A Small In Vitro Fermentation Model for Screening the Gut Microbiota Effects of Different Fiber Preparations

The development of prebiotic fibers requires fast high-throughput screening of their effects on the gut microbiota. We demonstrated the applicability of a mictotiter plate in the in vitro fermentation models for the screening of potentially-prebiotic dietary fibers. The effects of seven rye bran-, oat- and linseed-derived fiber preparations on the human fecal microbiota composition and short-chain fatty acid production were studied. The model was also used to study whether fibers can alleviate the harmful effects of amoxicillin-clavulanate on the microbiota. The antibiotic induced a shift in the bacterial community in the absence of fibers by decreasing the relative amounts of Bifidobacteriaceae, Bacteroidaceae, Prevotellaceae, Lachnospiraceae and Ruminococcaceae, and increasing proteobacterial Sutterilaceae levels from 1% to 11% of the total microbiota. The fermentation of rye bran, enzymatically treated rye bran, its insoluble fraction, soluble oat fiber and a mixture of rye fiber:soluble oat fiber:linseed resulted in a significant increase in butyrate production and a bifidogenic effect in the absence of the antibiotic. These fibers were also able to counteract the negative effects of the antibiotic and prevent the decrease in the relative amount of bifidobacteria. Insoluble and soluble rye bran fractions and soluble oat fiber were the best for controlling the level of proteobacteria at the level below 2%.

Download Full-text

Potential of phenolic compounds and their gut microbiota-derived metabolites to reduce microbial TMA formation: Application of an in vitro fermentation high throughput screening model

10.33774/chemrxiv-2021-q1q7z-v2 ◽

2022 ◽

Author(s):

Lisard Iglesias-Carres ◽

Emily Krueger ◽

Jacob Herring ◽

Jeffery Tessem ◽

Andrew Neilson

Keyword(s):

Gut Microbiota ◽

Caffeic Acid ◽

High Throughput Screening ◽

Ex Vivo ◽

Inhibitory Effects ◽

In Vitro Fermentation ◽

Choline Metabolism ◽

Fermentation Model

Trimethylamine N-oxide (TMAO) is a pro-atherosclerotic product of dietary choline metabolism generated by a microbiome-host axis. The first step in this pathway is enzymatic metabolism of choline to trimethylamine (TMA) by the gut microbiota. This reaction could be targeted to reduce atherosclerosis risk. We aimed to evaluate potential inhibitory effects of select dietary phenolics and their relevant gut microbial metabolites on TMA production via a human ex vivo-in vitro fermentation model. Various phenolics inhibited choline use and TMA production. The most bioactive compounds tested (caffeic acid, catechin and epicatechin) reduced TMA-d9 formation (compared to control) by 57.5 ± 1.3% to 72.5 ± 0.4% at 8 h and preserved remaining choline-d9 concentrations by 194.1 ± 6.4% to 256.1 ± 6.3% compared to control conditions at 8 h. These inhibitory effects were achieved without altering cell respiration or cell growth. However, inhibitory effects decreased at late fermentation times, which suggest that these compounds delay choline metabolism rather than completely inhibiting TMA formation. Overall, caffeic acid, catechin and epicatechin were the most effective non-cytotoxic inhibitors of choline use and TMA production. Thus, these compounds are proposed as lead bioactives to test in vivo.

Download Full-text

Potential of phenolic compounds and their gut microbiota-derived metabolites to reduce microbial TMA formation: Application of an in vitro fermentation high throughput screening model

10.33774/chemrxiv-2021-q1q7z ◽

2021 ◽

Author(s):

Lisard Iglesias-Carres ◽

Emily Krueger ◽

Jacob Herring ◽

Jeffery Tessem ◽

Andrew Neilson

Keyword(s):

Gut Microbiota ◽

High Throughput Screening ◽

Ex Vivo ◽

Inhibitory Effects ◽

In Vitro Fermentation ◽

Choline Metabolism ◽

Fermentation Model ◽

Dietary Choline

Trimethylamine N-oxide (TMAO) is a pro-atherosclerotic product of dietary choline metabolism generated by a microbiome-host axis. The first step in this pathway is enzymatic metabolism of choline to trimethylamine (TMA) by the gut microbiota. This reaction could be targeted to reduce atherosclerosis risk. We aimed to evaluate potential inhibitory effects of select dietary phenolics and their relevant gut microbial metabolites on TMA production via a human ex vivo-in vitro fermentation model. Various phenolics inhibited choline use and TMA production, especially larger compounds or their larger metabolites, without altering cell respiration or cell growth. However, inhibitory effects decreased at late fermentation times, which suggest that these compounds delay choline metabolism rather than completely inhibiting TMA formation. Overall, caffeic acid, catechin and epicatechin were the most effective non-cytotoxic inhibitors of choline use and TMA production. Thus, these compounds are proposed as lead bioactives to test in vivo.

Download Full-text

In Vitro Fermentation of Selected Prebiotics and Their Effects on the Composition and Activity of the Adult Gut Microbiota

International Journal of Molecular Sciences ◽

10.3390/ijms19103097 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3097 ◽

Cited By ~ 43

Author(s):

Sophie Fehlbaum ◽

Kevin Prudence ◽

Jasper Kieboom ◽

Margreet Heerikhuisen ◽

Tim van den Broek ◽

...

Keyword(s):

Gut Microbiota ◽

Fecal Microbiota ◽

Negative Control ◽

Dietary Fibers ◽

Beta Glucan ◽

Microbial Composition ◽

Fatty Acid Production ◽

Potential Health ◽

In Vitro Fermentation

Recently, the concept of prebiotics has been revisited to expand beyond non-digestible oligosaccharides, and the requirements for selective stimulation were extended to include microbial groups other than, and additional to, bifidobacteria and lactobacilli. Here, the gut microbiota-modulating effects of well-known and novel prebiotics were studied. An in vitro fermentation screening platform (i-screen) was inoculated with adult fecal microbiota, exposed to different dietary fibers that had a range of concentrations (inulin, alpha-linked galacto-oligosaccharides (alpha-GOS), beta-linked GOS, xylo-oligosaccharides (XOS) from corn cobs and high-fiber sugar cane, and beta-glucan from oats), and compared to a positive fructo-oligosaccharide (FOS) control and a negative control (no fiber addition). All dietary fibers displayed prebiotic activity, with beta-glucan showing more distinct effects on the microbial composition and metabolism compared to the other fibers. Beta-glucan induced the growth of Prevotella and Roseburia with a concomitant increase in propionate production. Inulin and both forms of GOS and XOS had a strong bifidogenic effect on the microbial composition. A dose-response effect was observed for butyrate when exposed to beta-glucan and inulin. The findings of this study support the potential for alpha-GOS, XOS, and oat beta-glucan to serve as novel prebiotics, due to their association with the positive shifts in microbiome composition and short-chain fatty acid production that point to potential health benefits.

Download Full-text

Effects of exopolysaccharide from Lactobacillus rhamnosus on human gut microbiota in in vitro fermentation model

LWT ◽

10.1016/j.lwt.2020.110524 ◽

2020 ◽

pp. 110524

Author(s):

Yuzhu Zhu ◽

Jia-Min Zhou ◽

Wei Liu ◽

Xionge Pi ◽

Qingqing Zhou ◽

...

Keyword(s):

Gut Microbiota ◽

Lactobacillus Rhamnosus ◽

Human Gut ◽

In Vitro Fermentation ◽

Human Gut Microbiota ◽

Fermentation Model

Download Full-text

Short Chain Fatty Acid Production from Mycoprotein and Mycoprotein Fibre in an In Vitro Fermentation Model

Nutrients ◽

10.3390/nu11040800 ◽

2019 ◽

Vol 11 (4) ◽

pp. 800 ◽

Cited By ~ 5

Author(s):

Hannah Harris ◽

Christine Edwards ◽

Douglas Morrison

Keyword(s):

Energy Intake ◽

Short Chain Fatty Acid ◽

Short Chain Fatty Acids ◽

Chain Fatty Acid ◽

Fibre Content ◽

Short Chain ◽

Fatty Acid Production ◽

In Vitro Fermentation ◽

Fermentation Model

Dietary mycoprotein (marketed as QuornTM) has many health benefits, including reductions in energy intake. The majority of studies evaluating mycoprotein focus on the protein content and very few consider the fibre content. Fibre consumption is also associated with decreased energy intake, which is partly attributed to short chain fatty acids (SCFAs) from fibre fermentation by colonic bacteria. To study the SCFA-producing capability of mycoprotein, in vitro batch fermentations were conducted, and SCFA production compared with that from extracted mycoprotein fibre, oligofructose (OF), rhamnose, and laminarin. Mycoprotein and mycoprotein fibre were both fermentable, resulting in a total SCFA production of 24.9 (1.7) and 61.2 (15.7) mmol/L, respectively. OF led to a significantly higher proportion of acetate compared to all other substrates tested (92.6 (2.8)%, p < 0.01). Rhamnose generated the highest proportion of propionate (45.3 (2.0)%, p < 0.01), although mycoprotein and mycoprotein fibre yielded a higher proportion of propionate compared with OF and laminarin. Butyrate proportion was the highest with laminarin (28.0 (10.0)although mycoprotein fibre led to a significantly higher proportion than OF (p < 0.01). Mycoprotein is a valuable source of dietary protein, but its fibre content is also of interest. Further evaluation of the potential roles of the fibre content of mycoprotein is required.

Download Full-text

In Vitro Fermentation of Sheep and Cow Milk Using Infant Fecal Bacteria

Nutrients ◽

10.3390/nu12061802 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1802 ◽

Cited By ~ 1

Author(s):

Natalie Ahlborn ◽

Wayne Young ◽

Jane Mullaney ◽

Linda M. Samuelsson

Keyword(s):

Fatty Acids ◽

Gut Microbiota ◽

Large Bowel ◽

Short Chain Fatty Acids ◽

Fecal Microbiota ◽

Cow Milk ◽

Fecal Material ◽

In Vitro Fermentation ◽

Sheep Milk

While human milk is the optimal food for infants, formulas that contain ruminant milk can have an important role where breastfeeding is not possible. In this regard, cow milk is most commonly used. However, recent years have brought interest in other ruminant milk. While many similarities exist between ruminant milk, there are likely enough compositional differences to promote different effects in the infant. This may include effects on different bacteria in the large bowel, leading to different metabolites in the gut. In this study sheep and cow milk were digested using an in vitro infant digestive model, followed by fecal fermentation using cultures inoculated with fecal material from two infants of one month and five months of age. The effects of the cow and sheep milk on the fecal microbiota, short-chain fatty acids (SCFA), and other metabolites were investigated. Significant differences in microbial, SCFA, and metabolite composition were observed between fermentation of sheep and cow milk using fecal inoculum from a one-month-old infant, but comparatively minimal differences using fecal inoculum from a five-month-old infant. These results show that sheep milk and cow milk can have differential effects on the gut microbiota, while demonstrating the individuality of the gut microbiome.

Download Full-text

In Vitro Digestion and Fermentation by Human Fecal Microbiota of Polysaccharides from Flaxseed

Molecules ◽

10.3390/molecules25194354 ◽

2020 ◽

Vol 25 (19) ◽

pp. 4354

Author(s):

Xin Zhou ◽

Zhao Zhang ◽

Fenghong Huang ◽

Chen Yang ◽

Qingde Huang

Keyword(s):

Gut Microbiota ◽

Reducing Sugars ◽

In Vitro Digestion ◽

Short Chain Fatty Acids ◽

Fecal Microbiota ◽

Gut Health ◽

Human Gut ◽

In Vitro Fermentation ◽

Composition And Structure

The digestion of flaxseed polysaccharides (FSP) in simulated saliva, gastric and small intestine conditions was assessed, as well as in vitro fermentation of FSP by human gut microbiota. FSP was not degraded in the simulated digestive systems (there was no change in molecular weight or content of reducing sugars), indicating that ingested FSP would reach the large intestine intact. Changes in carbohydrate content, reducing sugars and culture pH suggested that FSP could be broken down and used by gut microbiota. FSP modulated the composition and structure of the gut microbiota by altering the Firmicutes/Bacteroidetes ratio and increasing the relative abundances of Prevotella, Phascolarctobacterium, Clostridium and Megamonas, which can degrade polysaccharides. Meanwhile, FSP fermentation increased the concentration of short-chain fatty acids, especially propionic and butyric acids. Our results indicate that FSP might be developed as a functional food that benefits gut health.

Download Full-text