The Effect of Freezing on Faecal Microbiota Transplants' Microbe Composition

Abstract

Faecal Microbiota Transplantation is a treatment in which the faeces of a healthy person are transferred into a patient to restore the balance of their gut microbe composition. As it has become a more common treatment in Western medicine during the last decade, the need for faecal microbiota transplant providers such as Turku Clinical Microbiome Bank has increased. To provide safe and effective faecal microbiota transplantations, the effects of long-term frozen storage, transplant processing and individual donors on the microbe composition of the transplant need to be analysed. This study aims to analyse the significance of these effects on faecal microbiota transplants in order to validate and improve the protocols used in Turku Clinical Microbiome Bank. Additionally, the effects of 16S V3V4 rRNA sequencing, shotgun sequencing and different analysing methods on results and conclusions were analysed.

The main results of this research were that frozen storage for up to three years and transplant processing do not statistically significantly affect the microbe compositions of the transplants. However, differences between donors and genders (p-values <0.0001) were observed. The sequencing and analysing methods also differed from each other but the differences did not affect conclusions.

As no statistically significant differences due to frozen storage were found, further studies should be performed to conclude how long the transplants can be stored without affecting their microbe composition. Additionally, the differences observed between genders should be confirmed with a larger sample size.