Preparation of frozen stool suspensions for fecal microbiota transplantation

Fecal microbiota transplantation (FMT) is a recognized alternative to antibiotics for the treatment of recurrent Clostridium difficile infection. Its use is limited due to difficulties with treatment access. The aim of this work is to describe the production process of this preparation performed under the responsibility of the hospital pharmacist.

A protocol based on scientific literature was written.

The preparation is made in a laboratory fume hood dedicated to this activity. A universal donor is screened according to clinical and biological criteria. Feces of donor are collected immediately after defecation. They are diluted with a sterile solution [normal saline 0.9%/glycerin (90/10 v/v)] satured with helium: 50g of stools + 250mL of solution according to the stool consistency. This mixture is homogenized in a blender with a low speed during at least 30 seconds. The fecal suspension is filtered through sterile gauze. The filtrate is packaged into sterile vials (250mL in each vial) and is stored at -80°C. A sample of preparation and a sample of feces from the universal donor are also stored at -80°C. The day before the FMT, a vial is transferred to refrigerator (time required for thawing ≈12h). The day of the FMT, the thawed suspension is mixed with a blender prior to be transferred either to enema pocket (lower gastro intestinal tract delivery), or to syringes of 50 mL (colonoscopy delivery or duodenal or jejunal tubes administration). The shelf life is set at 6 hours between +2 and +8°C.

The production of frozen stool suspensions allows having a quickly available preparation and thus significantly reducing the time for the FMT. It also allows meeting the need of hospitals which do not have capacity to produce the preparation.