Changes in the gut microbiome in relation to the degree of gastric mucosal atrophy before and after Helicobacter pylori eradication

The association between oral microbiome and gastric precancerous lesions

Gastric precancerous lesions are thought to be precursors in the occurrence and development of gastric cancer through Correa's cascade. Recent studies have investigated the association between the oral microbiome and gastric precancerous lesions. However, there has yet to be a comprehensive synthesis review of the existing literature on the relationship between oral microbiome and gastric precancerous lesions. A systematic review was conducted to characterize the literature on the association between oral microbiome and gastric precancerous lesions. The studies show that oral microbiome is dynamic in individuals with gastric precancerous lesions. Oral-derived microorganisms were colonized in the gastric precancerous lesions. Interactions between oral and gastric microbiomes affect the response of the host immunity. The abnormal proliferation of oral-associated microorganisms may be linked to the reduction of gastric acid. The present review supports the potential association between oral microbiome and gastric precancerous lesions. However, the interactions are complex and multifaceted, which require further investigation.

Histopathological staging of atrophic lesions of gastric mucosa

Objective

To study the histopathological staging of atrophic lesions of the gastric mucosa.

Methods

Histology and immunohistochemistry were used to closely examine 2144 specimens of atrophic gastric mucosa that were taken from endoscopic biopsies.

Results

When the gastric mucosa epithelium is affected by infection, chemical stimulation, immune factors, genetic factors, and other factors, it may cause an atrophy of gastric mucosa epithelium and a decrease in the number of glands, intestinal metaplasia, hyperplasia of smooth muscle fibers, and atrophy of stem cells in the proliferative zone. In this study, we characterized the above lesions as atrophic lesions of the gastric mucosa. Based on the morphological and histological characteristics of the lesion, as well as the law of cell proliferation and transformation during its occurrence and development, we propose five stages. We also noted the onset age, gender correlation, and histopathological characteristics of each stage of gastric mucosal atrophies.

Conclusion

Understanding the pathological staging of gastric mucosal atrophy is essential for treating patients correctly and keeping track of changes in malignant cells. It is also very important in preventing the initiation of gastric cancer or from getting worse.

Effect of potassium-competitive acid blockers on human gut microbiota: a systematic review and meta-analysis

Background: Vonoprazan has been reported to exert more potent and long-lasting gastric acid inhibition than proton pump inhibitors, potentially leading to a greater impact on the gut microbiota. This study aimed to clarify changes in microbial diversity and bacterial composition after VPZ treatments. Methods: We searched from PubMed, Embase, WOS, Scopus, Cochrane Library, and ClinicalTrials.gov (all years up to May 2023). The primary outcomes were alpha and beta diversity, as well as differences in gut microbiota composition between before and after VPZ treatments. We performed a meta-analysis to uncover the potential changes in human gut microbiota among VPZ users by pooled mean difference (MD) with a 95% confidence interval (CI). The risk of bias was assessed using the ROBINS-I tool. Results: A total of 12 studies were included to compare differences before and after VPZ treatments. Compared with baseline, alpha diversity was significantly reduced after VPZ treatments and gradually returned to baseline with longer follow-up. At the phylum level, there was a decrease in the relative abundance of Firmicutes and Actinobacteria, while Bacteroidetes increased compared with baseline. At the genus level, we found a significant decrease in the relative abundance of Coprococcus and Bifidobacterium and a significant increase in the relative abundance of Bacteroides compared with those before treatment. In subgroup analyses according to country and participants, we found differences in microbial changes after VPZ treatments. Conclusion: Vonoprazan can affect the changes of gut microbiota, which may be potentially associated with its strong ability of acid inhibition. However, due to the large heterogeneity, further studies are required to validate these findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023412265.