Modulating the microbiome to improve therapeutic response in cancer

The impact of the gut microbiome on tumor immunotherapy: from mechanism to application strategies

Immunotherapy is one of the fastest developing areas in the field of oncology. Many immunological treatment strategies for refractory tumors have been approved and marketed. Nevertheless, much clinical and preclinical experimental evidence has shown that the efficacy of immunotherapy in tumor treatment varies markedly among individuals. The commensal microbiome mainly colonizes the intestinal lumen in humans, is affected by a variety of factors and exhibits individual variation. Moreover, the gut is considered the largest immune organ of the body due to its influence on the immune system. In the last few decades, with the development of next-generation sequencing (NGS) techniques and in-depth research, the view that the gut microbiota intervenes in antitumor immunotherapy through the immune system has been gradually confirmed. Here, we review important studies published in recent years focusing on the influences of microbiota on immune system and the progression of malignancy. Furthermore, we discuss the mechanism by which microbiota affect tumor immunotherapy, including immune checkpoint blockade (ICB) and adoptive T-cell therapy (ACT), and strategies for modulating the microbial composition to facilitate the antitumor immune response. Finally, opportunity and some challenges are mentioned to enable a more systematic understanding of tumor treatment in the future and promote basic research and clinical application in related fields.

Modulation of gut microbiota: a novel approach to enhancing the effects of immune checkpoint inhibitors

Although immune checkpoint inhibitors (ICIs) have greatly improved the prognosis of some cancer patients, the majority still fail to respond adequately, and the available biomarkers cannot reliably predict drug efficacy. The gut microbiota has received widespread attention among the various intrinsic and extrinsic factors contributing to drug resistance. As an essential regulator of physiological function, the impact of gut microbiota on host immunity and response to cancer therapy is increasingly recognized. Several studies have demonstrated significant differences in gut microbiota between responders and nonresponders. The gut microbiota associated with better clinical outcomes is called 'favorable gut microbiota'. Significantly, interventions can alter the gut microbiota. By shifting the gut microbiota to the 'favorable' one through various modifications, preclinical and clinical studies have yielded more pronounced responses and better clinical outcomes when combined with ICIs treatment, providing novel approaches to improve the efficacy of cancer immunotherapy. These findings may be attributed to the effects of gut microbiota and its metabolites on the immune microenvironment and the systemic immune system, but the underlying mechanisms remain to be discovered. In this review, we summarize the clinical evidence that the gut microbiota is strongly associated with the outcomes of ICI treatment and describe the gut microbiota characteristics associated with better clinical outcomes. We then expand on the current prevalent modalities of gut microbiota regulation, provide a comprehensive overview of preclinical and clinical research advances in improving the therapeutic efficacy and prognosis of ICIs by modulating gut microbiota, and suggest fundamental questions we need to address and potential directions for future research expansion.

Neoadjuvant Immunotherapy in Early, Triple-Negative Breast Cancers: Catching Up with the Rest

Despite breast cancer being long thought to be "immunologically cold," within early, triple-negative breast cancer (TNBC), there has been exciting advances with the use of immune checkpoint modulation combined with neoadjuvant chemotherapy. We review the major trials that have investigated combination immunochemotherapy in the neoadjuvant setting, reviewing both the pathological complete response rates and the maturing data regarding event-free and overall survival. Strategies to deescalate adjuvant therapy in patients with preserving excellent clinical outcome, as well as exploration of combinatorial adjuvant therapies to improve outcome in those with extensive residual are the next-generation challenges. In addition to refinement of existing biomarkers, such as PD-L1, TILs, and tumor mutational burden (TMB), exploration of topics like the microbiome as both a biomarker and a therapeutic has shown promise in other cancer types, which motivates investigating these in breast cancer.

Gut Microbiome in Patients With Early-Stage and Late-Stage Melanoma

Importance

The gut microbiome modulates the immune system and responses to immunotherapy in patients with late-stage melanoma. It is unknown whether fecal microbiota profiles differ between healthy individuals and patients with melanoma or if microbiota profiles differ among patients with different stages of melanoma. Defining gut microbiota profiles in individuals without melanoma and those with early-stage and late-stage melanoma may reveal features associated with disease progression.

Objective

To characterize and compare gut microbiota profiles between healthy volunteers and patients with melanoma and between patients with early-stage and late-stage melanoma.

Design, Setting, and Participants

This single-site case-control study took place at an academic comprehensive cancer center. Fecal samples were collected from systemic treatment-naive patients with stage I to IV melanoma from June 1, 2015, to January 31, 2019, and from healthy volunteers from June 1, 2021, to January 31, 2022. Patients were followed up for disease recurrence until November 30, 2021.

Main Outcomes and Measures

Fecal microbiota was profiled by 16S ribosomal RNA sequencing. Clinical and pathologic characteristics, treatment, and disease recurrence were extracted from electronic medical records. Fecal microbiome diversity, taxonomic profiles and inferred functional profiles were compared between groups.

Results

A total of 228 participants were enrolled (126 men [55.3%]; median age, 59 [range, 21-90] years), including 49 volunteers without melanoma, 38 patients with early-stage melanoma (29 with stage I or melanoma in situ and 9 with stage II), and 141 with late-stage melanoma (66 with stage III and 75 with stage IV). Community differences were observed between patients with melanoma and volunteers. Patients with melanoma had a higher relative abundance of Fusobacterium compared with controls on univariate analysis (0.19% vs 0.003%; P < .001), but this association was attenuated when adjusted for covariates (log2 fold change of 5.18 vs controls; P = .09). Microbiomes were distinct between patients with early-stage and late-stage melanoma. Early-stage melanoma had a higher alpha diversity (Inverse Simpson Index 14.6 [IQR, 9.8-23.0] vs 10.8 [IQR, 7.2-16.8]; P = .003), and a higher abundance of the genus Roseburia on univariate analysis (2.4% vs 1.2%; P < .001) though statistical significance was lost with covariate adjustment (log2 fold change of 0.86 vs controls; P = .13). Multiple functional pathways were differentially enriched between groups. No associations were observed between the microbial taxa and disease recurrence in patients with stage III melanoma treated with adjuvant immunotherapy.

Conclusions and Relevance

The findings of this case-control study suggest that fecal microbiota profiles were significantly different among patients with melanoma and controls and between patients with early-stage and late-stage melanoma. Prospective investigations of the gut microbiome and changes that occur with disease progression may identify future microbial targets for intervention.

Towards modulating the gut microbiota to enhance the efficacy of immune-checkpoint inhibitors

The gut microbiota modulates immune processes both locally and systemically. This includes whether and how the immune system reacts to emerging tumours, whether antitumour immune responses are reactivated during treatment with immune-checkpoint inhibitors (ICIs), and whether unintended destructive immune pathologies accompany such treatment. Advances over the past decade have established that the gut microbiota is a promising target and that modulation of the microbiota might overcome resistance to ICIs and/or improve the safety of treatment. However, the specific mechanisms through which the microbiota modulates antitumour immunity remain unclear. Understanding the biology underpinning microbial associations with clinical outcomes in patients receiving ICIs, as well as the landscape of a 'healthy' microbiota would provide a critical foundation to facilitate opportunities to effectively manipulate the microbiota and thus improve patient outcomes. In this Review, we explore the role of diet and the gut microbiota in shaping immune responses during treatment with ICIs and highlight the key challenges in attempting to leverage the gut microbiome as a practical tool for the clinical management of patients with cancer.

Diet-mediated gut microbial community modulation and signature metabolites as potential biomarkers for early diagnosis, prognosis, prevention and stage-specific treatment of colorectal cancer

BACKGROUND

Over the last decade, studies have shown an increased incidence of colorectal cancer (CRC), particularly early onset colorectal cancer (EOCRC). Researchers have demonstrated that dietary behavior, especially among young adults, influences alterations in the gut microbial community, leading to an increased accumulation of pathogenic gut microbiota and a decrease in beneficial ones. Unfortunately, CRC is likely to be diagnosed at a late stage, increasing CRC-related mortality. However, this alteration in the gut microbiota (gut dysbiosis) can be harnessed as a biomarker for non-invasive diagnosis, prognosis, prevention, and treatment of CRC in an effort to prevent late diagnosis and poor prognosis associated with CRC.

AIM OF REVIEW

This review discusses identification of potential biomarkers by targeting diet-mediated gut dysbiosis for the stage-specific diagnosis, prognosis, treatment, and prevention of CRC. Our findings provide a comprehensive insight into the potential of protumorigenic bacteria (e.g.pathogenic Escherichia coli,enterotoxigenic Bacteroides fragilis and Fusobacterium nucleatum) and their metabolites (e.g., colibactin and B. fragilis toxin) from gut dysbiosis as biomarkers for the diagnosis of CRC.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Collectively, a detailed understanding of the available data from current studies suggests that, further research on quantification of metabolites and stage-specific pathogenic microbial abundance is required for the diagnosis and treatment of CRC based on microbial dysbiosis. Specifically, future studies on faecal samples, from patient with CRC, should be conducted for F. nucleatum among different opportunistic bacteria, given its repeated occurrence in faecal samples and CRC biopsies in numerous studies. Finally, we discuss the potential of faecal microbial transplantation (FMT) as an intervention to restore damaged gut microbiota during CRC treatment and management.

Prevalence and influencing factors of probiotic usage among colorectal cancer patients in China: A national database study

Probiotics have become increasingly popular among cancer patients. However, there is limited data from a real-world setting. This study aims to conduct a retrospective analysis to understand the trend of probiotic prescriptions in Chinese colorectal cancer patients. The Mann-Kendall and Cochran-Armitage trend test was applied to estimate the trend significance. Gephi software identified the combination of probiotic strains. The binary logistic regression investigated influence factors, and Spearman's rank correlation coefficient calculated correlations between probiotics and antitumor drug usage. The probiotic prescription percentage increased from 3.3% in 2015 to 4.2% in 2021 (Z = 12.77, p < 0.001). Although 48.3% of probiotic prescriptions had no indication-related diagnosis, diarrhea (OR 10.91, 95% CI 10.57-11.26) and dyspepsia (3.97, 3.82-4.12) included prescriptions most likely to contain probiotics. Prescriptions from the tertiary hospital (1.43,1.36-1.50), clinics (1.30, 1.28-1.33), and senior patients (1.018 per year, 1.017-1.019) were more likely to contain probiotics. Most probiotic prescriptions (95.0%) contained one probiotic product but multiple strains (69.3%). Enterococcus faecalis (49.7%), Lactobacillus acidophilus (39.4%), and Clostridium butyricum (27.9%) were the most prescribed strains. The probiotics co-prescribed with antitumor agents increased rapidly from 6.6% to 13.8% in seven years (Z = 15.31, p < 0.001). Oral fluorouracil agents (2.35, 2.14-2.59), regorafenib (1.70,1.27-2.26), and irinotecan (1.27,1.15-1.41) had a higher probability to co-prescribed with probiotics. There was no correlation between probiotic strain selection and specific antitumor drug use. The increasing prescription of probiotics in colorectal cancer patients in China may be related to treating the gastrointestinal toxicity of anti-cancer drugs. With unapproved indications and a lack of strain selectivity, evidence-based guidelines are urgently needed to improve probiotic use in this population.

Stimulators of immunogenic cell death for cancer therapy: focusing on natural compounds

A growing body of evidence indicates that the anticancer effect of the immune system can be activated by the immunogenic modulation of dying cancer cells. Cancer cell death, as a result of the activation of an immunomodulatory response, is called immunogenic cell death (ICD). This regulated cell death occurs because of increased immunogenicity of cancer cells undergoing ICD. ICD plays a crucial role in stimulating immune system activity in cancer therapy. ICD can therefore be an innovative route to improve anticancer immune responses associated with releasing damage-associated molecular patterns (DAMPs). Several conventional and chemotherapeutics, as well as preclinically investigated compounds from natural sources, possess immunostimulatory properties by ICD induction. Natural compounds have gained much interest in cancer therapy owing to their low toxicity, low cost, and inhibiting cancer cells by interfering with different mechanisms, which are critical in cancer progression. Therefore, identifying natural compounds with ICD-inducing potency presents agents with promising potential in cancer immunotherapy. Naturally derived compounds are believed to act as immunoadjuvants because they elicit cancer stress responses and DAMPs. Acute exposure to DAMP molecules can activate antigen-presenting cells (APCs), such as dendritic cells (DCs), which leads to downstream events by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs). Natural compounds as inducers of ICD may be an interesting approach to ICD induction; however, parameters that determine whether a compound can be used as an ICD inducer should be elucidated. Here, we aimed to discuss the impact of multiple ICD inducers, mainly focusing on natural agents, including plant-derived, marine molecules, and bacterial-based compounds, on the release of DAMP molecules and the activation of the corresponding signaling cascades triggering immune responses. In addition, the potential of synthetic agents for triggering ICD is also discussed.

Gut microbiome in cancer immunotherapy: Current trends, translational challenges and future possibilities

Gut microbiota is regarded as a crucial regulator of the immune system. Healthy gut microbiota plays a specialized role in host xenobiotics, nutrition, drug metabolism, regulation of the structural integrity of the gut mucosal barrier, defense against infections, and immunomodulation. It is now understood that any imbalance in gut microbiota composition from that present in a healthy state is linked to genetic susceptibility to a number of metabolic disorders, including diabetes, autoimmunity, and cancer. Recent research has suggested that immunotherapy can treat many different cancer types with fewer side effects and better ability to eradicate tumors than conventional chemotherapy or radiotherapy. However, a significant number of patients eventually develop immunotherapy resistance. A strong correlation was observed between the composition of the gut microbiome and the effectiveness of treatment by examining the variations between populations that responded to immunotherapy and those that did not. Therefore, we suggest that modulating the microbiome could be a potential adjuvant therapy for cancer immunotherapy and that the architecture of the gut microbiota may be helpful in explaining the variation in treatment response. Herein, we focus on recent research on the interactions among the gut microbiome, host immunity, and cancer immunotherapy. In addition, we highlighted the clinical manifestations, future opportunities, and limitations of microbiome manipulation in cancer immunotherapy.

Combining gut microbiota modulation and chemotherapy by capecitabine-loaded prebiotic nanoparticle improves colorectal cancer therapy

Colorectal cancer (CRC) therapy efficiency can be influenced by the microbiota in the gastrointestinal tract. Compared with traditional intervention, prebiotics delivery into the gut is a more controllable method for gut microbiota modulatory therapy. Capecitabine (Cap), the first-line chemotherapeutic agent for CRC, lacks a carrier that can prolong its half-life. Here, we construct a Cap-loaded nanoparticle using the prebiotic xylan-stearic acid conjugate (SCXN). The oral administration of SCXN delays the drug clearance in the blood and increases the intra-tumoral Cap concentration in the CRC mouse model. SCXN also facilitates the probiotic proliferation and short chain fatty acid production. Compared with free Cap, SCXN enhances the anti-tumor immunity and increases the tumor inhibition rate from 5.29 to 71.78%. SCXN exhibits good biocompatibility and prolongs the median survival time of CRC mice from 14 to 33.5 d. This prebiotics-based nanoparticle provides a promising CRC treatment by combining gut microbiota modulation and chemotherapy.

Targeting microbiome, drug metabolism, and drug delivery in oncology

Recent emerging scientific evidence shows a relationship between gut microbiota (GM) and immunomodulation. In the recently published "Hallmarks of Cancer", the microbiome has been reported to play a crucial role in cancer research, and perspectives for its clinical implementation to improve the effectiveness of pharmacotherapy were explored. Several studies have shown that GM can affect the outcomes of pharmacotherapy in cancer, suggesting that GM may affect anti-tumor immunity. Thus, studies on GM that analyze big data using computer-based analytical methods are required. In order to successfully deliver GM to an environment conducive to the proliferation of immune cells both within and outside the tumor microenvironment (TME), it is crucial to address a variety of challenges associated with distinct delivery methods, specifically those pertaining to oral, endoscopic, and intravenous delivery. Clinical trials are in progress to evaluate the effects of targeting GM and whether it can enhance immunity or act on the TME, thereby to improve the clinical outcomes for cancer patients.

Oncomicrobial Community Profiling Identifies Clinicomolecular and Prognostic Subtypes of Colorectal Cancer

BACKGROUND & AIMS

Dysbiosis of gut microbiota is linked to the development of colorectal cancer (CRC). However, microbiota-based stratification of CRC tissue and how this relates to clinicomolecular characteristics and prognosis remains to be clarified.

METHODS

Tumor and normal mucosa from 423 patients with stage I to IV CRC were profiled by bacterial 16S rRNA gene sequencing. Tumors were characterized for microsatellite instability (MSI), CpG island methylator phenotype (CIMP), APC, BRAF, KRAS, PIK3CA, FBXW7, SMAD4, and TP53 mutations, subsets for chromosome instability (CIN), mutation signatures, and consensus molecular subtypes (CMS). Microbial clusters were validated in an independent cohort of 293 stage II/III tumors.

RESULTS

Tumors reproducibly stratified into 3 oncomicrobial community subtypes (OCSs) with distinguishing features: OCS1 (Fusobacterium/oral pathogens, proteolytic, 21%), right-sided, high-grade, MSI-high, CIMP-positive, CMS1, BRAF V600E, and FBXW7 mutated; OCS2 (Firmicutes/Bacteroidetes, saccharolytic, 44%), and OCS3 (Escherichia/Pseudescherichia/Shigella, fatty acid β-oxidation, 35%) both left-sided and exhibiting CIN. OCS1 was associated with MSI-related mutation signatures (SBS15, SBS20, ID2, and ID7) and OCS2 and OCS3 with SBS18 related to damage by reactive oxygen species. Among stage II/III patients, OCS1 and OCS3 both had poorer overall survival compared with OCS2 for microsatellite stable tumors (multivariate hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.15-2.99; P = .012; and HR, 1.52; 95% CI 1.01-2.29; P = .044, respectively) and left-sided tumors (multivariate HR, 2.66; 95% CI, 1.45-4.86; P = .002; and HR, 1.76; 95% CI, 1.03-3.02; P = .039, respectively).

CONCLUSIONS

OCS classification stratified CRCs into 3 distinct subgroups with different clinicomolecular features and outcomes. Our findings provide a framework for a microbiota-based stratification of CRC to refine prognostication and to inform the development of microbiota-targeted interventions.

The role of the gut microbiota in gastric cancer: the immunoregulation and immunotherapy

Gastric cancer (GC) is one of the most common cancers, leading to the deaths of millions of people worldwide. Therefore, early detection and effective therapeutic strategies are of great value for decreasing the occurrence of advanced GC. The human microbiota is involved not only in the maintenance of physiological conditions, but also in human diseases such as obesity, diabetes, allergic and atopic diseases, and cancer. Currently, the composition of the bacteria in the host, their functions, and their influence on disease progression and treatment are being discussed. Previous studies on the gut microbiome have mostly focused on Helicobacter pylori (Hp) owing to its significant role in the development of GC. Nevertheless, the enrichment and diversity of other bacteria that can modulate the tumor microenvironment are involved in the progression of GC and the efficacy of immunotherapy. This review provides systematic insight into the components of the gut microbiota and their application in GC, including the specific bacteria of GC, their immunoregulatory effect, and their diagnostic value. Furthermore, we discuss the relationship between the metabolism of microbes and their potential applications, which may serve as a new approach for the diagnosis and treatment of GC.

Flavonoid intake and survival after diagnosis of colorectal cancer: a prospective study in 2 US cohorts

BACKGROUND

Although experimental evidence supports anticancer effects of flavonoids, the influence of flavonoid intake on colorectal cancer (CRC) survival remains unknown.

OBJECTIVES

This study aimed to assess the association of postdiagnostic flavonoid intake with mortality.

METHODS

We prospectively assessed the association of postdiagnostic flavonoid intake with CRC-specific and all-cause mortality in 2552 patients diagnosed with stage I-III CRC in 2 cohort studies-the Nurses' Health Study and the Health Professionals Follow-up Study. We assessed the intake of total flavonoids and their subclasses using validated food frequency questionnaires. We used the inverse probability-weighted multivariable Cox proportional hazards regression model to calculate the hazard ratio (HR) of mortality after adjusting for prediagnostic flavonoid intake and other potential confounders. We performed spline analysis to evaluate dose-response relationships.

RESULTS

The mean [standard deviation (SD)] age of patients at diagnosis was 68.7 (9.4) y. During 31,026 person-y of follow-up, we documented 1689 deaths, of which 327 were due to CRC. The total flavonoid intake was not associated with mortality, but a higher intake of flavan-3-ols was suggestively associated with lower CRC-specific and all-cause mortality, with multivariable HR (95% CI) per 1-SD increases of 0.83 (0.69-0.99; P = 0.04) and 0.91 (0.84-0.99; P = 0.02), respectively. The spline analysis showed a linear relationship between postdiagnostic flavan-3-ol intake and CRC-specific mortality (P = 0.01 for linearity). As the major contributor to flavan-3-ol intake, tea showed an inverse association with CRC-specific and all-cause mortality, with multivariable HRs per 1 cup/d of tea of 0.86 (0.75-0.99; P = 0.03) and 0.90 (0.85-0.95; P < 0.001), respectively. No beneficial associations were found for other flavonoid subclasses.

CONCLUSIONS

Higher intake of flavan-3-ol after CRC diagnosis was associated with lower CRC-specific mortality. Small, readily achievable increases in the intake of flavan-3-ol-rich foods, such as tea, may help improve survival in patients with CRC.

Microbiota Regulates Pancreatic Cancer Carcinogenesis through Altered Immune Response

The microbiota is present in many parts of the human body and plays essential roles. The most typical case is the occurrence and development of cancer. Pancreatic cancer (PC), one of the most aggressive and lethal types of cancer, has recently attracted the attention of researchers. Recent research has revealed that the microbiota regulates PC carcinogenesis via an altered immune response. Specifically, the microbiota, in several sites, including the oral cavity, gastrointestinal tract, and pancreatic tissue, along with the numerous small molecules and metabolites it produces, influences cancer progression and treatment by activating oncogenic signaling, enhancing oncogenic metabolic pathways, altering cancer cell proliferation, and triggering chronic inflammation that suppresses tumor immunity. Diagnostics and treatments based on or in combination with the microbiota offer novel insights to improve efficiency compared with existing therapies.

Interactions of Nanomaterials with Gut Microbiota and Their Applications in Cancer Therapy

Cancer treatment is a challenge by its incredible complexity. As a key driver and player of cancer, gut microbiota influences the efficacy of cancer treatment. Modalities to manipulate gut microbiota have been reported to enhance antitumor efficacy in some cases. Nanomaterials (NMs) have been comprehensively applied in cancer diagnosis, imaging, and theranostics due to their unique and excellent properties, and their effectiveness is also influenced by gut microbiota. Nanotechnology is capable of targeting and manipulating gut microbiota, which offers massive opportunities to potentiate cancer treatment. Given the complexity of gut microbiota-host interactions, understanding NMs-gut interactions and NMs-gut microbiota interactions are important for applying nanotechnologies towards manipulating gut microbiota in cancer prevention and treatment. In this review, we provide an overview of NMs-gut interactions and NMs-gut microbiota interactions and highlight the influences of gut microbiota on the diagnosis and treatment effects of NMs, further illustrating the potential of nanotechnologies in cancer therapy. Investigation of the influences of NMs on cancer from the perspective of gut microbiota will boost the prospect of nanotechnology intervention of gut microbiota for cancer therapy.

Neutrophil diversity in inflammation and cancer

Neutrophils are the most abundant circulating leukocytes in humans and the first immune cells recruited at the site of inflammation. Classically perceived as short-lived effector cells with limited plasticity and diversity, neutrophils are now recognized as highly heterogenous immune cells, which can adapt to various environmental cues. In addition to playing a central role in the host defence, neutrophils are involved in pathological contexts such as inflammatory diseases and cancer. The prevalence of neutrophils in these conditions is usually associated with detrimental inflammatory responses and poor clinical outcomes. However, a beneficial role for neutrophils is emerging in several pathological contexts, including in cancer. Here we will review the current knowledge of neutrophil biology and heterogeneity in steady state and during inflammation, with a focus on the opposing roles of neutrophils in different pathological contexts.

Gut microbiome and cancer implications: Potential opportunities for fermented foods

There is a critical opportunity to improve response to immunotherapies and overall cancer survivorship via dietary interventions targeted to modify the gut microbiome, and in turn, potentially enhance anti-cancer immunity. A promising dietary intervention is fermented foods, which may alter gut microbiome composition and, in turn, improve immunity. In this article, we summarize the state of the literature pertaining to the gut microbiome and response to immunotherapy and other cancer treatments, potential clinical implications of utilizing a fermented foods dietary approach to improve cancer treatment outcomes, and existing gaps in the literature regarding the implementation of fermented food interventions among individuals with cancer or with a history of cancer. This review synthesizes a compelling rationale across different disciplines to lay a roadmap for future fermented food dietary intervention research aimed at modulating the gut microbiome to reduce cancer burden.

From adenoma to CRC stages: the oral-gut microbiome axis as a source of potential microbial and metabolic biomarkers of malignancy

BACKGROUND

Approximately 95% of Colorectal cancers (CRC) consist of adenocarcinomas originating from colonic Adenomatous polyps (AP). Increasing importance in CRC occurrence and progression has been attributed to the gut microbiota; however, a huge proportion of microorganisms inhabit the human digestive system. So, to comprehensively study the microbial spatial variations and their role in CRC progression, from AP to the different CRC phases, a holistic vision is imperative, including the simultaneous evaluation of multiple niches from the gastrointestinal system. Through an integrated approach, we identified potential microbial and metabolic biomarkers, able to discriminate human CRC from AP and/or also the different Tumor node metastasis (TNM) staging. In addition, as the microbiota contributes to the production of essential metabolic products detectable in fecal samples, we analysed and compared metabolites obtained from CRC and AP patients by using a Nuclear magnetic resonance (NMR) approach.

METHODS

In this observational study, saliva, tissue and stool samples from 61 patients, have been collected, including 46 CRC and 15 AP patients, age and sex-matched, undergoing surgery in 2018 at the Careggi University Hospital (Florence, Italy). First, the microbiota in the three-district between CRC and AP patients has been characterized, as well as in different CRC TNM stages. Subsequently, proton NMR spectroscopy has been used in combination with multivariate and univariate statistical approaches, to define the fecal metabolic profile of a restricted group of CRC and AP patients.

RESULTS

CRC patients display a different profile of tissue and fecal microbiota with respect to AP patients. Significant differences have been observed in CRC tissue microbial clades, with a rise of the Fusobacterium genus. In addition, significant taxa increase at the genus level has been observed in stool samples of CRC patients. Furthermore, Fusobacterium found in intestinal tissue has been positively correlated with fecal Parvimonas, for the first time. Moreover, as predicted by metagenomics pathway analysis, a significant increase of lactate (p=0.037) has been observed in the CRC fecal metabolic profiles, and positively correlated with Bifidobacterium (p=0.036). Finally, minor bacterial differences in CRC patients at stage T2 (TNM classification) have been detected, with a raise of the Spirochaetota phylum in CRC samples, with a slight increase of the Alphaproteobacteria class in fecal samples.

CONCLUSION

Our results suggest the importance of microbiota communities and oncometabolites in CRC development. Further studies on CRC/AP management with a focus on CRC assessment are needed to investigate novel microbial-related diagnostic tools aimed to improve therapeutic interventions.

Effects of prebiotic supplement on gut microbiota, drug bioavailability, and adverse effects in patients with colorectal cancer at different primary tumor locations receiving chemotherapy: study protocol for a randomized clinical trial

BACKGROUND

The prevalence of colorectal cancer (CRC) worldwide is a huge challenge to human health. Primary tumor locations found to impact prognosis and response to therapy. The important role of gut microbiota in the progression and treatment of CRC has led to many attempts of alleviating chemotherapy-induced adverse effects using microecologics. However, the underlying mechanism of the difference in the prognosis of different primary tumor locations and the synergistic effect of prebiotics on chemotherapy need to be further elucidated. This study aims to explore the differences in tumor microbiota and examine the effectiveness of xylooligosaccharides (XOS) on gut microbiota, adverse effects, and bioavailability of chemotherapy drugs in CRC patients at different primary tumor locations.

METHODS

This is a double-blinded, randomized, parallel controlled clinical trial. Participants with left-sided CRC (LSCRC, n = 50) and right-sided CC (RSCC, n = 50) will randomly allocated to prebiotic group (n = 25) or control group (n = 25) and will receive either a daily XOS (3 g/day) or placebo, respectively, for 12 weeks. The primary outcomes will be the differences in the mucosa microbiota composition at different tumor locations and differences in gut microbiota composition, adverse effects, and blood concentration of capecitabine posttreatment. The secondary outcomes will include other blood indicators, short-chain fatty acids (SCFAs) concentration, quality of life, and mental health.

DISCUSSION

This study will reveal the potential benefits of prebiotic for improving the gut microbiota composition, alleviating the adverse effects, and improving the efficacy of chemotherapy in patients with CRC. In addition, this study will provide data on the different distribution of tumor microbiota and the different changes of gut microbiota during treatment in LSCRC and RSCC, which may provide novel insights into personalized cancer treatment strategies based on primary tumor locations and gut microbiota in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( www.chictr.org.cn ): ChiCTR2100046237. Registered on 12 May 2021.

Antimicrobial exposure is associated with decreased survival in triple-negative breast cancer

Antimicrobial exposure during curative-intent treatment of triple-negative breast cancer (TNBC) may lead to gut microbiome dysbiosis, decreased circulating and tumor-infiltrating lymphocytes, and inferior outcomes. Here, we investigate the association of antimicrobial exposure and peripheral lymphocyte count during TNBC treatment with survival, using integrated electronic medical record and California Cancer Registry data in the Oncoshare database. Of 772 women with stage I-III TNBC treated with and without standard cytotoxic chemotherapy - prior to the immune checkpoint inhibitor era - most (654, 85%) used antimicrobials. Applying multivariate analyses, we show that each additional total or unique monthly antimicrobial prescription is associated with inferior overall and breast cancer-specific survival. This antimicrobial-mortality association is independent of changes in neutrophil count, is unrelated to disease severity, and is sustained through year three following diagnosis, suggesting antimicrobial exposure negatively impacts TNBC survival. These results may inform mechanistic studies and antimicrobial prescribing decisions in TNBC and other hormone receptor-independent cancers.

A gut response: Modulating chemotherapy efficacy with microbial metabolites

Despite clinical advances, chemotherapy largely fails in metastatic cancers. Commensal bacteria can indicate chemotherapy efficacy. In a recent issue of Nature, Tintelnot et al.¹ demonstrate that bacterial metabolite 3-IAA amplifies chemotherapy outcomes via autophagy pathways in metastatic pancreatic ductal adenocarcinoma.

The human and animals' malignant melanoma: comparative tumor models and the role of microbiome in dogs and humans

Currently, the most progressively occurring incident cancer is melanoma. The mouse is the most popular model in human melanoma research given its various benefits as a laboratory animal. Nevertheless, unlike humans, mice do not develop melanoma spontaneously, so they need to be genetically manipulated. In opposition, there are several reports of other animals, ranging from wild to domesticated animals, that spontaneously develop melanoma and that have cancer pathways that are similar to those of humans. The influence of the gut microbiome on health and disease is being the aim of many recent studies. It has been proven that the microbiome is a determinant of the host's immune status and disease prevention. In human medicine, there is increasing evidence that changes in the microbiome influences malignant melanoma progression and response to therapy. There are several similarities between some animals and human melanoma, especially between canine and human oral malignant melanoma as well as between the gut microbiome of both species. However, microbiome studies are scarce in veterinary medicine, especially in the oncology field. Future studies need to address the relevance of gut and tissue microbiome for canine malignant melanoma development, which results will certainly benefit both species in the context of translational medicine.

Urea cycle activation triggered by host-microbiota maladaptation driving colorectal tumorigenesis

Maladaptation of host-microbiota metabolic interplay plays a critical role in colorectal cancer initiation. Here, through a combination of single-cell transcriptomics, microbiome profiling, metabonomics, and clinical analysis on colorectal adenoma and carcinoma tissues, we demonstrate that host's urea cycle metabolism is significantly activated during colorectal tumorigenesis, accompanied by the absence of beneficial bacteria with ureolytic capacity, such as Bifidobacterium, and the overabundance of pathogenic bacteria lacking ureolytic function. Urea could enter into macrophages, inhibit the binding efficiency of p-STAT1 to SAT1 promotor region, and further skew macrophages toward a pro-tumoral phenotype characterized by the accumulation of polyamines. Treating a murine model using urea cycle inhibitors or Bifidobacterium-based supplements could mitigate urea-mediated tumorigenesis. Collectively, this study highlights the utility of urea cycle inhibitors or therapeutically manipulating microbial composition using probiotics to prevent colorectal cancer.

Complementary and Integrative Medicine in Pancreatic Cancer

PURPOSE OF REVIEW

Pancreatic cancer has high mortality and morbidity rates, associated with the issues of typically late diagnosis and the limited effectiveness of current treatments. Patients tend to experience multiple symptoms that can include anxiety, fear, depression, fatigue, weakness, peripheral neuropathy, and abdominal pain, which reduce quality of life (QoL) and may compromise the treatment continuum. Many of those symptoms are amenable to complementary and integrative medicine (CIM) therapies as a part of supportive and palliative care. This article reviews research findings on the beneficial effect of use of CIM modalities in regard to pancreatic cancer, with emphasis on pancreatic ductal adenocarcinoma (PDAC).

RECENT FINDINGS

Given the often-poor prognosis of the disease, patients with PDAC often seek integrative therapies to help manage the disease itself, to provide support through cancer treatment and its symptoms, and to provide emotional stress relief. Data is accumulating in the past few years on the potential benefits of CIM to the management of pancreatic cancer symptoms and treatment side effects, in order to augment supportive care. This data reveal that nutrition counselling; digestive enzyme therapy; microbiome support; dietary supplements; lifestyle interventions (physical activity and circadian health/sleep hygiene) appear to improve QoL of these patients through reduced symptom burden and meeting psychological needs, such as distress and fatigue. Acupuncture, mindfulness, yoga, reflexology, massage, and homeopathy may also contribute to symptom reduction, both physical and psychological, in all stages of the disease. There is supporting evidence that some CIM modalities may alleviate side effects and symptoms related to pancreatic cancer and its treatment, suggesting that practitioners might consider integrating these modalities in certain situations encountered in the treatment of pancreatic cancer. Further investigation is needed to define the optimal integration of CIM into the treatment and supportive care of patients affected by pancreatic cancer.

Microbiota-derived 3-IAA influences chemotherapy efficacy in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second most deadly cancer by 2040, owing to the high incidence of metastatic disease and limited responses to treatment1,2. Less than half of all patients respond to the primary treatment for PDAC, chemotherapy3,4, and genetic alterations alone cannot explain this5. Diet is an environmental factor that can influence the response to therapies, but its role in PDAC is unclear. Here, using shotgun metagenomic sequencing and metabolomic screening, we show that the microbiota-derived tryptophan metabolite indole-3-acetic acid (3-IAA) is enriched in patients who respond to treatment. Faecal microbiota transplantation, short-term dietary manipulation of tryptophan and oral 3-IAA administration increase the efficacy of chemotherapy in humanized gnotobiotic mouse models of PDAC. Using a combination of loss- and gain-of-function experiments, we show that the efficacy of 3-IAA and chemotherapy is licensed by neutrophil-derived myeloperoxidase. Myeloperoxidase oxidizes 3-IAA, which in combination with chemotherapy induces a downregulation of the reactive oxygen species (ROS)-degrading enzymes glutathione peroxidase 3 and glutathione peroxidase 7. All of this results in the accumulation of ROS and the downregulation of autophagy in cancer cells, which compromises their metabolic fitness and, ultimately, their proliferation. In humans, we observed a significant correlation between the levels of 3-IAA and the efficacy of therapy in two independent PDAC cohorts. In summary, we identify a microbiota-derived metabolite that has clinical implications in the treatment of PDAC, and provide a motivation for considering nutritional interventions during the treatment of patients with cancer.

The crosstalk between intestinal bacterial microbiota and immune cells in colorectal cancer progression

Different types of cells that are involved in tumor immunity play a significant part in antitumor therapy. The intestinal microbiota consist of the trillions of diverse microorganisms that inhabit the gastrointestinal tract. Recently, much emphasis has been paid to the link between these symbionts and colorectal cancer (CRC). This association might be anything from oncogenesis and cancer development to resistance or susceptibility to chemotherapeutic medicines. Cancer patients have a significantly different microbial composition in their guts compared to healthy persons. The microbiome may play a role in the development and development of cancer through the modulation of tumor immunosurveillance, as shown by these studies; however, the specific processes underlying this role are still poorly understood. This review focuses on the relationship between the intestinal bacterial microbiota and immune cells to determine how the commensal microbiome influences the initiation and development of CRC.

A composition-tunable cold atmospheric plasma chip for multiplex-treatment of cells

Cold atmospheric plasma treatment promises a targeted cancer therapy due to its selectivity and specificity in killing tumor cells. However, the current plasma exposure devices produce diverse and coupled reactive species, impeding the investigation of the underlying plasma-anticancer mechanisms. Also, the limited mono-sample and mono-dosage treatment modality result in tedious and manual experimental tasks. Here, we propose a cold atmospheric plasma chip producing targeted species, delivering multiple dosages, and treating multiple cell lines in a single treatment. Three modules are integrated into the chip. The environment control module and multi-inlet gas-feed module coordinately ignite component-tunable and uniformly distributed plasma. The multi-sample holding module enables multiplex treatment: multi-sample and -dosage treatment with single radiation. By exposing the HepG2 cell line to nitrogen-feed plasmas, we prove the crucial role of nitrogen-based species in inhibiting cell growth and stimulating apoptosis. By loading four-type cell lines on our chip, we can identify the most vulnerable cell line for plasma oncotherapy. Simultaneously, three-level treatment dosages are imposed on the cells with single radiation to optimize the applicable treatment dosage for plasma oncotherapy. Our chip will broaden the design principles of plasma exposure devices, potentially help clarify plasma-induced anticancer mechanisms, and guide the clinical application of plasma-based oncotherapy.

Impact of diet and host genetics on the murine intestinal mycobiome

The mammalian gut is home to a diverse microbial ecosystem, whose composition affects various physiological traits of the host. Next-generation sequencing-based metagenomic approaches demonstrated how the interplay of host genetics, bacteria, and environmental factors shape complex traits and clinical outcomes. However, the role of fungi in these complex interactions remains understudied. Here, using 228 males and 363 females from an advanced-intercross mouse line, we provide evidence that fungi are regulated by host genetics. In addition, we map quantitative trait loci associated with various fungal species to single genes in mice using whole genome sequencing and genotyping. Moreover, we show that diet and its' interaction with host genetics alter the composition of fungi in outbred mice, and identify fungal indicator species associated with different dietary regimes. Collectively, in this work, we uncover an association of the intestinal fungal community with host genetics and a regulatory role of diet in this ecological niche.

Sex-Related Effects of Gut Microbiota in Metabolic Syndrome-Related Diabetic Retinopathy

The metabolic syndrome (MetS) is a complex disease of metabolic abnormalities, including obesity, insulin resistance, hypertension and dyslipidaemia, and it is associated with an increased risk of cardiovascular disease (CVD). Diabetic retinopathy (DR) is the leading cause of vision loss among working-aged adults around the world and is the most frequent complication in type 2 diabetic (T2D) patients. The gut microbiota are a complex ecosystem made up of more than 100 trillion of microbial cells and their composition and diversity have been identified as potential risk factors for the development of several metabolic disorders, including MetS, T2D, DR and CVD. Biomarkers are used to monitor or analyse biological processes, therapeutic responses, as well as for the early detection of pathogenic disorders. Here, we discuss molecular mechanisms underlying MetS, the effects of biological sex in MetS-related DR and gut microbiota, as well as the latest advances in biomarker research in the field. We conclude that sex may play an important role in gut microbiota influencing MetS-related DR.

Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the third leading cause of tumor-related mortality worldwide. In recent years, the emergency of immune checkpoint inhibitor (ICI) has revolutionized the management of HCC. Especially, the combination of atezolizumab (anti-PD1) and bevacizumab (anti-VEGF) has been approved by the FDA as the first-line treatment for advanced HCC. Despite great breakthrough in systemic therapy, HCC continues to portend a poor prognosis owing to drug resistance and frequent recurrence. The tumor microenvironment (TME) of HCC is a complex and structured mixture characterized by abnormal angiogenesis, chronic inflammation, and dysregulated extracellular matrix (ECM) remodeling, collectively contributing to the immunosuppressive milieu that in turn prompts HCC proliferation, invasion, and metastasis. The tumor microenvironment coexists and interacts with various immune cells to maintain the development of HCC. It is widely accepted that a dysfunctional tumor-immune ecosystem can lead to the failure of immune surveillance. The immunosuppressive TME is an external cause for immune evasion in HCC consisting of 1) immunosuppressive cells; 2) co-inhibitory signals; 3) soluble cytokines and signaling cascades; 4) metabolically hostile tumor microenvironment; 5) the gut microbiota that affects the immune microenvironment. Importantly, the effectiveness of immunotherapy largely depends on the tumor immune microenvironment (TIME). Also, the gut microbiota and metabolism profoundly affect the immune microenvironment. Understanding how TME affects HCC development and progression will contribute to better preventing HCC-specific immune evasion and overcoming resistance to already developed therapies. In this review, we mainly introduce immune evasion of HCC underlying the role of immune microenvironment, describe the dynamic interaction of immune microenvironment with dysfunctional metabolism and the gut microbiome, and propose therapeutic strategies to manipulate the TME in favor of more effective immunotherapy.

Urogenital tract and rectal microbiota composition and its influence on reproductive outcomes in infertile patients

Introduction

Microbiota in the human body are closely related to human diseases. Female urogenital tract and rectal microbes have been considered as important factors affecting female pregnancy, but the mechanism is unknown.

Methods

Cervical, vaginal, urethral, and rectal swabs were collected from 22 infertile patients and 10 controls, and follicular fluid was extracted from 22 infertile patients. The microbial composition of different sampling sites of infertile patients was examined. By comparing the microbial composition difference between infertile patients and controls and combining bioinformatics methods to analyze the potential impact of the female urogenital tract (cervical, vaginal and urethral) and rectal microbial diversity on female infertility and pregnancy outcomes.

Results

Lactobacillus predominated in the female urogenital tract, but its abundance decreased in infertile patients, whereas the abundance of Gardnerella and Atopobium increased. The microbial changes in the urethra had the same trend as that in the vagina. Compared with healthy controls, the cervical and rectal microbial diversity of infertile patients were significantly increased and decreased, respectively. There might be interactions between microbes in different parts of female. Geobacillus thermogeniticans was enriched in the urogenital tract and rectum of infertile patients, and has a good predictive effect on infertility. Compared with infertile patients, L. johnsonii was enriched in the vagina, urethra, and intestine of the control group. L. acidophilus in follicular fluid might be associated with Non-pregnancy.

Conclusion

This study found that the microbial composition of infertile patients was changed compared with that of healthy people. The translocation of Lactobacillus between the rectum and urogenital tract might play a protective barrier role. The changes of Lactobacillus and Geobacillus might be related to female infertility or pregnancy outcome. The study provided a theoretical basis for the future treatment of female infertility from the perspective of microorganisms by detecting the microbial changes associated with female infertility.

Going big by going small: Trade-offs in microbiome explanations of cancer

Microbial factors have been implicated in cancer risk, disease progression, treatment and prevention. The key word, however, is "implicated." Our aim in this paper is to map out some of the tensions between competing methods, goals, and standards of evidence in cancer research with respect to the causal role of microbial factors. We discuss an array of pragmatic and epistemic trade-offs in this research area: prioritizing coarse-grained versus fine-grained explanations of the roles of microbiota in cancer; explaining general versus specific cancer targets; studying model organisms versus human patients; and understanding and explaining cancer versus developing diagnostic tools and treatments. In light of these trade-offs and the distinctive complexity and heterogeneity on both sides of the microbiome-cancer relationship, we suggest that it would be more productive and intellectually honest to frame much of this work, at least currently, in terms of generating causal hypotheses to investigate further. Claims of established causal connections between the microbiome and cancer are in many cases overstated. We also discuss the value of "black boxing" microbial causal variables in this research context and draw some general cautionary lessons for ongoing discussions of microbiomes and cancer.

Inflammatory Bowel Disease: A focus on the Role of Probiotics in Ulcerative Colitis

Inflammatory bowel disease (IBD) is a cluster of disorders of the gastrointestinal tract characterized by chronic inflammation and imbalance of the gut microbiota in a genetically vulnerable host. Crohn’s disease and ulcerative colitis (UC) are well-known types of IBD, and due to its high prevalence, IBD has attracted the attention of researchers globally. The exact etiology of IBD is still unknown; however, various theories have been proposed to provide some explanatory clues that include gene-environment interactions and dysregulated immune response to the intestinal microbiota. These diseases are manifested by several clinical symptoms that depend on the affected segment of the intestine such as diarrhea, abdominal pain, and rectal bleeding. In this era of personalized medicine, various options are developing starting from improved intestinal microecology, small molecules, exosome therapy, to lastly stem cell transplantation. From another aspect, and in parallel to pharmacological intervention, nutrition, and dietary support have shown effectiveness in IBD management. There is an increasing evidence supporting the benefit of probiotics in the prophylaxis and treatment of IBD. There are several studies that have demonstrated that different probiotics alleviate UC. The present review summarizes the progress in the IBD studies focusing and exploring more on the role of probiotics as a potential adjunct approach in UC management.

Association between gut microbiota and hepatocellular carcinoma from 2011 to 2022: Bibliometric analysis and global trends

Background

Hepatocellular carcinoma (HCC) is a primary malignant tumor responsible for approximately 90% of all liver cancers in humans, making it one of the leading public health problems worldwide. The gut microbiota is a complex microbial ecosystem that can influence tumor formation, metastasis, and resistance to treatment. Therefore, understanding the potential mechanisms of gut microbiota pathogenesis is critical for the prevention and treatment of HCC.

Materials and methods

A search was conducted in the Web of Science Core Collection (WoSCC) database for English literature studies on the relationship between gut microbiota and HCC from 2011 to 2022. Bibliometric analysis tools such as VOSviewer, CiteSpace, and R Studio were used to analyze global trends and research hotspots in this field.

Results

A total of 739 eligible publications, comprising of 383 articles and 356 reviews, were analyzed. Over the past 11 years, there has been a rapid increase in the annual number of publications and average citation levels, especially in the last five years. The majority of published articles on this topic originated from China (n=257, 34.78%), followed by the United States of America (n=203, 27.47%), and Italy (n=85, 11.50%). American scholars demonstrated high productivity, prominence, and academic environment influence in the research of this subject. Furthermore, the University of California, San Diego published the most papers (n=24) and had the highest average citation value (value=152.17) in the study of the relationship between gut microbiota and HCC. Schnabl B from the USA and Ohtani N from Japan were the authors with the highest number of publications and average citation value, respectively.

Conclusion

In recent years, research on the gut microbiota's role in HCC has made rapid progress. Through a review of published literature, it has been found that the gut microbiota is crucial in the pathogenesis of HCC and in oncotherapy.

Sparse tree-based clustering of microbiome data to characterize microbiome heterogeneity in pancreatic cancer

There is a keen interest in characterizing variation in the microbiome across cancer patients, given increasing evidence of its important role in determining treatment outcomes. Here our goal is to discover subgroups of patients with similar microbiome profiles. We propose a novel unsupervised clustering approach in the Bayesian framework that innovates over existing model-based clustering approaches, such as the Dirichlet multinomial mixture model, in three key respects: we incorporate feature selection, learn the appropriate number of clusters from the data, and integrate information on the tree structure relating the observed features. We compare the performance of our proposed method to existing methods on simulated data designed to mimic real microbiome data. We then illustrate results obtained for our motivating data set, a clinical study aimed at characterizing the tumor microbiome of pancreatic cancer patients.

Research gaps and opportunities in precision nutrition: an NIH workshop report

Precision nutrition is an emerging concept that aims to develop nutrition recommendations tailored to different people's circumstances and biological characteristics. Responses to dietary change and the resulting health outcomes from consuming different diets may vary significantly between people based on interactions between their genetic backgrounds, physiology, microbiome, underlying health status, behaviors, social influences, and environmental exposures. On 11-12 January 2021, the National Institutes of Health convened a workshop entitled "Precision Nutrition: Research Gaps and Opportunities" to bring together experts to discuss the issues involved in better understanding and addressing precision nutrition. The workshop proceeded in 3 parts: part I covered many aspects of genetics and physiology that mediate the links between nutrient intake and health conditions such as cardiovascular disease, Alzheimer disease, and cancer; part II reviewed potential contributors to interindividual variability in dietary exposures and responses such as baseline nutritional status, circadian rhythm/sleep, environmental exposures, sensory properties of food, stress, inflammation, and the social determinants of health; part III presented the need for systems approaches, with new methods and technologies that can facilitate the study and implementation of precision nutrition, and workforce development needed to create a new generation of researchers. The workshop concluded that much research will be needed before more precise nutrition recommendations can be achieved. This includes better understanding and accounting for variables such as age, sex, ethnicity, medical history, genetics, and social and environmental factors. The advent of new methods and technologies and the availability of considerably more data bring tremendous opportunity. However, the field must proceed with appropriate levels of caution and make sure the factors listed above are all considered, and systems approaches and methods are incorporated. It will be important to develop and train an expanded workforce with the goal of reducing health disparities and improving precision nutritional advice for all Americans.

Akkermansia muciniphila and Faecalibacterium prausnitzii in Immune-Related Diseases

Probiotics and synbiotics are used to treat chronic illnesses due to their roles in immune system modulation and anti-inflammatory response. They have been shown to reduce inflammation in a number of immune-related disorders, including systemic lupus erythematosus (SLE), human immunodeficiency virus (HIV), and chronic inflammatory skin conditions such as psoriasis and atopic dermatitis (AD). Akkermansia muciniphila (A. muciniphila) and Faecalibacterium prausnitzii (F. prausnitzii) are two different types of bacteria that play a significant part in this function. It has been established that Akkermansia and Faecalibacterium are abundant in normal populations and have protective benefits on digestive health while also enhancing the immune system, metabolism, and gut barrier of the host. They have the potential to be a therapeutic target in diseases connected to the microbiota, such as immunological disorders and cancer immunotherapy. There has not been a review of the anti-inflammatory effects of Akkermansia and Faecalibacterium, particularly in immunological diseases. In this review, we highlight the most recent scientific findings regarding A. muciniphila and F. prausnitzii as two significant gut microbiota for microbiome alterations and seek to provide cutting-edge insight in terms of microbiome-targeted therapies as promising preventive and therapeutic tools in immune-related diseases and cancer immunotherapy.

The Potential Functions and Mechanisms of Oat on Cancer Prevention: A Review

Oat is classified as a whole grain and contains high contents of protein, lipids, carbohydrates, vitamins, minerals, and phytochemicals (such as polyphenols, flavonoids, and saponins). In recent years, studies have focused on the effects of oat consumption on reducing the risk of a variety of diseases. Reports have indicated that an oat diet exerts certain biological functions, such as preventing cardiovascular diseases, reducing blood glucose, and promoting intestinal health, along with antiallergy, antioxidation, and cancer preventive effects. At present, cancer is the second leading cause of death worldwide. The natural products of oat are an important breakthrough for developing new strategies of cancer prevention, and their ability to interact with multiple cellular targets helps to combat the complexity of cancer pathogenesis. In addition, the comprehensive study of the cancer prevention activity and potential mechanism of oat nutrients and phytochemicals has become a research hotspot. In this Review, we focused on the potential functions of peptides, dietary fiber, and phytochemicals in oats on cancer prevention and further revealed novel mechanisms and prospects for clinical application. These findings might provide a novel approach to deeply understand the functions and mechanisms for cancer prevention of oat consumption.

Broad-spectrum antibiotics associated gut microbiome disturbance impairs T cell immunity and promotes lung cancer metastasis: a retrospective study

Background

Gut microbiome has been linked to a regulatory role in cancer progression. However, whether broad-spectrum antibiotics (ATB) associated gut microbiome dysbiosis contributes to an impaired T cell immune function, and ultimately promotes lung cancer metastasis is not well known.

Methods

In this study, a retrospective analysis was performed in a cohort of 263 patients initially diagnosed with non-small cell lung cancer (NSCLC) patients, including the ATB group (patients with broad-spectrum antibiotics treatment) (n = 124), and non-ATB group (n = 139) as control. ATB patients were prescribed ATB for over 5 days within 30 days prior to the collection of blood and fecal specimens and followed surgical treatment or first-line therapy. T cell immune function and metastasis-free survival (MFS) were evaluated between the two groups. Gut microbiota was evaluated by 16S rDNA sequencing. The predictive value of T cell immunity for MFS was evaluated by ROC analysis and Cox regression analysis.

Results

Our results suggest that broad-spectrum antibiotics (ATB) impair T cell immune function in patients with either early-stage or advanced NSCLC, which likely contribute to the promotion of lung cancer metastasis. Results of the survival analysis show that metastasis-free survival (MFS) is significantly shorter in the ATB patients than that in the non-ATB patients with stage III NSCLC. The 16S rDNA sequencing shows that ATB administration contributes to a significant dysbiosis of the composition and diversity of gut microbiota. Moreover, ROC analysis results of CD4 (AUC 0.642, p = 0.011), CD8 (AUC was 0.729, p < 0.001), CD16 + 56 + (AUC 0.643, p = 0.003), and the combination of CD4, CD8 and CD16 + 56+ (AUC 0.810, p < 0.001), or Cox regression analysis results of CD4 (HR 0.206, p < 0.001), CD8 (HR 0.555, p = 0.009), which is likely regulated by ATB administration, have significantly predictive values for MFS.

Conclusion

These results provide evidence of gut microbiome disturbance due to ATB administration is involved in the regulation of T cell immunity, and their predictive value for the tumor metastasis in lung cancer patients. Thus, gut microbiota may serve as a therapeutic target for lung cancer. Consequently, caution should be exercised before the long-term administration of broad-spectrum antibiotics in cancer patients.

Multi-Omics Approaches in Colorectal Cancer Screening and Diagnosis, Recent Updates and Future Perspectives

Colorectal cancer (CRC) is common Cancer as well as the third leading cause of mortality around the world; its exact molecular mechanism remains elusive. Although CRC risk is significantly correlated with genetic factors, the pathophysiology of CRC is also influenced by external and internal exposures and their interactions with genetic factors. The field of CRC research has recently benefited from significant advances through Omics technologies for screening biomarkers, including genes, transcripts, proteins, metabolites, microbiome, and lipidome unbiasedly. A promising application of omics technologies could enable new biomarkers to be found for the screening and diagnosis of CRC. Single-omics technologies cannot fully understand the molecular mechanisms of CRC. Therefore, this review article aims to summarize the multi-omics studies of Colorectal cancer, including genomics, transcriptomics, proteomics, microbiomics, metabolomics, and lipidomics that may shed new light on the discovery of novel biomarkers. It can contribute to identifying and validating new CRC biomarkers and better understanding colorectal carcinogenesis. Discovering biomarkers through multi-omics technologies could be difficult but valuable for disease genotyping and phenotyping. That can provide a better knowledge of CRC prognosis, diagnosis, and treatments.

Prospects of Probiotic Adjuvant Drugs in Clinical Treatment

In modern society, where new diseases and viruses are constantly emerging, drugs are still the most important means of resistance. However, adverse effects and diminished efficacy remain the leading cause of treatment failure and a major determinant of impaired health-related quality of life for patients. Clinical studies have shown that the disturbance of the gut microbial structure plays a crucial role in the toxic and side effects of drugs. It is well known that probiotics have the ability to maintain the balance of intestinal microecology, which implies their potential as an adjunct to prevent and alleviate the adverse reactions of drugs and to make medicines play a better role. In addition, in the past decade, probiotics have been found to have excellent prevention and alleviation effects in drug toxicity side effects, such as liver injury. In this review, we summarize the development history of probiotics, discuss the impact on drug side effects of probiotics, and propose the underlying mechanisms. Probiotics will be a new star in the world of complementary medicine.

Effects of gut microbiota on immune responses and immunotherapy in colorectal cancer

Accumulating evidence suggests that gut microbial dysbiosis is implicated in colorectal cancer (CRC) initiation and progression through interaction with host immune system. Given the intimate relationship between the gut microbiota and the antitumor immune responses, the microbiota has proven to be effective targets in modulating immunotherapy responses of preclinical CRC models. However, the proposed putative mechanisms of how these bacteria affect immune responses and immunotherapy efficacy remains obscure. In this review, we summarize recent findings of clinical gut microbial dysbiosis in CRC patients, the reciprocal interactions between gut microbiota and the innate and/or the adaptive immune system, as well as the effect of gut microbiota on immunotherapy response in CRC. Increased understanding of the gut microbiota-immune system interactions will benefit the rational application of microbiota to the clinical promising biomarker or therapeutic strategy as a cancer immunotherapy adjuvant.

Onco-biome in pharmacotherapy for lung cancer: a narrative review

BACKGROUND AND OBJECTIVE

The gut microbiota (GM) was recently recognized to play an important role in modulating systemic immune responses and is known to influence the effects or adverse events of immune checkpoint blockade (ICB) or carcinogenesis by crosstalk with regulators of cancer-related immunity, and this relationship is complex and multifactorial. Diversity in the gut microbiome and the abundance of specific bacterial species have been identified to be associated with better response and prognosis. Therefore, the purpose of the current interest in the gut microbiome is to enable modulation of the immune system in donor cancer patients by the administration of specific bacterial species and enabling their dominance. To understand this "terra incognita" is to uncover the role of the mechanisms underlying unknown organ functions, and this knowledge will lead to enhanced immunotherapy for lung cancer patients.

METHODS

In this article, we summarized the literature on the relationship between the microbiome and lung cancer and the potential of the microbiome as a therapeutic target.

KEY CONTENT AND FINDINGS

This article is organized into the following sections: introduction, methods, microbiota and cancer development, microbiota and lung cancer treatment, future directions, and conclusion.

CONCLUSIONS

The gut microbiome is currently becoming the hallmark of cancer research and has an established and critical role in regulating antitumor immunity and the response to ICB in patients with lung cancers.

Modulation of the Gut Microbiome to Enhance Immunotherapy Response in Metastatic Melanoma Patients: A Clinical Review

For patients with metastatic melanoma, immunotherapy agents represent a promising treatment option, and researchers are actively seeking to identify factors that may predict a favorable response in patients. Recent studies have elucidated possible associations between the gut microbiome and the effects of immunotherapy, where variations in the gut microbiome may influence treatment response and frequency of adverse effects. In this clinical review, we describe the current literature related to the gut microbiome in the setting of immunotherapy, and we provide an overview of interventions under investigation that may modulate the gut microbiome. These interventions include fecal microbiota transplantation, probiotics, and dietary modifications.

Microbial dysbiosis and epigenetics modulation in cancer development - A chemopreventive approach

An overwhelming number of research articles have reported a strong relationship of the microbiome with cancer. Microbes have been observed more commonly in the body fluids like urine, stool, mucus of people with cancer compared to the healthy controls. The microbiota is responsible for both progression and suppression activities of various diseases. Thus, to maintain healthy human physiology, host and microbiota relationship should be in a balanced state. Any disturbance in this equilibrium, referred as microbiome dysbiosis becomes a prime cause for the human body to become more prone to immunodeficiency and cancer. It is well established that some of these microbes are the causative agents, whereas others may encourage the formation of tumours, but very little is known about how these microbial communications causing change at gene and epigenome level and trigger as well as encourage the tumour growth. Various studies have reported that microbes in the gut influence DNA methylation, DNA repair and DNA damage. The genes and pathways that are altered by gut microbes are also associated with cancer advancement, predominantly those implicated in cell growth and cell signalling pathways. This study exhaustively reviews the current research advancements in understanding of dysbiosis linked with colon, lung, ovarian, breast cancers and insights into the potential molecular targets of the microbiome promoting carcinogenesis, the epigenetic alterations of various potential targets by altered microbiota, as well as the role of various chemopreventive agents for timely prevention and customized treatment against various types of cancers.

Drug-related adverse events potentially predict the efficacy of apatinib on advanced hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide every year, and most HCC patients are diagnosed with advanced disease and can only receive systemic treatment. TKIs are the most important components of the systemic treatment of HCC and have both good efficacy and adverse events (AEs). 

Methods

This analysis included 207 patients with locally advanced unresectable or metastatic HCC who received oral treatment with apatinib. We analyzed the overall survival (OS) and progression-free survival (PFS) of patients with or without corresponding AEs to evaluate which AEs can predict the efficacy of apatinib.

Results

Patients with hand-foot syndrome (HFS; p = 0.005), proteinuria (p = 0.006) and diarrhea (p < 0.001) had significantly better OS than those without corresponding AEs, and the appearance of HFS (p = 0.006) and proteinuria (p = 0.004) was associated with longer PFS.

Conclusion

Among all the AEs induced by apatinib in the treatment of advanced HCC, proteinuria could potentially predict PFS, and diarrhea was a potential predictor of OS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02542-0.