Esophageal Microbiome Research Articles

The paradox of Helicobacter pylori: How does H. pylori infection protect against esophageal cancer?

Helicobacter pylori is a microaerophilic gram-negative bacterium infecting around half of the world’s population. Despite its well-known role in gastric malignancies, its impact on esophageal cancer comes with a complex paradox. Several mechanisms have been proposed to explain its observed lack of carcinogenic activity in the esophagus, including the trigger of anti-inflammatory pathways, promoting atrophic gastritis, and esophageal microbiome modulation. However, recent studies have highlighted a significantly more complicated interplay, where H. pylori, typically considered a pathogen, may even deliver a protective effect against esophageal carcinogenesis. This paper aims to evaluate the prevalence of H. pylori infection among patients with esophageal carcinoma, discussing the underlying mechanisms of the paradoxical effects of H. pylori on esophageal cancer.

Lactate Suppresses Growth of Esophageal Adenocarcinoma Patient-Derived Organoids through Alterations in Tumor NADH/NAD+ Redox State.

Barrett's esophagus (BE) is a common precancerous lesion that can progress to esophageal adenocarcinoma (EAC). There are significant alterations in the esophageal microbiome in the progression from healthy esophagus to BE to EAC, including an increased abundance of a variety of lactate-producing bacteria and an increase of lactate in the tumor microenvironment, as predicted by metabolic modeling. The role of bacterial lactate in EAC is unknown. Here, we utilize patient-derived organoid (PDO) models of EAC and demonstrate that lactate inhibits the growth and proliferation of EAC PDOs through alterations in the tumor NADH/NAD+ redox state. Further RNA sequencing of EAC PDOs identifies ID1 and RSAD2 as potential regulatory molecules crucial in mediating lactate's ability to suppress glycolysis and proliferation. Gene ontology analysis also identifies the activation of inflammatory and immunological pathways in addition to alterations in the metabolic pathways in EAC PDOs exposed to lactate, suggesting a multi-faceted role for lactate in the pathogenesis of EAC.

Impact of Esophageal Motility on Microbiome Alterations in Symptomatic Gastroesophageal Reflux Disease Patients With Negative Endoscopy: Exploring the Role of Ineffective Esophageal Motility and Contraction Reserve.

Ineffective esophageal motility (IEM) is common in patients with gastroesophageal reflux disease (GERD) and can be associated with poor esophageal contraction reserve on multiple rapid swallows. Alterations in the esophageal microbiome have been reported in GERD, but the relationship to presence or absence of contraction reserve in IEM patients has not been evaluated. We aim to investigate whether contraction reserve influences esophageal microbiome alterations in patients with GERD and IEM. We prospectively enrolled GERD patients with normal endoscopy and evaluated esophageal motility and contraction reserve with multiple rapid swallows during high-resolution manometry. The esophageal mucosa was biopsied for DNA extraction and 16S ribosomal RNA gene V3-V4 (Illumina)/full-length (Pacbio) amplicon sequencing analysis. Among the 56 recruited patients, 20 had normal motility (NM), 19 had IEM with contraction reserve (IEM-R), and 17 had IEM without contraction reserve (IEM-NR). Esophageal microbiome analysis showed a significant decrease in microbial richness in patients with IEM-NR when compared to NM. The beta diversity revealed different microbiome profiles between patients with NM or IEM-R and IEM-NR (P = 0.037). Several esophageal bacterial taxa were characteristic in patients with IEM-NR, including reduced Prevotella spp. and Veillonella dispar, and enriched Fusobacterium nucleatum. In a microbiome-based random forest model for predicting IEM-NR, an area under the receiver operating characteristic curve of 0.81 was yielded. In symptomatic GERD patients with normal endoscopic findings, the esophageal microbiome differs based on contraction reserve among IEM. Absent contraction reserve appears to alter the physiology and microbiota of the esophagus.

Children with eosinophilic esophagitis non-responsive to combination therapy have distinct esophageal transcriptomic and microbiome profile.

A combination of proton-pump inhibitors (PPI) and topical steroids (TS) is used to treat children with eosinophilic esophagitis (EoE). However, a subset of children do not respond to this combination therapy. We aimed to identify the esophageal transcriptional, cell composition, and microbial differences between the non-responders (EoE-PPI-TSnr; n = 7) and responders (EoE-PPI-TSr; n = 7) to the combination therapy for EoE and controls (n = 9) using metatranscriptomics. Differential gene expression analysis was used to identify transcriptional differences, validated using the EoE diagnostic panel (EDP). Deconvolution analysis was performed to identify differences in their cell type composition. Microbiome analysis was conducted from esophageal biopsies RNAseq data, and microbial abundance was correlated with esophageal gene expression. In all, 3164 upregulated and 3154 downregulated genes distinguished EoE-PPI-TSnr from EoE-PPI-TSr. Eosinophilic inflammatory response, cytokine signaling, and collagen formation pathways were significantly upregulated in EoE-PPI-TSnr. There was a 56% overlap in dysregulated genes between EoE-PPI-TSnr and EDP, with a perfect agreement in the directionality of modulation. Eosinophils, dendritic cells (DCs), immature DCs, megakaryocytic-erythroid progenitors, and T helper type 1 cells were significantly higher in EoE-PPI-TSnr. There was no significant difference in microbiome diversity. The relative abundance of Fusobacterium sp. and Acinetobacter sp. notably differed in EoE-PPI-TSnr and correlated with the key pathways. Our results provide critical insights into the molecular, cellular, and microbial factors associated with the lack of response to PPI and TS combination therapy in children with EoE. This study advances our understanding of the pathobiology of EoE while guiding personalized treatment strategies.

Abstract 2177: Postbiotic metabolites secreted by L. acidophilus reduce DNA damage in an experimental model of Barrett’s tumorigenesis

Abstract The origins of esophageal adenocarcinoma (EAC) are commonly attributed to the progression from gastroesophageal reflux disease (GERD) to Barrett’s Esophagus (BE) and finally to esophageal adenocarcinoma. During GERD, various types of bile induce oxidative stress and generate reactive oxygen species (ROS), resulting in DNA damage and inflammation in cells. Although there has been much research documenting the shift in the esophageal microbiome from gram-positive to gram-negative bacteria during this progression, there has also been an observed increase in the presence of Lactobacillus, a gram-positive commensal bacterium with probiotic qualities, in the esophagus during the progression from GERD to BE and eventually to EAC. Our previous research has demonstrated the ability of Lactobacillus spp. to not only colonize the esophagus under in vitro conditions of GERD, but also their anti-inflammatory and anti-genotoxic properties on esophageal cells exposed to bile. To assess the extent of reflux-induced DNA damage and oxidative stress during the progression of BE, we exposed two BE cell lines, CP-B and BAR-T, and the EAC cell line FLO-1 to ox bile or deoxycholic acid. Both bile types demonstrated significant increases in phosphorylated H2AX, as a marker for pronounced DNA damage repair. Next, we supplemented both live L. acidophilus and its postbiotic metabolites to cells exposed to ox bile and deoxycholic acid. We show a significant reduction in DNA damage as measured by pH2AX with both the live treatment and the treatment with postbiotic metabolites when compared to untreated, bile-exposed cells at various stages of BE and EAC. Ongoing experiments include assessing anti-genotoxic effects of postbiotic metabolites through DNA repair protein RAD51, reductions in oxidative stress though ROS marker 8-oxo-guanine, and anti-inflammatory effects through NFkB-associated inflammation. BE and EAC cell viability and proliferation upon bile exposure and postbiotic metabolite administration will also be assessed. This study aims to determine the supplementation with Lactobacillus postbiotic metabolites in the prevention and intervention of esophageal adenocarcinoma development. Citation Format: Divya Joshi, Claudia Andl. Postbiotic metabolites secreted by L. acidophilus reduce DNA damage in an experimental model of Barrett’s tumorigenesis [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 2177.

Prebiotic proanthocyanidins inhibit bile reflux-induced esophageal adenocarcinoma through reshaping the gut microbiome and esophageal metabolome.

The gut and local esophageal microbiome progressively shift from healthy commensal bacteria to inflammation-linked pathogenic bacteria in patients with gastroesophageal reflux disease, Barrett's esophagus, and esophageal adenocarcinoma (EAC). However, mechanisms by which microbial communities and metabolites contribute to reflux-driven EAC remain incompletely understood and challenging to target. Herein, we utilized a rat reflux-induced EAC model to investigate targeting the gut microbiome-esophageal metabolome axis with cranberry proanthocyanidins (C-PAC) to inhibit EAC progression. Sprague-Dawley rats, with or without reflux induction, received water or C-PAC ad libitum (700 μg/rat/day) for 25 or 40 weeks. C-PAC exerted prebiotic activity abrogating reflux-induced dysbiosis and mitigating bile acid metabolism and transport, culminating in significant inhibition of EAC through TLR/NF-κB/TP53 signaling cascades. At the species level, C-PAC mitigated reflux-induced pathogenic bacteria (Streptococcus parasanguinis, Escherichia coli, and Proteus mirabilis). C-PAC specifically reversed reflux-induced bacterial, inflammatory, and immune-implicated proteins and genes, including Ccl4, Cd14, Crp, Cxcl1, Il6, Il1b, Lbp, Lcn2, Myd88, Nfkb1, Tlr2, and Tlr4, aligning with changes in human EAC progression, as confirmed through public databases. C-PAC is a safe, promising dietary constituent that may be utilized alone or potentially as an adjuvant to current therapies to prevent EAC progression through ameliorating reflux-induced dysbiosis, inflammation, and cellular damage.

Co-enrichment of cancer-associated bacterial taxa is correlated with immune cell infiltrates in esophageal tumor tissue

Esophageal carcinoma (ESCA) is a leading cause of cancer-related death worldwide, and certain oral and intestinal pathogens have been associated with cancer development and progression. We asked if esophageal microbiomes had shared alterations that could provide novel biomarkers for ESCA risk. We extracted DNA from tumor and non-tumor tissue of 212 patients in the NCI-MD case control study and sequenced the 16S rRNA gene (V3-4), with TCGA ESCA RNA-seq (n = 172) and WGS (n = 123) non-human reads used as validation. We identified four taxa, Campylobacter, Prevotella, Streptococcus, and Fusobacterium as highly enriched in esophageal cancer across all cohorts. Using SparCC, we discovered that Fusobacterium and Prevotella were also co-enriched across all cohorts. We then analyzed immune cell infiltration to determine if these dysbiotic taxa were associated with immune signatures. Using xCell to obtain predicted immune infiltrates, we identified a depletion of megakaryocyte-erythroid progenitor (MEP) cells in tumors with presence of any of the four taxa, along with enrichment of platelets in tumors with Campylobactor or Fusobacterium. Taken together, our results suggest that intratumoral presence of these co-occurring bacterial genera may confer tumor promoting immune alterations that allow disease progression in esophageal cancer.

The Salivary Microbiome and Predicted Metabolite Production Are Associated with Barrett's Esophagus and High-Grade Dysplasia or Adenocarcinoma.

Esophageal adenocarcinoma (EAC) is rising in incidence, and established risk factors do not explain this trend. Esophageal microbiome alterations have been associated with Barrett's esophagus (BE) and dysplasia and EAC. The oral microbiome is tightly linked to the esophageal microbiome; this study aimed to identify salivary microbiome-related factors associated with BE, dysplasia, and EAC. Clinical data and oral health history were collected from patients with and without BE. The salivary microbiome was characterized, assessing differential relative abundance of taxa by 16S rRNA gene sequencing and associations between microbiome composition and clinical features. Microbiome metabolic modeling was used to predict metabolite production. A total of 244 patients (125 non-BE and 119 BE) were analyzed. Patients with high-grade dysplasia (HGD)/EAC had a significantly higher prevalence of tooth loss (P = 0.001). There were significant shifts with increased dysbiosis associated with HGD/EAC, independent of tooth loss, with the largest shifts within the genus Streptococcus. Modeling predicted significant shifts in the microbiome metabolic capacities, including increases in L-lactic acid and decreases in butyric acid and L-tryptophan production in HGD/EAC. Marked dysbiosis in the salivary microbiome is associated with HGD and EAC, with notable increases within the genus Streptococcus and accompanying changes in predicted metabolite production. Further work is warranted to identify the biological significance of these alterations and to validate metabolic shifts. There is an association between oral dysbiosis and HGD/EAC. Further work is needed to establish the diagnostic, predictive, and causal potential of this relationship.

Barrier Dysfunction in Eosinophilic Esophagitis.

Compelling evidence over the past decade supports the central role of epithelial barrier dysfunction in the pathophysiology of eosinophilic esophagitis (EoE). The purpose of this review is to summarize the genetic, environmental, and immunologic factors driving epithelial barrier dysfunction, and how this impaired barrier can further promote the inflammatory response in EoE. Common environmental exposures, such as detergents, may have a direct impact on the esophageal epithelial barrier. In addition, the effects of IL-13 on barrier dysfunction may be reduced by 17β-estradiol, Vitamin D, and the short chain fatty acids butyrate and propionate, suggesting novel therapeutic targets. There are many genetic, environmental, and immunologic factors that contribute to epithelial barrier dysfunction in EoE. This leads to further skewing of the immune response to a "Th2" phenotype, alterations in the esophageal microbiome, and penetration of relevant antigens into the esophageal mucosa, which are central to the pathophysiology of EoE.

H influenzae LPS colocalization with Toll-like receptor 4 in eosinophilic esophagitis.

Patients with eosinophilic esophagitis (EoE) have a unique esophageal microbiome with increased presence of Haemophilus influenzae, but its role in the disease is unclear. Microbiome-derived bacterial LPS activation of Toll-like receptors (TLR) is a potential mechanism for inducing inflammation in other chronic inflammatory diseases, but it has not been studied in EoE. Our aim was therefore to study microbiome-derived bacterial LPS activation of TLRs in EoE. We studied 10 patients with active EoE, 9 patients with inactive EoE, and 10 control patients. Esophageal biopsy samples from the controls, patients with active EoE (>15 eosinophils/hpf), and patients with inactive EoE were immunostained for the presence of H influenzae LPS, presence of TLR4, and colocalization of LPS and TLR4. Staining intensity was measured by using confocal laser microscopy and scored on a scale from 0 to 3 as the average score assigned by 2 blinded observers. H influenzae LPS was detected by positive staining in 20 of the 29 patients (69.0%), including 9 of the 10 patients with active EoE (90.0%), 8 of the 9 patients with inactive EoE (89.9%), and 3 of the 10 controls (30%); its level was greater in the patients with active EoE than in the controls (P= .063). TLR4 was detected by positive staining in 19 of the 29 patients (65.5%), including 9 of the 10 patients with active EoE (90.0%), 4 of the 9 patients with inactive EoE (44.4%), and 6 of the 10 controls (60.0%); its level was higher in the patients with active EoE than in those with inactive EoE (P= .096). The result of testing for colocalization of LPS and TLR4 was positive in 8 of 10 patients with active EoE (80.0%), 1 of 9 patients with inactive EoE (11.1%), and 1 of 10 control patients (10.0%), with greater colocalization of H influenzae LPS and TLR4 staining density in the samples from patients with active EoE than in the controls or the patients with inactive EoE (P= .009 and P= .018, respectively). Esophageal microbiome-rich H influenzae LPS colocalizes to TLR4 in active EoE. These data lend further support to a role for the esophageal microbiome in modulating the activity of EoE.

Microbiome changes in esophageal cancer: implications for pathogenesis and prognosis.

Esophageal cancer (EC) is an aggressive malignancy with a poor prognosis. Various factors, including dietary habits, and antacid and antibiotic use, have been shown to influence the esophageal microbiome. Conversely, enrichment and diversity of the esophageal microbiome can also impact its function. Recent studies have revealed prevalent changes in the esophageal microbiome among patients with EC, thus suggesting the potential contribution of the esophageal microbiome to EC development. Additionally, distinct microbiome compositions have been observed in patients with different responses to radiotherapy and chemotherapy, indicating the role of the esophageal microbiome in modulating treatment outcomes. In this review, we have examined previous studies on the esophageal microbiome in healthy individuals and patients with EC or other esophageal diseases, with a focus on identifying microbial communities associated with EC pathogenesis and prognosis. Understanding the role of the microbiome in EC may aid in early detection and optimized treatment strategies, ultimately leading to better outcomes for patients.

Proton Pump Inhibitors Modulate Gene Expression Profile in Esophageal Mucosa and Microbiome.

Proton pump inhibitors (PPIs) are commonly used to manage children with upper gastrointestinal symptoms and without a formal diagnosis. We investigated the effect of PPIs on esophageal mucosal transcriptome and active microbiota in children with normal esophagi. Furthermore, we examined whether the differences in host esophageal mucosal gene expression were driven by an underlying esophageal epithelial cell type composition. Using metatranscriptomics, the host transcriptional and active microbial profiles were captured from 17 esophageal biopsy samples (PPI naïve [PPI-], n = 7; PPI exposed [PPI+], n = 10) collected from children without any endoscopic and histologic abnormalities in their esophagus (normal esophagus). Deconvolution computational analysis was performed with xCell to assess if the observed epithelial gene expression changes were related to the cell type composition in the esophageal samples. The median (IQR) age of our cohort was 14 years (12-16) with female (63%) preponderance. Both groups were similar in terms of their demographics and clinical features. Compared with PPI-, the PPI+ had upregulation of 27 genes including the MUC genes. The cell type composition was similar between the PPI- and PPI+ groups. Prevotella sp and Streptococcus sp were abundant in PPI+ group. In children with normal esophagus, PPI exposure can be associated with upregulation of esophageal mucosal homeostasis and epithelial cell function genes in a cell-type independent manner, and an altered esophageal microbiome. Additional studies are warranted to validate our findings and to investigate the causal effect of PPIs on the normal esophageal epithelium and microbial communities.

Eosinophilic esophagitis and esophageal microbiota.

Eosinophilic esophagitis (EoE) is an antigen-mediated chronic inflammatory disease of the esophagus, the prevalence of which has steadily increased in recent years. The pathogenesis of EoE is not yet well-defined; however, recent studies have demonstrated that the esophageal microbiota is an essential regulator of physiological and pathological processes of EoE. Currently, research on EoE and microbiota is an emerging field of study that is receiving increasing attention. Here, we review existing EoE-related esophageal microbiota studies to explore the potential mechanisms underlying esophageal microbiota-mediated EoE. The esophageal microbiome is altered in patients with EoE. Although α diversity is usually not significantly different, an increase in Haemophilus and a decrease in Firmicutes were observed in EoE patients. The role of microbiota in initiating and perpetuating inflammation is not fully understood. Current evidence suggests that the penetration of microbiota leads to the activation of epithelial cells as well as innate and adaptive immune cells, with the subsequent release of cytokines, leading to immune responses and inflammation. The involvement of toll-like receptors in EoE also supports the potential role of the microbiota in the progression of this disease. While EoE-induced inflammation can also lead to alterations in the local microbiome. Moreover, dietary modifications, proton pump inhibitors, and corticosteroids can modulate the esophageal microbiota; however, definitive conclusions about the alterations of microbes after treatment cannot be drawn. These findings provide promising avenues for future studies.

The Local Microbiome in Esophageal Cancer and Treatment Response: A Review of Emerging Data and Future Directions.

peer-reviewed, published studies describing the role of local, gastrointestinal-specific microbiota or the role of the gut microbiome in treatment responses were reviewed. PubMed was searched from 1 September 2022 to 1 November 2022, using the following terms in combination: "microbiome", "tumor microbiome", "esophageal cancer", "cancer", "cancer treatment", and "immunotherapy". Original research articles were considered, and other reviews or editorials were discarded. In total, approximately 250 articles were considered. over 70 studies describing microbiome research in either gastrointestinal carcinogenesis or the systemic treatment response were identified and reviewed. a growing body of evidence supports the role of the esophageal microbiome in both esophageal tumorigenesis and the immune checkpoint inhibitor response. More well-designed, comprehensive studies are required to collect the appropriate clinical, microbial, and immunophenotype data that are needed to clarify the precise role of the microbiome in esophageal carcinogenesis and treatment.

P-237 Esophageal microbiome correlates with post-esophagectomy anastomotic leak in cancer patients

P-237 Esophageal microbiome correlates with post-esophagectomy anastomotic leak in cancer patients

Characteristics of the esophageal microbiome in patients with achalasia and its changes before and after peroral endoscopic myotomy: A pilot study.

Achalasia often presents with chronic food stasis and fermentation in the esophageal lumen, which may lead to alterations of the esophageal microbiome, with associated mucosal inflammation and dysplastic changes. The study aims to evaluate the characteristics of the esophageal microbiome in achalasia and changes of the esophageal microbiome before and after peroral endoscopic myotomy (POEM). This is a prospective case-control study. This study enrolled patients with achalasia and asymptomatic subjects as control group. Endoscopic brushing for esophageal microbiome collection was performed in all subjects, with additional follow-up endoscopy and brushing 3months after POEM in achalasia patients. The composition of the esophageal microbiome was determined and compared between (1) achalasia patients and asymptomatic controls and (2) achalasia patients before and after POEM. Thirty-one achalasia patients (mean age 53.5±16.2years; male 45.2%) and 15 controls were analyzed. We observed a distinct esophageal microbial community structure in achalasia patients, with increased Firmicutes and decreased Proteobacteria when compared with the control group at the phylum level. The discriminating enriched genera in achalasia patients were Lactobacillus, followed by Megasphaera and Bacteroides, and the amount of Lactobacillus was associated with the severity of achalasia. Twenty patients were re-examined after POEM, and a high prevalence of erosive esophagitis (55%) was noted, alongside an increase in genus Neisseria and decrease in Lactobacillus and Bacteroides. The altered esophageal microenvironment in achalasia leads to dysbiosis with a high abundance of genus Lactobacillus. Increased Neisseria and decreased Lactobacillus were observed after POEM. The long-term effect of microbial changes warrants further study.

Abstract 4233: The anti-genotoxic function of Lactobacillus species in the context of bile-mediated DNA damage and inflammation in experimental models of GERD

Abstract Lactobacillus species are commensal organisms with probiotic characteristics found in the human oral cavity and gastrointestinal tract. It has been shown that gram-positive organisms, including lactobacilli, make up the majority of the microbiome in the healthy human esophagus. The general consensus is that the microbiome shifts from gram-positive to gram-negative bacteria during gastroesophageal reflux disease (GERD). In patients suffering from GERD, the esophageal tissue is injured by the low pH and bile acids present in the refluxate, resulting in Barrett’s esophagus if untreated. Interestingly, it has been reported that there is a proportional increase in gram-positive lactobacilli within the esophagus during the progression from GERD to Barrett’s esophagus, and finally esophageal adenocarcinoma. To investigate how lactobacilli are able to colonize and survive in a bile-rich environment of the esophagus during GERD, we first exposed three Lactobacillus species (L. acidophilus, L. plantarum, and L. fermentum) to cholate/deoxycholate bile salts or ox-bile as a more physiological model for human reflux. All three species exhibited bile resistance, in addition to bile adaptation after pre-exposure to sub-lethal concentrations. When assessed for changes in bacterial cell surface hydrophobicity, an indicator for bacterial adhesion to various surfaces, both bile types led to an increase of hydrophobicity in L. plantarum and L. fermentum, while L. acidophilus remained high. This provides mechanistic insight into how Lactobacillus species' attachment and colonization remain during reflux-related diseases. Next, we assessed the host-microbe interactions between lactobacilli and esophageal cells and the role these probiotic organisms may have in disease prevention. Acidic bile salts can induce inflammation and DNA damage to esophageal tissue through ROS during GERD, yet we found that the presence of lactobacilli co-cultured with bile-treated esophageal epithelial cells aids in the repair of bile-induced DNA damage in addition to NFKB reductions. To further investigate the host-microbe interactions, we supplemented epithelial cells with lactobacilli postbiotic metabolites and assessed cell viability during 48 hours of growth. Our current preliminary data show that postbiotic supplementation increases cell viability, providing insight into why lactobacilli are present within the normal and diseased human esophagus. This study demonstrates how the colonization of the esophagus during GERD with lactobacilli is based on their adaptability and survival due to changes in hydrophobicity thereby sustaining attachment. Furthermore, the anti-genotoxic and anti-inflammatory effects these organisms exhibit make them of significant interest in the prevention of Barrett’s esophagus and esophageal adenocarcinoma in patients with GERD. Citation Format: Joshua Bernard, Divya Joshi, Claudia Andl. The anti-genotoxic function of Lactobacillus species in the context of bile-mediated DNA damage and inflammation in experimental models of GERD. [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 4233.

Oral detergent exposure alters the esophageal microbiome and induces eosinophilic inflammation

Detergent exposure is a possible environmental factor recently implicated in the pathogenesis of eosinophilic esophagitis (EoE). We have shown the detergent sodium dodecyl sulfate (SDS) induces epithelial barrier dysfunction and eosinophilic inflammation in mice. We aimed to examine changes in the mouse esophageal microbiome following SDS exposure.

Esophageal cancer and bacterial part of gut microbiota - A multidisciplinary point of view.

There is an urgent need to search for new screening methods that allow early detection of esophageal cancer and thus achieve better clinical outcomes. Nowadays, it is known that the esophagus is not a sterile part of the gastrointestinal tract. It is colonized with various microorganisms therefore a "healthy" esophageal microbiome exists. The dysbiotic changes of esophageal microbiome can lead to the development of esophageal diseases including esophageal cancer. There is a strong consensus in the literature that the intestinal microbiome may be involved in esophageal carcinogenesis. Recently, emphasis has also been placed on the relationship between the oral microbiome and the occurrence of esophageal cancer. According to recent studies, some of the bacteria present in the oral cavity, such as Tannerella forsythia, Streptococcus anginosus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum may contribute to the development of this cancer. Moreover, the oral microbiome of patients with esophageal cancer differs significantly from that of healthy individuals. This opens new insights into the search for a microbiome-associated marker for early identification of patients at high risk for developing this cancer.

The microbial characteristics of patients with esophageal squamous cell carcinoma after chemotherapy and after immunotherapy.

e16049 Background: Esophageal squamous cell carcinoma (ESCC) is a common malignancy without effective therapy. Previous studies have shown that chemotherapy and immunotherapy is affected by esophageal microbiome. The effect of esophageal microbiota on the efficacy of chemotherapy and immunotherapy for ESCC remain poorly understood. Methods: DNA was extracted from blood, oral mucosal, saliva, urine, fecal samples from 14 ESCC patients after chemotherapy and 18 ESCC patients after immunotherapy. Total microbial genomic DNA samples were extracted using an OMEGA Soil DNA Kit (D5625-01). The V3–V4 regions of bacterial 16S rRNA genes were amplified by PCR using the forward primer and the reverse primer and were sequenced with Illumina MiSeq platform. In order to comprehensively evaluate the α diversity of microbial communities, we used Chao1 and Observed Species indices to characterize the richness, Shannon and Simpson indices to characterize the diversity. PCoA were used to analyze differences in β diversity. Functions of 16S rRNA sequences were predicted using the PICRUSt2 and KEGG databases. Results: The α diversity in patients with ESCC after immunotherapy were higher than those in patients with ESCC after chemotherapy. There was a statistically significant difference in β diversities between ESCC patients after chemotherapy and ESCC patients after immunotherapy. In terms of the microbial functions in ESCC patients after chemotherapy and immunotherapy, the metabolic pathways accounted for the most. Conclusions: This study is conducive to exploring new mechanisms for tumor cells to evade host immune surveillance, providing new ideas and new strategies for the microecology-based therapy of ESCC.