Preservation of human gut microbiota inoculums for in vitro fermentations studies

• Autor(a) principal: Carvalho, Nelson Mota de
• Data de Publicação: 2021
• Outros Autores: Oliveira, Diana Luazi, Saleh, Mayra Anton Dib, Pintado, Manuela, Madureira, Ana Raquel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.14/33189
• topic: Gut microbiota viability; Glycerol; Human in vitro models; Colon fermentation; Organic acids; Preservation

The use of fecal inoculums for in vitro fermentation models requires a viable gut microbiota, capable of fermenting the unabsorbed nutrients. Fresh samples from human donors are used; however, the availability of fresh fecal inoculum and its inherent variability is often a problem. This study aimed to optimize a method of preserving pooled human fecal samples for in vitro fermentation studies. Different conditions and times of storage at -20 degrees C were tested. In vitro fermentation experiments were carried out for both fresh and frozen inoculums, and the metabolic profile compared. In comparison with the fresh, the inoculum frozen in a PBS and 30% glycerol solution, had a significantly lower (p < 0.05) bacterial count (<1 log CFU/mL). However, no significant differences (p < 0.05) were found between the metabolic profiles after 48 h. Hence, a PBS and 30% glycerol solution can be used to maintain the gut microbiota viability during storage at -20 degrees C for at least 3 months, without interfering with the normal course of colonic fermentation.