Effect of Freezing on Gut Microbiota Composition and Functionality for In Vitro Fermentation Experiments
Metadata
Show full item recordAuthor
Pérez Burillo, Sergio; Hinojosa Nogueira, Daniel José; Navajas Porras, Beatriz; Blasco, Telmo; Balzerani, Francesco; Lerma Aguilera, Alberto; León, Daniel; Pastoriza de la Cueva, Silvia; Apaolaza, Iñigo; Planes, Francisco J.; Francino, M. Pilar; Rufián Henares, José ÁngelEditorial
MDPI
Materia
Gut microbiota Freezing Storage Foods Bioactive compounds
Date
2021Referencia bibliográfica
Pérez-Burillo, S.; Hinojosa-Nogueira, D.; Navajas-Porras, B.; Blasco, T.; Balzerani, F.; Lerma-Aguilera, A.; León, D.; Pastoriza, S.; Apaolaza, I.; Planes, F.J.; et al. Effect of Freezing on Gut Microbiota Composition and Functionality for In Vitro Fermentation Experiments. Nutrients 2021, 13, 2207. https://doi.org/ 10.3390/nu13072207
Sponsorship
“Plan propio de Investigación y Transferencia” - “Intensificación de la Investigación, modalidad B” - University of Granada; European Research Commission (Research Executive Agency) - Stance4Health (Grant Contract No. 816303)Abstract
The gut microbiota has a profound effect on human health and is modulated by food and
bioactive compounds. To study such interaction, in vitro batch fermentations are performed with
fecal material, and some experimental designs may require that such fermentations be performed
with previously frozen stools. Although it is known that freezing fecal material does not alter the
composition of the microbial community in 16S rRNA gene amplicon and metagenomic sequencing
studies, it is not known whether the microbial community in frozen samples could still be used for
in vitro fermentations. To explore this, we undertook a pilot study in which in vitro fermentations
were performed with fecal material from celiac, cow’s milk allergic, obese, or lean children that
was frozen (or not) with 20% glycerol. Before fermentation, the fecal material was incubated in a
nutritious medium for 6 days, with the aim of giving the microbial community time to recover from
the effects of freezing. An aliquot was taken daily from the stabilization vessel and used for the
in vitro batch fermentation of lentils. The microbial community structure was significantly different
between fresh and frozen samples, but the variation introduced by freezing a sample was always
smaller than the variation among individuals, both before and after fermentation. Moreover, the
potential functionality (as determined in silico by a genome-scaled metabolic reconstruction) did not
differ significantly, possibly due to functional redundancy. The most affected genus was Bacteroides, a
fiber degrader. In conclusion, if frozen fecal material is to be used for in vitro fermentation purposes,
our preliminary analyses indicate that the functionality of microbial communities can be preserved
after stabilization.