Fecal Microbiome Transplantation Research Articles

Development of an in vitro biofilm model of the human supra-gingival microbiome for Oral microbiome transplantation

The high prevalence of dental caries and periodontal disease place a significant burden on society, both socially and economically. Recent advances in genomic technologies have linked both diseases to shifts in the oral microbiota – a community of >700 bacterial species that live within the mouth. The development of oral microbiome transplantation draws on the success of fecal microbiome transplantation for the treatment of gut pathologies associated with disease. Many current in vitro oral biofilm models have been developed but do not fully capture the complexity of the oral microbiome which is required for successful OMT. To address this, we developed an in vitro biofilm system that maintained an oral microbiome with 252 species on average over 14 days. Six human plaque samples were grown in 3D printed flow cells on hydroxyapatite discs using artificial saliva medium (ASM). Biofilm composition and growth were monitored by high throughput sequencing and confocal microscopy/SEM, respectively. While a significant drop in bacterial diversity occurred, up to 291 species were maintained in some flow cells over 14 days with 70% viability grown with ASM. This novel in vitro biofilm model represents a marked improvement on existing oral biofilm systems and provides new opportunities to develop oral microbiome transplant therapies.

Effects of microbiome-based interventions on neurodegenerative diseases: a systematic review and meta-analysis

Neurodegenerative diseases (NDDs) are characterized by neuronal damage and progressive loss of neuron function. Microbiome-based interventions, such as dietary interventions, biotics, and fecal microbiome transplant, have been proposed as a novel approach to managing symptoms and modulating disease progression. Emerging clinical trials have investigated the efficacy of interventions modulating the GM in alleviating or reversing disease progression, yet no comprehensive synthesis have been done. A systematic review of the literature was therefore conducted to investigate the efficacy of microbiome-modulating methods. The search yielded 4051 articles, with 15 clinical trials included. The overall risk of bias was moderate in most studies. Most microbiome-modulating interventions changed the GM composition. Despite inconsistent changes in GM composition, the meta-analysis showed that microbiome-modulating interventions improved disease burden (SMD, − 0.57; 95% CI − 0.93 to − 0.21; I2 = 42%; P = 0.002) with a qualitative trend of improvement in constipation. However, current studies have high methodological heterogeneity and small sample sizes, requiring more well-designed and controlled studies to elucidate the complex linkage between microbiome, microbiome-modulating interventions, and NDDs.

Gut Microbes in Polycystic Ovary Syndrome and Associated Comorbidities; Type 2 Diabetes, Non-Alcoholic Fatty Liver Disease (NAFLD), Cardiovascular Disease (CVD), and the Potential of Microbial Therapeutics.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine anomalies among females of reproductive age, highlighted by hyperandrogenism. PCOS is multifactorial as it can be associated with obesity, insulin resistance, low-grade chronic inflammation, and dyslipidemia. PCOS also leads to dysbiosis by lowering microbial diversity and beneficial microbes, such as Faecalibacterium, Roseburia, Akkermenisa, and Bifidobacterium, and by causing a higher load of opportunistic pathogens, such as Escherichia/Shigella, Fusobacterium, Bilophila, and Sutterella. Wherein, butyrate producers and Akkermansia participate in the glucose uptake by inducing glucagon-like peptide-1 (GLP-1) and glucose metabolism, respectively. The abovementioned gut microbes also maintain the gut barrier function and glucose homeostasis by releasing metabolites such as short-chain fatty acids (SCFAs) and Amuc_1100 protein. In addition, PCOS-associated gut is found to be higher in gut-microbial enzyme β-glucuronidase, causing the de-glucuronidation of conjugated androgen, making it susceptible to reabsorption by entero-hepatic circulation, leading to a higher level of androgen in the circulatory system. Overall, in PCOS, such dysbiosis increases the gut permeability and LPS in the systemic circulation, trimethylamine N-oxide (TMAO) in the circulatory system, chronic inflammation in the adipose tissue and liver, and oxidative stress and lipid accumulation in the liver. Thus, in women with PCOS, dysbiosis can promote the progression and severity of type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases (CVD). To alleviate such PCOS-associated complications, microbial therapeutics (probiotics and fecal microbiome transplantation) can be used without any side effects, unlike in the case of hormonal therapy. Therefore, this study sought to understand the mechanistic significance of gut microbes in PCOS and associated comorbidities, along with the role of microbial therapeutics that can ease the life of PCOS-affected women.

Supplementation of Silymarin Alone or in Combination with Salvianolic Acids B and Puerarin Regulates Gut Microbiota and Its Metabolism to Improve High-Fat Diet-Induced NAFLD in Mice.

Silymarin, salvianolic acids B, and puerarin were considered healthy food agents with tremendous potential to ameliorate non-alcoholic fatty liver disease (NAFLD). However, the mechanisms by which they interact with gut microbiota to exert benefits are largely unknown. After 8 weeks of NAFLD modeling, C57BL/6J mice were randomly divided into five groups and fed a normal diet, high-fat diet (HFD), or HFD supplemented with a medium or high dose of Silybum marianum extract contained silymarin or polyherbal extract contained silymarin, salvianolic acids B, and puerarin for 16 weeks, respectively. The untargeted metabolomics and 16S rRNA sequencing were used for molecular mechanisms exploration. The intervention of silymarin and polyherbal extract significantly improved liver steatosis and recovered liver function in the mice, accompanied by an increase in probiotics like Akkermansia and Blautia, and suppressed Clostridium, which related to changes in the bile acids profile in feces and serum. Fecal microbiome transplantation confirmed that this alteration of microbiota and its metabolites were responsible for the improvement in NAFLD. The present study substantiated that alterations of the gut microbiota upon silymarin and polyherbal extract intervention have beneficial effects on HFD-induced hepatic steatosis and suggested the pivotal role of gut microbiota and its metabolites in the amelioration of NAFLD.

Staunch the Age Related Decline into Dementia, Cancer, Autoimmunity (Long Covid), Obesity, and Other Diseases with a Prebiotic, Probiotic, Postbiotic Triple Play

“All diseases originate in the gut.” Hippocrates (400 BC) A healthy gut microbiome via the gut-brain-axis elevates heart rate variability (HRV), a general measure of health and well-being. A dysbiotic gut microbiome, low in biodiversity and butyrate producers, can alter tryptophan metabolism (ATM) and increase the kynurenine to tryptophan ratio (KTR) with release of proinflammatory cytokines, predominantly TNF-α, IL-6, and IL-1β. These also characterize chronic inflammation, oxidative stress, and a multitude of diseases. Also proposed is the gut-lung dysbiosis concept and consequent degradation of ACE2 (richest in lungs and gut). Leaky gut (and lung) induced autoantibodies (AAs) related to G-protein coupled receptors (GPCRs) in combination with increased Ang II further potentiate oxidative stress. The underappreciated pathogenic role of these receptors on invading Candida hyphae is explored. The efficacy of fecal microbiome transplantation (FMT) in treating dementia, cancer, and autoimmunity supports the plausibility of success with “FMT-lite”. This triple play of prebiotic (d-mannose), probiotic (bifidobacteria and lactobacilli), and postbiotic (butyrate) might improve intestinal barrier integrity, oppose entry of GPCR antigens (epitopes), suppress the inflammatory cytokine triad, balance IFN-γ and TGF-β, suppress oxidative stress, depress KTR, elevate HRV, and extend lifespan and its quality.

Dermal injury drives a skin to gut axis that disrupts the intestinal microbiome and intestinal immune homeostasis in mice

The composition of the microbial community in the intestine may influence the functions of distant organs such as the brain, lung, and skin. These microbes can promote disease or have beneficial functions, leading to the hypothesis that microbes in the gut explain the co-occurrence of intestinal and skin diseases. Here, we show that the reverse can occur, and that skin directly alters the gut microbiome. Disruption of the dermis by skin wounding or the digestion of dermal hyaluronan results in increased expression in the colon of the host defense genes Reg3 and Muc2, and skin wounding changes the composition and behavior of intestinal bacteria. Enhanced expression Reg3 and Muc2 is induced in vitro by exposure to hyaluronan released by these skin interventions. The change in the colon microbiome after skin wounding is functionally important as these bacteria penetrate the intestinal epithelium and enhance colitis from dextran sodium sulfate (DSS) as seen by the ability to rescue skin associated DSS colitis with oral antibiotics, in germ-free mice, and fecal microbiome transplantation to unwounded mice from mice with skin wounds. These observations provide direct evidence of a skin-gut axis by demonstrating that damage to the skin disrupts homeostasis in intestinal host defense and alters the gut microbiome.

Staunch the Age Related Decline into Dementia, Cancer, Autoimmunity (Long Covid), Obesity, and Other Diseases with a Prebiotic, Probiotic, Postbiotic Triple Play

“All diseases originate in the gut.” Hippocrates (400 BC) A healthy gut microbiome via the gut-brain-axis elevates heart rate variability (HRV), a general measure of health and well-being. A dysbiotic gut microbiome, low in biodiversity and butyrate producers, can alter tryptophan metabolism (ATM) and increase the kynurenine to tryptophan ratio (KTR) with release of proinflammatory cytokines, predominantly TNF-α, IL-6, and IL-1β. These also characterize chronic inflammation, oxidative stress, and a multitude of diseases. Also proposed is the gut-lung dysbiosis concept and consequent degradation of ACE2 (richest in lungs and gut). Leaky gut (and lung) induced autoantibodies (AAs) related to G-protein coupled receptors (GPCRs) in combination with increased Ang II further potentiate oxidative stress. The underappreciated pathogenic role of Candida is explored. The efficacy of fecal microbiome transplantation (FMT) in treating dementia, cancer, and autoimmunity supports the plausibility of success with “FMT-lite”. This triple play of prebiotic (d-mannose), probiotic (bifidobacteria and lactobacilli), and postbiotic (butyrate) might improve intestinal barrier integrity, oppose entry of GPCR antigens, suppress the inflammatory cytokine triad, balance IFN-γ and TGF-β, suppress oxidative stress, depress KTR, elevate HRV, and extend lifespan and its quality.

Staunch the Age Related Decline into Dementia, Cancer, Autoimmunity (Long Covid), Obesity, and Other Diseases with a Prebiotic, Probiotic, Postbiotic Triple Play

“All diseases originate in the gut.” Hippocrates (400 BC) A healthy gut microbiome via the gut-brain-axis elevates heart rate variability (HRV), a general measure of health and well-being. A dysbiotic gut microbiome, low in biodiversity and butyrate producers, can alter tryptophan metabolism (ATM) and increase the kynurenine to tryptophan ratio (KTR) with release of proinflammatory cytokines, predominantly TNF-α, IL-6, and IL-1β. These also characterize chronic inflammation, oxidative stress, and a multitude of diseases. Also proposed is the gut-lung dysbiosis concept and consequent degradation of ACE2 (richest in lungs and gut). Leaky gut (and lung) induced autoantibodies (AAs) related to G-protein coupled receptors (GPCRs) in combination with increased Ang II further potentiate oxidative stress. The underappreciated pathogenic role of Candida is explored. The efficacy of fecal microbiome transplantation (FMT) in treating dementia, cancer, and autoimmunity supports the plausibility of success with “FMT-lite”. This triple play of prebiotic (d-mannose), probiotic (bifidobacteria and lactobacilli), and postbiotic (butyrate) might improve intestinal barrier integrity, oppose entry of GPCR antigens, suppress the inflammatory cytokine triad, balance IFN-γ and TGF-β, suppress oxidative stress, depress KTR, elevate HRV, and extend lifespan and its quality.

Transplant of microbiota from Crohn’s disease patients to germ-free mice results in colitis

ABSTRACT Although the role of the intestinal microbiota in the pathogenesis of inflammatory bowel disease (IBD) is beyond debate, attempts to verify the causative role of IBD-associated dysbiosis have been limited to reports of promoting the disease in genetically susceptible mice or in chemically induced colitis. We aimed to further test the host response to fecal microbiome transplantation (FMT) from Crohn’s disease patients on mucosal homeostasis in ex-germ-free (xGF) mice. We characterized and transferred fecal microbiota from healthy patients and patients with defined Crohn’s ileocolitis (CD_L3) to germ-free mice and analyzed the resulting microbial and mucosal homeostasis by 16S profiling, shotgun metagenomics, histology, immunofluorescence (IF) and RNAseq analysis. We observed a markedly reduced engraftment of CD_L3 microbiome compared to healthy control microbiota. FMT from CD_L3 patients did not lead to ileitis but resulted in colitis with features consistent with CD: a discontinued pattern of colitis, more proximal colonic localization, enlarged isolated lymphoid follicles and/or tertiary lymphoid organ neogenesis, and a transcriptomic pattern consistent with epithelial reprograming and promotion of the Paneth cell-like signature in the proximal colon and immune dysregulation characteristic of CD. The observed inflammatory response was associated with persistently increased abundance of Ruminococcus gnavus, Erysipelatoclostridium ramosum, Faecalimonas umbilicate, Blautia hominis, Clostridium butyricum, and C. paraputrificum and unexpected growth of toxigenic C. difficile, which was below the detection level in the community used for inoculation. Our study provides the first evidence that the transfer of a dysbiotic community from CD patients can lead to spontaneous inflammatory changes in the colon of xGF mice and identifies a signature microbial community capable of promoting colonization of pathogenic and conditionally pathogenic bacteria.

Abstract 6691: Engraftment as a determinant of response in fecal microbiome transplantation interventions for immunotherapy in melanoma

Abstract Background: Distinct gut microbiome signatures are associated with response, resistance, and toxicity to immune checkpoint blockade (ICB). Fecal microbiome transplants (FMT) have validated the importance of the gut microbiome in enhancing response and overcoming resistance to immunotherapy. However, donor selection remains a key challenge for FMT. Heterogenous responses using Healthy Donors (HD) and ICB Complete Responders (CR) as FMT donors suggest donor characteristics alone do not determine response. Here, we posit that donor-recipient relationships are critical in determining clinical responses to FMT. Methods: We studied a cohort of ICB-refractory, metastatic melanoma patients treated with combined FMT and ICB (10 recipients, 2 donors). Patient gut microbiomes were profiled using whole metagenomic sequencing (WMS) of longitudinal stool collections (baseline, day 7, day 31, and day 65 post-FMT). Immune infiltration of on-treatment tumor and colon biopsies was quantified with immunohistochemistry. mTraCX, an Earth Mover’s Distance-based algorithm, was used to evaluate taxonomic engraftment between donors and recipients. Bray-Curtis distance was used to measure functional similarities between donor and recipient gut microbiome. Clinical findings were validated in pre-clinical FMT experiments performed on BrafV600EPten−/− melanoma-bearing mice. Results: One-third of recipients (3/10) developed an objective response (R) to ICB following FMT. mTraCX demonstrated an association between clinical response to FMT and durable engraftment of donor microbiota at day 65 post-FMT (p=0.025). Taxonomic engraftment (mTraCX) correlated positively with functional engraftment (Bray-Curtis distance) (r=0.89, p<0.0001). Enhanced engraftment was associated with increased CD4 (r = -0.87, p=0.0045) and CD8 (r = -0.6, p=0.09) T-cell infiltration in the colon, and a trend towards increased CD8 T-cell infiltration (r = -0.5, p=0.2) in the tumor following treatment with FMT+ICB. Pre-clinical models paralleled our clinical findings as responding mice showed better donor engraftment than non-responding mice (p<0.0001 on day 4 and day 24 following FMT). Conclusions: Our data shows that donor engraftment is a favorable prognostic factor for ICB treatments combined with FMT. Future investigations will aim to develop donor-recipient matching criteria to enhance the feasibility and integration of FMTs into clinical practice. Citation Format: Manoj Chelvanambi, Ashish V. Damania, Sarah B. Johnson, Golnaz Morad, Rossana N. Lazcano, Beth A. Helmink, Lon W. Fong, Khalida Wani, Y David Seo, Elizabeth M. Park, Reed I. Ayabe, Bhavana Singh, Matthew C. Wong, Davis R. Ingram, Michael G. White, Alexander J. Lazar, Aditya K. Mishra, Nadim J. Ajami, Erez N. Baruch, Jennifer A. Wargo. Engraftment as a determinant of response in fecal microbiome transplantation interventions for immunotherapy in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6691.

Abstract 6694: Gut microbial drivers of response to bladder-sparing therapy in human muscle-invasive bladder cancer enhance immunotherapy efficacy and limit immunosuppression following fecal microbiome transplantation in vivo

Abstract BACKGROUND: Radiation therapy (RT) is a bladder-sparing option for Muscle-Invasive Bladder Cancer (MIBC), yet encounters a 30% non-response rate, with half of the patients succumbing to metastasis. Preclinical models demonstrate enhanced antitumor responses with RT combined with PD-1/PD-L1 blockade but give limited insight into the determinants of success for such combination therapies (CT). The gut microbiome, pivotal in conditioning local and peripheral immunity, influences PD-1-based immunotherapy efficacy in various cancers. Immune profiling indicates heightened systemic and antitumor immunity in responders with a favorable gut microbiome, enriched in Akkermansia muciniphila, Bifidobacterium, and Faecalibacterium. Oral gavage of immunogenic bacteria further enhances combined RT and anti-PD-L1 therapy. We thus aim to 1) elucidate the role of patients’ microbiome in shaping anti-tumor immune responses to CT, and 2) use its composition as a predictive factor for CT success. METHODS: We performed shotgun metagenomics on microbial DNA from fecal materials of MIBC RT responders (R, n=26) and non-responders (NR, n=11). Fecal homogenates from donors were gavaged into germ-free (GF) mice. Three weeks post-gavage, MB49 tumor cells were subcutaneously delivered to mice, randomized into four groups: control, anti-PD-L1, RT, and RT + anti-PD-L1. Tumors were harvested seven days post-treatment for single-cell RNA-seq and TCR sequencing (10X Genomics), while stool samples were collected weekly for 16S sequencing. RESULTS: Significant gut microbial disparities were observed between R and NR MIBC patients, with particular enrichment in known promoters of anti-PD-L1 response, such as Phocaeicola dorei in R. Transplantation of R microbiome into GF mice resulted in significant increases in predicted survival, tumor growth delay, and counts of effector CD4+ T cell infiltration in the RT+PD-L1 arm. Conversely, NR microbiome transplantation correlated with increased neutrophil and Treg infiltration, abrogating the survival tumor growth delay benefits of the combination arm. Spatial tissue analyses revealed higher neutrophil densities around CD8+ T cells in all NR arms. Single-cell RNA-seq of tumor-infiltrating immune cells unveiled skewed CD4 and CD8 polarization between R and NR in vivo batches. SIGNIFICANCE: To our knowledge, this is the first study to use FMT as a modulator of response in the context of radiation therapy combinations in MIBC. Our results highlight that the gut microbiome alone may condition a favorable immune terrain for combinatorial therapies involving radiation. This offers strong predictive value for personalized therapeutic approaches in selecting patients who will benefit the most from bladder-sparing therapies. Citation Format: Eva Michaud, Sabina Fehric, Cynthia Faubert, Bertrand Routy, Irah King, José Joao Mansure, Wassim Kassouf. Gut microbial drivers of response to bladder-sparing therapy in human muscle-invasive bladder cancer enhance immunotherapy efficacy and limit immunosuppression following fecal microbiome transplantation in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6694.

The gut microbiome from middle-aged women with depression modulates depressive-like behaviors and plasma fatty acid metabolism in female middle-aged mice

BackgroundIntestinal dysbacteriosis has frequently been involved in the context of depression. Nonetheless, only scant information is available about the features and functional changes of gut microbiota in female middle-aged depression (MAD). ObjectiveThis study aims to explore whether there are characteristic changes in the gut microbes of female MAD and whether these changes are associated with depressive-like behaviors. Meanwhile, this study observed alterations in the lipid metabolism function of gut microbes and further examined changes in plasma medium- and long-chain fatty acids (MLCFAs) in mice that underwent fecal microbiota transplantation (FMT). MethodsStool samples obtained from 31 MAD, along with 24 healthy individuals (HC) were analyzed by 16 S rRNA gene sequencing. Meanwhile, 14-month-old female C57BL/6J mice received antibiotic cocktails and then oral gavage of the microbiota suspension of MAD or HC for 3 weeks to reconstruct gut microbiota. The subsequent depressive-like behaviors, the composition of gut microbiota, as well as MLCFAs in the plasma were evaluated. ResultsA noteworthy disruption in gut microbial composition in MAD individuals compared to HC was observed. Several distinct bacterial taxa, including Dorea, Butyricicoccus, and Blautia, demonstrated associations with the demographic variables. A particular microbial panel encompassing 49 genera effectively differentiated MAD patients from HC (AUC = 0.82). Fecal microbiome transplantation from MAD subjects led to depressive-like behaviors and dysfunction of plasma MLCFAs in mice. ConclusionsThese findings suggest that microbial dysbiosis is linked to the pathogenesis of MAD, and its role may be associated with the regulation of MLCFAs metabolism.

Ovarian Cancer and the Microbiome: Connecting the Dots for Early Diagnosis and Therapeutic Innovations-A Review.

Ovarian cancer, which ranks eighth among global female cancers and fifth in fatality, poses a significant health challenge owing to its asymptomatic early stages. Understanding the pathogenesis requires extensive research. Recent studies have emphasized the role of the gut and cervicovaginal microbiota in ovarian cancer. This review explores the current understanding of the relationship between the microbiome and ovarian cancer, considering the potential of biomarkers in the serum and various tissues. Insights into the influence of the microbiome on treatments, including surgery and chemotherapy, open doors to innovative approaches, such as fecal microbiome transplantation. This synthesis of recent findings provides crucial insights into the intricate interplay between the microbiome and ovarian cancer, thereby shaping diagnostic and treatment strategies.

Gut microbiome features and metabolites in non-alcoholic fatty liver disease among community-dwelling middle-aged and older adults

BackgroundThe specific microbiota and associated metabolites linked to non-alcoholic fatty liver disease (NAFLD) are still controversial. Thus, we aimed to understand how the core gut microbiota and metabolites impact NAFLD.MethodsThe data for the discovery cohort were collected from the Guangzhou Nutrition and Health Study (GNHS) follow-up conducted between 2014 and 2018. We collected 272 metadata points from 1546 individuals. The metadata were input into four interpretable machine learning models to identify important gut microbiota associated with NAFLD. These models were subsequently applied to two validation cohorts [the internal validation cohort (n = 377), and the prospective validation cohort (n = 749)] to assess generalizability. We constructed an individual microbiome risk score (MRS) based on the identified gut microbiota and conducted animal faecal microbiome transplantation experiment using faecal samples from individuals with different levels of MRS to determine the relationship between MRS and NAFLD. Additionally, we conducted targeted metabolomic sequencing of faecal samples to analyse potential metabolites.ResultsAmong the four machine learning models used, the lightGBM algorithm achieved the best performance. A total of 12 taxa-related features of the microbiota were selected by the lightGBM algorithm and further used to calculate the MRS. Increased MRS was positively associated with the presence of NAFLD, with odds ratio (OR) of 1.86 (1.72, 2.02) per 1-unit increase in MRS. An elevated abundance of the faecal microbiota (f__veillonellaceae) was associated with increased NAFLD risk, whereas f__rikenellaceae, f__barnesiellaceae, and s__adolescentis were associated with a decreased presence of NAFLD. Higher levels of specific gut microbiota-derived metabolites of bile acids (taurocholic acid) might be positively associated with both a higher MRS and NAFLD risk. FMT in mice further confirmed a causal association between a higher MRS and the development of NAFLD.ConclusionsWe confirmed that an alteration in the composition of the core gut microbiota might be biologically relevant to NAFLD development. Our work demonstrated the role of the microbiota in the development of NAFLD.

Immunotherapy of Human Melanoma: Past, Present, Future.

Immunotherapy with immune checkpoint inhibitors (ICIs) is a promising therapeutic schedule in advanced solid cancers. In this review, clinical trials from highly reputable journals are interpreted for safety and efficacy evaluation of the common anti-programmed death-1 (PD-1) inhibitor nivolumab and/or the most known anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) inhibitor ipilimumab in advanced melanoma. Current progress in the field of melanoma immunotherapy is the focus of this review. Solo nivolumab and combo nivolumab-ipilimumab show higher responses compared to solo ipilimumab or chemotherapy. BRAF and programmed death-ligand 1 (PDL1) expression states are seemingly not reliable biomarkers of response to ICI therapy in melanoma. Solo ipilimumab and particularly a combination of nivolumab-ipilimumab show higher adverse events (AEs) compared with solo nivolumab or chemotherapy. Besides, ICI therapy is safer in mucosal melanoma, but its efficacy is higher in the cutaneous subtype. Patients receiving combination regimens who are experiencing serious AEs can discontinue such regimens until recovery and still maintain clinical benefits. To conclude, combo nivolumab-ipilimumab represents more therapeutic advantages compared with solo nivolumab or ipilimumab, but the rate of AEs is higher for combination regimens. Resistance to combo nivolumab-ipilimumab demands the application of novel approaches to go with ICIs in melanoma immunotherapy. Immunogenic agents, alternative immune checkpoints, vaccination, oncolytic viruses, extracellular vesicles (EVs) and fecal microbiome transplantation (FMT) are novel strategies in patients developing ICI resistance.

Effects of fecal microbiota transplantation on metabolic health of DBA mice.

Numerous studies have demonstrated that C57BL/6 mice exhibit superior growth rates and overall growth performance compared to DBA mice. To investigate whether this discrepancy in growth performance is linked to the composition of gut microorganisms, we conducted fecal microbiome transplantation (FMT) experiments. Specifically, we transplanted fecal fluids from adult C57BL/6 mice, high-fat C57BL/6 mice, and Wistar rats into weaned DBA mice (0.2mL/d), and subsequently analyzed their gut contents and gene expression through 16S rRNA sequencing and transcriptome sequencing. During the test period, C57BL/6 mice and Wistar rats were provided with a normal diet, and high-fat C57BL/6 mice were provided with a high-fat diet. The results of our study revealed that mice receiving FMT from all three donor groups exhibited significantly higher daily weight gain and serum triglyceride (TG) levels compared to mice of CK group. 16S rRNA sequensing unveiled substantial differences in the abundance and function of the gut microbiota between the FMT groups and the CK group. Transcriptome analysis revealed a total of 988 differential genes, consisting of 759 up-regulated genes and 187 down-regulated genes, between the three experimental groups and the CK group. Functional Gene Ontology (GO) annotation suggested that these genes were primarily linked to lipid metabolism, coagulation, and immunity. Pearson correlation analysis was performed on the differential genes and clusters, and it revealed significant correlations, mainly related to processes such as fatty acid metabolism, fat digestion and absorption, and cholesterol metabolism. In summary, FMT from dominant strains improved the growth performance of DBA mice, including body weight gain, institutional growth, and immune performance. This change may be due to the increase of probiotic content in the intestinal tract by FMT and subsequent alteration of intestinal gene expression. However, the effects of cross-species fecal transplantation on the intestinal flora and gene expression of recipient mice were not significant.

Abstract TMP118: Aged Maternal Gut Microbiome Impairs Offspring Behavior and Exacerbates Stroke Outcome

The microbiome plays a significant role in influencing general health. A disruption of the gut biome homeostasis, dysbiosis, can be both the effect of disease or a precondition. The maternal biome has been shown to play a vital role in offspring brain and immune development by shaping the metabolic environment for the embryo. Therefore, an aged dysbiotic maternal biome may increase stroke risk factors among offspring and additionally, worsen stroke outcome. Young female C57B6 mice 3-month (M) of age had their host gut bacteria cleared via antibiotic treatment prior to recolonization via fecal microbiome transplants from 3M control, and 14M middle aged female mice. After breeding, the subsequent offspring was aged to 14 months, followed by behavioral tests, glucose tolerance, prior to a transient 60-minute middle cerebral artery occlusion (MCAO or sham surgery). The maternal biome had a significant effect on offspring biome at 2M, 6M and 9M of age, shifting the beta-diversity of females significantly (p=<0.01), and males to a lesser extent (p=0.241), extending into adulthood. Additional sex specific changes were observed in adult mouse behavior with decreased motor function and increased anxiety being prevalent in male offspring at 2 months of age (p=0.0338 and 0.0261 respectively) but not in females. At 6 months of age female offspring from dysbiotic mothers exhibited significantly impaired object recognition abilities compared to control (p=>0.01). Once the offspring had been subjected to a 60 min MCAO, a spontaneous recovery was observed in NDS scores in all females and in the control males, but not in males from dysbiotic mothers, suggesting that male stroke outcome is negatively affected by dysbiotic mothers. The maternal microbiome has a significant impact on offspring biome composition and health. Mice from mothers with aged microbiome exhibited sex specific early life motor function and cognitive impairment. Additionally, male offspring from dysbiotic mothers have a worsened stroke outcome.

Identification of Muscle Strength-Related Gut Microbes through Human Fecal Microbiome Transplantation.

The gut microbiome is well known for its influence on human physiology and aging. Therefore, we speculate that the gut microbiome may affect muscle strength in the same way as the host's own genes. To demonstrate candidates for gut microbes affecting muscle strength, we remodeled the original gut microbiome of mice into human intestinal microbiome through fecal microbiome transplantation (FMT), using human feces and compared the changes in muscle strength in the same mice before and three months after FMT. After comparing before and after FMT, the mice were divided into three groups based on the observed changes in muscle strength: positive, none, and negative changes in muscle strength. As a result of analyzing the α-diversity, β-diversity, and co-occurrence network of the intestinal microbial community before and after FMT, it was observed that a more diverse intestinal microbial community was established after FMT in all groups. In particular, the group with increased muscle strength had more gut microbiome species and communities than the other groups. Fold-change comparison showed that Eisenbergiella massiliensis and Anaeroplasma abactoclasticum from the gut microbiome had positive contributions to muscle strength, while Ileibacterium valens and Ethanoligenens harbinense had negative effects. This study identifies candidates for the gut microbiome that contribute positively and those that contribute negatively to muscle strength.

Altered intestinal microbiota enhances adenoid hypertrophy by disrupting the immune balance.

Adenoid hypertrophy (AH) is a common upper respiratory disorder in children. Disturbances of gut microbiota have been implicated in AH. However, the interplay of alteration of gut microbiome and enlarged adenoids remains elusive. 119 AH children and 100 healthy controls were recruited, and microbiome profiling of fecal samples in participants was performed using 16S rRNA gene sequencing. Fecal microbiome transplantation (FMT) was conducted to verify the effects of gut microbiota on immune response in mice. In AH individuals, only a slight decrease of diversity in bacterial community was found, while significant changes of microbial composition were observed between these two groups. Compared with HCs, decreased abundances of Akkermansia, Oscillospiraceae and Eubacterium coprostanoligenes genera and increased abundances of Bacteroides, Faecalibacterium, Ruminococcus gnavus genera were revealed in AH patients. The abundance of Bacteroides remained stable with age in AH children. Notably, a microbial marker panel of 8 OTUs were identified, which discriminated AH from HC individuals with an area under the curve (AUC) of 0.9851 in the discovery set, and verified in the geographically different validation set, achieving an AUC of 0.9782. Furthermore, transfer of mice with fecal microbiota from AH patients dramatically reduced the proportion of Treg subsets within peripheral blood and nasal-associated lymphoid tissue (NALT) and promoted the expansion of Th2 cells in NALT. These findings highlight the effect of the altered gut microbiota in the AH pathogenesis.

Anemoside B4 ameliorates dextran sulfate sodium (DSS)-induced colitis through inhibiting NLRP3 inflammasome and modulating gut microbiota

Ulcerative colitis (UC) has been recognized as a chronic and relapsing inflammatory disease of the gastrointestinal tract. Clinically, aminosalicylates, immunosuppressants and biological agents are commonly used to treat UC at different stages of the disease. However, these drugs often have side effects. Here, we investigated the anti-UC activity of Anemoside B4 (AB4) in mice with dextran sulfate sodium (DSS) induced colitis. Colon tissues, serum, and colonic contents were collected for assessment of intestinal barrier function, inflammatory cytokines production and microenvironment of intestinal microbiota. Results showed that AB4 alleviated colon shortening, weight lossing and histopathological damage in DSS-induced mice. In addition, we demonstrated both in vivo and in vitro that AB4 remarkably ameliorated colonic inflammation through suppressing NLRP3 pathway. Moreover, AB4 strengthened the intestinal epithelial barrier by regulating myosin light chain kinase (MLCK)-phosphorylated myosin light chain 2 (pMLC2) signaling pathway. Furthermore, we performed 16 S rRNA gene sequencing and fecal microbiome transplantation (FMT) experiments to demonstrate that AB4 alleviated colitis through regulating dysbiosis of intestinal microbiota. These results revealed that AB4 effectively ameliorate experimental UC mainly through regulating MLCK/pMLC2 pathway, NLRP3 pathway and dysbiosis of microbiota, provided new insights into the development of novel anti-UC drugs.