Food for thought! Inulin-type fructans: does the food matrix matter?

Food matrices can be described as the final composition of a food product which results from complex interactions between compounds found within different ingredients and the processing parameters used in production. These factors, not only impact on the final structure of a product, but also have the potential to alter both the structural integrity and bioavailability of potentially beneficial compounds present, for example, dietary fibres. As a result, there is growing curiosity amongst the scientific community on whether the food matrix may impact on the prebiotic efficacy of inulin-type fructans. Therefore, the purpose of this review is to explore previous food-based inulin-type fructan supplementation studies to determine whether the food matrix directly impacts on their prebiotic efficacy. Our working hypothesis is that other potentially prebiotic ingredients and components present within the food may alter inulin-type fructans prebiotic effect

Short chain fatty acids in human gut and metabolic health

Peer reviewedPublisher PD

Genome-wide analysis of starch metabolism genes in potato (Solanum tuberosum L.)

Background Starch is the principle constituent of potato tubers and is of considerable importance for food and non-food applications. Its metabolism has been subject of extensive research over the past decades. Despite its importance, a description of the complete inventory of genes involved in starch metabolism and their genome organization in potato plants is still missing. Moreover, mechanisms regulating the expression of starch genes in leaves and tubers remain elusive with regard to differences between transitory and storage starch metabolism, respectively. This study aimed at identifying and mapping the complete set of potato starch genes, and to study their expression pattern in leaves and tubers using different sets of transcriptome data. Moreover, we wanted to uncover transcription factors co-regulated with starch accumulation in tubers in order to get insight into the regulation of starch metabolism. Results We identified 77 genomic loci encoding enzymes involved in starch metabolism. Novel isoforms of many enzymes were found. Their analysis will help to elucidate mechanisms of starch biosynthesis and degradation. Expression analysis of starch genes led to the identification of tissue-specific isoenzymes suggesting differences in the transcriptional regulation of starch metabolism between potato leaf and tuber tissues. Selection of genes predominantly expressed in developing potato tubers and exhibiting an expression pattern indicative for a role in starch biosynthesis enabled the identification of possible transcriptional regulators of tuber starch biosynthesis by co-expression analysis. Conclusions This study provides the annotation of the complete set of starch metabolic genes in potato plants and their genomic localizations. Novel, so far undescribed, enzyme isoforms were revealed. Comparative transcriptome analysis enabled the identification of tuber- and leaf-specific isoforms of starch genes. This finding suggests distinct regulatory mechanisms in transitory and storage starch metabolism. Putative regulatory proteins of starch biosynthesis in potato tubers have been identified by co-expression and their expression was verified by quantitative RT-PCR

How Potato Plants Take the Heat?

AbstractPotato is the third most important food crop in the world after rice and wheat. Because of its widely distributed cultivation and high yields, it is considered a critical species in terms of food security in face of a growing world population. However, potato is particularly vulnerable to high temperature during various stages of its life cycle. Elevated temperatures strongly suppress tuberization, negatively affect storage and shelf life of tubers and reduce fitness of seed potatoes. Breeding new heat-stress tolerant cultivars is therefore an urgent need for sustainable increases in potato production. To achieve this goal an integrated approach combining physiology, biochemistry and molecular genetics is followed to analyze the impact of elevated temperatures on source-sink relations of potato plants, potato tuber development, starch accumulation and tuber quality and tuber dormancy. First results indicate that heat effects source-sink relations by altered expression of the tuber inducing signal FT, by stimulating shade-avoidance responses of the shoot and by decreasing sink-strength of developing tubers. Sink strength of growing potato tubers is mainly regulated by the activity of sucrose synthase. Measuring sucrose synthase expression and activity of heat grown potato tubers revealed a significant down-regulation of the enzyme which is consistent with reduced tuber growth. Interestingly, genetic variation in the activity of sucrose synthase exists, potentially enabling selection of potato varieties with heat-tolerant sucrose synthase isoforms. Although FT seems to play a major role in regulating tuberization, sink-derived and additional source signals are likely to be involved in orchestrating the heat-induced shift in assimilate allocation. This assumption is based on experiments in which soil and air temperatures of pot grown potato plants were independently controlled in growth chambers and transcript as well as sugar and enzyme profiles were recorded. Results of this analysis and their implication to improve heat tolerance of potato plants will be discussed

Effects of food matrix on the prebiotic efficacy of inulin-type fructans: a randomised trial

Recently there is much debate in the scientific community over the impact of the food matrix on prebiotic efficacy of inulin-type fructans. Previous studies suggest that prebiotic selectivity of inulin-type fructans towards bifidobacteria is unaffected by the food matrix. Due to differences in study design, definitive conclusions cannot be drawn from these findings with any degree of certainty. In this randomised trial, we aimed to determine the effects that different food matrices had on the prebiotic efficacy of inulin-type fructans following a standardised 10-day, 4-arm, parallel, randomised protocol with inulin either in pure form or incorporated into shortbread biscuits, milk chocolate or a rice drink. Similar increases in Bifidobacterium counts were documented across all four interventions using both fluorescence in situ hybridisation (pure inulin: 0.63; shortbread: 0.59; milk chocolate: 0.65 and rice drink: 0.71 (log10 cells/g wet faeces) and 16S rRNA sequencing quantitative microbiome profiling data (pure inulin: 1.21 × 109; shortbread: 1.47 × 109; milk chocolate: 8.59 × 108 and rice drink: 1.04 × 109 (cells/g wet faeces) (all ). From these results, we can confirm that irrespective of the food matrix, the selectivity of inulin-type fructans towards Bifidobacterium is unaffected, yet the compositional make-up of the food matrix may have implications regarding wider changes in the microbiota

Oligofructose, 2'fucosyllactose and β-glucan in combination induce specific changes in microbial composition and short-chain fatty acid production compared to sole supplementation

In this study, we explored the effects that the prebiotic inulin-type fructans, and prebiotic candidates: 2'fucosyllactose and β-glucan from barley, singular and in combination had on microbial load, microbiome profile, and short-chain fatty acid production. This was carried out as a prescreening tool to determine combinations that could be taken forward for use in a human intervention trial. Effects of inulin-type fructans, 2'fucosyllactose and β-glucan from barley in singular and combination on microbial load and profile and short-chain fatty acid production (SCFA) was conducted using in vitro batch culture fermentation over 48 h. Changes in microbial load and profile were assessed by fluorescence in situ hybridization flow cytometry (FISH-FLOW) and 16S rRNA sequencing, and changes in SCFA via gas chromatography. All substrates generated changes in microbial load and profile, achieving peak microbial load at 8 h fermentation with the largest changes in profile across all substrates in Bifidobacterium (Q < 0.05). This coincided with significant increases in acetate observed throughout fermentation (Q < 0.05). In comparison to sole supplementation combinations of oligofructose, β-glucan and 2'fuscosyllactose induced significant increases in both propionate and butyrate producing bacteria (Roseburia and Faecalibacterium praunitzii), and concentrations of propionate and butyrate, the latter being maintained until the end of fermentation (all Q < 0.05). Combinations of oligofructose, with β-glucan and 2'fucosyllactose induced selective changes in microbial combination and SCFA namely Roseburia, F. praunitzii, propionate and butyrate compared to sole supplementation. [Abstract copyright: © The Author(s) 2022. Published by Oxford University Press on behalf of Applied Microbiology International.

Inulin-type fructans and 2'fucosyllactose alter both microbial composition and appear to alleviate stress-induced mood state in a working population compared to placebo (maltodextrin): the EFFICAD Trial, a randomized, controlled trial

There is increasing interest in the bi-directional relationship existing between the gut and brain and the effects of both oligofructose and 2'fucosyllactose to alter microbial composition and mood state. Yet, much remains unknown about the ability of oligofructose and 2'fucosyllactose to improve mood state via targeted manipulation of the gut microbiota. We aimed to compare the effects of oligofructose and 2'fucosyllactose alone and in combination against maltodextrin (comparator) on microbial composition and mood state in a working population. We conducted a 5-week, 4-arm, parallel, double-blind, randomised, placebo-controlled trial in 92 healthy adults with mild-to-moderate levels of anxiety and depression. Subjects were randomised to oligofructose 8 g/day (plus 2 g/day maltodextrin); maltodextrin 10 g/day; oligofructose 8 g/day plus 2'fucosyllactose (2 g/day) or 2'fucosyllactose 2 g/day plus (8 g/day maltodextrin). Changes in microbial load (FISH-FLOW) and composition (16s rRNA sequencing) were the primary outcomes. Secondary outcomes included gastrointestinal sensations, bowel habits and mood state parameters. There were significant increases in several bacterial taxa including Bifidobacterium, Bacteroides, Roseburia and Faecalibacterium prausnitzii in both the oligofructose and oligofructose/2'fucosyllactose interventions (all P ≤ 0.05). Changes in bacterial taxa were highly heterogenous upon 2'fuscoyllactose supplementation. Significant improvements in Beck Depression Inventory, State Trait Anxiety Inventory Y1 and Y2, and Positive and Negative Affect Schedule scores and cortisol awakening response were detected across oligofructose, and 2'fucosyllactose and oligofructose/2'fucosyllactose combination interventions (all P ≤ 0.05). Both sole oligofructose and oligofructose/2'fuscosyllactose combination interventions outperformed both sole 2'fucosyllactose and maltodextrin in improvements in several mood state parameters (all P ≤ 0.05). The results of this study indicate that oligofructose and combination of oligofructose/2'fucosyllactose, can beneficially alter microbial composition along with improving mood state parameters. Future work is needed to understand key microbial differences separating individual responses to 2'fucosyllactose supplementation. ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT05212545): NCT05212545

What led Tel Aviv to become a leading entrepreneurial ecosystem?

“How has Tel Aviv become a leading entrepreneurial ecosystem? ” This thesis investigates the factors behind the growing success of Tel Aviv as an entrepreneurial scene. The economic capital of Israel has become one of the most important clusters of innovation in the World (Engel & del-Palacio, 2011). By analysing these factors with key entrepreneurial actors, the hopes were to find new qualitative evidence to back up the statistics. The aim of the thesis was to use qualitative interviews with chosen entrepreneurs and investors to give insights in Tel Aviv and how it has become a flourishing ecosystem. This has in turn enhanced the previous research on Knowledge-Intensive entrepreneurship by adding a singular case study. Analysing the Tel Aviv ecosystem allowed me to find ten different factors of its success. These can potentially be used as inspiration points for stimulating clusters of innovation around the World.MSc in Knowledge-based Entrepreneurshi