Microbiome changes in esophageal cancer: implications for pathogenesis and prognosis

The Bidirectional Impact of Cancer Radiotherapy and Human Microbiome: Microbiome as Potential Anti-tumor Treatment Efficacy and Toxicity Modulator

Microbiome and radiotherapy represent bidirectionally interacting entities. The human microbiome has emerged as a pivotal modulator of the efficacy and toxicity of radiotherapy; however, a reciprocal effect of radiotherapy on microbiome composition alterations has also been observed. This review explores the relationship between the microbiome and extracranial solid tumors, particularly focusing on the bidirectional impact of radiotherapy on organ-specific microbiome. This article aims to provide a systematic review on the radiotherapy-induced microbial alteration in-field as well as in distant microbiomes. In this review, particular focus is directed to the oral and gut microbiome, its role in the development and progression of cancer, and how it is altered throughout radiotherapy. This review concludes with recommendations for future research, such as exploring microbiome modification to optimize radiotherapy-induced toxicities or enhance its anti-cancer effects.

Role of Helicobacter pylori in esophageal carcinogenesis: Friend or foe?

In this letter, we comment on the article by López-Gómez et al, which explores the prevalence of Helicobacter pylori (H. pylori) infection among patients with esophageal carcinoma (EC) in a cohort of Spain population. The relationship between H. pylori infection and EC is very complex. Previous research results are often contradictory due to the influence of dietary habits, age, region, and other factors. López-Gómez et al reported a very low prevalence of previous H. pylori infection in their cohort of patients with EC, and most of them had previously received or concomitantly received proton pump inhibitors treatment. These results are similar to previous results, which suggest that H. pylori infection is related to the low incidence of EC. Therefore, this study may provide a direction for preventing EC and eradicating H. pylori in Spain.

Is Helicobacter pylori infection protective against esophageal cancer?

Helicobacter pylori (H. pylori) infection affects a substantial proportion of the global population and causes various gastric disorders, including gastric cancer. Recent studies have found an inverse relationship between H. pylori infection and esophageal cancer (EC), suggesting a protective role against EC. This editorial focuses on the possible mechanisms underlying the role of H. pylori infection in EC and explores the role of gut microbiota in esophageal carcinogenesis and the practicality of H. pylori eradication. EC has two major subtypes: Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), which have different etiologies and risk factors. Gut microbiota can contribute to EC via inflammation-induced carcinogenesis, immunomodulation, lactagenesis, and genotoxin production. H. pylori infection is said to be inversely related to EAC, protecting against EAC by inducing atrophic gastritis, altering serum ghrelin levels, and triggering cancer cell apoptosis. Though H. pylori infection has no significant association with ESCC, COX-2-1195 polymorphisms and endogenous nitrosamine production can impact the risk of ESCC in H. pylori-infected individuals. There are concerns regarding a plausible increase in EC after H. pylori eradication treatments. However, H. pylori eradication is not associated with an increased risk of EC, making it safe from an EC perspective.

Unravelling the role of intratumoral bacteria in digestive system cancers: current insights and future perspectives

Recently, research on the human microbiome, especially concerning the bacteria within the digestive system, has substantially advanced. This exploration has unveiled a complex interplay between microbiota and health, particularly in the context of disease. Evidence suggests that the gut microbiome plays vital roles in digestion, immunity and the synthesis of vitamins and neurotransmitters, highlighting its significance in maintaining overall health. Conversely, disruptions in these microbial communities, termed dysbiosis, have been linked to the pathogenesis of various diseases, including digestive system cancers. These bacteria can influence cancer progression through mechanisms such as DNA damage, modulation of the tumour microenvironment, and effects on the host's immune response. Changes in the composition and function within the tumours can also impact inflammation, immune response and cancer therapy effectiveness. These findings offer promising avenues for the clinical application of intratumoral bacteria for digestive system cancer treatment, including the potential use of microbial markers for early cancer detection, prognostication and the development of microbiome-targeted therapies to enhance treatment outcomes. This review aims to provide a comprehensive overview of the pivotal roles played by gut microbiome bacteria in the development of digestive system cancers. Additionally, we delve into the specific contributions of intratumoral bacteria to digestive system cancer development, elucidating potential mechanisms and clinical implications. Ultimately, this review underscores the intricate interplay between intratumoral bacteria and digestive system cancers, underscoring the pivotal role of microbiome research in transforming diagnostic, prognostic and therapeutic paradigms for digestive system cancers.

Causal relationship between gut microbiota and risk of esophageal cancer: evidence from Mendelian randomization study

BACKGROUND

The causative implications remain ambiguous. Consequently, this study aims to evaluate the putative causal relationship between gut microbiota and Esophageal cancer (EC).

METHODS

The genome-wide association study (GWAS) pertaining to the microbiome, derived from the MiBioGen consortium-which consolidates 18,340 samples across 24 population-based cohorts-was utilized as the exposure dataset. Employing the GWAS summary statistics specific to EC patients sourced from the GWAS Catalog and leveraging the two-sample Mendelian randomization (MR) methodology, the principal analytical method applied was the inverse variance weighted (IVW) technique. Cochran's Q statistic was utilized to discern heterogeneity inherent in the data set. Subsequently, a reverse MR analysis was executed.

RESULTS

Findings derived from the IVW technique elucidated that the Family Porphyromonadaceae (P = 0.048) and Genus Candidatus Soleaferrea (P = 0.048) function as deterrents against EC development. In contrast, the Genus Catenibacterium (P = 0.044), Genus Eubacterium coprostanoligenes group (P = 0.038), Genus Marvinbryantia (P = 0.049), Genus Ruminococcaceae UCG010 (P = 0.034), Genus Ruminococcus1 (P = 0.047), and Genus Sutterella (P = 0.012) emerged as prospective risk contributors for EC. To assess reverse causal effect, we used EC as the exposure and the gut microbiota as the outcome, and this analysis revealed associations between EC and seven different types of gut microbiota. The robustness of the MR findings was substantiated through comprehensive heterogeneity and pleiotropy evaluations.

CONCLUSIONS

This research identified certain microbial taxa as either protective or detrimental elements for EC, potentially offering valuable biomarkers for asymptomatic diagnosis and prospective therapeutic interventions for EC.