Search bioRxiv⌕ Search

bioRxiv · 10.1101/2022.06.10.495602

Gut microbiota modulation in response to combination of Escherichia coli Nissle 1917 and sugars: Lessons from comparative analysis of fecal microbiota of two healthy donors from 2019-2021

Abstract

The Escherichia coli Nissle 1917 strain (EcN) has shown its probiotic efficacy against many enteric pathogenic bacteria infecting human, including Vibrio cholerae, either alone or in combination with prebiotics. Understanding of these mechanisms of infection control requires the basic knowledge of probiotic mediated gut microbial community alterations especially in presence of different prebiotics. The present study has used the ex-vivo microbiota model and Next Generation Sequencing techniques to demonstrate the effect of EcN along with different sugars, namely glucose, galactose and starch, on the human gut microbiome community composition. The microbiome compositional changes have been observed at two different time-points, set one and a half years apart, in fecal slurries obtained from two donors. The study has indicated that the extent of microbiome alterations varies with different carbohydrate prebiotics and EcN probiotic and most of the alterations are broadly dependent upon the existing gut microbial community structure of the donors. The major distinct compositional changes have been found in the conditions where glucose and starch were administered, both with and without EcN, in spite of the inter-donor microbial community variation. Several of these microbiome component variations also remain consistent for both the time-points, including genus like Bacteroides, Prevotella and Lactobacillus. Altogether, the present study has shown the effectiveness of EcN along with glucose and starch towards specific changes of microbial community alterations independent of initial microbial composition. This type of model study can be implemented for hypothesis testing in case of therapeutic and prophylactic use of probiotic and prebiotic combinations.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Bhowmik, D., Heer, K., Kaur, M., Raychaudhuri, S., Paul, S.. 2022-06-10. Gut microbiota modulation in response to combination of Escherichia coli Nissle 1917 and sugars: Lessons from comparative analysis of fecal microbiota of two healthy donors from 2019-2021. https://doi.org/10.1101/2022.06.10.495602

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A population-scale landscape of the subgingival microbiome reveals divergent routes to periodontal dysbiosis

Periodontitis is an archetypical mucosal inflammatory disease in which microbiome dysbiosis at the tooth-epithelial interface interacts with host genetic and behavioral risk factors to drive immune-mediated tissue destruction. Although subgingival microbiome compositional shifts are thought to parallel disease severity, microbiome variation at the population-level and its relationship to periodontal clinical phenotypes and disease-modifying factors remain poorly defined. Here, we use unsupervised manifold learning to map the compositional landscape of the subgingival microbiome in 1,355 adults spanning periodontal health to severe periodontitis. We identified eight latent microbiome states organized along a branching continuum from eubiosis to dysbiosis. An intermediate microbial configuration marked ecological destabilization and bifurcation into two distinct periodontitis-associated dysbiotic trajectories, distinguished by links to gingival inflammation and smoking. Although the microbiome trajectories broadly tracked periodontal destruction, a minority of individuals showed discordant microbiome-clinical phenotypes, with some individuals with periodontitis retaining otherwise eubiotic microbiomes enriched for low-abundance pathobionts, while some cases of health or mild disease had highly dysbiotic communities, suggesting distinct host susceptibility. Together, these findings define a population-scale ecological landscape of the subgingival microbiome, reveal divergent trajectories to periodontal dysbiosis, and highlight heterogeneity in the relationship between microbial community structure and clinical disease expression.

microbiology↗

The iron-binding siderophore enterobactin is required for the response of multi-drug resistant Klebsiella pneumoniae to zinc limitation

To persist during infection Klebsiella pneumoniae must overcome nutrient iron and zinc limitation imposed by the host immune system through a process called nutritional immunity. Secreted small molecule siderophores are a major virulence determinant of Klebsiella pneumoniae pathogenesis and are presumed to overcome nutritional immunity by binding iron for bacterial acquisition. In this work, we set out to identify how a multi-drug resistant K. pneumoniae grows in zinc limited environments. Using unbiased transcriptomics, proteomics, and an arrayed transposon screen, we identified that synthesis and uptake of the siderophore enterobactin is required to allow for growth in low zinc conditions. Iron-specific chelators did not replicate this phenotype and addition of supplemental iron through heme in growth media could not complement severe growth defects of enterobactin mutant K. pneumoniae experiencing zinc limitation. Finally, zinc starvation induced enterobactin production independent of the canonical zinc uptake regulator (Zur) transcription factor suggesting an unidentified regulatory mechanism by which Gram-negative pathogens may respond to zinc stress. Together, these studies expand the role of enterobactin beyond iron regulation and highlight a previously unreported link between iron and zinc homeostasis in Klebsiella pneumoniae.

microbiology↗

A microbiota-derived protease links phage susceptibility to host epithelial responses

Bacteriophages are major ecological drivers of gut microbial ecology, yet whether bacterial mechanisms that determine phage susceptibility have consequences for the mammalian host remains poorly understood. Here, we identify dipeptidyl peptidase 11 (Dpp11a), the predominant active serine protease of the prevalent gut commensal Phocaeicola vulgatus, as an unexpected bacterial defence factor. Dpp11a protects against environmental proteases and confers resistance to bacteriophage infection. Metatranscriptomic analyses further reveal increased expression of both dpp11a and P. vulgatus-associated phage transcripts in ulcerative colitis stool samples, indicating that both components of this interaction are transcriptionally active in disease-associated human microbiomes. Using the microfluidic gut-on-a-chip co-culture model HuMiX, we show that the absence of Dpp11 is accompanied by altered epithelial tight-junction remodelling during phage-bacterial infection. Together, our findings reveal that the consequences of bacterial phage defence can extend beyond phage-bacterium interactions to the mammalian epithelium.

microbiology↗