Relationship between fiber consumption, short chain fatty acids and Clostridia class members in healthy adults

Trabajo presentado al X Workshop de la Sociedad Española de Probióticos y Prebióticos (SEPYP), celebrado en Gran Canaria del 6 al 8 de febrero 2019.
[Background]: The promotion of beneficial commensal bacteria in the gut, along with an increased short chain fatty acid production (SCFA), have been postulated as potential mechanisms involved in the beneficial effects of a high fiber intake on health. [Objective]: To assess the influence of fiber consumption on short chain fatty acid production and the abundance of bacteria belonging to Clostridia class in healthy adults. [Methodology]: 261 adults aged between 25-50 y, not suffering chronic disease or following medical treatment were included (51% males). Short chain fatty acid production (acetic, propionic, butyric, isobutyric, valeric and isovaleric) was analysed by gas chromatography, and gut microbiota composition through 16S rRNA gene amplicon sequencing (V3+V4 gene regions. MiSeq 2x270 Illumina) and taxonomic analysis. Fiber consumption (FC) habits were analyzed by a food frequency questionnaire, and the following groups were considered: Low (25 g/day). General linear models were used to assess fiber consumption effect on the studied variables, with FC groups, gender and BMI-fat groups as fixed factors, and age and energy as covariables. Bonferroni test was used for pairwise comparisons. [Results]: The levels of acetic and butyric acid were higher in the high and medium FC groups compared to the low FC group, only reaching statistical significance for the latter (Medium vs. Low: P=0.021 and P=0.034, respectively). On the other hand, the high FC group showed higher levels of Clostridiaceae compared to the low FC group (P=0.026), as well as higher Faecalibacterium prausnitzii levels (P=0.018). In addition, both acetic and butyric acids were positively correlated to F.prausnitzii levels (P