Fecal Microbiome Transplantation Research Articles

NCOG-26. THERAPEUTIC POTENTIAL OF FECAL MICROBIOME TRANSPLANT TO IMPROVE COGNITIVE DYSFUNCTION INDUCED BY CRANIAL IRRADIATION IN MICE

Abstract Radiation therapy (RT) is a crucial treatment for brain tumors, but radiation-induced cognitive dysfunction (RICD) affects 50-90% of patients, significantly impacting their quality of life. Evidence suggests that gut microbiome dysfunction may contribute to progressive cognitive dysfunction (CD). Prior studies in aging and stroke models show that fecal microbiome transplants (FMT) from healthy hosts can promote recovery and improve cognition. To investigate the link between RICD and the gut microbiome, we subjected mice to Sham/9Gy/15Gy cranial irradiation, followed by cognitive tests using the Y-maze and Novel Object Recognition Test (NORT) at various time points. Both 9Gy and 15Gy irradiation resulted in significant cognitive dysfunction, as indicated by altered performance in both tests at 7 and 30 days post-irradiation. Fecal samples were collected before irradiation and at 10 and 30 days post-RT. Microbial DNA was extracted, and the 16S rRNA gene was sequenced and analyzed using the bioinformatics visualization toolkit, ATIMA. Significant gut dysbiosis was observed in both 9Gy and 15Gy irradiated mice compared to pre-irradiation samples, with the 15Gy group showing more pronounced and consistent changes in fecal microbiome diversity, particularly at 30 days post-RT. We hypothesized that FMT from healthy hosts (non-radiated mice) could prevent or ameliorate RICD by modulating microbial, metabolomic, and immunologic profiles. To test this, a separate cohort of mice received 15Gy cranial irradiation and FMT via oral gavage. After a 20-day post-irradiation period, cognitive and gut permeability tests were conducted. The FMT group exhibited significantly improved gut permeability and cognitive performance compared to controls. Our findings suggest that gut dysbiosis plays a crucial role in RICD and that FMT may be a potential strategy to mitigate RICD and improve the quality of life in brain tumor patients undergoing cranial RT.

Isomalto-Oligosaccharide Potentiates Alleviating Effects of Intermittent Fasting on Obesity-Related Cognitive Impairment during Weight Loss and the Rebound Weight Gain.

Obesity-related cognitive dysfunction poses a significant threat to public health. The present study demonstrated mitigating effects of intermittent fasting (IF) and its combination with isomalto-oligosaccharides and IF (IF + IMO) on cognitive impairments induced by a high-fat-high-fructose (HFHF) diet in mice, with IF + IMO exhibiting superior effects. Transcriptomic analysis of the hippocampus revealed that the protective effects on cognition might be attributed to the suppression of toll-like receptor 4 (TLR4)/NFκB signaling, oxidative phosphorylation, and neuroinflammation. Moreover, both IF and IF + IMO modulated the gut microbiome and promoted the production of short-chain fatty acids, with IF + IMO displaying more pronounced effects. IF + IMO-modulated gut microbiota, metabolites, and molecular targets associated with cognitive impairments were further corroborated using human data from public databases Gmrepo and gutMgene. Furthermore, the fecal microbiome transplantation confirmed the direct impacts of IF + IMO-derived microbiota on improving cognition functions by suppressing TLR4/NFκB signaling and increasing BDNF levels. Notably, prior exposure to IF + IMO prevented weight-regain-induced cognitive decline, suppressed TLR4/NFκB signaling and inflammatory cytokines in the hippocampus, and mitigated weight regain-caused gut dysbacteriosis without altering body weight. Our study underscores that IMO-augmented alleviating effects of IF on obesity-related cognitive impairment particularly during weight-loss and weight-regain periods, presenting a novel nutritional strategy to tackle obesity-related neurodegenerative disorders.

Fecal microbiome transplantation alleviates manganese-induced neurotoxicity by altering the composition and function of the gut microbiota via the cGAS–STING/NLRP3 pathway

Manganese (Mn) is an environmental pollutant, and overexposure can cause neurodegenerative disorders similar to Alzheimer's disease and Parkinson's disease that are characterized by β-amyloid (Aβ) overexpression, Tau hyperphosphorylation and neuroinflammation. However, the mechanisms of Mn neurotoxicity are not clearly defined. In our study, a knockout mouse model of Mn exposure combined with gut flora-induced neurotoxicity was constructed to investigate the effect of gut flora on Mn neurotoxicity. The results showed that the levels of Tau, p-Tau and Aβ in the hippocampus of C57BL/6 mice were greater than those in the hippocampus of control mice after 5 weeks of continuous exposure to manganese chloride (Mn content of 200 mg/L). Transplanted normal and healthy fecal microbiota from mice significantly downregulated Tau, p-Tau and Aβ expression and ameliorated brain pathology. Moreover, Mn exposure activated the cGAS–STING pathway and altered the cecal microbiota profile, characterized by an increase in Clostridiales, Pseudoflavonifractor, Ligilactobacillus and Desulfovibrio, and a decrease in Anaerotruncus, Eubacterium_ruminantium_group, Fusimonas and Firmicutes, While fecal microbiome transplantation (FMT) treatment inhibited this pathway and restored the microbiota profile. FMT alleviated Mn exposure-induced neurotoxicity by inhibiting activation of the NLRP3 inflammasome triggered by overactivation of the cGAS–STING pathway. Deletion of the cGAS and STING genes and FMT altered the gut microbiota composition and its predictive function. Phenotypic prediction revealed that FMT markedly decreased the abundances of anaerobic and stress-tolerant bacteria and significantly increased the abundances of facultative anaerobic bacteria and biofilm-forming bacteria after blocking the cGAS–STING pathway compared to the Mn-exposed group. FMT from normal and healthy mice ameliorated the neurotoxicity of Mn exposure, possibly through alterations in the composition and function of the microbiome associated with the cGAS–STING/NLRP3 pathway. This study provides a prospective direction for future research on the mechanism of Mn neurotoxicity.

A gut reaction? The role of the microbiome in aggression

Recent research has unveiled conflicting evidence regarding the link between aggression and the gut microbiome. Here, we compared behavior profiles of control, germ-free (GF), and antibiotic-treated mice, as well as re-colonized GF mice to understand the impact of the gut microbiome on aggression using the resident-intruder paradigm. Our findings revealed a link between gut microbiome depletion and higher aggression, accompanied by notable changes in urine metabolite profiles and brain gene expression. This study extends beyond classical murine models to humanized mice to reveal the clinical relevance of early-life antibiotic use on aggression. Fecal microbiome transplant from infants exposed to antibiotics in early life (and sampled one month later) into mice led to increased aggression compared to mice receiving transplants from unexposed infants. This study sheds light on the role of the gut microbiome in modulating aggression and highlights its potential avenues of action, offering insights for development of therapeutic strategies for aggression-related disorders.

Beyond the Gut: The intratumoral microbiome's influence on tumorigenesis and treatment response.

The intratumoral microbiome (TM) refers to the microorganisms in the tumor tissues, including bacteria, fungi, viruses, and so on, and is distinct from the gut microbiome and circulating microbiota. TM is strongly associated with tumorigenesis, progression, metastasis, and response to therapy. This paper highlights the current status of TM. Tract sources, adjacent normal tissue, circulatory system, and concomitant tumor co-metastasis are the main origin of TM. The advanced techniques in TM analysis are comprehensively summarized. Besides, TM is involved in tumor progression through several mechanisms, including DNA damage, activation of oncogenic signaling pathways (phosphoinositide 3-kinase [PI3K], signal transducer and activator of transcription [STAT], WNT/β-catenin, and extracellular regulated protein kinases [ERK]), influence of cytokines and induce inflammatory responses, and interaction with the tumor microenvironment (anti-tumor immunity, pro-tumor immunity, and microbial-derived metabolites). Moreover, promising directions of TM in tumor therapy include immunotherapy, chemotherapy, radiotherapy, the application of probiotics/prebiotics/synbiotics, fecal microbiome transplantation, engineered microbiota, phage therapy, and oncolytic virus therapy. The inherent challenges of clinical application are also summarized. This review provides a comprehensive landscape for analyzing TM, especially the TM-related mechanisms and TM-based treatment in cancer.

Berberine hydrochloride alleviates chronic prostatitis/chronic pelvic pain syndrome by modifying gut microbiome signaling.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is highly prevalent worldwide and poses a significant threat to men's health, particularly affecting young men. However, the exact causes and mechanisms behind CP/CPPS remain unclear, leading to challenges in its treatment. In this research, a CP/CPPS rat model was established with complete Freund's adjuvant (CFA), and berberine hydrochloride was administered through daily gavage to assess its therapeutic effects. The alterations in the gut microbiome induced by CP/CPPS and berberine hydrochloride were investigated through 16S ribosomal RNA sequencing of cecum content and colonic epithelial cells. To investigate the impact of the gut microbiome on CP/CPPS, a pseudo germ-free rat model was established, and fecal microbiome transplantation (FMT) was performed on these rats. In all, berberine hydrochloride demonstrated effective reduction of inflammation and oxidative stress in the prostate, offering significant therapeutic advantages for CP/CPPS. Through analysis of the gut microbiome using 16S ribosome RNA sequencing, distinct differences were observed between CP/CPPS rats and control rats, and Clostridium butyricum was identified as a key bacteria. Pseudo germ-free rats that underwent FMT from CP/CPPS rats or rats treated with berberine hydrochloride displayed varying levels of inflammatory cytokine production, oxidative stress, and activity of associated signaling pathways. In conclusion, the therapeutic potential of berberine hydrochloride in addressing CP/CPPS is highly significant. The gut microbiome has emerged as a critical factor in the development of CP/CPPS and plays a pivotal role in mediating the therapeutic effects of berberine hydrochloride.

The Relationship between Canine Behavioral Disorders and Gut Microbiome and Future Therapeutic Perspectives.

Canine behavioral disorders have become one of the most common concerns and challenging issues among dog owners. Thus, there is a great demand for knowledge about various factors affecting dogs' emotions and well-being. Among them, the gut-brain axis seems to be particularly interesting, especially since in many instances the standard treatment or behavioral therapies insufficiently improve animal behavior. Therefore, to face this challenge, the search for novel therapeutic methods is highly required. Existing data show that mammals' gut microbiome, immune system, and nervous system are in continuous communication and influence animal physiology and behavior. This review aimed to summarize and discuss the most important scientific evidence on the relationship between mental disorders and gut microbiota in dogs, simultaneously presenting comparable outcomes in humans and rodent models. A comprehensive overview of crucial mechanisms of the gut-brain axis is included. This refers especially to the neurotransmitters crucial for animal behavior, which are regulated by the gut microbiome, and to the main microbial metabolites-short-chain fatty acids (SCFAs). This review presents summarized data on gut dysbiosis in relation to the inflammation process within the organism, as well as the activation of the hypothalamic-pituitary-adrenal (HPA) axis. All of the above mechanisms are presented in this review in strict correlation with brain and/or behavioral changes in the animal. Additionally, according to human and laboratory animal studies, the gut microbiome appears to be altered in individuals with mental disorders; thus, various strategies to manipulate the gut microbiota are implemented. This refers also to the fecal microbiome transplantation (FMT) method, based on transferring the fecal matter from a donor into the gastrointestinal tract of a recipient in order to modulate the gut microbiota. In this review, the possible effects of the FMT procedure on animal behavioral disorders are discussed.

The potential liver injury induced by metronidazole-provoked disturbance of gut microbiota: modulatory effect of turmeric supplementation.

It has been reported that the gut-liver axis and intestinal microbiome contribute crucially to different liver diseases. So, targeting this hepato-intestinal connection may provide a novel treatment modality for hepatic disorders such as drug-induced liver injury (DILI). The present study thought to investigate the protective effect of turmeric (TUR) on metronidazole (MNZ)-induced liver damage and the possible association of the gut-liver axis and gut microbiota as a suggested underlying mechanism. In the first experiment, a MNZ-induced liver injury rat model was reproduced after 130mg/kg oralMNZ administration for 30days. Meanwhile, the treatment group was orallytreated with 100mg/kg turmeric daily. In the second experiment, fecal microbiome transplantation (FMT) was conducted, in which the fecal microbiome of each group in the first experiment was transplanted to a healthy corresponding group in the second experiment. The liver enzymes (aminotransferase (ALT) and aspartate aminotransferase (AST)) and histopathological examination were estimated to assess liver function. Inflammatory cytokines and oxidative markers were evaluated in the liver tissues. Histological analysis, intestinal barrier markers, and expression of tight junction proteins were measured for assessment of the intestinal injury. Changes in the gut microbial community and possible hepatic bacterial transmission were analyzed using 16S rRNA sequencing. MNZ induced intestinal and liver injuries which were significantly improved by turmeric. Increased firmicutes/bacteroidetes ratio and bacterial transmission due to gut barrier disruption were suggested. Moreover, TUR has maintained the gut microbial community by rebalancing and restoring bacterial proportions and abundance, thereby repairing the gut mucosal barrier and suppressing bacterial translocation. TUR protected against MNZ-induced gut barrier disruption. Reshaping of the intestinal bacterial composition and prohibition of the hepatic microbial translocation were suggested turmeric effects, potentially mitigating MNZ-related liver toxicity.

Integrated bioinformatics and multiomics reveal Liupao tea extract alleviating NAFLD via regulating hepatic lipid metabolism and gut microbiota

BackgroundNon-alcoholic fatty liver disease (NAFLD) poses a significant global public health concern. Liupao tea (LPT) is a Chinese national geographical indication product renowned for its lipid-lowering properties. However, the precise mechanisms and active constituents contributing to the efficacy of LPT against NAFLD remain unclear. PurposeThis study aims to comprehensively explore the therapeutic potential of Liupao tea extract (LPTE) in alleviating NAFLD through an integrated strategy. MethodsInitially, network pharmacology analysis was conducted based on LPTE chemical ingredient analysis, identifying core targets and key components. Potential active ingredients were validated through chemical standards based on LC-MS/MS. To confirm the pharmacological efficacy of LPTE in NAFLD, NAFLD mice models were employed. Alterations in hepatic lipid metabolism were comprehensively elucidated through integration of metabolomics, lipidomics, network pharmacology analysis, and real-time PCR analysis. To further explore the binding interactions between key components and core targets, molecular docking and microscale thermophoresis (MST) analysis were employed. Furthermore, to investigate LPTE administration effectiveness on gut microbiota in NAFLD mice, a comprehensive approach was employed. This included Metorigin analysis, 16S rRNA sequencing, molecular docking, and fecal microbiome transplantation (FMT). ResultsStudy identified naringenin, quercetin, luteolin, and kaempferol as the potential active ingredients of LPTE. These compounds exhibited therapeutic potential for NAFLD by targeting key proteins such as PTGS2, CYP3A4, and ACHE, which are involved in the metabolic pathways of hepatic linoleic acid (LA) and glycerophospholipid (GP) metabolism. The therapeutic effectiveness of LPTE was observed to be comparable to that of simvastatin. Furthermore, LPTE exhibited notable efficacy in alleviating NAFLD by influencing alterations in gut microbiota composition (Proteobacteria phylum, Lactobacillus and Dubosiella genus) that perhaps impact LA and GP metabolic pathways. ConclusionLPTE could be effective in preventing high-fat diet (HFD)-induced NAFLD by modulating hepatic lipid metabolism and gut microbiota. This study firstly integrated bioinformatics and multi-omics technologies to identify the potential active components and key microbiota associated with LPTE's effects, while also primally elucidating the action mechanisms of LPTE in alleviating NAFLD. The findings offer a conceptual basis for LPTE's potential transformation into an innovative pharmaceutical agent for NAFLD prevention.

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.