Ruminococcus Obeum Research Articles

Analyzing the gut microbiome in adolescent and young adult patients with melanoma receiving immune checkpoint blockade.

9563 Background: Melanoma is the third most common cancer in adolescent and young adults (AYA), a unique cohort defined as patients between 15-39 years of age per the National Cancer Institute. Immune checkpoint inhibitors (ICI) have changed the landscape for advanced melanoma treatment, and the gut microbiota has been shown to remodel the tumor microenvironment to improve ICI efficacy. There is a paucity of research in this cohort, however studies show that AYA patients, in general, have historically not seen the same survival gains as other age groups. Furthermore, literature shows that survival was much worse for AYA's with stage IV melanoma than observed among older adults. Methods: The AYA cohort in this retrospective review is from the 2021 Science publication entitled "Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response". This cohort was matched on a 2:1 basis with older non-AYA patients 50-70 years of age. We controlled for sex, BMI, race, treatment naivety, stage of disease, as well as smoking, drug, and alcohol status. Results: Our AYA cohort of 23 patients is comprised of 15 females, 22 Caucasians, 20 with primary cutaneous melanoma, 12 with stage III at the start of treatment and 11 with stage IV, 17 were BRAF positive, 8 received combined immunotherapy, 20 were treatment naïve, and 11 were responders. We found no difference in alpha or beta diversity in AYA and older non-AYA patients, however alpha diversity increased with age. This is consistent with literature regarding aging gut microbiomes. Furthermore, we noted the most common microbes found between these groups varied considerably. Using differential analyses, we found, for example, a higher abundance of Ruminococcaceae, at the family level, in older non-AYA patients and a higher abundance of Bacteroides stercoris in AYA patients. Literature shows the relative abundance of Ruminococcaceae increased with age and was significantly higher in older patients. Furthermore, Bacteroides stercoris correlates positively with fiber, grain, and vegetable intake. Additionally, Blautia massiliensia, Blautia obeum, and Dorea longicatena were found to be significantly more prevalent (p=0.010, p=0.34, and p=0.035, respectively)) in older non-AYA patients. These species are all known to be obesity biomarkers. Conclusions: We found that the gut microbiota of AYA and older non-AYA melanoma patients differ. Older non-AYA patients have bacterial species associated with negative biomarkers which may be due to an aging gut microbiome. Establishing microbial features in the AYA population can help with microbiome modulation as a therapeutic strategy. Enriching modalities include fecal microbiota transplantation, probiotics, and improving diet as well as fiber intake. Further research should explore if the gut microbiome influences worse outcomes in AYA's with late stage melanoma.

P1230 Integrated analysis of microbiome and metabolome reveals disease-specific profiles in inflammatory bowel disease and intestinal Behcet’s disease

Abstract Background Gut microbial and metabolic characteristics in intestinal Behcet’s disease (BD), a condition sharing many clinical similarites with ulcerative colitis (UC) and Crohn’s disease (CD), are largely unexplored. This study aimed to investigate the gut microbial and metabolic characteristics, as well as potential biomarkers in intestinal BD, comparing them with UC and CD, along with healthy controls. Methods Patients with UC, CD, and intestinal BD, along with healthy volunteers undergoing diagnostic endoscopies, were enrolled. Colon tissue and stool samples were analyzed using 16S ribosomal RNA sequencing, assessing microbial diversity, taxonomic composition, and functional profiling by phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). Plasma metabolomic analysis was performed using gas chromatography and ultra-performance liquid chromatography-time-of-flight mass spectrometry, and quantitative enrichment analysis (QEA) was performed. Results In total, 100 patients (35 UC, 30 CD, and 35 BD) and 41 healthy volunteers were enrolled. While CD exhibited reduced microbial diversity in colon tissue, BD showed no significant decrease. The taxonomic profile of intestinal BD resembled healthy controls more than UC or CD but exhibited specific distinct features. Common changes across all conditions included a decrease in five beneficial bacteria producing short-chain fatty acids (Fusicatenibacter saccharivorans, Coprococcus comes, Blautia obeum, Dorea formicigenerans, and Roseburai ceciola). Additional changes in intestinal BD included a decreased abundance of Subdoligranulum variable and Blautia wexlerae, which were shared features with either UC or CD. Intestinal BD-specific alterations involved decreased abundance of certain bacteria, including Bacteroides fragilis. Metabolomic profiles of intestinal BD by QEA showed similarity to CD and distinction from UC and controls, with pronounced functional changes in energy metabolism and genetic information processing, correlating with microbial functional analysis by PICRUSt. Conclusion This integrative analysis unveiled both common and distinctive profiles in intestinal BD when compared to UC, CD, and controls. The study identified potential biomarkers, contributing to a deeper comprehension of the unique features in these diseases, which could serve as key elements for elucidating their pathogenesis.

P1205 Features of the gut microbiota that associate with clinical outcomes of fecal microbiota transplantation in Ulcerative Colitis: a systematic review and meta-analysis

Abstract Background Evidence continues to accumulate highlighting the potential of fecal microbiota transplantation (FMT) to induce remission in patients with ulcerative colitis (UC). However, rational donor and recipient selection strategies and predictive biomarkers are needed to increase its efficacy. This systematic review provides a comprehensive evaluation of the current literature on microbial factors of FMT donors and UC recipients that relate to clinical outcomes. Methods The MEDLINE, Embase and Cochrane databases were systematically searched through April 2023 for relevant studies. The quality of studies and risk of bias was analyzed with Joanna Briggs tools and a compound critical appraisal-score. Additionally, species-level data from two randomized controlled trials (TURN and FOCUS) were re-analyzed from a compositional perspective. Results Out of 2983 citations identified, 47 met the inclusion criteria, of which 20 fulfilled quality appraisal. Higher clinical response rates were associated with higher bacterial alpha-diversity of stools of UC recipients at baseline and following FMT, and with higher FMT donor alpha-diversity. Engraftment of the donors’ microbiota was often reported but could not be clearly linked to clinical response, possibly because not every donor has an ideal microbiome. Taxa most frequently reported to be related to response included members of the Lachnospiraceae family (e.g., Eubacterium rectale, Blautia obeum) and Oscillospiraceae family (e.g., Faecalibacterium prausnitzii, Ruminococcus bromii) whereas members of the Proteobacteria and Fusobacteria phyla and Ruminococcus gnavus were reported to correlate to non-response. Low virome richness and low Caudovirales bacteriophages at baseline as well as a decrease of Candida levels following FMT, were associated with clinical response. Compositional analyses showed that a clinical response is associated with a shift away from a low diversity, Bacteroides2-enterotype-like composition towards one of high diversity either dominated by various butyrate producers, the Christensenellaceae-Methanobrevibacter trophic network or a high diversity composition with abundant but not excessive levels of Prevotella copri. Conclusion In this systematic review we found distinctive features of microbial profiles of both donors and UC recipients to relate to clinical response to FMT. The predictive value of microbial markers should be further explored in future clinical studies to move towards a personalized FMT approach and delineate ‘super-donor’ profiles.

Gut microbiota from patients with Parkinson's disease causes motor deficits in honeybees.

Parkinson's disease (PD) is possibly caused by genetic factors, environmental factors, and gut microbiota dysbiosis. This study aims to explore whether the microbiota contributes to the behavior abnormalities of PD. We transplanted gut microbiota from patients with PD or healthy controls (HC) into microbiota-free honeybees. We also established two more groups, namely the rotenone (ROT) group, in which PD-like symptoms of honeybees were induced by rotenone, and the conventional (CV) group, in which honeybees were colonized with conventional gut microbiota. The climbing assay was performed to assess the motor capabilities of honeybees. Histopathological examination was conducted to evaluate the integrity of gut mucosa. Tyrosine hydroxylase (TH) gene expression levels and dopamine (DA) concentrations in the brain were also examined. Additionally, metagenomics and full-length 16S rRNA analyses were performed to identify alterations in gut microbiota profiles, both in PD patients and honeybees. Honeybees in the PD and ROT groups exhibited slower climbing speeds, downregulated TH gene expression, and impaired gut barriers. Both the HC and PD groups of honeybees successfully harbored a portion of gut microbiota from corresponding human donors, and differences in microbial composition were identified. Morganella morganii and Erysipelatoclostridium ramosum exhibited significantly increased relative abundance in the HC group, while Dorea longicatena, Collinsella aerofaciens, Lactococcus garvieae, Holdemanella biformis, Gemmiger formicilis, and Blautia obeum showed significantly increased relative abundance in the PD group. Functional predictions of microbial communities in the PD group indicated an increased synthesis of hydrogen sulfide and methane. A novel PD model was induced in honeybees with rotenone and gut microbiota from PD patients. This study linked PD-related behaviors to altered gut microbiota, highlighting a potential gut microbiota-brain axis involvement in PD pathogenesis. We identify previously unrecognized associations of Dorea longicatena, Collinsella aerofaciens, Lactococcus garvieae, Holdemanella biformis, Gemmiger formicilis, and Blautia obeum with PD. Additionally, pathways related to hydrogen sulfide and methane synthesis have been previously suggested as potential contributors to the development of PD, and our research further supports this hypothesis.

Role of Gut Microbiota in Statin-Associated New-Onset Diabetes-A Cross-Sectional and Prospective Analysis of the FINRISK 2002 Cohort.

Dyslipidemia is treated effectively with statins, but treatment has the potential to induce new-onset type-2 diabetes. Gut microbiota may contribute to this outcome variability. We assessed the associations of gut microbiota diversity and composition with statins. Bacterial associations with statin-associated new-onset type-2 diabetes (T2D) risk were also prospectively evaluated. We examined shallow-shotgun-sequenced fecal samples from 5755 individuals in the FINRISK-2002 population cohort with a 17+-year-long register-based follow-up. Alpha-diversity was quantified using Shannon index and beta-diversity with Aitchison distance. Species-specific differential abundances were analyzed using general multivariate regression. Prospective associations were assessed with Cox regression. Applicable results were validated using gradient boosting. Statin use associated with differing taxonomic composition (R2, 0.02%; q=0.02) and 13 differentially abundant species in fully adjusted models (MaAsLin; q<0.05). The strongest positive association was with Clostridium sartagoforme (β=0.37; SE=0.13; q=0.02) and the strongest negative association with Bacteroides cellulosilyticus (β=-0.31; SE=0.11; q=0.02). Twenty-five microbial features had significant associations with incident T2D in statin users, of which only Bacteroides vulgatus (HR, 1.286 [1.136-1.457]; q=0.03) was consistent regardless of model adjustment. Finally, higher statin-associated T2D risk was seen with [Ruminococcus] torques (ΔHRstatins, +0.11; q=0.03), Blautia obeum (ΔHRstatins, +0.06; q=0.01), Blautia sp. KLE 1732 (ΔHRstatins, +0.05; q=0.01), and beta-diversity principal component 1 (ΔHRstatin, +0.07; q=0.03) but only when adjusting for demographic covariates. Statin users have compositionally differing microbiotas from nonusers. The human gut microbiota is associated with incident T2D risk in statin users and possibly has additive effects on statin-associated new-onset T2D risk.

Ginsenoside Rg3 enriches SCFA-producing commensal bacteria to confer protection against enteric viral infection via the cGAS-STING-type I IFN axis

The microbiota-associated factors that influence host susceptibility and immunity to enteric viral infections remain poorly defined. We identified that the herbal monomer ginsenoside Rg3 (Rg3) can shape the gut microbiota composition, enriching robust short-chain fatty acid (SCFA)-producing Blautia spp. Colonization by representative Blautia coccoides and Blautia obeum could protect germ-free or vancomycin (Van)-treated mice from enteric virus infection, inducing type I interferon (IFN-I) responses in macrophages via the MAVS-IRF3-IFNAR signaling pathway. Application of exogenous SCFAs (acetate/propionate) reproduced the protective effect of Rg3 and Blautia spp. in Van-treated mice, enhancing intracellular Ca2+- and MAVS-dependent mtDNA release and activating the cGAS-STING-IFN-I axis by stimulating GPR43 signaling in macrophages. Our findings demonstrate that macrophage sensing of metabolites from specific commensal bacteria can prime the IFN-I signaling that is required for antiviral functions.

Optimizing Fecal Occult Blood Test (FOBT) Colorectal Cancer Screening Using Gut Bacteriome as a Biomarker

BackgroundColorectal cancer (CRC) is a major cause of cancer mortality in the world. One of the most widely used screening tests for CRC is the immunochemical fecal occult blood test (iFOBT), which detects human hemoglobin from patient's stool sample. Although it is highly efficient in detecting blood from patients with gastro-intestinal lesions, such as polyps and cancers, the iFOBT has a high rate of false positive discovery. Recent studies suggested gut bacteria as a promising noninvasive biomarker for improving the diagnosis of CRC. In this study, we examined the composition of gut bacteria using iFOBT leftover from patients undergoing screening test along with a colonoscopy. MethodsAfter collecting data from more than 800 patients, we considered 4 groups for this study. The first and second groups were respectively “healthy” in which the patients had either no blood in their stool or had blood but no lesions. The third and fourth groups of patients had both blood in their stools with precancerous and cancerous lesions and considered either as low-grade and high-grade lesion groups, respectively. An amplification of 16S rRNA (V4 region) gene was performed, followed by sequencing along with various statistical and bioinformatic analysis. ResultsWe analyzed the composition of the gut bacteriome at phylum, class, genus, and species levels. Although members of the Firmicute phylum increased in the 3 groups compared to healthy patients, the phylum Actinobacteriota was found to decrease. Moreover, Blautia obeum and Anaerostipes hadrus from the phylum Firmicutes were increased and Collinsella aerofaciens from phylum Actinobacteriota was found decreased when healthy group is compared to the patients with high-grade lesions. Finally, among the 5 machine learning algorithms used to perform our analysis, both elastic net (AUC > 0.7) and random forest (AUC > 0.8) performs well in differentiating healthy patients from 3 other patient groups having blood in their stool. ConclusionOur study integrates the iFOBT screening tool with gut bacterial composition to improve the prediction of CRC lesions.

Weight Loss Promotion in Individuals with Obesity through Gut Microbiota Alterations with a Multiphase Modified Ketogenic Diet.

The occurrence of obesity and related metabolic disorders is rising, necessitating effective long-term weight management strategies. With growing interest in the potential role of gut microbes due to their association with responses to different weight loss diets, understanding the mechanisms underlying the interactions between diet, gut microbiota, and weight loss remains a challenge. This study aimed to investigate the potential impact of a multiphase dietary protocol, incorporating an improved ketogenic diet (MDP-i-KD), on weight loss and the gut microbiota. Using metagenomic sequencing, we comprehensively analyzed the taxonomic and functional composition of the gut microbiota in 13 participants before and after a 12-week MDP-i-KD intervention. The results revealed a significant reduction in BMI (9.2% weight loss) among obese participants following the MDP-i-KD intervention. Machine learning analysis identified seven key microbial species highly correlated with MDP-i-KD, with Parabacteroides distasonis exhibiting the highest response. Additionally, the co-occurrence network of the gut microbiota in post-weight-loss participants demonstrated a healthier state. Notably, metabolic pathways related to nucleotide biosynthesis, aromatic amino acid synthesis, and starch degradation were enriched in pre-intervention participants and positively correlated with BMI. Furthermore, species associated with obesity, such as Blautia obeum and Ruminococcus torques, played pivotal roles in regulating these metabolic activities. In conclusion, the MDP-i-KD intervention may assist in weight management by modulating the composition and metabolic functions of the gut microbiota. Parabacteroides distasonis, Blautia obeum, and Ruminococcus torques could be key targets for gut microbiota-based obesity interventions.

Oral and anal microbiome from HIV-exposed individuals: role of host-associated factors in taxa composition and metabolic pathways

Evidence indicates that the microbiome plays a significant role in HIV immunopathogenesis and associated complications. This study aimed to characterize the oral and anal microbiome of Men who have Sex with Men (MSM) and Transgender Women (TGW), with and without HIV. One hundred and thirty oral and anal DNA-derived samples were obtained from 78 participants and subjected to shotgun metagenomics sequencing for further microbiome analysis. Significant differences in the microbiome composition were found among subjects associated with HIV infection, gender, sex behavior, CD4+ T-cell counts, antiretroviral therapy (ART), and the presence of HPV-associated precancerous anal lesions. Results confirm the occurrence of oncogenic viromes in this high HIV-risk population. The oral microbiome in HIV-associated cases exhibited an enrichment of bacteria associated with periodontal disease pathogenesis. Conversely, anal bacteria showed a significant decrease in HIV-infected subjects (Coprococcus comes, Finegoldia magna, Blautia obeum, Catenibacterium mitsuokai). TGW showed enrichment in species related to sexual transmission, which concurs that most recruited TGW are or have been sex workers. Prevotella bivia and Fusobacterium gonidiaformans were positively associated with anal precancerous lesions among HIV-infected subjects. The enrichment of Holdemanella biformis and C. comes was associated with detectable viral load and ART-untreated patients. Metabolic pathways were distinctly affected by predominant factors linked to sexual behavior or HIV pathogenesis. Gene family analysis identified bacterial gene signatures as potential prognostic and predictive biomarkers for HIV/AIDS-associated malignancies. Conclusions: Identified microbial features at accessible sites are potential biomarkers for predicting precancerous anal lesions and therapeutic targets for HIV immunopathogenesis.

Characteristics of gut microbiota in patients with metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is rising in incidence and is an increasingly common cause of cirrhosis and hepatocellular carcinoma (HCC). Alterations in the gut microbiota have been shown to correlate with the development and progression of MAFLD. However, little is known regarding differences in the gut microbiomes of MAFLD patients and healthy cohorts, and subgroups at the abnormal activity of hepatic enzymes in China. In this study, we enrolled 81 MAFLD patients and 25 healthy volunteers. The fecal microbiota was assessed using 16S rRNA gene sequencing and metagenomic sequencing. The results suggested that Ruminococcus obeum and Alistipes were most enriched in healthy individuals when compared with MAFLD patients. Microbe‐set Enrichment Analysis (MSEA) results showed Dorea, Lactobacillus and Megasphaera are enriched in MAFLD group. We also found that Alistipes has negatively related to serum glucose (GLU), gamma-glutamyl transferase (GGT), and alanine aminotransferase (ALT). Moreover, the abundance of Dorea was found to be significantly overrepresented in the MAFLD patients and the degree of enrichment increased with the increasing abnormal liver enzyme. An increase in Dorea, combined with decreases in Alistipes appears to be characteristic of MAFLD patients. Further study of microbiota may provide a novel insight into the pathogenesis of MAFLD as well as a novel treatment strategy.

#3953 TOXIC MICROBIOME AND CHRONIC KIDNEY DISEASE: INSIGHTS FROM THE CKD-REIN COHORT STUDY

Abstract Background and Aims Many uremic toxins (UTs) originate from gut microbiome, and contribute to chronic kidney disease (CKD) progression and cardiovascular morbidity. In order to reduce uremic symptoms and CKD progression, patients have several dietary restrictions, which may influence gut microbiome composition, and impact UTs production. An altered microbiome may contribute to UTs increase in those patients. However, the role of key bacterial taxa in producing UTs and the impact of diet on UTs variance in non-dialyzed patients are not well known. The objectives of this study were, first, to compare microbial features between CKD patients and healthy controls, and, second, to investigate the relation of gut microbiome with uremic toxicity, as well as the potential impact of diet on such relationship. Method Characterization of gut metagenomes, 10 UTs and 3 precursors’ serum concentrations by LC-MS/MS, host characteristics and diet were obtained from 240 non-dialysis CKD patients from the CKD-REIN cohort (mean ± SD): age: 68 ± 11 years, 71% male, estimated glomerular filtration rate (eGFR): 33.2 ± 12.7 ml/min/1.73m². First, to identify microbial biomarkers characterizing the gut microbiome-related toxicity in CKD, we compared microbiome features between 78 CKD patients and 78 age-, sex-, and BMI-matched healthy controls from the Milieu Interieur (MI) cohort: age: 58 ± 10 years, 60% male, eGFR: 89 ± 13. Second, we performed a multiomics’ data integration analysis via a supervised modelling to investigate cross-sectionally the association between host characteristics, gut microbiome, UTs, and diet-related features according to CKD severity (eGFR&amp;lt;30, n = 110 vs eGFR ≥30 mL/min/1.73m², n = 130). Results Compared to healthy controls, CKD patients had a significant reduced gut microbiome health index. Several Metagenomic Species Pan-genomes (MSPs) were significantly contrasted between MI and CKD cohorts: 43 species were enriched in CKD patients vs 24 in controls. Species most enriched in CKD patients included several UTs producers such as Lachnospiraceae spp, Dysosmobacter – Oscillibacter spp, Butyricimonas faecihominis, Victivallis vadensis and Hungatella spp, some of which were positively correlated with the following UTs: 3-Carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), trimethylamine-N-oxide (TMAO), and indole-3-acetic acid (3-IAA). Moreover, species belonging to Enterocloster and Hungatella genera (both members of Lachnospiraceae family) were found to be negatively correlated with eGFR. Among species associated with CKD severity, species carrying genes for UTs production were observed such as Desuflovibiro fairfieldensis, Bacteroides clarus and Blautia obeum along with increasing alcohol and hot drinks consumption, CRP and several UTs (kynurenic acid, indoxyl sulfate and Phenylacetylglutamine) levels. In contrast, some taxa like Faecalibacterium prausnitzii and Dysosmobacter welbionis were associated with legume intake but not with UTs. Conclusion Our study highlights an alteration of gut microbiome in CKD patients compared to healthy controls, with increased abundance of UTs producer species. The results of the multidimensional data integration modelling suggest a strong interplay between food intake, gut microbiome modifications, UTs accumulation and clinical features. These findings might open to promising therapeutic strategies to reduce microbiome-related toxicity.

Abstract 5882: Prevention of antibiotic-induced dysbiosis in human volunteers by DAV132 and preservation of responsiveness to anti-PD-1 demonstrated by transplantation of human feces into tumor-bearing mice

Abstract Background: Over the last decade, studies unraveled the cancer-immune dialogue in the setting of immune checkpoint inhibitors (ICI) and influenced by the gut microbiota. The first evidence of the key role of the microbiota in ICI modulation was observed during antibiotics (ATB) treatment, where altering the microbiota composition by ATB inhibited ICI responses. DAV132 (DAV) is an orally administered colon-targeted ATB adsorbent capsules designed to prevent ATB-induced dysbiosis. We investigated whether DAV co-administered with ATB could prevent ATB-related dysbiosis and ICI response. Methods: 72 human healthy volunteers (HV) were randomized to receive either IV ceftazidime-avibactam (CZA) or Piperacillin tazobactam (PTZ) alone or in combination with oral DAV. CZA and PTZ plasmatic and fecal pharmacodynamic levels were measured using HPLC-MS/MS. Microbiome was profiled with metagenomics at different timepoints. FMT experiments in germ-free mice were performed using fecal samples from HV from the trial, before (D1) or after 6 days (D6) of CZA or PTZ+/-DAV; subsequently mice were inoculated with MCA205 or B16 tumors and treated with anti-PD-1. Tumor infiltrating lymphocytes (TILs) were analyzed by flow cytometry. Results: DAV did not impact plasmatic CZA or PTZ concentrations, but significantly reduced ceftazidime and piperacillin concentrations in feces compared to ATB groups alone. DAV significantly prevented the reduction in microbiota alpha-diversity at D6 and was associated with a rapid return to baseline microbiota. 50 and 43 metagenomics species were preserved in the CZA+DAV vs CZA, or PTZ-DAV vs PTZ such as Faecalibacterium praunistzii, Alistipes Spp and Blautia obeum. FMT in germ-free mice using feces collected at D1 exhibited a significant anti-PD-1 activity. This anti-tumor response was inhibited in two tumors models in mice transplanted with D6 feces from patients in the CZA or PTZ alone groups. Conversely, the anti-tumor response was maintained in mice transplanted with D6 feces from HV treated with CZA+DAV or PTZ+DAV groups. Flow cytometry on TILs demonstrated that CZA decreased CD8+T cell and CD8+/Treg ratio compared to CZA+DAV. Conclusions: DAV prevented ATB-induced dysbiosis in HV treated with CZA or PTZ without influencing plasmatic concentrations. In avatar mice FMT from HV treated with CZA+DAV was able to preserve anti-PD-1 efficacy. These results provide rationale to launch clinical trials combining DAV in patients on ATB amenable to ICI. Citation Format: Meriem Messaoudene, Nathalie Saint-Lu, Frédérique Sablier-Gallis, Stéphanie Ferreira, Mayra Ponce, Clément Le Bescop, Thomas Loppinet, Tanguy Corbel, Céline Féger, Fabien Vitry, Antoine Andremont, Jean de Gunzburg, Bertrand Routy. Prevention of antibiotic-induced dysbiosis in human volunteers by DAV132 and preservation of responsiveness to anti-PD-1 demonstrated by transplantation of human feces into tumor-bearing mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5882.

Abstract 4435: A causal modeling platform for testing lifestyle interventions on the microbiome and response to immunotherapy

Abstract Rational manipulation of the gut microbiome by diet or other interventions is a promising approach to improving the efficacy and safety of cancer immunotherapy. However, linking lifestyle variables to specific microbial populations and the host immune response to cancer therapies is challenging due to their complexity. We established an experimental system to examine such complexity by linking a human dietary intervention and fecal biospecimens to mouse models to test the response to immunotherapy. Longitudinal human microbiome samples collected before and after a specific dietary or other intervention allow us to test the hypothesis that an intervention alters the response to immunotherapy via impact on the host microbiome. One set of samples was taken from the BEWELL study, which examined the impact of 2 × 80 mL black raspberry (BRB) drink boxes per day for 4 weeks in people at high risk for lung cancer. Participant samples were chosen based on enrichment of specific taxa. Pre- and post-BRB intervention samples were gavaged into mice. Mouse mc38 cells were injected subcutaneously and treated with anti-PD1 Ab or isotype control. Tumor size was monitored, and at the end of the study, tumor immune cell composition data were collected. Tumor growth over time was modeled using a linear mixed-effects model with tumor volume as the outcome variable and the predictor variables of time and treatment (PD1 vs. IgG) interacting with gavage and quadratic time to accommodate non-linear tumor growth and including random effects by mouse. For sample 68, enriched for Roseburia CAG 309, the interaction between time, gavage post-BRB, and Anti-PD1 treatment significantly affected tumor volume (p &amp;lt; 0.05) relative control. The same significant effect (p &amp;lt; 0.05) was also seen for sample 79, enriched for Lachnospira pectinoschiza, and samples 84 and 85, enriched for Blautia obeum. To determine the mechanism by which this might occur, we analyzed the tumor's immune cell composition. Post-BRB mice treated with Anti-PD1 showed a significant increase in tumor-infiltrating CD8+ immune cells relative control, as compared to mice gavaged with pre-BRB stool. Modeling results showed samples whose response was improved slightly after the BRB dietary intervention. These samples were associated with the enrichment of the taxon Roseburia CAG 309. A black-raspberry dietary intervention in humans modified the microbiomes of several participants in a way that is hypothesized to improve response to PD1 treatment. Future directions include supplementing individual microbes into pre-intervention gavages to confirm which taxa improve response. These results suggest that this modeling platform is an effective system for testing microbiome modification on tumor growth and assessing mechanisms by which this might occur and is extendable to other lifestyle-based interventions where pre- and post-intervention specimens are collected. Citation Format: Aaditya Pallerla, Bailey Conrad, Amna Bibi, Nyelia Williams, Caroline Wheeler, Rebecca Hoyd, Shankar Suman, Joseph Amann, Yangyang Liu, Marisa Bittoni, Shiqi Zhang, Madison Grogan, Alvin Anand, Najma Afrah, Carolyn Presley, Fred K. Tabung, Lang Li, Yael Vodovotz, Jiangjiang Zhu, David P. Carbone, Steven K. Clinton, Daniel Spakowicz. A causal modeling platform for testing lifestyle interventions on the microbiome and response to immunotherapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4435.

MP34-11 URINARY GLYCOSAMINOGLYCANS ARE ASSOCIATED WITH RECURRENT UTI AND UROBIOME ECOLOGY IN POSTMENOPAUSAL WOMEN

You have accessJournal of UrologyCME1 Apr 2023MP34-11 URINARY GLYCOSAMINOGLYCANS ARE ASSOCIATED WITH RECURRENT UTI AND UROBIOME ECOLOGY IN POSTMENOPAUSAL WOMEN Michael L. Neugent, Neha V. Hulyalkar, Philippe E. Zimmern, Kelli L. Palmer, Vladimir Shulaev, and Nicole J. De Nisco Michael L. NeugentMichael L. Neugent More articles by this author , Neha V. HulyalkarNeha V. Hulyalkar More articles by this author , Philippe E. ZimmernPhilippe E. Zimmern More articles by this author , Kelli L. PalmerKelli L. Palmer More articles by this author , Vladimir ShulaevVladimir Shulaev More articles by this author , and Nicole J. De NiscoNicole J. De Nisco More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003268.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The composition of urinary glycosaminoglycans (GAGs) is not fully understood. The luminal urothelial GAG layer is likely an important interface between the human host and the resident urobiome, which has been shown to be altered in postmenopausal (PM) women with history of recurrent urinary tract infection (rUTI).1 We sought to profile the urinary GAG distribution and associate urinary GAGs with the ecology of the resident urobiome in a controlled cohort of PM women designed to study rUTI. METHODS: Clean catch midstream urine was collected from a controlled cohort of PM women (n=75) who passed a set of exclusion criteria for an ongoing study of rUTI.1 GAGs were extracted from urine via macromolecular filtration and then enzymatically digested into constituent disaccharides for chondroitin Sulfate (CS), heparin Sulfate (HS), and hyaluronic Acid (HA) following a published protocol.2 The liberated disaccharides were analyzed and quantified via targeted liquid chromatography-mass spectrometry (LC-MS/MS). For whole genome metagenomics, DNA was purified from matched urine and prepared libraries were sequenced on an Illumina NextSeq500 and analyzed for taxonomic enrichment as described previously.1 RESULTS: We find that CS is the major urinary GAG in PM women and women who were experiencing an active UTI exhibited significantly higher urinary CS compared to those with no UTI (Figure 1). Lastly, we find that two urobiome bacterial species, Atopobium vaginae and Blautia obeum exhibit significant negative associations with urinary CS. CONCLUSIONS: Our findings of increased urinary CS during active UTI may be a sign of tissue damage during infection. We find negative associations between bacterial species known to be associated with vaginal dysbiosis and urinary CS levels. These associations may be indicators of bladder dysbiosis and alterations of urothelial GAG composition.

Exercise effect on the gut microbiota in young adolescents with subthreshold depression: A randomized psychoeducation-controlled Trial

This 3-month randomized psychoeducation-controlled trial (RCT) of exercise was undertaken in young adolescents with subthreshold depression to examine the impact on gut microbiota. Participants (aged 12–14 years) were randomly assigned to an exercise or a psychoeducation-controlled group. The exercise intervention arm took moderate-intensity exercise, comprised of 30 min of running per day, 4 days a week for 3 months. Psychoeducation intervention consisted of 6 sessions of group activity including gaming, reading, and singing. The gut microbiota was assessed by metagenomic sequencing. After 3-month moderate-intensity exercise, the intervention group increased the relative abundance of Coprococcus, Blautia, Dorea, Tyzzerella at the genus level, as well as Tyzzerella nexilis, Ruminococcus obeum at species level when compared to the psychoeducation-controlled group. Moreover, EggNOG analyses showed that the defense and signal transduction mechanism were highly enriched after the active intervention, and changes were correlated with improvements in depressive symptoms measured by Chinese Patient Depression Questionnaire 9. The KEGG pathway of neurodegenerative diseases was depleted in the microbiome in young adolescents with subthreshold depression after exercise intervention. This 3-month RCT suggests that at both the genus and species levels, aerobic group exercise intervention improved in depressive symptoms and revealed changes in gut microbiota suggesting beneficial effects.

Potential Prebiotic Effect of Cava Lees: Changes in Gut Microbiota

Lees are a winery by-product with a fiber-rich composition that could have a potential prebiotic effect on gut microbiota. Prebiotics cannot be digested by humans but can be used by bacteria found in the large intestine. To evaluate the potential prebiotic effect of lees, they were administered to Wistar rats for 14 days. Feces were collected daily, and DNA was extracted and analyzed by shot gun sequencing. The supplementation with lees did not affect weight, food intake, or water consumption of the studied rats. It was found that lees promoted the increase of relative abundance of probiotic bacteria belonging to the Lactobacillaceae family, as well as other potentially probiotic species such as Blautia hansenii, Roseburia intestinalis, and Ruminococcus obeum. Moreover, lees supplementation also reduced the abundance of certain pathogenic bacteria. In conclusion, lees can improve the presence of beneficial bacteria in the gastrointestinal tract and can be re-valorized as a new ingredient in food formulation.

Lactobacillus acidophilus CGMCC 878 impacts colorectal cancer in Sprague-Dawley rats through changing the gut microbiota

A main cause of cancer-related mortality, colorectal cancer (CRC) is one of the most prevalent cancers in the world. A number of variables, including a poor dietary and lifestyle, genetics, metabolic problems, and inheritance, are linked to the risk of CRC. However, it has been studied extensively about the involvement of various environmental factors which facilitates the development of this particular type of cancer in both genders. These elements includes excessive consumption of meat, refined grain and their products, starch, sugars in distinct forms, and alcohol are at top of the list. Hence, to execute the significance of Lactobacillus acidophilus CGMCC 878 (L.A 878) which may possibly hinder the development as well as progression of chemically induce colorectal tumor in in-vivo model via transformation of gut microbiota. We had established CRC in male Sprague-Dawley rats through subcutaneously inject the carcinogen named 1,2 dimethylhydrazine hydrochloride (DMH). We had detected the microbial diversity among different groups which included in the study by evaluation of stool samples by the virtue of molecular genetic computation. Although, we had targeted the bacterial V3 region by using classic molecular technique of PCR-DGGE (Polymerase chain reaction- Denaturing Gradient Gel Electrophoresis) followed by excision of amplified bands and were cloned for sequencing. The DGGE profiles of distinct groups demonstrated significant alterations between DMH group, short-term L. acidophilus group (p ​< ​0.05), and the long-term L. acidophilus group (P 0.001). The fecal-glucuronidase was significantly overexpressed in DMH group associated with long-term L. acidophilus group (p ​< ​0.05). Hence, prolong administration of L.A 878 could reduce the development of colorectal tumors in rats by altering the intestinal pathogenic bacteria (Ruminococcus obeum, Clostridium thermocellum, Bacteroides vulgates, Mycoplasma leachii, Porphyromonas asaccharolytica) and beneficial bacteria (Lactobacillus reuteri, Lactobacillus). These observations suggested that Lactobacillus acidophilus CGMCC 878 may have therapeutic potential in attenuating carcinogenesis of gastrointestinal (GI) tract.

Genomic and microbial factors affect the prognosis of anti-pd-1 immunotherapy in nasopharyngeal carcinoma.

Antibodies targeting the programmed cell death protein-1 (PD-1) molecule have been reported to hold promising antitumor activities in patients with nasopharyngeal carcinoma (NPC). However, only a small subset of NPC patients benefits from the anti-PD-1 monotherapy and factors that affect the treatment response need further investigation. This study aimed to examine the impact of multiple genetic and environmental factors on outcome of anti-PD-1 immunotherapy by identifying tumor size, tumor mutation burden (TMB) based on whole exon sequencing, human leukocyte antigen class I (HLA-I) homo-/heterozygosity and supertypes, blood Epstein-Barr virus (EBV) DNA load, T cell proportions, and interferon-γ(IFN-γ) levels in a cohort of 57 NPC patients that received Nivolumab or Camrelizumab treatment. Moreover, we profiled the longitudinal changes in gut microbiota composition using shotgun metagenomics sequencing. We observed that high TMB combined with HLA-I heterozygosity was associated with improved clinical outcomes. In agreement with previous studies, we found that patients with higher plasma EBV DNA load showed worse progression-free survival. We found no evidence for an effect of gut bacterial diversity on the treatment response, but identified a higher abundance of seven specific gut bacteria at baseline of non-responders, including Blautia wexlera and Blautia obeum, as well as four other bacteria belonging to the Clostridiales order, and one Erysipelatoclostridium. Combined, this study provides insight into the influence of several genetic and environmental factors on anti-PD-1 immunotherapy responses in NPC patients.

Histidine Intake, Human Gut Microbiome, Plasma Levels of Imidazole Propionate, and Coronary Heart Disease Risk in US Adults

ObjectivesImidazole propionate (ImP), a microbiota metabolite from histidine, has been linked to cardiometabolic conditions in humans. The current study aimed to elucidate inter-relationships between histidine intake, gut microbial composition and functional potentials, circulating ImP levels, and the risk of coronary heart disease (CHD) in U.S. adults.MethodsA total of 896 fecal samples and 462 blood samples were collected from 298 healthy men in the Men's Lifestyle Validation Study. Multivariate Association with Linear Models 2 was used to analyze the associations between microbial features and plasma ImP levels. Associations between plasma ImP and CHD risk was examined using Cox proportional hazards regression models among 7,793 participants pooled from the Health Professionals Follow-up Study, Nurses’ Health Study (NHS), and NHSII with existing ImP measurements.ResultsThe overall microbial composition was associated with plasma ImP levels (PERMANOVA p = 0.001). Multivariable taxa-wide association analysis identified 14 bacterial species, such as Ruminococcus Obeum, Clostridium clostridioforme, C. nexile, C. symbiosum and Gordonibacter pamelaeae, that were significantly (FDR P < 0.05) associated with plasma ImP levels. A non-parametric score was derived to summarize the abundance of the 14 species. Higher intake of red meat and histidine was significantly associated with higher ImP levels among participants with a higher ImP-Species Score (for red meat, P-inter = 0.04; for histidine, P-inter = 0.01), but not among others (P > 0.05). In the pooled cohort, compared with participants in the lowest ImP tertile, the relative risk (95% CI) of CHD was 2.06 (1.96, 2.43) among those in the highest ImP tertile (P- trend = 0.0001). Histidine consumption was not associated with CHD risk in the same study population.ConclusionsWe identified multiple microbiota species that were associated with plasma ImP concentrations and collectively predicted stronger associations of histidine or red meat intake with ImP concentrations. Plasma ImP concentrations were significantly associated with an increased risk of developing CHD. These data emphasize the role of human gut microbiota in modulating the production of ImP through histidine intake.Funding SourcesThe National Institutes of Health Boston Nutrition Obesity Research Centre.

Gut Microbial and Metabolic Signatures are Altered in Adolescents with Type 1 Diabetes

BackgroundEvidence suggests that the pathogenesis and development of Type 1 Diabetes (T1D) are driven by both genetic predisposition and immune dysfunction which may be influenced by gut microbiota. The present study aimed to investigate the composition and functional pathways of the gut microbiome in adolescents with T1D, determine the association between gut microbes and clinical and dietary factors in T1D, and identify features predictive of T1D.MethodsHealthy adolescents (n=35) and adolescents with T1D (n=30) were recruited and microbial profiling in participants’ stool samples was performed using deep shotgun metagenomic sequencing. The bioBakery3 pipeline (Kneaddata, Metaphlan3 and HUMAnN) was used to analyze the reads to assign taxonomy and functional annotations. The differences in taxonomic abundances were identified using Linear Discriminant Analysis (LDA) Effect Size (LEfSe) and ecological measures (diversity) were assessed using standard methods. The association between the abundance of specific bacterial species and the metadata (HbA1C, skin carotenoids, diet and physical activity) was assessed by performing Spearman’s correlation. Random forest modeling (using the MUVR package) was used to identify features predictive of T1D.ResultsAdolescents with T1D exhibited a significant increase in Simpson α‐diversity index as compared to healthy adolescents. β‐diversity was similar between the two groups. LEfSe indicated a significant difference in the microbial community at different taxonomic levels between the two groups. Seven taxa were enriched in adolescents with T1D at the species level that includes Alistipes Shahii, Asaccharobacter celatus, Blautia obeum, Coprococcus eutactus, Coprobacillus cateniformis, Clostridium symbiosum, and Eggerthella lenta. Three species Alistripes Putredins, Dialister invisus, and Eubacterium ventriosum were enriched in healthy adolescents. Further, 33 out of 400 microbial metabolic pathways were significantly different between the two groups. Importantly, biosynthesis of amino acids, vitamins, enzyme cofactors, and electron carrier were downregulated whereas fermentation pathways were upregulated in adolescents with T1D as compared to healthy adolescents. Association analysis indicated that specific bacterial species are correlated with HbA1C, skin carotenoids, dietary factors and physical activity. Most of the bacterial species associated with these measures were different between the two groups. MUVR identified bacterial taxa predictive of T1D status (0.82 sensitivity and 0.63 specificity). The top features in using genus level abundance included Coprococcus, Faecalibaterium and Streptococcus.ConclusionThe present study indicates an extensive alteration in the composition and functional capacity of gut microbiota in adolescents with T1D providing new insight into microbial and metabolic signatures in adolescents with T1D.