Pérez-Burillo, SergioHinojosa-Nogueira, DanielNavajas-Porras, BeatrizBlasco, TelmoBalzerani, FrancescoLerma-Aguilera, AlbertoLeón, DanielPastoriza, SilviaApaolaza, IñigoPlanes, Francisco J.Francino, Maria PilarRufián-Henares, José Ángel2022-04-202022-04-202021-06-27Pérez-Burillo S, Hinojosa-Nogueira D, Navajas-Porras B, Blasco T, Balzerani F, Lerma-Aguilera A, et al. Effect of Freezing on Gut Microbiota Composition and Functionality for In Vitro Fermentation Experiments. Nutrients 2021, 13, 2207.http://hdl.handle.net/10668/3548The 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.enAtribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/Gut microbiotaFreezingStorageFoodsBioactive compoundsMicrobioma gastrointestinalCongelaciónAlimentosFitoquímicosMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Artiodactyla::Ruminants::CattleMedical Subject Headings::Anatomy::Fluids and Secretions::FecesMedical Subject Headings::Technology and Food and Beverages::Technology, Industry, and Agriculture::Industry::Food Industry::Food Handling::Food StorageMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Phenomena and Processes::Microbiological Phenomena::MicrobiotaMedical Subject Headings::Anatomy::Fluids and Secretions::Bodily Secretions::MilkMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Study Characteristics as Topic::Pilot ProjectsMedical Subject Headings::Chemicals and Drugs::Nucleic Acids, Nucleotides, and Nucleosides::Nucleic Acids::RNA::RNA, Ribosomal::RNA, Ribosomal, 16SMedical Subject Headings::Phenomena and Processes::Chemical Phenomena::Biochemical Phenomena::Biochemical Processes::Carbohydrate Metabolism::FermentationMedical Subject Headings::Phenomena and Processes::Physical Phenomena::Physical Processes::Phase Transition::FreezingMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Study Characteristics as Topic::Pilot ProjectsMedical Subject Headings::Organisms::Eukaryota::AnimalsMedical Subject Headings::Diseases::Nutritional and Metabolic Diseases::Nutrition Disorders::Overnutrition::ObesityMedical Subject Headings::Organisms::Bacteria::Bacteroidetes::Bacteroidaceae::Bacteroidesresearch article34199047Acceso abierto10.3390/nu130722072072-6643PMC8308218