Microbiota-Centered Interventions: The Next Breakthrough in Immuno-Oncology?

Current and future immunotherapeutic approaches in pancreatic cancer treatment

Pancreatic cancer is a major cause of cancer-related death, but despondently, the outlook and prognosis for this resistant type of tumor have remained grim for a long time. Currently, it is extremely challenging to prevent or detect it early enough for effective treatment because patients rarely exhibit symptoms and there are no reliable indicators for detection. Most patients have advanced or spreading cancer that is difficult to treat, and treatments like chemotherapy and radiotherapy can only slightly prolong their life by a few months. Immunotherapy has revolutionized the treatment of pancreatic cancer, yet its effectiveness is limited by the tumor's immunosuppressive and hard-to-reach microenvironment. First, this article explains the immunosuppressive microenvironment of pancreatic cancer and highlights a wide range of immunotherapy options, including therapies involving oncolytic viruses, modified T cells (T-cell receptor [TCR]-engineered and chimeric antigen receptor [CAR] T-cell therapy), CAR natural killer cell therapy, cytokine-induced killer cells, immune checkpoint inhibitors, immunomodulators, cancer vaccines, and strategies targeting myeloid cells in the context of contemporary knowledge and future trends. Lastly, it discusses the main challenges ahead of pancreatic cancer immunotherapy.

A viable remedy for overcoming resistance to anti-PD-1 immunotherapy: Fecal microbiota transplantation

Anti-PD-1 immunotherapy is a cancer therapy that focuses explicitly on the PD-1 receptor found on the surface of immune cells. This targeted therapeutic strategy is specifically designed to amplify the immune system's innate capacity to detect and subsequently eliminate cells that have become cancerous. Nevertheless, it should be noted that not all patients exhibit a favourable response to this particular therapeutic modality, necessitating the exploration of novel strategies to augment the effectiveness of immunotherapy. Previous studies have shown that fecal microbiota transplantation (FMT) can enhance the efficacy of anti-PD-1 immunotherapy in advanced melanoma patients. To investigate this intriguing possibility further, we turned to PubMed and conducted a comprehensive search for studies that analyzed the interplay between FMT and anti-PD-1 therapy in the context of tumor treatment. Our search criteria were centred around two key phrases: "fecal microbiota transplantation" and "anti-PD-1 therapy." The studies we uncovered all echo a similar sentiment. They pointed towards the potential of FMT to improve the effectiveness of immunotherapy. FMT may enhance the effectiveness of immunotherapy by altering the gut microbiota and boosting the patient's immunological response. Although promising, additional investigation is needed to improve the efficacy of FMT in the context of cancer therapy and attain a comprehensive understanding of the possible advantages and drawbacks associated with this therapeutic strategy.

Microbiota enterotoxigenic Bacteroides fragilis-secreted BFT-1 promotes breast cancer cell stemness and chemoresistance through its functional receptor NOD1

Tumor-resident microbiota in breast cancer promotes cancer initiation and malignant progression. However, targeting microbiota to improve the effects of breast cancer therapy has not been investigated in detail. Here, we evaluated the microbiota composition of breast tumors and found that enterotoxigenic Bacteroides fragilis (ETBF) was highly enriched in the tumors of patients who did not respond to taxane-based neoadjuvant chemotherapy. ETBF, albeit at low biomass, secreted the toxic protein BFT-1 to promote breast cancer cell stemness and chemoresistance. Mechanistic studies showed that BFT-1 directly bound to NOD1 and stabilized NOD1 protein. NOD1 was highly expressed on ALDH+ breast cancer stem cells (BCSCs) and cooperated with GAK to phosphorylate NUMB and promote its lysosomal degradation, thereby activating the NOTCH1-HEY1 signaling pathway to increase BCSCs. NOD1 inhibition and ETBF clearance increase the chemosensitivity of breast cancer by impairing BCSCs.

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.

Exploring the casual association between gut microbiome, circulating inflammatory cytokines and chronic pancreatitis: A Mendelian randomization analysis

It has been established that gut dysbiosis contributed to the pathogenesis of digestive disorders. We aimed to explore the causal relationships between intestinal microbiota, circulating inflammatory cytokines and chronic pancreatitis (CP). Summary statistics of genome-wide association studies (GWAS) of intestinal microbiome was retrieved from the MiBioGen study and the GWAS data of 91 circulating inflammatory cytokines and CP were obtained from the GWAS catalog. The 2-sample bidirectional Mendelian randomization (MR) analysis was performed between gut microbiota, circulating inflammatory cytokines and CP, in which the inverse variance weighted (IVW) method was regarded as the primary analysis approach. To prove the reliability of the causal estimations, multiple sensitivity analyses were utilized. IVW results revealed that genetically predicted 2 genera, including Sellimonas and Eubacteriumventriosumgroup, and plasm C-C motif chemokine 23 (CCL23) level were positively associated with CP risk, while genus Escherichia Shigella, Eubacteriumruminantiumgroup and Prevotella9, and plasma Caspase 8, Adenosine Deaminase (ADA), and SIR2-like protein 2 (SIRT2) level, demonstrated an ameliorative effect on CP. Leave-one-out analysis confirmed the robustness of the aforementioned causal effects and no significant horizontal pleiotropy or heterogeneity of the instrumental variables was detected. However, no association was found from the identified genera to the CP-related circulating inflammatory cytokines. Besides, the reverse MR analysis demonstrated no causal relationship from CP to the identified genera and circulating inflammatory cytokines. Taken together, our comprehensive analyses offer evidence in favor of the estimated causal connections from the 5 genus-level microbial taxa and 4 circulating inflammatory cytokines to CP risk, which may help to reveal the underlying pathogenesis of CP.

Efficacy and safety of chemoimmunotherapy in advanced non-small cell lung cancer patients with antibiotics-induced dysbiosis: a propensity-matched real-world analysis

PURPOSE

The gut microbiota is hypothesized as a prognostic biomarker for cancer immunotherapy. Antibiotic-induced dysbiosis negatively affects the clinical outcomes of immunotherapy. However, the effect of dysbiosis on the efficacy and safety of Chemoimmunotherapy (chemo-IOs), the frontline standard of care, in advanced non-small cell lung cancer (NSCLC) remains unknown. We aimed to compare the efficacy and safety of chemo-IOs in patients exposed to antibiotics before treatment with those of patients who were not exposed.

METHODS

We retrospectively reviewed patients with advanced NSCLC treated with first-line chemo-IOs between 2018 and 2020 at the National Cancer Center Hospital. The patients were divided into two groups: those exposed to antibiotics within 30 days before induction therapy (ABx group) and those did not antibiotics (Non-ABx group). Propensity score matching was used to control for potential confounding factors. Clinical outcomes including progression-free survival (PFS), overall survival (OS), and immune-related adverse events (irAEs) were compared.

RESULTS

Of 201 eligible patients, 21 were in the ABx group, and 42 were in the non-ABx group after propensity score matching. No differences in PFS or OS emerged between the two groups (ABx group vs. Non-ABx group) (PFS:7.0 months vs. 6.4 months, hazard ratio [HR] 0.89; 95% confidence interval [CI], 0.49-1.63, OS:20.4 months vs. 20.1 months, HR 0.87; 95% CI 0.44-1.71). The frequency of irAEs before propensity score matching was similar across any-grade irAEs (39.4% vs. 42.9%) or grade 3 or higher irAEs (9.1% vs. 11.3%).

CONCLUSION

Antibiotic-induced dysbiosis may not affect the efficacy of chemo-IOs in patients with advanced NSCLC.

Cancer and the Metaorganism

SUMMARY

Pathogenic shifts in the gut microbiota are part of the "ecological" alterations that accompany tumor progression and compromise immunosurveillance. The future management of health and disease including cancer will rely on the diagnosis of such shifts and their therapeutic correction by general or personalized strategies, hence restoring metaorganismal homeostasis.

Longitudinal gut microbiome changes in immune checkpoint blockade-treated advanced melanoma

Multiple clinical trials targeting the gut microbiome are being conducted to optimize treatment outcomes for immune checkpoint blockade (ICB). To improve the success of these interventions, understanding gut microbiome changes during ICB is urgently needed. Here through longitudinal microbiome profiling of 175 patients treated with ICB for advanced melanoma, we show that several microbial species-level genome bins (SGBs) and pathways exhibit distinct patterns from baseline in patients achieving progression-free survival (PFS) of 12 months or longer (PFS ≥12) versus patients with PFS shorter than 12 months (PFS <12). Out of 99 SGBs that could discriminate between these two groups, 20 were differentially abundant only at baseline, while 42 were differentially abundant only after treatment initiation. We identify five and four SGBs that had consistently higher abundances in patients with PFS ≥12 and <12 months, respectively. Constructing a log ratio of these SGBs, we find an association with overall survival. Finally, we find different microbial dynamics in different clinical contexts including the type of ICB regimen, development of immune-related adverse events and concomitant medication use. Insights into the longitudinal dynamics of the gut microbiome in association with host factors and treatment regimens will be critical for guiding rational microbiome-targeted therapies aimed at enhancing ICB efficacy.

Influence of microbiota-associated metabolic reprogramming on clinical outcome in patients with melanoma from the randomized adjuvant dendritic cell-based MIND-DC trial

Tumor immunosurveillance plays a major role in melanoma, prompting the development of immunotherapy strategies. The gut microbiota composition, influencing peripheral and tumoral immune tonus, earned its credentials among predictors of survival in melanoma. The MIND-DC phase III trial (NCT02993315) randomized (2:1 ratio) 148 patients with stage IIIB/C melanoma to adjuvant treatment with autologous natural dendritic cell (nDC) or placebo (PL). Overall, 144 patients collected serum and stool samples before and after 2 bimonthly injections to perform metabolomics (MB) and metagenomics (MG) as prespecified exploratory analysis. Clinical outcomes are reported separately. Here we show that different microbes were associated with prognosis, with the health-related Faecalibacterium prausnitzii standing out as the main beneficial taxon for no recurrence at 2 years (p = 0.008 at baseline, nDC arm). Therapy coincided with major MB perturbations (acylcarnitines, carboxylic and fatty acids). Despite randomization, nDC arm exhibited MG and MB bias at baseline: relative under-representation of F. prausnitzii, and perturbations of primary biliary acids (BA). F. prausnitzii anticorrelated with BA, medium- and long-chain acylcarnitines. Combined, these MG and MB biomarkers markedly determined prognosis. Altogether, the host-microbial interaction may play a role in localized melanoma. We value systematic MG and MB profiling in randomized trials to avoid baseline differences attributed to host-microbe interactions.

Multi-omics of the gut microbial ecosystem in patients with microsatellite-instability-high gastrointestinal cancer resistant to immunotherapy

Despite the encouraging efficacy of anti-PD-1/PD-L1 immunotherapy in microsatellite-instability-high/deficient mismatch repair (MSI-H/dMMR) advanced gastrointestinal cancer, many patients exhibit primary or acquired resistance. Using multi-omics approaches, we interrogate gut microbiome, blood metabolome, and cytokines/chemokines of patients with MSI-H/dMMR gastrointestinal cancer (N = 77) at baseline and during the treatment. We identify a number of microbes (e.g., Porphyromonadaceae) and metabolites (e.g., arginine) highly associated with primary resistance to immunotherapy. An independent validation cohort (N = 39) and mouse model are used to further confirm our findings. A predictive machine learning model for primary resistance is also built and achieves an accuracy of 0.79 on the external validation set. Furthermore, several microbes are pinpointed that gradually changed during the process of acquired resistance. In summary, our study demonstrates the essential role of gut microbiome in drug resistance, and this can be utilized as a preventative diagnosis tool and therapeutic target in the future.

Melanoma and microbiota: Current understanding and future directions

Over the last decade, the composition of the gut microbiota has been found to correlate with the outcomes of cancer patients treated with immunotherapy. Accumulating evidence points to the various mechanisms by which intestinal bacteria act on distal tumors and how to harness this complex ecosystem to circumvent primary resistance to immune checkpoint inhibitors. Here, we review the state of the microbiota field in the context of melanoma, the recent breakthroughs in defining microbial modes of action, and how to modulate the microbiota to enhance response to cancer immunotherapy. The host-microbe interaction may be deciphered by the use of "omics" technologies, and will guide patient stratification and the development of microbiota-centered interventions. Efforts needed to advance the field and current gaps of knowledge are also discussed.

Gut microbiome predicts gastrointestinal toxicity outcomes from chemoradiation therapy in patients with head and neck squamous cell carcinoma

OBJECTIVES

Chemoradiation (CRT) in patients with locally advanced head and neck squamous cell cancer (HNSCC) is associated with significant toxicities, including mucositis. The gut microbiome represents an emerging hallmark of cancer and a potentially important biomarker for CRT-related adverse events. This prospective study investigated the association between the gut microbiome composition and CRT-related toxicities in patients with HNSCC, including mucositis.

MATERIALS AND METHODS

Stool samples from patients diagnosed with locally advanced HNSCC were prospectively collected prior to CRT initiation and analyzed using shotgun metagenomic sequencing to evaluate gut microbiome composition at baseline. Concurrently, clinicopathologic data, survival outcomes and the incidence and grading of CRT-emergent adverse events were documented in all patients.

RESULTS

A total of 52 patients were included, of whom 47 had baseline stool samples available for metagenomic analysis. Median age was 62, 83 % patients were men and 54 % had stage III-IV disease. All patients developed CRT-induced mucositis, including 42 % with severe events (i.e. CTCAE v5.0 grade ≥ 3) and 25 % who required enteral feeding. With a median follow-up of 26.5 months, patients with severe mucositis had shorter overall survival (HR = 3.3, 95 %CI 1.0-10.6; p = 0.02) and numerically shorter progression-free survival (HR = 2.8, 95 %CI, 0.8-9.6; p = 0.09). The gut microbiome beta-diversity of patients with severe mucositis differed from patients with grades 1-2 mucositis (p = 0.04), with enrichment in Mediterraneibacter (Ruminococcus gnavus) and Clostridiaceae family members, including Hungatella hathewayi. Grade 1-2 mucositis was associated with enrichment in Eubacterium rectale, Alistipes putredinis and Ruminococcaceae family members. Similar bacterial profiles were observed in patients who required enteral feeding.

CONCLUSION

Patients who developed severe mucositis had decreased survival and enrichment in specific bacteria associated with mucosal inflammation. Interestingly, these same bacteria have been linked to immune checkpoint inhibitor resistance.

Association of Clostridium butyricum Therapy Using the Live Bacterial Product CBM588 with the Survival of Patients with Lung Cancer Receiving Chemoimmunotherapy Combinations

The gut microbiota has emerged as a key regulator of immune checkpoint inhibitor (ICI) efficacy. Therapeutic approaches aimed at manipulating the microbiota through targeted reconstitution to enhance cancer treatment outcomes have garnered considerable attention. A single live microbial biotherapeutic bacterium, Clostridium butyricum MIYAIRI 588 strain (CBM588), has been shown to enhance the effects of ICI monotherapy in patients with advanced lung cancer. However, whether CBM588 affects the outcomes of chemoimmunotherapy combinations in lung cancer remains unknown. We hypothesized that CBM588 augments the effect of chemoimmunotherapy combinations and restores diminished effectiveness in patients with non-small cell lung cancer (NSCLC) receiving dysbiosis-inducing drugs. To validate this hypothesis, we retrospectively analyzed 106 patients with stage IV or recurrent metastatic NSCLC consecutively treated with chemoimmunotherapy combinations. A survival analysis was performed employing univariate and multivariate Cox proportional hazard models with inverse probability of treatment weighting (IPTW) using propensity scores. Forty-five percent of patients received Clostridium butyricum therapy. CBM588 significantly extended overall survival in patients with NSCLC receiving chemoimmunotherapy. The favorable impact of CBM588 on the efficacy of chemoimmunotherapy combinations varied based on tumor-programmed cell death ligand 1 (PD-L1) expression. The survival benefit of CBM588 in the PD-L1 <1% cohort was higher than that in the PD-L1 1-49% and PD-L1 ≥ 50% cohorts. Furthermore, CBM588 was associated with improved overall survival in patients receiving proton pump inhibitors and/or antibiotics. CBM588-induced manipulation of the commensal microbiota holds the potential to enhance the efficacy of chemoimmunotherapy combinations, warranting further exploration of the synergy between CBM588 and immunotherapy.

Early T Cell Infiltration Correlates with Anti-CTLA4 Treatment Response in Murine Cancer Models

Immune checkpoint inhibitor (ICI) Abs are a revolutionary class of cancer treatment, but only ∼30% of patients receive a lasting benefit from therapy. Preclinical studies using animals from the same genetic backgrounds, challenged with the same cancer models, also show nonuniform responses. Most mouse studies that have evaluated tumor-infiltrating leukocytes after ICI therapy cannot directly correlate their findings with treatment outcomes, because terminal methods were used to acquire immune infiltrate data. In the present study, we used fine-needle aspiration (a nonterminal sampling method) to collect multiple aspirates over several days from s.c. implanted P815, CT26, and 4T1 mouse cancer models treated with ICI Abs. These aspirates were then analyzed with flow cytometry to directly correlate tumor-infiltrating leukocyte populations with treatment success. We found that the P815 and CT26 models respond well to anti-CTLA4 therapies. Among P815-challenged animals, mice that regressed following anti-CTLA4 treatment showed significant increases in CD8+ T cells on days 3, 5, and 7 and in CD4+ T cells on days 5 and 7 and a decrease in macrophages and monocytes on days 3, 5, and 7 after treatment. Similar results were obtained in the CT26 model on day 11 posttreatment. Our study is the first, to our knowledge, to directly correlate early tumor infiltration of T cells with anti-CTLA4 treatment success, thus providing a mechanistic clue toward understanding why alloidentical mice challenged with identical tumors do not respond uniformly to ICI therapies.

Helicobacter pylori infection reduces the efficacy of cancer immunotherapy: A systematic review and meta-analysis

BACKGROUND

Cancer immunotherapy has shown promising results in several tumors, but its efficacy is influenced by the immune state of the body. Helicobacter pylori (H. pylori) infection can modulate the immune function of the body through various pathways, ultimately affecting the effectiveness of cancer immunotherapy.

AIM

In this meta-analysis, we aimed to explore the association between H. pylori infection and the efficacy of cancer immunotherapy.

METHODS

We conducted a comprehensive search of PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials to identify relevant articles. We extracted and pooled the hazard ratio (HR) of the overall survival (OS) and progression-free survival (PFS) by Review Manager 5.4.

RESULTS

Our analysis included four studies with a total of 263 participants. Compared to the control group, patients receiving cancer immunotherapy with H. pylori infection had a shorter OS (HR = 2.68, 95% CI: 2.00-4.11, p < 0.00001) and PFS (HR = 2.25, 95% CI: 1.66-3.60, p < 0.00001).

CONCLUSION

Our meta-analysis suggested that H. pylori infection has a detrimental effect on cancer immunotherapy.

γδ T cells: origin and fate, subsets, diseases and immunotherapy

The intricacy of diseases, shaped by intrinsic processes like immune system exhaustion and hyperactivation, highlights the potential of immune renormalization as a promising strategy in disease treatment. In recent years, our primary focus has centered on γδ T cell-based immunotherapy, particularly pioneering the use of allogeneic Vδ2+ γδ T cells for treating late-stage solid tumors and tuberculosis patients. However, we recognize untapped potential and optimization opportunities to fully harness γδ T cell effector functions in immunotherapy. This review aims to thoroughly examine γδ T cell immunology and its role in diseases. Initially, we elucidate functional differences between γδ T cells and their αβ T cell counterparts. We also provide an overview of major milestones in γδ T cell research since their discovery in 1984. Furthermore, we delve into the intricate biological processes governing their origin, development, fate decisions, and T cell receptor (TCR) rearrangement within the thymus. By examining the mechanisms underlying the anti-tumor functions of distinct γδ T cell subtypes based on γδTCR structure or cytokine release, we emphasize the importance of accurate subtyping in understanding γδ T cell function. We also explore the microenvironment-dependent functions of γδ T cell subsets, particularly in infectious diseases, autoimmune conditions, hematological malignancies, and solid tumors. Finally, we propose future strategies for utilizing allogeneic γδ T cells in tumor immunotherapy. Through this comprehensive review, we aim to provide readers with a holistic understanding of the molecular fundamentals and translational research frontiers of γδ T cells, ultimately contributing to further advancements in harnessing the therapeutic potential of γδ T cells.

Prior antibiotic administration disrupts anti-PD-1 responses in advanced gastric cancer by altering the gut microbiome and systemic immune response

Evidence on whether prior antibiotic (pATB) administration modulates outcomes of programmed cell death protein-1 (PD-1) inhibitors in advanced gastric cancer (AGC) is scarce. In this study, we find that pATB administration is consistently associated with poor progression-free survival (PFS) and overall survival (OS) in multiple cohorts consisting of patients with AGC treated with PD-1 inhibitors. In contrast, pATB does not affect outcomes among patients treated with irinotecan. Multivariable analysis of the overall patients treated with PD-1 inhibitors confirms that pATB administration independently predicts worse PFS and OS. Administration of pATBs is associated with diminished gut microbiome diversity, reduced abundance of Lactobacillus gasseri, and disproportional enrichment of circulating exhaustive CD8+ T cells, all of which are associated with worse outcomes. Considering the inferior treatment response and poor survival outcomes by pATB administration followed by PD-1 blockade, ATBs should be prescribed with caution in patients with AGC who are planning to receive PD-1 inhibitors.

Dietary fibers affecting gastrointestinal immunity

Dietary fibers, including chitin, have a major impact on gastrointestinal (GI) physiology and immunity. Two recent articles, by Parrish et al. and Kim et al., credit depletion of dietary fibers or supplementation with chitin, with negative and positive effects, respectively, on the immune system of the murine digestive tract. This has relevant implications for food allergies and systemic metabolism.

From mucosal infection to successful cancer immunotherapy

The clinical management of advanced malignancies of the upper and lower urinary tract has been revolutionized with the advent of immune checkpoint blockers (ICBs). ICBs reinstate or bolster pre-existing immune responses while creating new T cell specificities. Immunogenic cancers, which tend to benefit more from immunotherapy than cold tumours, harbour tumour-specific neoantigens, often associated with a high tumour mutational burden, as well as CD8+ T cell infiltrates and ectopic lymphoid structures. The identification of beneficial non-self tumour antigens and natural adjuvants is the focus of current investigation. Moreover, growing evidence suggests that urinary or intestinal commensals, BCG and uropathogenic Escherichia coli influence long-term responses in patients with kidney or bladder cancer treated with ICBs. Bacteria infecting urothelium could be a prominent target for T follicular helper cells and B cells, linking innate and cognate CD8+ memory responses. In the urinary tract, commensal flora differ between healthy and tumoural mucosae. Although antibiotics can affect the prognosis of urinary tract malignancies, bacteria can have a major influence on cancer immunosurveillance. Beyond their role as biomarkers, immune responses against uropathogenic commensals could be harnessed for the design of future immunoadjuvants that can be advantageously combined with ICBs.

The microbial metabolite desaminotyrosine enhances T-cell priming and cancer immunotherapy with immune checkpoint inhibitors

BACKGROUND

Inter-individual differences in response to immune checkpoint inhibitors (ICI) remain a major challenge in cancer treatment. The composition of the gut microbiome has been associated with differential ICI outcome, but the underlying molecular mechanisms remain unclear, and therapeutic modulation challenging.

METHODS

We established an in vivo model to treat C57Bl/6j mice with the type-I interferon (IFN-I)-modulating, bacterial-derived metabolite desaminotyrosine (DAT) to improve ICI therapy. Broad spectrum antibiotics were used to mimic gut microbial dysbiosis and associated ICI resistance. We utilized genetic mouse models to address the role of host IFN-I in DAT-modulated antitumour immunity. Changes in gut microbiota were assessed using 16S-rRNA sequencing analyses.

FINDINGS

We found that oral supplementation of mice with the microbial metabolite DAT delays tumour growth and promotes ICI immunotherapy with anti-CTLA-4 or anti-PD-1. DAT-enhanced antitumour immunity was associated with more activated T cells and natural killer cells in the tumour microenvironment and was dependent on host IFN-I signalling. Consistent with this, DAT potently enhanced expansion of antigen-specific T cells following vaccination with an IFN-I-inducing adjuvant. DAT supplementation in mice compensated for the negative effects of broad-spectrum antibiotic-induced dysbiosis on anti-CTLA-4-mediated antitumour immunity. Oral administration of DAT altered the gut microbial composition in mice with increased abundance of bacterial taxa that are associated with beneficial response to ICI immunotherapy.

INTERPRETATION

We introduce the therapeutic use of an IFN-I-modulating bacterial-derived metabolite to overcome resistance to ICI. This approach is a promising strategy particularly for patients with a history of broad-spectrum antibiotic use and associated loss of gut microbial diversity.

FUNDING

Melanoma Research Alliance, Deutsche Forschungsgemeinschaft, German Cancer Aid, Wilhelm Sander Foundation, Novartis Foundation.

The Gut Microbiome from a Biomarker to a Novel Therapeutic Strategy for Immunotherapy Response in Patients with Lung Cancer

The gastrointestinal microbiome has been shown to play a key role in determining the responses to cancer immunotherapy, including immune checkpoint inhibitor (ICI) therapy and CAR-T. In patients with non-small cell lung cancer (NSCLC), increasing evidence suggests that a microbiome composition signature is associated with clinical response to ICIs as well as with the development of immune-related adverse events. In support of this, antibiotic (ATB)-related dysbiosis has been consistently linked with the deleterious impact of ICI response, shortening the overall survival (OS) among patients on ATBs prior to ICI initiation. In parallel, several preclinical experiments have unravelled various strategies using probiotics, prebiotics, diet, and fecal microbiota transplantation as new therapeutic tools to beneficially shift the microbiome and enhance ICI efficacy. These approaches are currently being evaluated in clinical trials and have achieved encouraging preliminary results. In this article, we reviewed the recent studies on the gut microbiome as a potential biomarker and an adjuvant therapy to ICIs in NSCLC patients.

Efficacy of anti-programmed cell death protein 1 monoclonal antibody combined with bevacizumab and/or Pseudomonas aeruginosa injection in transplanted tumor of mouse forestomach carcinoma cell gastric cancer in mice and its mechanism in regulating tumor immune microenvironment

Tumor immunotherapy represented by programmed cell death protein 1 (PD-1) inhibitors is considered as the most promising cancer treatment method and has been widely used in the treatment of advanced gastric cancer (GC). However, the effective rate of PD-1 inhibitor monotherapy is low. In this study, we constructed a transplanted tumor model in GC mice by inoculating mouse forestomach carcinoma cell (MFC) GC cells into 615 mice. Interventions were conducted with normal saline, anti-PD-1 monoclonal antibody (mAb), bevacizumab, Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA), anti-PD-1 mAb combined with bevacizumab, anti-PD-1 mAb combined with PA-MSHA, bevacizumab combined with PA-MSHA, anti-PD-1 mAb combined with bevacizumab and PA-MSHA, respectively. The tumor growth curves were drawn. TUNEL assay, western blotting, and immunohistochemistry were used to detect tumor proliferation and apoptosis. Flow cytometry and ELISA were used to detect the expression of tumor infiltrating lymphocytes and cytokines. This study found that anti-PD-1 mAb alone could not significantly inhibit the growth of transplanted tumors in mice. Anti-PD-1 mAb combined with bevacizumab, anti-PD-1 mAb combined with PA-MSHA, anti-PD-1 mAb combined with bevacizumab and PA-MSHA could all significantly inhibit tumor growth in mice, and the combination of three drugs presented the highest tumor inhibition rate. Anti-PD-1 mAb combined with bevacizumab and PA-MSHA could significantly upregulate the number of Th1-type cells, CD8 + T cells, and Type I tumor-associated macrophages (TAMs), while downregulate the number of Th2-type cells, myeloid-derived suppressor cells, regulatory T cells, and Type II TAMs. Therefore, we conclude that anti-PD-1 mAb combined with bevacizumab and/or PA-MSHA has a synergistic effect. Bevacizumab and PA-MSHA can transform the tumor immunosuppressive microenvironment into a supportive immune microenvironment, thus maximizing the antitumor effect of anti-PD-1 mAb.

Drug-microbiota interactions: an emerging priority for precision medicine

Individual variability in drug response (IVDR) can be a major cause of adverse drug reactions (ADRs) and prolonged therapy, resulting in a substantial health and economic burden. Despite extensive research in pharmacogenomics regarding the impact of individual genetic background on pharmacokinetics (PK) and pharmacodynamics (PD), genetic diversity explains only a limited proportion of IVDR. The role of gut microbiota, also known as the second genome, and its metabolites in modulating therapeutic outcomes in human diseases have been highlighted by recent studies. Consequently, the burgeoning field of pharmacomicrobiomics aims to explore the correlation between microbiota variation and IVDR or ADRs. This review presents an up-to-date overview of the intricate interactions between gut microbiota and classical therapeutic agents for human systemic diseases, including cancer, cardiovascular diseases (CVDs), endocrine diseases, and others. We summarise how microbiota, directly and indirectly, modify the absorption, distribution, metabolism, and excretion (ADME) of drugs. Conversely, drugs can also modulate the composition and function of gut microbiota, leading to changes in microbial metabolism and immune response. We also discuss the practical challenges, strategies, and opportunities in this field, emphasizing the critical need to develop an innovative approach to multi-omics, integrate various data types, including human and microbiota genomic data, as well as translate lab data into clinical practice. To sum up, pharmacomicrobiomics represents a promising avenue to address IVDR and improve patient outcomes, and further research in this field is imperative to unlock its full potential for precision medicine.

The Evolving Landscape of Fecal Microbial Transplantation

The human gastrointestinal tract houses an enormous microbial ecosystem. Recent studies have shown that the gut microbiota plays significant physiological roles and maintains immune homeostasis in the human body. Dysbiosis, an imbalanced gut microbiome, can be associated with various disease states, as observed in infectious diseases, inflammatory diseases, autoimmune diseases, and cancer. Modulation of the gut microbiome has become a therapeutic target in treating these disorders. Fecal microbiota transplantation (FMT) from a healthy donor restores the normal gut microbiota homeostasis in the diseased host. Ample evidence has demonstrated the efficacy of FMT in recurrent Clostridioides difficile infection (rCDI). The application of FMT in other human diseases is gaining attention. This review aims to increase our understanding of the mechanisms of FMT and its efficacies in human diseases. We discuss the application, route of administration, limitations, safety, efficacies, and suggested mechanisms of FMT in rCDI, autoimmune diseases, and cancer. Finally, we address the future perspectives of FMT in human medicine.

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.

Killing tumor-associated bacteria with a liposomal antibiotic generates neoantigens that induce anti-tumor immune responses

Increasing evidence implicates the tumor microbiota as a factor that can influence cancer progression. In patients with colorectal cancer (CRC), we found that pre-resection antibiotics targeting anaerobic bacteria substantially improved disease-free survival by 25.5%. For mouse studies, we designed an antibiotic silver-tinidazole complex encapsulated in liposomes (LipoAgTNZ) to eliminate tumor-associated bacteria in the primary tumor and liver metastases without causing gut microbiome dysbiosis. Mouse CRC models colonized by tumor-promoting bacteria (Fusobacterium nucleatum spp.) or probiotics (Escherichia coli Nissle spp.) responded to LipoAgTNZ therapy, which enabled more than 70% long-term survival in two F. nucleatum-infected CRC models. The antibiotic treatment generated microbial neoantigens that elicited anti-tumor CD8+ T cells. Heterologous and homologous bacterial epitopes contributed to the immunogenicity, priming T cells to recognize both infected and uninfected tumors. Our strategy targets tumor-associated bacteria to elicit anti-tumoral immunity, paving the way for microbiome-immunotherapy interventions.

Characterization and description of Gabonibacter chumensis sp. nov., isolated from feces of a patient with non-small cell lung cancer treated with immunotherapy

A polyphasic taxonomic approach, incorporating analysis of phenotypic features, cellular fatty acid profiles, 16S rRNA gene sequences, and determination of average nucleotide identity (ANI) plus digital DNA-DNA hybridization (dDDH), was applied to characterize an anaerobic bacterial strain designated KD22T isolated from human feces. 16S rRNA gene-based phylogenetic analysis showed that strain KD22T was found to be most closely related to species of the genus Gabonibacter. At the 16S rRNA gene level, the closest species from the strain KD22T corresponded with Gabonibacter massiliensis GM7T, with a similarity of 97.58%. Cells of strain KD22T were Gram-negative coccobacillus, positive for indole and negative for catalase, nitrate reduction, oxidase, and urease activities. The fatty acid analysis demonstrated the presence of a high concentration of iso-C15: 0 (51.65%). Next, the complete whole-genome sequence of strain KD22T was 3,368,578 bp long with 42 mol% of DNA G + C contents. The DDH and ANI values between KD22T and type strains of phylogenetically related species were 67.40% and 95.43%, respectively. These phylogenetic, phenotypic, and genomic results supported the affiliation of strain KD22T as a novel bacterial species within the genus Gabonibacter. The proposed name is Gabonibacter chumensis and the type strain is KD22T (= CSUR Q8104T = DSM 115208 T).

Gut OncoMicrobiome Signatures (GOMS) as next-generation biomarkers for cancer immunotherapy

Oncogenesis is associated with intestinal dysbiosis, and stool shotgun metagenomic sequencing in individuals with this condition might constitute a non-invasive approach for the early diagnosis of several cancer types. The prognostic relevance of antibiotic intake and gut microbiota composition urged investigators to develop tools for the detection of intestinal dysbiosis to enable patient stratification and microbiota-centred clinical interventions. Moreover, since the advent of immune-checkpoint inhibitors (ICIs) in oncology, the identification of biomarkers for predicting their efficacy before starting treatment has been an unmet medical need. Many previous studies addressing this question, including a meta-analysis described herein, have led to the description of Gut OncoMicrobiome Signatures (GOMS). In this Review, we discuss how patients with cancer across various subtypes share several GOMS with individuals with seemingly unrelated chronic inflammatory disorders who, in turn, tend to have GOMS different from those of healthy individuals. We discuss findings from the aforementioned meta-analysis of GOMS patterns associated with clinical benefit from or resistance to ICIs across different cancer types (in 808 patients), with a focus on metabolic and immunological surrogate markers of intestinal dysbiosis, and propose practical guidelines to incorporate GOMS in decision-making for prospective clinical trials in immuno-oncology.

Gut microbiota interactions with antitumor immunity in colorectal cancer: From understanding to application

Colorectal cancer (CRC) is one of highly prevalent cancer. Immunotherapy with immune checkpoint inhibitors (ICIs) has dramatically changed the landscape of treatment for many advanced cancers, but CRC still exhibits suboptimal response to immunotherapy. The gut microbiota can affect both anti-tumor and pro-tumor immune responses, and further modulate the efficacy of cancer immunotherapy, particularly in the context of therapy with ICIs. Therefore, a deeper understanding of how the gut microbiota modulates immune responses is crucial to improve the outcomes of CRC patients receiving immunotherapy and to overcome resistance in nonresponders. The present review aims to describe the relationship between the gut microbiota, CRC, and antitumor immune responses, with a particular focus on key studies and recent findings on the effect of the gut microbiota on the antitumor immune activity. We also discuss the potential mechanisms by which the gut microbiota influences host antitumor immune responses as well as the prospective role of intestinal flora in CRC treatment. Furthermore, the therapeutic potential and limitations of different modulation strategies for the gut microbiota are also discussed. These insights may facilitate to better comprehend the interplay between the gut microbiota and the antitumor immune responses of CRC patients and provide new research pathways to enhance immunotherapy efficacy and expand the patient population that could be benefited by immunotherapy.

The Value of Microbes in Cancer Neoantigen Immunotherapy

Tumor neoantigens are widely used in cancer immunotherapy, and a growing body of research suggests that microbes play an important role in these neoantigen-based immunotherapeutic processes. The human body and its surrounding environment are filled with a large number of microbes that are in long-term interaction with the organism. The microbiota can modulate our immune system, help activate neoantigen-reactive T cells, and play a great role in the process of targeting tumor neoantigens for therapy. Recent studies have revealed the interconnection between microbes and neoantigens, which can cross-react with each other through molecular mimicry, providing theoretical guidance for more relevant studies. The current applications of microbes in immunotherapy against tumor neoantigens are mainly focused on cancer vaccine development and immunotherapy with immune checkpoint inhibitors. This article summarizes the related fields and suggests the importance of microbes in immunotherapy against neoantigens.

Fecal microbiota transplantation plus anti-PD-1 immunotherapy in advanced melanoma: a phase I trial

Fecal microbiota transplantation (FMT) represents a potential strategy to overcome resistance to immune checkpoint inhibitors in patients with refractory melanoma; however, the role of FMT in first-line treatment settings has not been evaluated. We conducted a multicenter phase I trial combining healthy donor FMT with the PD-1 inhibitors nivolumab or pembrolizumab in 20 previously untreated patients with advanced melanoma. The primary end point was safety. No grade 3 adverse events were reported from FMT alone. Five patients (25%) experienced grade 3 immune-related adverse events from combination therapy. Key secondary end points were objective response rate, changes in gut microbiome composition and systemic immune and metabolomics analyses. The objective response rate was 65% (13 of 20), including four (20%) complete responses. Longitudinal microbiome profiling revealed that all patients engrafted strains from their respective donors; however, the acquired similarity between donor and patient microbiomes only increased over time in responders. Responders experienced an enrichment of immunogenic and a loss of deleterious bacteria following FMT. Avatar mouse models confirmed the role of healthy donor feces in increasing anti-PD-1 efficacy. Our results show that FMT from healthy donors is safe in the first-line setting and warrants further investigation in combination with immune checkpoint inhibitors. ClinicalTrials.gov identifier NCT03772899 .

Understanding the mechanisms and translational implications of the microbiome for cancer therapy innovation

The intersection of the microbiota and cancer and the mechanisms that define these interactions are a fascinating, rapidly evolving area of cancer biology and therapeutics. Here we present recent insights into the mechanisms by which specific bacteria or their communities contribute to carcinogenesis and discuss the bidirectional interplay between microbiota and host gene or epigenome signaling. We conclude with comments on manipulation of the microbiota for the therapeutic benefit of patients with cancer.

Immune Checkpoint Inhibitors and the Exposome: Host-Extrinsic Factors Determine Response, Survival, and Toxicity

Cancer immunotherapy, largely represented by immune checkpoint inhibitors (ICI), has led to substantial changes in preclinical cancer research and clinical oncology practice over the past decade. However, the efficacy and toxicity profiles of ICIs remain highly variable among patients, with only a fraction achieving a significant benefit. New combination therapeutic strategies are being investigated, and the search for novel predictive biomarkers is ongoing, mainly focusing on tumor- and host-intrinsic components. Less attention has been directed to all the external, potentially modifiable factors that compose the exposome, including diet and lifestyle, infections, vaccinations, and concomitant medications, that could affect the immune system response and its activity against cancer cells. We hereby provide a review of the available clinical evidence elucidating the impact of host-extrinsic factors on ICI response and toxicity.

Following your gut: the emerging role of the gut microbiota in predicting and treating immune-related adverse events

PURPOSE OF REVIEW

Although immune checkpoint inhibition has reshaped the therapeutic landscape leading to improved outcomes across an array of both solid and hematologic malignancies, a significant source of morbidity is caused by immune-related adverse events (irAEs) caused by these agents.

RECENT FINDINGS

The gut microbiota has emerged as a biomarker of response to these agents, and more recently, also as a key determinant of development of irAEs. Emerging data have revealed that enrichment of certain bacterial genera is associated with an increased risk of irAEs, with the most robust evidence pointing to an intimate connection with the development of immune-related diarrhea and colitis. These bacteria include Bacteroides , Enterobacteriaceae, and Proteobacteria (such as Klebsiella and Proteus ) . Lachnospiraceae spp. and Streptococcus spp. have been implicated irAE-wide in the context of ipilimumab.

SUMMARY

We review recent lines of evidence pointing to the role of baseline gut microbiota on the development of irAE, and the potentials for therapeutic manipulation of the gut microbiota in order to reduce irAE severity. The connections between gut microbiome signatures of response and toxicity will need to be untangled in further studies.

The tumor immune microenvironment in pancreatic cancer and its potential in the identification of immunotherapy biomarkers

INTRODUCTION

Pancreatic cancer (PC) has an extremely poor prognosis, even with surgical resection and triplet chemotherapy treatment. Cancer immunotherapy has been recently approved for tumor-agnostic treatment with genome analysis, including in PC. However, it has limited efficacy.

AREAS COVERED

In addition to the low tumor mutation burden, one of the difficulties of immunotherapy in PC is the presence of abundant stromal cells in its microenvironment. Among stromal cells, cancer-associated fibroblasts (CAFs) play a major role in immunotherapy resistance, and CAF-targeted therapies are currently under development, including those in combination with immunotherapies. Meanwhile, microbiomes and tumor-derived exosomes (TDEs) have been shown to alter the behavior of distant receptor cells in PC. This review discusses the role of CAFs, microbiomes, and TDEs in PC tumor immunity.

EXPERT OPINION

Elucidating the mechanisms by which CAFs, microbiomes, and TDEs are involved in the tumorigenesis of PC will be helpful for developing novel immunotherapeutic strategies and identifying companion biomarkers for immunotherapy. Spatial single-cell analysis of the tumor microenvironment will be useful for identifying biomarkers of PC immunity. Furthermore, given the complexity of immune mechanisms, artificial intelligence models will be beneficial for predicting the efficacy of immunotherapy.

Bile acids regulate MAdCAM-1 expression to link the gut microbiota to cancer immunosurveillance

In a recent paper in Science, Fidelle et al. unravel a gut immune checkpoint that is subverted by antibiotic treatment. Post-antibiotic dysbiosis of the ileum causes an increase in bile acids that downregulate MAdCAM-1, thereby triggering the exodus of immunosuppressive T cells from gut-associated lymphoid tissues toward tumors.

Potential role of gut microbes in the efficacy and toxicity of immune checkpoints inhibitors

In recent years, Immune checkpoint inhibitors have been extensively used in the treatment of a variety of cancers. However, the response rates ranging from 13% to 69% depending on the tumor type and the emergence of immune-related adverse events have posed significant challenges for clinical treatment. As a key environmental factor, gut microbes have a variety of important physiological functions such as regulating intestinal nutrient metabolism, promoting intestinal mucosal renewal, and maintaining intestinal mucosal immune activity. A growing number of studies have revealed that gut microbes further influence the anticancer effects of tumor patients through modulation of the efficacy and toxicity of immune checkpoint inhibitors. Currently, faecal microbiota transplantation (FMT) have been developed relatively mature and suggested as an important regulator in order to enhance the efficacy of treatment. This review is dedicated to exploring the impact of differences in flora composition on the efficacy and toxicity of immune checkpoint inhibitors as well as to summarizing the current progress of FMT.

A microbiota-modulated checkpoint directs immunosuppressive intestinal T cells into cancers

Antibiotics (ABX) compromise the efficacy of programmed cell death protein 1 (PD-1) blockade in cancer patients, but the mechanisms underlying their immunosuppressive effects remain unknown. By inducing the down-regulation of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) in the ileum, post-ABX gut recolonization by Enterocloster species drove the emigration of enterotropic α4β7+CD4+ regulatory T 17 cells into the tumor. These deleterious ABX effects were mimicked by oral gavage of Enterocloster species, by genetic deficiency, or by antibody-mediated neutralization of MAdCAM-1 and its receptor, α4β7 integrin. By contrast, fecal microbiota transplantation or interleukin-17A neutralization prevented ABX-induced immunosuppression. In independent lung, kidney, and bladder cancer patient cohorts, low serum levels of soluble MAdCAM-1 had a negative prognostic impact. Thus, the MAdCAM-1-α4β7 axis constitutes an actionable gut immune checkpoint in cancer immunosurveillance.

Gut microbiome homeostasis and the future of probiotics in cancer immunotherapy

The gut microbiome has an impact on cancer immune surveillance and immunotherapy, with recent studies showing categorical differences between immunotherapy-sensitive and immunotherapy-resistant cancer patient cohorts. Although probiotics are traditionally being supplemented to promote treatments or sustain therapeutic benefits; the FDA has not approved any for use with immunotherapy. The first step in developing probiotics for immunotherapy is identifying helpful or harmful bacteria down to the strain level. The gut microbiome's heterogeneity before and during treatment is also being investigated to determine microbial strains that are important for immunotherapy. Moreover, Dietary fiber intake, prebiotic supplementation and fecal microbiota transplantation (FMT) were found to enhance intratumoral CD8+ T cell to T-reg ratio in the clinics. The possibility of probiotic immunotherapy as a "living adjuvant" to CAR treatment and checkpoint blockade resistance is actively being investigated.

Fecal microbiota transplantation holds the secret to youth

Aging shows itself not just at the cellular level, with shortened telomeres and cell cycle arrest, but also at the organ and organismal level, with diminished brainpower, dry eyes, intestinal inflammation, muscular atrophy, wrinkles, etc. When the gut microbiota, often called the "virtual organ of the host," fails to function normally, it can lead to a cascade of health problems including, but not limited to, inflammatory bowel disease, obesity, metabolic liver disease, type II diabetes, cardiovascular disease, cancer, and even neurological disorders. An effective strategy for restoring healthy gut bacteria is fecal microbiota transplantation (FMT). It can reverse the effects of aging on the digestive system, the brain, and the vision by transplanting the functional bacteria found in the excrement of healthy individuals into the gut tracts of patients. This paves the way for future research into using the microbiome as a therapeutic target for disorders associated with aging.

Harnessing the Microbiome to Reduce Pancreatic Cancer Burden

Pancreatic cancer mortality is expected to rise in the next decades. This aggressive malignancy has a dismal prognosis due to late diagnosis and resistance to treatment. Increasing evidence indicates that host-microbiome interactions play an integral role in pancreatic cancer development, suggesting that harnessing the microbiome might offer promising opportunities for diagnostic and therapeutic interventions. Herein, we review the associations between pancreatic cancer and the intratumoral, gut and oral microbiomes. We also explore the mechanisms with which microbes influence cancer development and the response to treatment. We further discuss the potentials and limitations of using the microbiome as a target for therapeutic interventions, in order to improve pancreatic cancer patient outcomes.

Impact of Helicobacter pylori infection on the efficacy of immune checkpoint inhibitors for cancer treatment: a meta-analysis

Aim: The present systematic review and meta-analysis was designed to assess the impact of Helicobacter pylori infection on the efficacy of immune checkpoint inhibitors (ICIs). Materials & methods: PubMed, Scopus, Web of Science and EMBASE databases were systematically searched up to 1 February 2023. Results: Three studies comprising 263 patients treated with ICIs were included. The results of pooled analysis showed that H. pylori infection was associated with reduced overall survival and progression-free survival. Furthermore, the rate of progressive disease after administration of ICIs was higher in H. pylori-positive patients relative to H. pylori-negative patients. Conclusion: H. pylori infection status is a novel potential response biomarker for predicting the efficacy of ICIs in different cancers.

Biomimetic Active Materials Guided Immunogenic Cell Death for Enhanced Cancer Immunotherapy

Despite immunotherapy emerging as a vital approach to improve cancer treatment, the activation of efficient immune responses is still hampered by immunosuppression, especially due to the low tumor immunogenicity. Immunogenic cell death (ICD) is a promising strategy to reshape the tumor microenvironment (TME) for achieving high immunogenicity. Various stimuli are able to effectively initiate their specific ICD by utilizing the corresponding ICD-inducer. However, the ICD-guided antitumor immune effects are usually impaired by various biological barriers and TME-associated immune resistance. Biomimetic active materials are being extensively explored as guided agents for ICD due to their unique advantages. In this review, two major strategies are systematically introduced that have been employed to exploit biomimetic active materials guided ICD for cancer immunotherapy, mainly including naive organism-derived nanoagents and engineered bioactive platforms. This review outlines the recent advances in the field at biomimetic active materials guided physiotherapy, chemotherapy, and biotherapy for ICD induction. The advances and challenges of biomimetic active materials guided ICD for cancer immunotherapy applications are further discussed in future clinical practice. This review provides an overview of the advances of biomimetic active materials for targeting immunoregulation and treatment and can contribute to the future of advanced antitumor combination therapy.

Future indications and clinical management for fecal microbiota transplantation (FMT) in immuno-oncology

The gut microbiota has rapidly emerged as one of the "hallmarks of cancers" and a key contributor to cancer immunotherapy. Metagenomics profiling has established the link between microbiota compositions and immune checkpoint inhibitors response and toxicity, while murine experiments demonstrating the synergistic benefits of microbiota modification with immune checkpoint inhibitors (ICIs) pave a clear path for translation. Fecal microbiota transplantation (FMT) is one of the most effective treatments for patients with Clostridioides difficile, but its utility in other disease contexts has been limited. Nonetheless, promising data from the first trials combining FMT with ICIs have provided strong clinical rationale to pursue this strategy as a novel therapeutic avenue. In addition to the safety considerations surrounding new and emerging pathogens potentially transmissible by FMT, several other challenges must be overcome in order to validate the use of FMT as a therapeutic option in oncology. In this review, we will explore how the lessons learned from FMT in other specialties will help shape the design and development of FMT in the immuno-oncology arena.

Comedications with Immune Checkpoint Inhibitors: Involvement of the Microbiota, Impact on Efficacy and Practical Implications

Immune checkpoint inhibitors (ICIs) have been a major breakthrough in solid oncology over the past decade. The immune system and the gut microbiota are involved in their complex mechanisms of action. However, drug interactions have been suspected of disrupting the fine equilibrium necessary for optimal ICI efficacy. Thus, clinicians are facing a great deal of sometimes contradictory information on comedications with ICIs and must at times oppose conflicting objectives between oncological response and comorbidities or complications. We compiled in this review published data on the role of the microbiota in ICI efficacy and the impact of comedications. We found mostly concordant results on detrimental action of concurrent corticosteroids, antibiotics, and proton pump inhibitors. The timeframe seems to be an important variable each time to preserve an initial immune priming at ICIs initiation. Other molecules have been associated with improved or impaired ICIs outcomes in pre-clinical models with discordant conclusions in retrospective clinical studies. We gathered the results of the main studies concerning metformin, aspirin, and non-steroidal anti-inflammatory drugs, beta blockers, renin-angiotensin-aldosterone system inhibitors, opioids, and statins. In conclusion, one should always assess the necessity of concomitant treatment according to evidence-based recommendations and discuss the possibility of postponing ICI initiation or switching strategies to preserve the critical window.

Macrolide antibiotics activate the integrated stress response and promote tumor proliferation

Macrolide antibiotics are widely used antibacterial agents that are associated with autophagy inhibition. This study aimed to investigate the association between macrolide antibiotics and malignant tumors, as well as the effect on autophagy, reactive oxygen species (ROS) accumulation and integrated stress response (ISR). The meta-analysis indicated a modestly higher risk of cancer in macrolide antibiotic ever-users compared to non-users. Further experiments showed that macrolides block autophagic flux by inhibiting lysosomal acidification. Additionally, azithromycin, a representative macrolide antibiotic, induced the accumulation of ROS, and stimulated the ISR and the activation of transcription factor EB (TFEB) and TFE3 in a ROS-dependent manner. Finally, animal experiments confirmed that azithromycin promoted tumor progression in vivo, which could be receded by N-acetylcysteine, an inhibitor of ROS and ISR. Overall, this study reveals the potential role of macrolide antibiotics in malignant progression and highlights the need for further investigation into their effects.

The Gut Microbiome and Metastatic Renal Cell Carcinoma

The introduction of targeted therapy (TT) and immuno-oncology (IO) agents have revolutionized the treatment of metastatic renal cell carcinoma (mRCC). However, despite the significant improvements in survival and clinical response yielded by these agents, a significant percentage of patients still experience progressive disease. Evidence now suggests that microorganisms living in the gut (i.e., the gut microbiome) could be used as a biomarker for response and may also have utility in increasing response to these treatments. In this review, we present an overview of the role of the gut microbiome in cancer and its potential implications in the treatment of mRCC.

Learning from the nexus of autoimmunity and cancer

The immune system plays critical roles in both autoimmunity and cancer, diseases at opposite ends of the immune spectrum. Autoimmunity arises from loss of T cell tolerance against self, while in cancer, poor immunity against transformed self fails to control tumor growth. Blockade of pathways that preserve self-tolerance is being leveraged to unleash immunity against many tumors; however, widespread success is hindered by the autoimmune-like toxicities that arise in treated patients. Knowledge gained from the treatment of autoimmunity can be leveraged to treat these toxicities in patients. Further, the understanding of how T cell dysfunction arises in cancer can be leveraged to induce a similar state in autoreactive T cells. Here, we review what is known about the T cell response in autoimmunity and cancer and highlight ways in which we can learn from the nexus of these two diseases to improve the application, efficacy, and management of immunotherapies.