Duodenal microbiome in patients with or without Helicobacter pylori infection

Impacts of Helicobacter pylori infection and eradication on gastrointestinal microbiota: An up-to-date critical review and future perspectives

ABSTRACT

Helicobacter pylori ( H. pylori ) infects approximately half of the population worldwide and causes chronic gastritis, peptic ulcers, and gastric cancer. Test-and-treat strategies have been recommended for the prevention of H. pylori -associated diseases. Advancements in high-throughput sequencing technologies have broadened our understanding of the complex gastrointestinal (GI) microbiota and its role in maintaining host homeostasis. Recently, an increasing number of studies have indicated that the colonization of H. pylori induces dramatic alterations in the gastric microbiota, with a predominance of H. pylori and a reduction in microbial diversity. Dysbiosis of the gut microbiome has also been observed after H. pylori infection, which may play a role in the development of colorectal cancer. However, there is concern regarding the impact of antibiotics on the gut microbiota during H. pylori eradication. In this review, we summarize the current literature concerning how H. pylori infection reshapes the GI microbiota and the underlying mechanisms, including changes in the gastric environment, immune responses, and persistent inflammation. Additionally, the impacts of H. pylori eradication on GI microbial homeostasis and the use of probiotics as adjuvant therapy are also discussed. The shifts in the GI microbiota and their crosstalk with H. pylori  may provide potential targets for H. pylori -related gastric diseases and extragastric manifestations.

Combination of Simo Decoction and Golden Bifid alleviates functional dyspepsia through a mechanism involving intestinal microbiota and short-chain fatty acids

BACKGROUND AND STUDY AIMS

The integration of traditional Chinese medicine and Western medicine holds promise for the treatment of gastrointestinal disorders, which are influenced by intestinal microbiota and metabolites. This study reports a possible mechanism for the combination of Simo Decoction and Golden Bifid in functional dyspepsia (FD) by regulating intestinal microbiota and short-chain fatty acids (SCFAs).

PATIENTS AND METHODS

A mouse model of food stagnation was constructed and treated with Simo Decoction combined with different concentrations of Golden Bifid. Meta-genomics sequencing was conducted to analyze the cecum contents of the mice. Following analyses of the composition and abundance of intestinal microbiota, gas chromatography-mass spectrometry was performed to measure SCFAs in the colonic content of mice. Finally, ELISA was utilized to determine the levels of pro-inflammatory factors in the duodenal mucosa of mice and the infiltration of eosinophils in the duodenum was observed by immunohistochemical staining.

RESULTS

Combination of Simo Decoction and Golden Bifid more significantly alleviated dyspepsia in mice with food stagnation compared with Simo Decoction alone. The optimal ratio of combined treatment was 0.0075 mL/g (body weight) Simo Decoction and 0.0032 mg/g (body weight) Golden Bifid. The combined treatment increased the abundance of Bifidobacterium and Bacteroides in the intestine. The levels of SCFAs in the colonic contents of mice were increased after the combined treatment, contributing to diminished pro-inflammatory factors in the duodenal mucosa and reduced eosinophil infiltration.

CONCLUSION

Combination of Simo Decoction and Golden Bifid increases the abundance of Bacteroides and Bifidobacterium and promotes the production of SCFAs, which is instrumental for alleviation of FD.

Alterations of the duodenal mucosal microbiome in patients with metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is associated with altered gut microbiota; however, there has been a focus on fecal samples, which are not representative of the entire digestive tract. Mucosal biopsies of the descending duodenum were collected. Five regions of the 16S rRNA gene were amplified and sequenced. Other assessments conducted on the study subjects included body mass index, transient elastography, liver enzymes, and lipid profile. Fifty-one subjects (36 with MASLD and 15 controls) were evaluated. There was no significant difference between the two groups regarding alpha- or beta-diversity of the duodenal mucosal microbiota. Linear discriminant analysis effect size (LEfSe) analysis showed that the genera Serratia and Aggregatibacter were more abundant in the duodenal mucosa of patients with MASLD, whereas the duodenal mucosal microbiota of the healthy controls was enriched with the genus Petrobacter. PICRUSt2 analysis revealed that genes associated with amino acid degradation and carboxylate degradation were significantly enriched in the duodenal mucosal microbiota of patients with MASLD. Our findings reveal the duodenal mucosal microbiota in patients with MASLD, which could contribute to future studies investigating the causal relationship between duodenal microbiota and MASLD.

Therapeutic Approach Targeting Gut Microbiome in Gastrointestinal Infectious Diseases

While emerging evidence highlights the significance of gut microbiome in gastrointestinal infectious diseases, treatments like Fecal Microbiota Transplantation (FMT) and probiotics are gaining popularity, especially for diarrhea patients. However, the specific role of the gut microbiome in different gastrointestinal infectious diseases remains uncertain. There is no consensus on whether gut modulation therapy is universally effective for all such infections. In this comprehensive review, we examine recent developments of the gut microbiome's involvement in several gastrointestinal infectious diseases, including infection of Helicobacter pylori, Clostridium difficile, Vibrio cholerae, enteric viruses, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa Staphylococcus aureus, Candida albicans, and Giardia duodenalis. We have also incorporated information about fungi and engineered bacteria in gastrointestinal infectious diseases, aiming for a more comprehensive overview of the role of the gut microbiome. This review will provide insights into the pathogenic mechanisms of the gut microbiome while exploring the microbiome's potential in the prevention, diagnosis, prediction, and treatment of gastrointestinal infections.

Duodenal microbiota and weight-loss following sleeve gastrectomy and Roux-en-Y gastric bypass - a pilot study

BACKGROUND

Bariatric surgery is the most effective method of morbid obesity treatment. Microbiota has many functions in human body and many of them remain to be unknown. The aim of this study was to establish if the composition of duodenal microbiota influences success rate of bariatric surgery.

METHODS

It was a prospective cohort study. The data concerning demographics and comorbidities was collected perioperatively. The duodenal biopsies were collected prior to surgery with the gastroscope. Then DNA analysis was conducted. The data connected to the operation outcomes was gathered after 6 and 12 months after surgery.

RESULTS

Overall, 32 patients were included and divided into two groups (successful - group 1 and unsuccessful - group 0) based on percentage excess weight loss after 6 months were created. The Total Actual Abundance was higher in group 0. In group 0 there was a significantly higher amount of Roseburia and Arthrobacter (p = 0.024, p = 0.027, respectively). Genus LDA effect size analysis showed Prevotella, Megasphaera and Pseudorhodobacter in group 1 to be significant. Whereas abundance of Roseburia and Arthrobacter were significant in group 0.

CONCLUSIONS

Duodenal microbiota composition may be a prognostic factor for the success of the bariatric surgery but further research on the larger group is needed.

The emerging role of the small intestinal microbiota in human health and disease

The human gut microbiota continues to demonstrate its importance in human health and disease, largely owing to the countless number of studies investigating the fecal microbiota. Underrepresented in these studies, however, is the role played by microbial communities found in the small intestine, which, given the essential function of the small intestine in nutrient absorption, host metabolism, and immunity, is likely highly relevant. This review provides an overview of the methods used to study the microbiota composition and dynamics along different sections of the small intestine. Furthermore, it explores the role of the microbiota in facilitating the small intestine in its physiological functions and discusses how disruption of the microbial equilibrium can influence disease development. The evidence suggests that the small intestinal microbiota is an important regulator of human health and its characterization has the potential to greatly advance gut microbiome research and the development of novel disease diagnostics and therapeutics.

CagA+Helicobacter pylori, Not CagA–Helicobacter pylori, Infection Impairs Endothelial Function Through Exosomes-Mediated ROS Formation

Background

Helicobacter pylori (H. pylori) infection increases the risk for atherosclerosis, and ROS are critical to endothelial dysfunction and atherosclerosis. CagA is a major H. pylori virulence factor associated with atherosclerosis. The present study aimed to test the hypothesis that CagA+H. pylori effectively colonizes gastric mucosa, and CagA+H. pylori, but not CagA–H. pylori, infection impairs endothelial function through exosomes-mediated ROS formation.

Methods

C57BL/6 were used to determine the colonization ability of CagA+H. pylori and CagA–H. pylori. ROS production, endothelial function of thoracic aorta and atherosclerosis were measured in CagA+H. pylori and CagA–H. pylori infected mice. Exosomes from CagA+H. pylori and CagA–H. pylori or without H. pylori infected mouse serum or GES-1 were isolated and co-cultured with bEND.3 and HUVECs to determine how CagA+H. pylori infection impairs endothelial function. Further, GW4869 was used to determine if CagA+H. pylori infection could lead to endothelial dysfunction and atherosclerosis through an exosomes-mediated mechanism.

Results

CagA+H. pylori colonized gastric mucosa more effectively than CagA–H. pylori in mice. CagA+H. pylori, not CagA–H. pylori, infection significantly increased aortic ROS production, decreased ACh-induced aortic relaxation, and enhanced early atherosclerosis formation, which were prevented with N-acetylcysteine treatment. Treatment with CagA-containing exosomes significantly increased intracellular ROS production in endothelial cells and impaired their function. Inhibition of exosomes secretion with GW4869 effectively prevented excessive aortic ROS production, endothelial dysfunction, and atherosclerosis in mice with CagA+H. pylori infection.

Conclusion

These data suggest that CagA+H. pylori effectively colonizes gastric mucosa, impairs endothelial function, and enhances atherosclerosis via exosomes-mediated ROS formation in mice.

The double-edged sword of probiotic supplementation on gut microbiota structure in Helicobacter pylori management

As Helicobacter pylori management has become more challenging and less efficient over the last decade, the interest in innovative interventions is growing by the day. Probiotic co-supplementation to antibiotic therapies is reported in several studies, presenting a moderate reduction in drug-related side effects and a promotion in positive treatment outcomes. However, the significance of gut microbiota involvement in the competence of probiotic co-supplementation is emphasized by a few researchers, indicating the alteration in the host gastrointestinal microbiota following probiotic and drug uptake. Due to the lack of long-term follow-up studies to determine the efficiency of probiotic intervention in H. pylori eradication, and the delicate interaction of the gut microbiota with the host wellness, this review aims to discuss the gut microbiota alteration by probiotic co-supplementation in H. pylori management to predict the comprehensive effectiveness of probiotic oral administration.Abbreviations: acyl-CoA- acyl-coenzyme A; AMP- antimicrobial peptide; AMPK- AMP-activated protein kinase; AP-1- activator protein 1; BA- bile acid; BAR- bile acid receptor; BCAA- branched-chain amino acid; C2- acetate; C3- propionate; C4- butyrate; C5- valeric acid; CagA- Cytotoxin-associated gene A; cAMP- cyclic adenosine monophosphate; CD- Crohn's disease; CDI- C. difficile infection; COX-2- cyclooxygenase-2; DC- dendritic cell; EMT- epithelial-mesenchymal transition; FMO- flavin monooxygenases; FXR- farnesoid X receptor; GPBAR1- G-protein-coupled bile acid receptor 1; GPR4- G protein-coupled receptor 4; H2O2- hydrogen peroxide; HCC- hepatocellular carcinoma; HSC- hepatic stellate cell; IBD- inflammatory bowel disease; IBS- irritable bowel syndrome; IFN-γ- interferon-gamma; IgA immunoglobulin A; IL- interleukin; iNOS- induced nitric oxide synthase; JAK1- janus kinase 1; JAM-A- junctional adhesion molecule A; LAB- lactic acid bacteria; LPS- lipopolysaccharide; MALT- mucosa-associated lymphoid tissue; MAMP- microbe-associated molecular pattern; MCP-1- monocyte chemoattractant protein-1; MDR- multiple drug resistance; mTOR- mammalian target of rapamycin; MUC- mucin; NAFLD- nonalcoholic fatty liver disease; NF-κB- nuclear factor kappa B; NK- natural killer; NLRP3- NLR family pyrin domain containing 3; NOC- N-nitroso compounds; NOD- nucleotide-binding oligomerization domain; PICRUSt- phylogenetic investigation of communities by reconstruction of unobserved states; PRR- pattern recognition receptor; RA- retinoic acid; RNS- reactive nitrogen species; ROS- reactive oxygen species; rRNA- ribosomal RNA; SCFA- short-chain fatty acids; SDR- single drug resistance; SIgA- secretory immunoglobulin A; STAT3- signal transducer and activator of transcription 3; T1D- type 1 diabetes; T2D- type 2 diabetes; Th17- T helper 17; TLR- toll-like receptor; TMAO- trimethylamine N-oxide; TML- trimethyllysine; TNF-α- tumor necrosis factor-alpha; Tr1- type 1 regulatory T cell; Treg- regulatory T cell; UC- ulcerative colitis; VacA- Vacuolating toxin A.

Interactions between H. pylori and the Gastric Microbiome: Impact on Gastric Homeostasis and Disease

Like many seemingly inhospitable environments on our planet, the highly acidic human stomach harbors a diverse bacterial microflora. The best-known member of the human gastric flora, Helicobacter pylori, causes a number of gastric diseases, including peptic ulcer disease and gastric adenocarcinoma. In the absence of Helicobacter pylori infection, the gastric microbiota displays some features similar to the oral cavity with Firmicutes the most common phylum, followed by Proteobacteria and Bacteroidetes. When present, H. pylori dominates the gastric microbiome and reduces diversity and composition of other taxa. The composition of the gastric microbiome also is altered in the setting of proton pump inhibitor therapy and gastric neoplasia. This review summarizes foundational and recent studies that have investigated the composition of the human gastric microbiome in a variety of patient groups, with a focus on potential mechanisms involved in regulation of gastric microbial community structure.