A Guide for Ex Vivo Handling and Storage of Stool Samples Intended for Fecal Microbiota Transplantation. Burz Sebastian D,Abraham Anne-Laure,Fonseca Fernanda,David Olivier,Chapron Audrey,Béguet-Crespel Fabienne,Cénard Stéphanie,Le Roux Karine,Patrascu Orlane,Levenez Florence,Schwintner Carole,Blottière Hervé M,Béra-Maillet Christel,Lepage Patricia,Doré Joël,Juste Catherine Scientific reports Owing to the growing recognition of the gut microbiota as a main partner of human health, we are expecting that the number of indications for fecal microbiota transplantation (FMT) will increase. Thus, there is an urgent need for standardization of the entire process of fecal transplant production. This study provides a complete standardized procedure to prepare and store live and ready-to-use transplants that meet the standard requirements of good practices to applied use in pharmaceutical industry. We show that, if time before transformation to transplants would exceed 24 hours, fresh samples should not be exposed to temperatures above 20 °C, and refrigeration at 4 °C can be a safe solution. Oxygen-free atmosphere was not necessary and simply removing air above collected samples was sufficient to preserve viability. Transplants prepared in maltodextrin-trehalose solutions, stored in a -80 °C standard freezer and then rapidly thawed at 37 °C, retained the best revivification potential as  proven by 16S rRNA profiles, metabolomic fingerprints, and flow cytometry assays over a 3-month observation period. Maltodextrin-trehalose containing cryoprotectants were also efficient in preserving viability of lyophilized transplants, either in their crude or purified form, an option that can be attractive for fecal transplant biobanking and oral formulation. 10.1038/s41598-019-45173-4

Freeze-dried fecal samples are biologically active after long-lasting storage and suited to fecal microbiota transplantation in a preclinical murine model of infection. Reygner Julie,Charrueau Christine,Delannoy Johanne,Mayeur Camille,Robert Véronique,Cuinat Céline,Meylheuc Thierry,Mauras Aurélie,Augustin Jérémy,Nicolis Ioannis,Modoux Morgane,Joly Francisca,Waligora-Dupriet Anne-Judith,Thomas Muriel,Kapel Nathalie Gut microbes Fecal microbiota transplantation is now recommended for treating recurrent forms of infection. Recent studies have reported protocols using capsules of either frozen or freeze-dried stool allowing oral administration in in- and out-patient settings. However, a central question remains the viability, engraftment, and efficacy of the microbiome over time during storage life. This study shows that both the freeze-drying and freezing procedures for fecal samples allowed preserving viability, short-chain fatty acids concentration, and anti- properties of microbiota without significant alteration after storage for 12 months. Fecal transplantation with freeze-dried microbiota allowed engraftment of microbiota leading to clearance of infection in a preclinical murine model with a survival rate of 70% 53-60% in mice treated with frozen inocula, and 20% in the untreated group. Moreover, the freeze-dried powder can be used to fill oral hard capsules using a very low amount (0.5%) of glidant excipient, allowing oral formulation. Altogether, this study showed that freeze-dried inocula can be used for the treatment of infection with long-lasting stability of the fecal microbiota. This formulation facilitates biobanking and allows the use of hard capsules, an essential step to simplify patient access to treatment. 10.1080/19490976.2020.1759489

Faecal freezing preservation period influences colonization ability for faecal microbiota transplantation. Takahashi M,Ishikawa D,Sasaki T,Lu Y J,Kuwahara-Arai K,Kamei M,Shibuya T,Osada T,Hiramatsu K,Nagahara A Journal of applied microbiology AIMS:There has been growing interest in faecal microbiota transplantation (FMT) as treatment. Although, frozen donor faeces preserved at -20°C has been widely used for practical advantages, freezing at -20°C can affect bacterial viability. Adequacy evaluation of fresh and frozen faeces as the transplant is necessary for the methodological improvement of FMT. METHODS AND RESULTS:The viable bacterial compositions of faecal specimens under fresh and freezing conditions were compared by a microbiome analysis using propidium monoazide (PMA microbiome). In addition, recovery abilities from bacterial reduction by antibiotics were compared between fresh and frozen FMT using a murine model. PMA microbiome results suggested that freezing and freeze-thawing did not significantly affect in vitro faecal bacterial viability. However, the recovery effect from antimicrobial cleansing in frozen FMT was reduced in a freezing time-dependent manner, especially prominent in Actinobacteria and Bacteroidetes phyla. CONCLUSIONS:Short-term freezing preservation of faeces exhibited maintenance of enteric colonization ability in frozen FMT in comparison to 1 month -20°C-preservation. SIGNIFICANCE AND IMPACT OF THE STUDY:Long-term -20°C-preservation of transplanted faeces can result in instability of the clinical outcome in FMT therapy. The standardization of practical procedures of FMT therapy according to disease types is desirable. 10.1111/jam.14167