Evaluation of fecal microbial transplant as a treatment method for disruption of the gut microbiota associated with short bowel syndrome in neonates.

  • Author / Creator
    Hinchliffe, Tierah
  • Background
    Short bowel syndrome (SBS) is the leading cause of intestinal failure (IF), wherein either the function of the intestines is suboptimal, or length has been reduced due to congenital or acquired conditions, such that parenteral nutrition (PN) is required for >6 weeks. The most common etiology in neonates is necrotizing enterocolitis (NEC), a condition resulting from disruption or poor establishment of the microbiota that allows inflammatory species to proliferate and cause tissue damage. Repeated rounds of antibiotics to treat central line infections and small intestinal bacterial overgrowth are necessary, but further exacerbate dysbiosis. Sepsis with gut-derived organisms and IF-associated liver disease, which is partly caused by bacterial translocation, are now the leading causes of mortality in children with SBS. Treatment for dysbiosis must replace beneficial organisms, rather than simply remove harmful ones, in order to support normal growth and development of children with SBS. Probiotics are one option that have had success in preventing NEC, but some Lactobacilli have been associated with inhibition of adaptation in some instances of single species supplementation, and in others with an increase in sepsis. In this experiment, we looked at using fecal microbial transplant (FMT) as a way of restoring a healthy diverse microbiota in a single treatment in neonatal piglets with SBS.
    Neonatal male Duroc piglets aged 3-7 days were assigned to saline (SAL, n=12), fecal microbial transplant (FMT, n=12), or sow-fed control (SOW, n=6) treatment groups. SAL and FMT underwent 75% distal SBS surgery on day 0, and treatment on day 2 (100 mL saline or FMT material, respectively). Donor FMT material was collected from a healthy female gilt, filtered, stored at -80 °C, and thawed at 4 °C overnight before use. SOW piglets remained with their litter, and were terminated on day 7 along with their treatment piglet littermates. Tissue samples were collected at baseline and termination surgeries, as well as daily stool samples pre-treatment, post-treatment, and on the mornings of day 3-6. Microbial DNA was extracted, analyzed for 16S rRNA, and compared to established databases for taxonomy assignment. Percent relative composition of bacterial taxa was analyzed and compared between groups, as well as alpha and beta diversities.
    No piglets developed sepsis or experienced disease-specific mortality, and FMT was well-tolerated. FMT piglets showed increased Actinobacteria and Firmicutes families, and increased alpha diversity, compared with SAL post-treatment and on day 3, but these increases in general did not persist afterwards. FMT and SAL piglets had significantly different beta diversity post and day 3, but the Donor material was significantly different at all time points. SOW piglet term tissue sample alpha diversity in jejunum and colon, and beta diversity in the colon, was significantly higher than treatment piglets.
    Piglets in this trial demonstrated no disease-specific mortality and no increase in sepsis rates compared with our previous SBS trials. Differences in bacterial taxa were measurable in stool samples only through the day after FMT treatment. It is possible this was due to inadequate dietary fiber sources for establishment of the donor communities, given the neonatal piglets were fed enteral nutrition (EN) that contained only simple carbohydrates. Differences in beta diversity between SAL and FMT were present in the colonic mucosal-associated bacteria at termination, indicating small numbers of some species were able to establish and survive. Supplementation with complex fiber sources accessible by butyrate-producing species should be added to EN in the future to aid in persistence of beneficial species.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.