Method of preparing a faecal microbiota sample

A method of preparing a sample of faecal microbiota from a donor subject, comprising the following steps:

• a) taking at least one sample of faecal microbiota from the donor subject,
• b) placing said sample obtained in a) in an oxygen-tight collecting device,
• c) mixing the sample obtained in b) with at least one saline aqueous solution comprising 5% by weight relative to the total volume of solution of at least one cryoprotectant selected from the group consisting of glycerol, mannitol, sorbitol, DMSO, propylene glycol, ethylene glycol, trehalose, saccharose, galactose-lactose and mixtures thereof, and 15% by weight relative to the total volume of solution of maltodextrins to form a mixture, wherein the sample obtained in b) is mixed with said saline aqueous solution in a respective weight in g/volume in mL ratio comprising between 0.5 g of sample per 10 mL of solution to 2 g of sample per 2 mL of solution,
• d) optionally, filtering the mixture obtained in c), and
• e) storing the mixture obtained in c) or d) by freezing at a temperature between −15° C. and −100° C., steps b) to e) being carried out under anaerobiosis,
• wherein the faecal microbiota viability is preserved.