Trehalose-Induced Remodelling of the Human Microbiota Affects Clostridioides difficile Infection Outcome in an In Vitro Colonic Model: A Pilot Study

Abstract

Within the human intestinal tract, dietary, microbial- and host-derived compounds are used as signals by many pathogenic organisms, including Clostridioides difficile. Trehalose has been reported to enhance virulence of certain C. difficile ribotypes; however, such variants are widespread and not correlated with clinical outcomes for patients suffering from C. difficile infection (CDI). Here, we make preliminary observations on how trehalose supplementation affects the microbiota in an in vitro model and show that trehalose-induced changes can reduce the outgrowth of C. difficile, preventing simulated CDI. Three clinically reflective human gut models simulated the effects of sugar (trehalose or glucose) or saline ingestion on the microbiota. Models were instilled with sugar or saline and further exposed to C. difficile spores. The recovery of the microbiota following antibiotic treatment and CDI induction was monitored in each model. The human microbiota remodelled to utilise the bioavailable trehalose. Clindamycin induction caused simulated CDI in models supplemented with either glucose or saline; however, trehalose supplementation did not result in CDI, although limited spore germination did occur. The absence of CDI in trehalose model was associated with enhanced abundances of Finegoldia, Faecalibacterium and Oscillospira, and reduced abundances of Klebsiella and Clostridium spp., compared with the other models. Functional analysis of the microbiota in the trehalose model revealed differences in the metabolic pathways, such as amino acid metabolism, which could be attributed to prevention of CDI. Our data show that trehalose supplementation remodelled the microbiota, which prevented simulated CDI, potentially due to enhanced recovery of nutritionally competitive microbiota against C. difficile.

Profiling the Effects of Systemic Antibiotics for Acne, Including the Narrow-Spectrum Antibiotic Sarecycline, on the Human Gut Microbiota

“…Bacterial populations were sampled daily in each of the three models, in which a 10-fold dilution series of this sample was plated out onto various selective and non-selective agars for enumeration as described previously ( Buckley et al, 2021 ). Bacterial colonies were enumerated and confirmed using microbiological and biochemical techniques.…”

“…The concentration of each antibiotic was determined by bioassays as previously described ( Buckley et al, 2021 ). Briefly, to determine the concentration of sarecycline and minocycline, indicator organism Kocuria rhizophila (ATCC 9341) was inoculated into Wilkins-Chalgren agar plates.…”

“…Bacterial 16S rRNA V4 region libraries were prepared as previously detailed ( Buckley et al, 2021 ). Sequencing was performed on a MiSeq (Illumina) with 250 bp paired end reads.…”

Encapsulated Fecal Microbiota Transplantation: Development, Efficacy, and Clinical Application

“…Trehalose was found superior in preserving bacterial viability, with membrane integrity tests comparable to frozen products ( Staley et al., 2017a ), and it appears to work consistently among other groups pursuing lyophilized encapsulated microbiota ( Xu et al., 2021 ). While the use of trehalose has been suggested to enhance the virulence of some strains of C. difficile ( Collins et al., 2018 ), there are several studies that show trehalose supplementation does not interfere with the clinical efficacy of cFMT ( Saund et al., 2020 ; Buckley et al., 2021 ).…”

Wolf in Sheep’s Clothing: Clostridioides difficile Biofilm as a Reservoir for Recurrent Infections

“…It will, however, be more difficult to define the role of biofilms in recurrent CDI. Recent studies provide evidence that biofilm formation is dependent on metabolism and excreted metabolites [ 192 , 270 ]. Therefore, we think there is a need to refine our view on the infectious cycle of C. difficile .…”