In vitro gut microbiome response to carbohydrate supplementation is acutely affected by a sudden change in diet

Abstract

Background Interactions between diet, stress and the gut microbiome are of interest as a means to modulate health and performance. Here, in vitro fermentation was used to explore the effects of a sudden change in diet, 21 days sole sustenance on the Meal, Ready-to-Eat (MRE) U.S. military combat ration, on inter-species competition and functional potential of the human gut microbiota. Human fecal samples collected before and after MRE intervention or consuming a habitual diet (HAB) were introduced to nutrient-rich media supplemented with starch for in vitro fermentation under ascending colon conditions. 16S rRNA amplicon and Whole-metagenome sequencing (WMS) were used to measure community composition and functional potential. Specific statistical analyses were implemented to detect changes in relative abundance from taxa, genes and pathways. Results Differential changes in relative abundance of 11 taxa, Dorea, Lachnospira, Bacteroides fragilis, Akkermansia muciniphila, Bifidobacterium adolescentis, Betaproteobacteria, Enterobacteriaceae, Bacteroides egerthii, Ruminococcus bromii, Prevotella, and Slackia, and nine Carbohydrate-Active Enzymes, specifically GH13_14, over the 24 h fermentation were observed as a function of the diet intervention and correlated to specific taxa of interest. Conclusions These findings suggest that consuming MRE for 21 days acutely effects changes in gut microbiota structure in response to carbohydrate but may induce alterations in metabolic capacity. Additionally, these findings demonstrate the potential of starch as a candidate supplemental strategy to functionally modulate specific gut commensals during stress-induced states.

In Vitro Fermentation Shows Polyphenol and Fiber Blends Have an Additive Beneficial Effect on Gut Microbiota States

“…The study was reviewed and approved by the US Army Research Institute of Environmental Medicine Institutional Review Board, and all participants provided written informed consent prior to participation. Fecal sample collection was adapted from [ 21 ] and protocol has been described in detail in Pantoja-Feliciano et al [ 22 ].…”

“…Parallel batch fermentations ( n = 3) were designed to include vessels for blend-specific supplementation, non-supplemented (fecal-only, F), and fecal-deficient (medium-only, NF) using an HEL BioXplorer 100 (HEL Group, Borehamwood, UK) 8-vessel parallel bioreactor simulating the ascending colon (pH 5.5). The fermentation medium, Colonic Complex Medium (CCM) was prepared based on Pantoja-Feliciano et al [ 22 ] with slight modifications: addition of resazurin (1 µg/L). The medium was added to the fermentation vessels (125 mL/vessel) with pH, temperature, and oxidation–reduction potential (Applikon Biotechnologies, Foster City, CA, USA) probes attached.…”

“…BAA-2280, and Faecalibacterium prausnitzii 27768. The specific taxa were selected based on previous studies [ 17 , 22 ]. Briefly, organism-specific quantitative polymerase chain reaction (qPCR) primers were selected for the eight organisms included [ 17 , 24 ] ( Table S2 ).…”

Unveiling the gut-eye axis: how microbial metabolites influence ocular health and disease

“…The lower biomass complicates sampling of the neonatal gut, and there is a lack of consensus on the species present. However, Proteobacteria and Actinobacteria seem to dominate (22,23), though Lactobacillus species (phylum Firmicutes) are commonly present as well (24). By the age of three, the gut bacterial population stabilizes and resembles that of adulthood (25).…”