Candida albicans aggravates duodenal ulcer perforation induced by administration of cysteamine in rats

Causal effect of gut microbiota on Gastroduodenal ulcer: a two-sample Mendelian randomization study

Background

Gastroduodenal ulcers are associated with Helicobacter pylori infection and the use of nonsteroidal anti-inflammatory drugs (NSAIDs). However, the causal relationship between gastroduodenal ulcers and gut microbiota, especially specific gut microbiota, remains unclear.

Methods

We conducted an analysis of published data on the gut microbiota and Gastroduodenal ulcer using genome-wide association studies (GWAS). Two-sample Mendelian randomization (MR) analysis was performed to determine the causal relationship between gut microbiota and Gastroduodenal ulcer. Sensitivity, heterogeneity, and pleiotropy analyses were conducted to confirm the accuracy of the research findings.

Results

Our study showed that the abundance of Enterobacteriaceae, Butyricicoccus, Candidatus Soleaferrea, Lachnospiraceae NC2004 group, Peptococcus, and Enterobacteriales was negatively correlated with the risk of Gastroduodenal ulcer. Conversely, the abundance of Streptococcaceae, Lachnospiraceae UCG010, Marvinbryantia, Roseburia, Streptococcus, Mollicutes RF9, and NB1n was positively correlated with the risk of Gastroduodenal ulcer. MR analysis revealed causal relationships between 13 bacterial genera and Gastroduodenal ulcer.

Conclusion

This study represents a groundbreaking endeavor by furnishing preliminary evidence regarding the potentially advantageous or detrimental causal link between the gut microbiota and Gastroduodenal ulcer, employing Mendelian Randomization (MR) analysis for the first time. These discoveries have the potential to yield fresh perspectives on the prevention and therapeutic approaches concerning Gastroduodenal ulcer, with a specific focus on the modulation of the gut microbiota.

Sodium houttuyfonate attenuates dextran sulfate sodium associated colitis precolonized with Candida albicans through inducing β-glucan exposure

Inflammatory bowel disease (IBD) including Crohn's disease and ulcerative colitis is a chronic intestinal disease most likely associated with gut dysbiosis. Candida related mycobiota has been demonstrated to play a role in IBD progression. Traditional Chinese herbal medicines (TCHMs) with antifungal activity have a potential in prevention and treatment of fungi-related IBD. Sodium houttuyfonate (SH) is a promising anti-Candida TCHMs. In this study, a dextran sulfate sodium induced colitis model with Candida albicans precolonization is established. SH gavage can significantly decrease the fungal burdens in feces and colon tissues, reduce disease activity index score, elongate colon length, and attenuate colonic damages. Moreover, SH markedly inhibits the levels of anti-Saccharomyces cerevisiae antibodies, β-glucan, and proinflammatory cytokine (IL-1β, IL-6, IL-8, TNF-α), and increases anti-inflammatory factor IL-10 level in serum and colon tissue. Further experiments demonstrate that SH could induce β-glucan exposure, priming intestinal macrophages to get rid of colonized C. albicans through the collaboration of Dectin-1 and TLR2/4. With the decreased fungal burden, the protein levels of Dectin-1, TLR2, TLR4, and NF-κBp65 are fallen back, indicating the primed macrophages calm down and the colitis is alleviated. Collectively, these results manifest that SH can attenuate C. albicans associated colitis via β-glucan exposure, deepening our understanding of TCHMs in the prevention and treatment of fungi associated IBD.

Colonic mucosa-associated candida assessed by biopsy culture is associated with disease severity in ulcerative colitis: A prospective study

OBJECTIVE

To evaluate the relationship of mucosa-associated candida (MAC) and disease severity in patients with ulcerative colitis (UC).

METHODS

We prospectively investigated the presence, nature, and quantification of MAC in patients with UC and its relationship with disease severity. Consecutive patients with UC were assessed for clinical, endoscopic, histological features and serum markers of disease severity. All patients underwent mucosal brushing cytology, brushing culture, and biopsy culture for candida growth. MAC was considered present if mucosal biopsy culture grew candida. Candida spp. identification was performed by matrix-assisted laser desorption/ionization. Serum β-D-glucan was measured with a Fungitell assay. Patients with irritable bowel syndrome who had undergone similar investigations were included as controls.

RESULTS

Ninety-six patients with UC showed evidence of MAC more often than the controls (n = 20) based on biopsy culture (33.3% vs 5.0%, P = 0.011), brush cytology (30.2% vs 5.0%, P = 0.019), and brush culture (36.5% vs 10.0%, P = 0.021). Patients with UC had higher candida colony counts (≥10³ CFU/mL) than controls (34.4% vs 5.0%, P = 0.007). Median β-D-glucan values were higher in patients with UC than in controls (103.26 pg/mL vs 66.51 pg/mL, P = 0.011). The UC group with MAC had a higher median total Mayo score, C-reactive protein, fecal calprotectin, β-D-glucan, and histological activity than those without MAC.

CONCLUSIONS

Patients with UC more often show evidence of MAC and a higher candida colony count than controls. The presence of MAC is associated with high disease severity in patients with UC.

Inflammation and gastrointestinal Candida colonization

Candida organisms commonly colonize the human gastrointestinal tract as a component of the resident microbiota. Their presence is generally benign. Recent studies, however, show that high level Candida colonization is associated with several diseases of the gastrointestinal tract. Further, results from animal models argue that Candida colonization delays healing of inflammatory lesions and that inflammation promotes colonization. These effects may create a vicious cycle in which low-level inflammation promotes fungal colonization and fungal colonization promotes further inflammation. Both inflammatory bowel disease and gastrointestinal Candida colonization are associated with elevated levels of the pro-inflammatory cytokine IL-17. Therefore, effects on IL-17 levels may underlie the ability of Candida colonization to enhance inflammation. Because Candida is a frequent colonizer, these effects have the potential to impact many people.