Evaluation of an optimal preparation of XXXX standardized fecal inocula for in vitro fermentation studies.

@entity1 @entity4876 @entity844 @entity4919 @entity598 @entity653
UNASSIGNED: This study investigated the optimal preservation approach to prepare @entity1 feces as inoculum for in vitro fermentations as an alternative to the use of fresh feces. The four treatments studied were: Treatment 1) fresh feces resuspended in dialysate solution+ @entity653 ; Treatment 2) fresh feces resuspended in dialysate solution+ @entity653 and then stored at -80  C; Treatment 3) fecal sample frozen with 1.5g @entity653 ; and Treatment 4) fecal sample frozen. All the treatments contained 8.75g of feces, 3.5ml dialysate and 4.9ml @entity653 when inoculated in TIM-2 in vitro system. Treatment 1 (fresh fecal preparation) was used as a reference. The effects were evaluated in terms of i) metabolic activity and ii) composition of the microbiota using fermentation experiments in the TIM-2 in vitro system. In all treatments, high levels of @entity598 were produced followed by @entity4876 and @entity4919 . However, the metabolic activity of the bacteria, in terms of short-chain @entity844 production, was affected by the different treatments. Microbiota composition was analyzed using the IS-pro profiling technique. Diversity in Actinobacteria, Firmicutes, Fusobacteria and Verrucomicrobia and Proteobacteria groups seemed to be preserved in all treatments whereas it was observed to decline in the Bacteroidetes group. Preparing a @entity1 fecal inoculum resuspended in dialysate solution with @entity653 and then stored at -80  C showed high similarities to the results obtained with fresh feces, and is proposed as the optimal way to freeze fecal material as an alternative to fresh feces for in vitro fermentation studies.
