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The current study evaluated the effect of five yeast-derived formulations (T1-T5) on microbial metabolism and composition of the canine and feline gut microbiota using a novel in vitro colonic incubation approach. This novel in vitro model allowed for growth of the entire spectrum of dog- and cat-derived bacteria from the inoculum, thus offering an excellent platform to evaluate effects of nutritional interventions on the gut microbiota. Further, yeast-derived ingredients differentially increased production of acetate, propionate, butyrate, ammonium, and branched short-chain fatty acids, with T5 and T1 consistently stimulating propionate and butyrate, respectively. 16S-targeted Illumina sequencing coupled with flow cytometry provided unprecedented high-resolution quantitative insights in canine and feline microbiota modulation by yeast-derived ingredients, revealing that effects on propionate production were related to Prevotellaceae, Tannerellaceae, Bacteroidaceae, and Veillonellaceae members, while effects on butyrate production were related to Erysipelotrichaceae, Lachnospiraceae, Ruminococcaceae, and Fusobacteriaceae. Overall, these findings strengthen the health-promoting potential of yeast-derived ingredients.

Enrichment of food crops with iodine is an option to alleviate dietary deficiencies. Therefore, foliar iodine fertilizer was applied on wheat and rice, in the presence and absence of the other micronutrients zinc and selenium. This treatment increased the concentration of iodine, as well as zinc and selenium, in the staple grains. Subsequently, potential iodine losses during preparation of foodstuffs with the enriched grains were studied. Oven-heating did not affect the iodine content in bread. Extraction of bran from flour lowered the iodine in white bread compared to wholegrain bread, but it was still markedly higher compared to the control. During subsequent in vitro gastrointestinal digestion, a higher percentage of iodine was released from foods based on extracted flour (82-92%) compared to wholegrain foods (50-76%). The foliar fertilization of wheat was found to be adequate to alleviate iodine deficiency in a population with a moderate to high intake of bread.

We used a standardized in vitro simulation of the intestinal environment of three human donors to investigate the effect of six oat ingredients, which were produced by the application of different processing techniques, on the gut microbial community. Fructooligosaccharide was used as the positive control. Consistent changes in pH and gas production, on average -0.4 pH units and +32 kPa, indicated the high fermentability of the oat ingredients, and the resulting increased production of metabolites that are considered as beneficial for human health. These metabolites included acetate and lactate, but mostly propionate (+13.6 mM on average). All oat ingredients resulted in increased bifidobacteria levels with an average increase of 0.73 log. Moreover, a decreased production of proteolytic markers was observed, including branched short-chain fatty acids and ammonium. The results were donor-specific and product-specific. The results suggested an association between the total amounts of dietary fiber and the prebiotic potentials of different ingredients. Furthermore, as mechanical processing of oat products has previously been linked to increased extractability of dietary fibers, the obtained results suggest that different processing techniques might have impacted the potential functional properties of the final ingredients., Competing Interests: The authors declare the following competing financial interest(s): A.K., L.F., Y.C., and P.D.C. are employees from PepsiCo, Inc.

Fecal batch fermentations coupled to cocultures of epithelial cells and macrophages were used to compare how arabinoxylo-oligosaccharides (AXOS) and inulin modulate gut microbial activity and composition of three different human donors and subsequently the epithelial permeability and immune response. Both inulin and AXOS decreased the pH during incubation (-1.5 pH units), leading to increased productions of acetate, propionate, and butyrate. Differences in terms of metabolites production could be linked to specific microbial alterations at genus level upon inulin/AXOS supplementation (i.e., Bifidobacterium, Bacteroides, Prevotella and unclassified Erysipelotrichaceae), as shown by 16S-targeted Illumina sequencing. Both products stimulated gut barrier and immune function with increases in TEER, NF-KB, IL-10, and IL-6. Ingredients with different structures selectively modulate the microbiota of a specific donor leading to differential changes at metabolic level. The extent of this effect is donor specific and is linked to a final specific modulation of the host's immune system.

Fecal samples are an obvious choice for metabolomic approaches, since they can be obtained noninvasively and allow one to study the interactions between the gut microbiota and the host. The use of ultrahigh performance liquid chromatography hyphenated to Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) in this field is unique. Hence, this study relied on Orbitrap HRMS to develop and validate a metabolic fingerprinting workflow for human feces and in vitro digestive fluids. After chemometric sample extraction optimization, an aqueous dilution appeared necessary to comply to the dynamic range of the MS. The method was proven "fit-for-purpose" through a validation procedure that monitored endogenous metabolites in quality control samples, which displayed in both matrices an excellent linearity (R(2) > 0.990), recoveries ranging from 93% to 105%, and precision with coefficients of variation (CVs) < 15%. Finally, feces from 10 healthy individuals and 13 patients diagnosed with inflammatory bowel disease were subjected to metabolomic fingerprinting. 9553 ions were detected, as well as differentiating profiles between Crohn's disease and ulcerative colitis by means of (orthogonal) partial least-square analysis ((O)PLS)-DA (discriminate analysis) models. Additionally, samples from the dynamic gastrointestinal tract simulator (SHIME (Simulator of the Human Intestinal Microbial Ecosystem) platform) were analyzed resulting in 6446 and 5010 ions for the proximal and distal colonic samples, respectively. Supplementing SHIME feed with antibiotics resulted in a significant shift (P < 0.05) of 27.7% of the metabolites from the proximal data set and 34.3% for the distal one. As a result, the presented fingerprinting approach provided predictive modeling of the gastrointestinal metabolome in vivo and in vitro, offering a window to reveal disease related biomarkers and potential insight into the mechanisms behind pathologies.

EpiCor, derived from Saccharomyces cerevisiae, has been shown to have immunomodulating properties in human clinical trials and in vitro. However, the underlying mechanisms behind its immune protection via the gut remain largely unknown. Therefore, the aim of this study was to use an integrated in vitro approach to evaluate the metabolism of EpiCor by the intestinal microflora, its modulating effect on the gut microbiota, and its anti-inflammatory activity on human-derived cell lines. Using the SHIME model, in combination with a mucus adhesion assay, has shown that low doses of EpiCor have a prebiotic-like modulatory effect on the luminal- and mucosa-associated microbiota. These include gradual changes in general community structure, reduction of potential pathogens, quantitative increase in lactobacilli, and qualitative modulation of bifidobacteria. Moreover, by combination of the SHIME with Caco-2 cells and Caco-2/THP1 cocultures, a significant decrease in pro-inflammatory cytokines was observed at the end of the treatment period.

Aggregation and membrane penetration of porphyrinic photosensitizers play crucial roles for their efficacy in photodynamic therapy. The current study was aimed at comparing the aggregation behavior of selected photosensitizers and correlating it with membrane affinity. Self-assembling properties of 15 amphiphilic free-base chlorin and porphyrin derivatives bearing carboxylate substituents were studied in phosphate buffered saline (PBS) by (1)H NMR spectroscopy, making use of ring current induced aggregation shifts. All compounds exhibited aggregation in PBS to a different degree with dimers or oligomers showing slow aggregate growth over time. Aggregate structures were proposed on the basis of temperature dependent chemical shift changes. All chlorin compounds revealed similar aggregation maps with their hydrophobic sides overlapping and their carboxylate groups protruding toward the exterior. In contrast, for the porphyrin compounds, the carboxylate groups were located in overlapping regions. Membrane interactions were probed using 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer vesicles and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) micelles as models. The chlorin derivatives had higher membrane affinity and were all monomerized by DHPC micelles as opposed to the porphyrin compounds. The observed differences were attributed to the different aggregate structures proposed for the chlorin and porphyrin derivatives. Free accessibility of the carboxylate groups seemed to promote initial surface interaction with phospholipid bilayers and micelles.

The triethylborane-methanol system used in radical deoxygenation and dehalogenation processes has been investigated. Unambiguous evidence for the formation of a complex between triethylborane and methanol is provided. It was shown that the complexation process is exothermic (ΔH° ≈ -7.6 kcal mol(-1)) while being entropically disfavored (ΔS° ≈ -24 cal mol(-1) K(-1)). This study demonstrates that only very small quantities of complex (1-2%) are present in most of the reported conditions used in dehalogenation and deoxygenation processes. Recalculating the rate constant for the hydrogen transfer to a secondary alkyl radical with this concentration suggests a value in the 10(6) M(-1) s(-1) range for the complex itself, indicating a much more important activation of the O-H bond than previously thought. The importance of solvent effects is also highlighted. The formation of a larger amount of complex by the addition of methanol is accompanied by its deactivation via hydrogen bonding. These observations open new opportunitites for the future preparation of more effective hydrogen atom donors involving borane complexes.

(1)H HR-MAS NMR spectroscopy was applied to apple tissue samples deriving from 3 different cultivars. The NMR data were statistically evaluated by analysis of variance (ANOVA), principal component analysis (PCA), and partial least-squares-discriminant analysis (PLS-DA). The intra-apple variability of the compounds was found to be significantly lower than the inter-apple variability within one cultivar. A clear separation of the three different apple cultivars could be obtained by multivariate analysis. Direct comparison of the NMR spectra obtained from apple tissue (with HR-MAS) and juice (with liquid-state HR NMR) showed distinct differences in some metabolites, which are probably due to changes induced by juice preparation. This preliminary study demonstrates the feasibility of (1)H HR-MAS NMR in combination with multivariate analysis as a tool for future chemometric studies applied to intact fruit tissues, e.g. for investigating compositional changes due to physiological disorders, specific growth or storage conditions.

The pH-dependent membrane adsorption and distribution of three chlorin derivatives, chlorin e6 (CE), rhodin G7 (RG), and monoaspartyl-chlorin e6 (MACE), in the physiological pH range (pH 6-8) were probed by NMR spectroscopy. Unilamellar vesicles consisting of dioleoyl-phosphatidyl-choline (DOPC) were used as membrane models. The chlorin derivatives were characterized with respect to their aggregation behavior, the pK(a) values of individual carboxylate groups, the extent of membrane adsorption, and their flip-flop rates across the bilayer membrane for pH 6-8. External membrane adsorption was found to be lower for RG than for CE and MACE. Both electrostatic interactions and the extent of aggregation seemed to be the main determinants of membrane adsorption. Rate constants for chlorin transfer across the membrane were found to correlate strongly with the pH of the surrounding medium, in particular, for CE and RG. In acidic solution, CE and RG transfer across the membrane was strongly accelerated, and in basic solution, all compounds were retained, mostly in the outer monolayer. In contrast, MACE flip-flop across the membrane remained very low even at pH 6. The protonation of ionizable groups is suggested to be a major determinant of chlorin transfer rates across the bilayer. pK(a) values of CE and RG were found to be between 6 and 8, and two of the carboxylate groups in MACE had pK(a) values below 6. For CE and RG, the kinetic profiles at acidic pH indicated that the initial fast membrane distribution was followed by secondary steps that are discussed in this article.