Gastric Microbiota Gender Differences in Subjects with Healthy Stomachs and Autoimmune Atrophic Gastritis

Gender Differences in Quality of Bowel Preparation for Colonoscopy: Post Hoc Analysis of a Randomized Controlled Trial

OBJECTIVE

Bowel cleansing is a key element for a quality colonoscopy. Despite recent advances, not all predictors of successful cleansing are fully known. This post hoc analysis of an RCT aims to explore gender differences in bowel cleansing quality.

METHODS

The "OVER" trial was a multicenter phase-4 RCT including 478 patients randomized 1:1 to receive split-dose 1L polyethylene glycol plus ascorbate (PEG+ASC) or 4L-PEG. In this post hoc analysis, multivariable logistic regression models were designed to assess predictors of cleansing success (CS) and adenoma detection rate (ADR) by gender.

RESULTS

Of the 478 randomized patients, 50.2% were males and 49.8% females.Overall, CS was comparable between females and males (87.1% vs 88.4, P = 0 .6), whereas CS in the right (95.7% vs 90.9, P = 0.049) and transverse colon (98.6% vs 93.9, P =0.011) was significantly higher in females.At multivariable regression analysis for CS outpatient setting (OR = 5.558) and higher withdrawal time (OR = 1.294) were independently associated with CS in females, whereas screening/surveillance indication (OR = 6.776) was independently associated with CS in males.At multivariable regression analysis for ADR, running time <5 hours (OR = 3.014) and higher withdrawal time (OR = 1.250) were independently associated with ADR in females, whereas older age (OR = 1.040) and higher withdrawal time (OR = 1.093) were independently associated with ADR in males.

CONCLUSIONS

This study showed different results in bowel preparation quality and different predictors of CS and ADR by gender. These findings suggest the need for further research to explore gender-specific approaches for bowel preparation.

Role of Mushroom Polysaccharides in Modulation of GI Homeostasis and Protection of GI Barrier

Edible and medicinal mushroom polysaccharides (EMMPs) have been widely studied for their various biological activities. It has been shown that EMMPs could modulate microbiota in the large intestine and improve intestinal health. However, the role of EMMPs in protecting the gastric barrier, regulating gastric microbiota, and improving gastric health cannot be ignored. Hence, this review will elucidate the effect of EMMPs on gastric and intestinal barriers, with emphasis on the interaction of EMMPs with microbiota in maintaining overall gastrointestinal health. Additionally, this review highlights the gastroprotective effects and underlying mechanisms of EMMPs against gastric mucosa injury, gastritis, gastric ulcer, and gastric cancer. Furthermore, the effects of EMMPs on intestinal diseases, including inflammatory bowel disease, colorectal cancer, and intestinal infection, are also summarized. This review will also discuss the future perspective and challenges in the use of EMMPs as a dietary supplement or a nutraceutical in preventing and treating gastrointestinal diseases.

Dysbiosis of the Upper Gastrointestinal Tract in Head-and-Neck Cancer Survivors: A Pilot Study Using the Capsule Sponge Device

BACKGROUND

A non-endoscopic capsule-sponge device allows sampling the entire length of the esophagus. Here, we compared microbiomes of the oral cavity, esophagus, and gastric corpus collected by oral swab, capsule-sponge device, and endoscopic biopsy, respectively, in patients representing three distinct risk profiles for esophageal squamous cell carcinoma (ESCC).

METHODS

The study enrolled 11 patients with esophageal squamous intraepithelial neoplasia, 21 patients after curative treatment for head and neck squamous cell cancer (HNSCC) (HNSCC survivors), and 40 patients with functional dyspeptic (FD) symptoms. Microbial genomic DNA was analyzed using 16S rRNA gene amplicon sequencing.

RESULTS

The Shannon index of the capsule-sponge sample microbiota was significantly higher in FD group than in patients after treatment for HNSCC, and the Chao index of gastric samples differed between HNSCC survivors and FD patients. Analysis of the β-diversity of FD patients, HNSCC, and esophageal squamous intraepithelial neoplasia showed that different genera formed at each location. The abundance of 205, 116, and 9 genera differed between FD patients and HNSCC survivors in the gastric, capsule-sponge, and oral samples, respectively; 33 genera differed between the FD group and patients with esophageal squamous intraepithelial neoplasia in capsule-sponge samples.

CONCLUSIONS

The bacterial communities of the upper digestive tract were clustered according to the anatomic site. Despite substantial differences in gastric and esophageal microbiota samples between FD patients and HNSCC survivors, the microbial members and diversity showed small differences between FD patients and those with esophageal squamous intraepithelial neoplasia. It remains unclear whether gastric and esophageal dysbiosis is associated with or is a consequence of treatment for HNSCC.

Autoimmune gastritis studies and gastric cancer: True renaissance or bibliometric illusion

A bibliometric analysis of studies dedicated to autoimmune gastritis (AIG) recently published demonstrated a noteworthy surge in publications over the last three years. This can be explained by numerous publications from different regions of the world reporting the results of several studies that stimulated reassessment of our view of AIG as a precancerous condition. Follow-up studies and retrospective analyses showed that the risk of gastric cancer (GC) in AIG patients is much lower than expected if the patients ever being infected with Helicobacter pylori (H. pylori) were excluded. The low prevalence of precancerous lesions, such as the incomplete type of intestinal metaplasia, may explain the low risk of GC in AIG patients because the spasmolytic polypeptide-expressing metaplasia commonly observed in AIG does not involve clonal reprogramming of the gastric gland and can be considered as an adaptive change rather than a true precancerous lesion. However, changes in gastric secretion due to the progression of gastric atrophy during the course of AIG cause changes in the gastric mic-robiome, stimulating the growth of bacterial species such as streptococci, which may promote the development of precancerous lesions and GC. Thus, Streptococcus anginosus exhibited a robust proinflammatory response and induced the gastritis-atrophy-metaplasia-dysplasia sequence in mice, reproducing the well-established process for carcinogenesis associated with H. pylori. Prospective studies in H. pylori-naïve patients evaluating gastric microbiome changes during the long-term course of AIG might provide an explanation for the enigmatic increase in GC incidence in the last decades in younger cohorts, which has been reported in economically developed countries.

Autoimmune Gastritis and Hypochlorhydria: Known Concepts from a New Perspective

Autoimmune atrophic gastritis is an immune-mediated disease resulting in autoimmune destruction of the specialized acid-producing gastric parietal cells. As a consequence, in autoimmune atrophic gastritis, gastric acid secretion is irreversibly impaired, and the resulting hypochlorhydria leads to the main clinical manifestations and is linked, directly or indirectly, to the long-term neoplastic complications of this disease. In the last few years, autoimmune atrophic gastritis has gained growing interest leading to the acquisition of new knowledge on different aspects of this disorder. Although reliable serological biomarkers are available and gastrointestinal endoscopy techniques have substantially evolved, the diagnosis of autoimmune atrophic gastritis is still affected by a considerable delay and relies on histopathological assessment of gastric biopsies. One of the reasons for the diagnostic delay is that the clinical presentations of autoimmune atrophic gastritis giving rise to clinical suspicion are very different, ranging from hematological to neurological-psychiatric up to gastrointestinal and less commonly to gynecological-obstetric symptoms or signs. Therefore, patients with autoimmune atrophic gastritis often seek advice from physicians of other medical specialties than gastroenterologists, thus underlining the need for increased awareness of this disease in a broad medical and scientific community.