPS1B is therefore a promising candidate to prevent inflammation and augment intestinal health.

Microbiome dynamics in immune checkpoint blockade

Immune checkpoint blockade (ICB) is one of the leading immunotherapies, although a variable extent of resistance has been observed among patients and across cancer types. Among the efforts underway to overcome this challenge, the microbiome has emerged as a factor affecting the responsiveness and efficacy of ICB. Active research, facilitated by advances in sequencing techniques, is assessing the predominant influence of the intestinal microbiome, as well as the effects of the presence of an intratumoral microbiome. In this review, we describe recent findings from clinical trials, observational studies of human patients, and animal studies on the impact of the microbiome on the efficacy of ICB, highlighting the role of the intestinal and tumor microbiomes and the contribution of methodological advances in their study.

Recent Advances in Bacterium-Based Therapeutic Modalities for Melanoma Treatment

Melanoma is one of the most severe skin cancer indications with rapid progression and a high risk of metastasis. However, despite the accumulated advances in melanoma treatment including adjuvant radiation, chemotherapy, and immunotherapy, the overall melanoma treatment efficacy in the clinics is still not satisfactory. Interestingly, bacterial therapeutics have demonstrated unique properties for tumor-related therapeutic applications, such as tumor-targeted motility, tailorable cytotoxicity, and immunomodulatory capacity of the tumor microenvironment, which have emerged as a promising platform for melanoma therapy. Indeed, the recent advances in genetic engineering and nanotechnologies have boosted the application potential of bacterium-based therapeutics for treating melanoma by further enhancing their tumor-homing, cell-killing, drug delivery, and immunostimulatory capacities. This review provides a comprehensive summary of the state-of-the-art bacterium-based anti-melanoma modalities, which are categorized according to their unique functional merits, including tumor-specific cytotoxins, tumor-targeted drug delivery platforms, and immune-stimulatory agents. Furthermore, a perspective is provided discussing the potential challenges and breakthroughs in this area. The insights in this review may facilitate the development of more advanced bacterium-based therapeutic modalities for improved melanoma treatment efficacy.

Disentangling the molecular mystery of tumour-microbiota interactions: Microbial metabolites

The profound impact of the microbiota on the initiation and progression of cancer has been a focus of attention. In recent years, many studies have shown that microbial metabolites serve as key hubs that connect the microbiome and cancer progression, but the underlying molecular mechanisms have not been fully elucidated. Multiple mechanisms that influence tumour development and therapy resistance, including disrupting cellular signalling pathways, triggering oxidative stress, inducing metabolic reprogramming and reshaping tumour immune microenvironment, are reviewed. Focusing on recent advancements in this field, this review also summarises the methodological framework of studies regarding microbial metabolites. In this review, we outline the current state of research on tumour-associated microbial metabolites and describe the challenges in future scientific research and clinical applications. KEY POINTS: Metabolites derived from both gut and intratumoural microbiota play important roles in cancer initiation and progression. The dual roles of microbial metabolites pose an obstacle for clinical translations. Absolute quantification and tracing techniques of microbial metabolites are essential for addressing the gaps in studies on microbial metabolites. Integrating microbial metabolomics with multi-omics transcends current research paradigms.

Annexin A1: a key regulator of T cell function and bone marrow adiposity in aplastic anaemia

This study investigates the role of Annexin A1 (ANXA1) in regulating T cell function and its implications in bone marrow adiposity in aplastic anaemia (AA). Utilizing single-cell sequencing analysis, we compared bone marrow tissues from AA patients and healthy individuals, focusing on T cell subgroups and their impact on bone marrow pathology. Our findings reveal a significant activation of CD8+ T cells in AA, driven by reduced ANXA1 expression. This heightened T cell activity promotes adipogenesis in bone marrow-derived mesenchymal stem cells via IFN-γ secretion. Overexpression of ANXA1 was found to suppress this process, suggesting its therapeutic potential in AA treatment. The study highlights ANXA1 as a crucial regulator in the AA-associated immune microenvironment and bone marrow adiposity. KEY POINTS: This study found that ANXA1 is significantly downregulated in AA and provides detailed insights into its critical role in the disease. The study demonstrates the excessive activation of CD8+ T cells in the progression of AA. The research shows that the overexpression of ANXA1 can effectively inhibit the activation of CD8+ T cells. The study confirms that overexpression of ANXA1 reduces the secretion of the cytokine IFN-γ, decreases adipogenesis in bone marrow-derived mesenchymal stem cells and may improve AA symptoms. This research provides new molecular targets for the treatment of AA.

A multi-glycomic platform for the analysis of food carbohydrates

Carbohydrates comprise the largest fraction of most diets and exert a profound impact on health. Components such as simple sugars and starch supply energy, while indigestible components, deemed dietary fiber, reach the colon to provide food for the tens of trillions of microbes that make up the gut microbiota. The interactions between dietary carbohydrates, our gastrointestinal tracts, the gut microbiome and host health are dictated by their structures. However, current methods for analysis of food glycans lack the sensitivity, specificity and throughput needed to quantify and elucidate these myriad structures. This protocol describes a multi-glycomic approach to food carbohydrate analysis in which the analyte might be any food item or biological material such as fecal and cecal samples. The carbohydrates are extracted by ethanol precipitation, and the resulting samples are subjected to rapid-throughput liquid chromatography (LC)-tandem mass spectrometry (LC-MS/MS) methods. Quantitative analyses of monosaccharides, glycosidic linkages, polysaccharides and alcohol-soluble carbohydrates are performed in 96-well plates at the milligram scale to reduce the biomass of sample required and enhance throughput. Detailed stepwise processes for sample preparation, LC-MS/MS and data analysis are provided. We illustrate the application of the protocol to a diverse set of foods as well as different apple cultivars and various fermented foods. Furthermore, we show the utility of these methods in elucidating glycan-microbe interactions in germ-free and colonized mice. These methods provide a framework for elucidating relationships between dietary fiber, the gut microbiome and human physiology. These structures will further guide nutritional and clinical feeding studies that enhance our understanding of the role of diet in nutrition and health.

Exploring the Interplay of Diet, Obesity, Immune Function, and Cancer

This commentary provides an in-depth exploration of the intricate relationships among diet, obesity, immune function, and cancer, highlighting the potential role of dietary interventions as complementary therapies in cancer treatment. Multiple analyses underscore the importance of personalized dietary strategies in cancer management and identify opportunities for further research in this evolving field.

Design of probiotic delivery systems and their therapeutic effects on targeted tissues

The microbiota at different sites in the body is closely related to disease. The intake of probiotics is an effective strategy to alleviate diseases and be adjuvant in their treatment. However, probiotics may suffer from harsh environments and colonization resistance, making it difficult to maintain a sufficient number of live probiotics to reach the target sites and exert their original probiotic effects. Encapsulation of probiotics is an effective strategy. Therefore, probiotic delivery systems, as effective methods, have been continuously developed and innovated to ensure that probiotics are effectively delivered to the targeted site. In this review, initially, the design of probiotic delivery systems is reviewed from four aspects: probiotic characteristics, processing technologies, cell-derived wall materials, and interactions between wall materials. Subsequently, the review focuses on the effects of probiotic delivery systems that target four main microbial colonization sites: the oral cavity, skin, intestine, and vagina, as well as disease sites such as tumors. Finally, this review also discusses the safety concerns of probiotic delivery systems in the treatment of disease and the challenges and limitations of implementing this method in clinical studies. It is necessary to conduct more clinical studies to evaluate the effectiveness of different probiotic delivery systems in the treatment of diseases.

Dietary Sugar and Saturated Fat Consumption Associated with the Gastrointestinal Microbiome during Pregnancy

BACKGROUND

Growing evidence supports changes in the gastrointestinal microbiome over the course of pregnancy may have an impact on the short- and long-term health of both the mother and the child.

OBJECTIVE

Our objective was to explore the association of diet quality, as measured by the Healthy Eating Index (HEI), with the composition and gene ontology (GO) representation of microbial function in the maternal gastrointestinal microbiome during pregnancy.

METHODS

We conducted a retrospective, observational analysis of n = 185 pregnant participants in the Pregnancy Eating Attributes Study. Maternal dietary intake was assessed in the first trimester using the automated self-administered 24-h recall method, from which the HEI 2015 was calculated. Rectal swabs were obtained in the second trimester and sequenced using the NovaSeq 6000 system shotgun platform. We used unsupervised clustering to identify microbial enterotypes representative of maternal taxa and GO functional term composition. Multivariable linear models were used to identify associations between taxa, functional terms, and food components while controlling for relevant covariates. Multinomial regression was then used to predict enterotype membership based on a participant's HEI food component score.

RESULTS

Those in the high diet quality tertile had a lower early pregnancy BMI [mean (M) = 23.48 kg/m2, SD = 3.38] compared with the middle (M = 27.35, SD = 6.01) and low (M = 27.49, SD = 6.99) diet quality tertiles (P < 0.01). There were no statistically significant associations between the HEI components or the total HEI score and the 4 alpha diversity measures. Differences in taxa and GO term enterotypes were found in participants with, but not limited to, a higher saturated fat component score (β = 1.35, P = 0.01), added sugar HEI component (β = 0.07, P < 0.001), and higher total dairy score (β = 1.58, P = 0.01).

CONCLUSIONS

Specific dietary components are associated with microbial composition and function in the second trimester of pregnancy. These findings provide a foundation for future testable hypotheses.

Immune-related adverse events in a nationwide cohort of real-world melanoma patients treated with adjuvant anti-PD1 - Seasonal variation and association with outcome

INTRODUCTION

Immune checkpoint inhibitors (ICIs) carry the risk of immune-related adverse events (irAEs), a significant concern as therapy has transitioned to the adjuvant setting. Balancing therapeutic benefits against potential risks is crucial, necessitating real-world data from an unselected patient population in addition to clinical trial data to ensure optimal clinical decision-making.

METHODS

This nationwide real-world study assessed irAEs in patients receiving adjuvant anti-PD1 therapy, primarily nivolumab, for resected stage III-IV melanoma between 2018-2022. Data were retrieved from two national databases: the IMMUNOTOX database and the Danish Metastatic Melanoma Database (DAMMED). IrAEs were sub-grouped according to organ systems graded using CTCAE ver. 5.0 ranging from mild toxicities (grade 1-2) to severe (grade 3-4) and fatal (grade 5).

RESULTS

Among 792 included patients, (55 % male, median age 62 years (range 16-88)), 697 patients (88 %) experienced an irAE. Severe irAEs occurred in 116 patients (15 %) and five (0.6 %) died due to toxicity. A landmark analysis showed that patients who experienced at least one irAE before the 1st evaluation at 90 days had an increased progression free survival (PFS) (p = 0.032) and overall survival (OS) (p = 0.0071). Additionally, a seasonal pattern was noted with higher incidence of irAEs during summer.

CONCLUSION

The prevalence of irAEs in real-world patients is comparable to the observed risk in clinical trials. Patients experiencing irAEs demonstrate a lower risk of melanoma relapse. Further, gender, age and seasonal variation may impact the incidence of irAEs.

Fecal microbial transplants as investigative tools in cancer

The gut microbiome plays a critical role in the development, progression, and treatment of cancer. As interest in microbiome-immune-cancer interactions expands, the prevalence of fecal microbial transplant (FMT) models has increased proportionally. However, current literature does not provide adequate details or consistent approaches to allow for necessary rigor and experimental reproducibility. In this review, we evaluate key studies using FMT to investigate the relationship between the gut microbiome and various types of cancer. In addition, we will discuss the common pitfalls of these experiments and methods for improved standardization and validation as the field uses FMT with greater frequency. Finally, this review focuses on the impacts of the gut and extraintestinal microbes, prebiotics, probiotics, and postbiotics in cancer risk and response to therapy across a variety of tumor types.NEW & NOTEWORTHY The microbiome impacts the onset, progression, and therapy response of certain types of cancer. Fecal microbial transplants (FMTs) are an increasingly prevalent tool to test these mechanisms that require standardization by the field.

Effects of gut microbiota on immune checkpoint inhibitors in multi-cancer and as microbial biomarkers for predicting therapeutic response

BACKGROUND

Gut bacteria are related to immune checkpoint inhibitors (ICIs). However, there is inconsistency in ICI-associated species, while the role of non-bacterial microbes in immunotherapy remains elusive. Here, we evaluated the association of trans-kingdom microbes with ICIs by multi-cohort multi-cancer analyses.

METHODS

We retrieved fecal metagenomes from 1,359 ICI recipients with four different cancers (metastatic melanoma [MM], non-small cell lung carcinoma [NSCLC], renal cell cancer [RCC], and hepatocellular carcinoma) from 12 published datasets. Microbiota composition was analyzed using the Wilcoxon rank test. The performance of microbial biomarkers in predicting ICI response was assessed by random forest. Key responder-associated microbes were functionally examined in vitro and in mice.

FINDINGS

Trans-kingdom gut microbiota (bacteria, eukaryotes, viruses, and archaea) was significantly different between ICI responders and non-responders in multi-cancer. Bacteria (Faecalibacterium prausnitzii, Coprococcus comes) and eukaryotes (Nemania serpens, Hyphopichia pseudoburtonii) were consistently enriched in responders of ≥2 cancer types or from ≥3 cohorts, contrasting with the depleted bacterium Hungatella hathewayi. Responder-associated species in each cancer were revealed, such as F. prausnitzii in MM and 6 species in NSCLC. These signature species influenced ICI efficacy by modulating CD8+ T cell activity in vitro and in mice. Moreover, bacterial and eukaryotic biomarkers showed great performance in predicting ICI response in patients from discovery and two validation cohorts (MM: area under the receiver operating characteristic curve [AUROC] = 72.27%-80.19%; NSCLC: AUROC = 72.70%-87.98%; RCC: AUROC = 83.33%-89.58%).

CONCLUSIONS

This study identified trans-kingdom microbial signatures associated with ICI in multi-cancer and specific cancer types. Trans-kingdom microbial biomarkers are potential predictors of ICI response in patients with cancer.

FUNDING

Funding information is shown in the acknowledgments.

A whole food, plant-based diet reduces amino acid levels in patients with metastatic breast cancer

Background

Amino acids are critical to tumor survival. Tumors can acquire amino acids from the surrounding microenvironment, including the serum. Limiting dietary amino acids is suggested to influence their serum levels. Further, a plant-based diet is reported to contain fewer amino acids than an animal-based diet. The extent to which a plant-based diet lowers the serum levels of amino acids in patients with cancer is unclear.

Methods

Patients with metastatic breast cancer (n=17) were enrolled in a clinical trial with an ad libitum whole food, plant-based diet for 8 weeks without calorie or portion restriction. Dietary changes by participants were monitored using a three-day food record. Serum was collected from participants at baseline and 8 weeks. Food records and serum were analyzed for metabolic changes.

Results

We found that a whole food, plant-based diet resulted in a lower intake of calories, fat, and amino acids and higher levels of fiber. Additionally, body weight, serum insulin, and IGF were reduced in participants. The diet contained lower levels of essential and non-essential amino acids, except for arginine (glutamine and asparagine were not measured). Importantly, the lowered dietary intake of amino acids translated to reduced serum levels of amino acids in participants (5/9 essential amino acids; 4/11 non-essential amino acids).

Conclusions

These findings provide a tractable approach to limiting amino acid levels in persons with cancer. This data lays a foundation for studying the relationship between amino acids in patients and tumor progression. Further, a whole-food, plant-based diet has the potential to synergize with cancer therapies that exploit metabolic vulnerabilities.

Trial Registration

The clinical trial was registered with ClinicalTrials.gov identifier NCT03045289 on 2017-02-07.

Microbiome research in autoimmune and immune-mediated inflammatory diseases: lessons, advances and unmet needs

The increasing prevalence of autoimmune and immune-mediated diseases (AIMDs) underscores the need to understand environmental factors that contribute to their pathogenesis, with the microbiome emerging as a key player. Despite significant advancements in understanding how the microbiome influences physiological and inflammatory responses, translating these findings into clinical practice remains challenging. This viewpoint reviews the progress and obstacles in microbiome research related to AIMDs, examining molecular techniques that enhance our understanding of microbial contributions to disease. We discuss significant discoveries linking specific taxa and metabolites to diseases such as rheumatoid arthritis, systemic lupus erythematosus and spondyloarthritis, highlighting the role of gut dysbiosis and host-microbiome interactions. Furthermore, we explore the potential of microbiome-based therapeutics, including faecal microbiota transplantation and pharmacomicrobiomics, while addressing the challenges of identifying robust microbial targets. We advocate for integrative, transdisease studies and emphasise the need for diverse cohort research to generalise findings across populations. Understanding the microbiome's role in AIMDs will pave the way for personalised medicine and innovative therapeutic strategies.

Targeting the Intestinal Microbiota: A Novel Direction in the Treatment of Inflammatory Bowel Disease

Over the past decade, there has been a rapid increase in the incidence of inflammatory bowel disease. It has been suggested that multifactorial interactions of environmental factors, genetic factors, immune response and intestinal microbiota are involved in the pathogenesis of inflammatory bowel disease. It is widely recognized that the intestinal microbiota are essential for human metabolism, the immune system and pathogen resistance, and are integral to human health. Therefore, the dysbiosis of the microbiota is a critical step leading to intestinal mucosal damage and a key factor in the pathogenesis of inflammatory bowel disease. Regulating the microbiota through interventions such as enteral nutrition, fecal microbiota transplantation, and probiotic supplementation has the potential to prevent or even reverse intestinal dysbiosis, opening up new perspectives for the treatment of inflammatory bowel disease.

Influence of the gut microbiota on immune cell interactions and cancer treatment

The tumour microenvironment represents a novel frontier in oncological research. Over the past decade, accumulating evidence has underscored the importance of the tumour microenvironment (TME), including tumour cells, stromal cells, immune cells, and various secreted factors, which collectively influence tumour growth, invasion, and responses to therapeutic agents. Immune cells within the TME are now widely acknowledged to play pivotal roles in tumour development and treatment. While some perspectives have posited that immune cells within the TME facilitate tumour progression and confer resistance to therapeutic interventions, contrasting conclusions also exist. Affirmative and negative conclusions appear to be context dependent, and a unified consensus has yet to be reached. The burgeoning body of research on the relationship between the gut microbiota and tumours in recent years has led to a growing understanding. Most studies have indicated that specific components of the gut microbiota, such as unique bacterial communities or specific secretory factors, play diverse roles in regulating immune cells within the TME, thereby influencing the prognosis and outcomes of cancer treatments. A detailed understanding of these factors could provide novel insights into the TME and cancer therapy. In this study, we aimed to synthesise information on the interactions between the gut microbiota and immune cells within the TME, providing an in-depth exploration of the potential guiding implications for future cancer therapies.

The gut microbiome and dietary fibres: implications in obesity, cardiometabolic diseases and cancer

Dietary fibres constitute a heterogeneous class of nutrients that are key in the prevention of various chronic diseases. Most dietary fibres are fermented by the gut microbiome and may, thereby, modulate the gut microbial ecology and metabolism, impacting human health. Dietary fibres may influence the occurrence of specific bacterial taxa, with this effect varying between individuals. The effect of dietary fibres on microbial diversity is a matter of debate. Most intervention studies with dietary fibres in the context of obesity and related metabolic disorders reveal the need for an accurate assessment of the microbiome to better understand the variable response to dietary fibres. Epidemiological studies confirm that a high dietary fibre intake is strongly associated with a reduced occurrence of many types of cancer. However, there is a need to determine the impact of intervention with specific dietary fibres on cancer risk, therapy efficacy and toxicity, as well as in cancer cachexia. In this Review, we summarize the mechanisms by which the gut microbiome can mediate the physiological benefits of dietary fibres in the contexts of obesity, cardiometabolic diseases and cancer, their incidence being clearly linked to low dietary fibre intake.

The immunomodulatory effects of vitamins in cancer

Nutrition may affect animal health due to the strong link between them. Also, diets improve the healing process in various disease states. Cancer is a disease, where the harmful consequences of tumors severely impair the body. The information regarding the evolution of this disease is extrapolated from human to animal because there are few specific studies regarding nutritional needs in animals with cancer. Thus, this paper aims to review the literature regarding the immunomodulatory effects of vitamins in mammal cancer. An adequate understanding of the metabolism and requirements of nutrients for mammals is essential to ensuring their optimal growth, development, and health, regardless of their food sources. According to these: 1) Some species are highly dependent on vitamin D from food, so special attention must be paid to this aspect. Calcitriol/VDR signaling can activate pro-apoptotic proteins and suppress anti-apoptotic ones. 2) Nitric oxide (NO) production is modulated by vitamin E through inhibiting transcription nuclear factor kappa B (NF-κB) activation. 3) Thiamine supplementation could be responsible for the stimulation of tumor cell proliferation, survival, and resistance to chemotherapy. 4) Also, it was found that the treatment with NO-Cbl in dogs is a viable anti-cancer therapy that capitalizes on the tumor-specific properties of the vitamin B12 receptor. Therefore, diets should contain the appropriate class of compounds in adequate proportions. Also, the limitations of this paper are that some vitamins are intensively studied and at the same time regarding others, there is a lack of information, especially in animals. Therefore, some subsections are longer and more heavily debated than others.

Advances in targeting tumor microenvironment for immunotherapy

The tumor microenvironment (TME) provides essential conditions for the occurrence, invasion, and spread of cancer cells. Initial research has uncovered immunosuppressive properties of the TME, which include low oxygen levels (hypoxia), acidic conditions (low pH), increased interstitial pressure, heightened permeability of tumor vasculature, and an inflammatory microenvironment. The presence of various immunosuppressive components leads to immune evasion and affects immunotherapy efficacy. This indicates the potential value of targeting the TME in cancer immunotherapy. Therefore, TME remodeling has become an effective method for enhancing host immune responses against tumors. In this study, we elaborate on the characteristics and composition of the TME and how it weakens immune surveillance and summarize targeted therapeutic strategies for regulating the TME.

Microbiome and Immunotherapy for Melanoma: Are We Ready for Clinical Application?

The microbiome plays a substantial role in the efficacy of immune checkpoint blockade (ICB) in patients with metastatic melanoma. While the exact gut microbiome composition and the pathways involved in this interaction are not clearly delineated, novel studies and ongoing clinical trials are likely to reveal findings applicable to the clinical setting for the prediction and optimization of response to ICB. Nevertheless, lifestyle modifications, including high fiber diet, avoidance of unnecessary antibiotic prescriptions, and careful use of probiotics may be helpful to optimize the "health" of the gut microbiome and potentially enhance response to ICB in patients with melanoma.

Impact of the Lung Microbiota on Development and Progression of Lung Cancer

The past several years have provided a more profound understanding of the role of microbial species in the lung. The respiratory tract is a delicate ecosystem of bacteria, fungi, parasites, and viruses. Detecting microbial DNA, pathogen-associated molecular patterns (PAMPs), and metabolites in sputum is poised to revolutionize the early diagnosis of lung cancer. The longitudinal monitoring of the lung microbiome holds the potential to predict treatment response and side effects, enabling more personalized and effective treatment options. However, most studies into the lung microbiota have been observational and have not adequately considered the impact of dietary intake and air pollutants. This gap makes it challenging to establish a direct causal relationship between environmental exposure, changes in the composition of the microbiota, lung carcinogenesis, and tumor progression. A holistic understanding of the lung microbiota that considers both diet and air pollutants may pave the way to improved prevention and management strategies for lung cancer.

The Role of Microbial Metabolites in the Progression of Neurodegenerative Diseases-Therapeutic Approaches: A Comprehensive Review

The objective of this review is to provide a comprehensive examination of the role of microbial metabolites in the progression of neurodegenerative diseases, as well as to investigate potential therapeutic interventions targeting the microbiota. A comprehensive literature search was conducted across the following databases: PubMed, Scopus, Web of Science, ScienceDirect, and Wiley. Key terms related to the gut microbiota, microbial metabolites, neurodegenerative diseases, and specific metabolic products were used. The review included both preclinical and clinical research articles published between 2000 and 2024. Short-chain fatty acids have been demonstrated to play a crucial role in modulating neuroinflammation, preserving the integrity of the blood-brain barrier, and influencing neuronal plasticity and protection. Furthermore, amino acids and their derivatives have been demonstrated to exert a significant influence on CNS function. These microbial metabolites impact CNS health by regulating intestinal permeability, modulating immune responses, and directly influencing neuroinflammation and oxidative stress, which are integral to neurodegenerative diseases. Therapeutic strategies, including prebiotics, probiotics, dietary modifications, and fecal microbiota transplantation have confirmed the potential to restore microbial balance and enhance the production of neuroprotective metabolites. Furthermore, novel drug developments based on microbial metabolites present promising therapeutic avenues. The gut microbiota and its metabolites represent a promising field of research with the potential to advance our understanding of and develop treatments for neurodegenerative diseases.

The DAV132 colon-targeted adsorbent does not interfere with plasma concentrations of antibiotics but prevents antibiotic-related dysbiosis: a randomized phase I trial in healthy volunteers

The deleterious impact of antibiotics (ATB) on the microbiome negatively influences immune checkpoint inhibitors (ICI) response in patients with cancer. We conducted a randomized phase I study (EudraCT:2019-A00240-57) with 148 healthy volunteers (HV) to test two doses of DAV132, a colon-targeted adsorbent, alongside intravenous ceftazidime-avibactam (CZA), piperacillin-tazobactam (PTZ) or ceftriaxone (CRO) and a group without ATB. The primary objective of the study was to assess the effect of DAV132 on ATB plasma concentrations and both doses of DAV132 did not alter ATB levels. Secondary objectives included safety, darkening of the feces, and fecal ATB concentrations. DAV132 was well tolerated, with no severe toxicity and similar darkening at both DAV132 doses. DAV132 led to significant decrease in CZA or PTZ feces concentration. When co-administered with CZA or PTZ, DAV132 preserved microbiome diversity, accelerated recovery to baseline composition and protected key commensals. Fecal microbiota transplantation (FMT) in preclinical cancer models in female mice from HV treated with CZA or PTZ alone inhibited anti-PD-1 response, while transplanted samples from HV treated with ATB + DAV132 circumvented resistance to anti-PD-1. This effect was linked to activated CD8+ T cell populations in the tumor microenvironment. DAV132 represents a promising strategy for overcoming ATB-related dysbiosis and further studies are warranted to evaluate its efficacy in cancer patients.

Gut microbiota influence on lung cancer risk through blood metabolite mediation: from a comprehensive Mendelian randomization analysis and genetic analysis

Background

Gut microbiota (GM) and metabolic alterations play pivotal roles in lung cancer (LC) development and host genetic variations are known to contribute to LC susceptibility by modulating the GM. However, the causal links among GM, metabolite, host genes, and LC remain to be fully delineated.

Method

Through bidirectional MR analyses, we examined the causal links between GM and LC, and utilized two-step mediation analysis to identify potential mediating blood metabolite. We employed diverse MR methods, including inverse-variance-weighted (IVW), weighted median, MR-Egger, weighted mode, and simple mode, to ensure a robust examination of the data. MR-Egger intercept test, Radial MR, MR-PRESSO, Cochran Q test and Leave-one-out (LOO) analysis were used for sensitivity analyses. Analyses were adjusted for smoking, alcohol intake frequency and air pollution. Linkage disequilibrium score regression and Steiger test were used to probe genetic causality. The study also explored the association between specific host genes and the abundance of gut microbes in LC patients.

Results

The presence of Bacteroides clarus was associated with an increased risk of LC (odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.03-1.11, p = 0.012), whereas the Eubacteriaceae showed a protective effect (OR = 0.82, 95% CI: 0.75-0.89, p = 0.001). These findings remained robust after False Discovery Rate (FDR) correction. Our mediator screening identified 13 blood metabolites that significantly influence LC risk after FDR correction, underscoring cystine and propionylcarnitine in reducing LC risk, while linking specific lipids and hydroxy acids to an increased risk. Our two-step mediation analysis demonstrated that the association between the bacterial pathway of synthesis of guanosine ribonucleotides and LC was mediated by Fructosyllysine, with mediated proportions of 11.38% (p = 0.037). LDSC analysis confirmed the robustness of these associations. Our study unveiled significant host genes ROBO2 may influence the abundance of pathogenic gut microbes in LC patients. Metabolic pathway analysis revealed glutathione metabolism and glutamate metabolism are the pathways most enriched with significant metabolites related to LC.

Conclusion

These findings underscore the importance of GM in the development of LC, with metabolites partly mediating this effect, and provide dietary and lifestyle recommendations for high-risk lung cancer populations.

Long-distance microbial mechanisms impacting cancer immunosurveillance

The intestinal microbiota determines immune responses against extraintestinal antigens, including tumor-associated antigens. Indeed, depletion or gross perturbation of the microbiota undermines the efficacy of cancer immunotherapy, thereby compromising the clinical outcome of cancer patients. In this review, we discuss the long-distance effects of the gut microbiota and the mechanisms governing antitumor immunity, such as the translocation of intestinal microbes into tumors, migration of leukocyte populations from the gut to the rest of the body, including tumors, as well as immunomodulatory microbial products and metabolites. The relationship between these pathways is incompletely understood, in particular the significance of the tumor microbiota with respect to the identification of host and/or microbial products that regulate the egress of bacteria and immunocytes toward tumor beds.

Pharmacomicrobiomics in precision cancer therapy: bench to bedside

The burgeoning field of pharmacomicrobiomics offers promising insights into the intricate interplay between the microbiome and cancer, shaping responses to diverse treatment modalities. This review aims to analyze the molecular mechanisms underlying interactions between distinct microbiota types and cancer, as well as their influence on treatment outcomes. We explore how the microbiome impacts antitumor immunity, and response to chemotherapy, immunotherapy, and radiation therapy, unveiling its multifaceted roles in cancer progression and therapy resistance. Moreover, we discuss the challenges hindering the development of microbiome-based interventions in cancer therapy, including standardization, validation, and clinical translation. By synthesizing clinical evidence, we underscore the transformative potential of harnessing pharmacomicrobiomics in guiding cancer treatment decisions, paving the way for improved patient outcomes in clinical practice.

The gut microbiome modulate response to immunotherapy in cancer

Gut microbiota have been reported to play an important role in the occurrence and development of malignant tumors. Currently, clinical studies have identified specific gut microbiota and its metabolites associated with efficacy of immunotherapy in multiple types of cancers. Preclinical investigations have elucidated that gut microbiota modulate the antitumor immunity and affect the efficacy of cancer immunotherapy. Certain microbiota and its metabolites may favorably remodel the tumor microenvironment by engaging innate and/or adaptive immune cells. Understanding how the gut microbiome interacts with cancer immunotherapy opens new avenues for improving treatment strategies. Fecal microbial transplants, probiotics, dietary interventions, and other strategies targeting the microbiota have shown promise in preclinical studies to enhance the immunotherapy. Ongoing clinical trials are evaluating these approaches. This review presents the recent advancements in understanding the dynamic interplay among the host immunity, the microbiome, and cancer immunotherapy, as well as strategies for modulating the microbiome, with a view to translating into clinical applications.