Review article: The complex interplay between diet and Escherichia coli in inflammatory bowel disease

Genetic insights into the gut microbiota, herpes zoster, and postherpetic neuralgia: a bidirectional two-sample Mendelian randomization study

Background

An increasing amount of evidence suggests that gastrointestinal diseases are risk factors for herpes zoster (HZ) and postherpetic neuralgia (PHN). Among them, the gut microbiota may play a crucial role in this process. Therefore, this study aims to explore the potential causal association between the gut microbiota and HZ and PHN.

Methods

Bidirectional two-sample Mendelian randomization (MR) analysis was used to detect the causal effect between HZ and PHN and the gut microbiota. Gut microbiota data were derived from the MiBioGen consortium, while HZ and PHN data were obtained from the FinnGen database. We selected single-nucleotide polymorphisms (SNPs) as instrumental variables with a threshold of p < 1 × 10⁻⁵ for the association with the gut microbiota in forward MR analysis and p < 5 × 10⁻8 for the association with HZ or PHN in reverse MR analysis and then removed SNPs in linkage disequilibrium (r 2 < 0.001) within a distance of 10,000 kb for both the gut microbiota and HZ and PHN. These SNPs were utilized to assess the causal effect between exposures and outcomes using inverse-variance weighting (IVW), MR-Egger, weighted mean, and weighted median tests.

Results

The class Deltaproteobacteria, order Desulfovibrionales, family Desulfovibrionaceae, and genus Coprococcus 2 were found to reduce the risk of HZ, while the phylum Cyanobacteria, genus Eubacterium rectale group appeared to increase it. The class Coriobacteriia, order Coriobacteriales, family Coriobacteriaceae, genus Lachnospiraceae NK4A136 and genus Ruminococcaceae UCG011 were found to reduce the risk of PHN, while the genus Candidatus Soleaferrea, genus Eubacterium rectale group, and genus Methanobrevibacter appeared to increase it. Moreover, the onset of HZ was found to increase the level of the genus Eubacterium rectale group. These findings remained robust and unaffected by heterogeneity or horizontal pleiotropy among SNPs in both forward and reverse MR analysis.

Conclusion

This MR study provided evidence supporting a potential causal relationship between the gut microbiota and HZ and PHN. Moreover, we found that the causal effect between the gut microbiota and HZ is bidirectional. Further studies are required to clarify the biological mechanisms linking the gut microbiota and these conditions.

Letter: Diet-microbiome interactions in inflammatory bowel disease-Navigating towards individualised dietary strategies

This article is linked to Faqerah et al paper. To view this article, visit https://doi.org/10.1111/apt.17720

Probiotics for inflammatory bowel disease: Is there sufficient evidence?

Inflammatory bowel disease (IBD) refers to chronic inflammatory disorders of the gut. Ulcerative colitis (UC) and Crohn's disease (CD) are two subtypes of IBD. Evidence suggests that the intestinal microbiota plays a role in the pathogenesis of IBD, so probiotics have garnered a lot of interest as a potential treatment or prevention for IBD. However, clinical evidence of the efficacy of probiotics is still debatable. We performed a literature review. An advanced search considered clinical studies on probiotic for IBD from inception to 2023 in PubMed, Embase, Cochrane Library, and Web of Science. In the treatment of UC with probiotics, only Escherichia coli Nissle 1917 for maintenance treatment of UC in remission, and Bifidobacterium and VSL#3 for induction of remission in patients with mild to moderately active UC have shown strong evidence. Currently, there are no definitive conclusions regarding the effectiveness of probiotics in CD. The mechanism of probiotic treatment for IBD may be related to reducing oxidative stress, repairing the intestinal barrier, regulating intestinal flora balance, and modulating intestinal immune response. Differences in the benefits of probiotics between CD and UC may be attributable to the different lesion extent and immune-mediated pathophysiology. More robust randomized clinical trials are required to validate the efficacy and safety of diverse probiotic strains in IBD.

Interaction between diet and genetics in patients with inflammatory bowel disease

In this editorial, we comment on the article by Marangoni et al, published in the recent issue of the World Journal of Gastroenterology 2023; 29: 5618-5629, about "Diet as an epigenetic factor in inflammatory bowel disease". The authors emphasized the role of diet, especially the interaction with genetics, in promoting the inflammatory process in inflammatory bowel disease (IBD) patients, focusing on DNA methylation, histone modifications, and the influence of microRNAs. In this editorial, we explore the interaction between genetics, gut microbiota, and diet, in an only way. Furthermore, we provided dietary recommendations for patients with IBD. The Western diet, characterized by a low fiber content and deficiency the micronutrients, impacts short-chain fatty acids production and may be related to the pathogenesis of IBD. On the other hand, the consumption of the Mediterranean diet and dietary fibers are associated with reduced risk of IBD flares, particularly in Crohn's disease (CD) patients. According to the dietary guidance from the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD), the regular consumption of fruits and vegetables while reducing the consumption of saturated, trans, dairy fat, additives, processed foods rich in maltodextrins, and artificial sweeteners containing sucralose or saccharine is recommended to CD patients. For patients with ulcerative colitis, the IOIBD recommends the increased intake of natural sources of omega-3 fatty acids and follows the same restrictive recommendations aimed at CD patients, with the possible inclusion of red meats. In conclusion, IBD is a complex and heterogeneous disease, and future studies are needed to elucidate the influence of epigenetics on diet and microbiota in IBD patients.

Letter: The multifaceted role of Escherichia coli in influencing disorders of the industrial populations-Authors' reply

This article is linked to Faqerah et al papers. To view these articles, visit https://doi.org/10.1111/apt.17720 and https://doi.org/10.1111/apt.17865

Letter: The multifaceted role of Escherichia coli in influencing disorders of industrial populations

This article is linked to Faqerah et al papers. To view these articles, visit https://doi.org/10.1111/apt.17720 and https://doi.org/10.1111/apt.17883