The bioavailability of soy isoflavones in vitro and their effects on gut microbiota in the simulator of the human intestinal microbial ecosystem

Background: Enterococci are used in a large number of dairy products, such as starter cultures in food supplements and in foods considered functional. In vitro gut fermentation models present an unmatched opportunity of performing studies frequently allenged in humans and animals owing to ethical concerns. A dynamic model of the human intestinal microbial ecosystem (SHIME) was designed to better simulate conditions intestinal microbiota.Methods: The SHIME model was used to study the effect of Enterococuus faecium CRL 183 on the fermentation pattern of the colon microbiota. Initially, an inoculum prepared from human feces was introduced into the reactor vessels and stabilized over 2 wk using a culture medium. This stabilization period was followed by a 2-wk control period during which the microbiota were monitored. The microbiota were then subjected to a 4-wk treatment period by adding 108 CFU/mL of the Enterococcus faecium CRL 183 to vessel one (the stomach compartment).Results: The addition resulted into an overall increase of bacterial marker populations (Enterobacteriaceae, Lactobacillus spp., Bifidobacterium spp. and Clostridium spp.), with a significant increase of the Lactobacillus sp. and Bifidobacterium sp populations. The short-chain fatty acid (SCFA) concentration increased during the supplementation period; this was due mainly to a significant increase in the levels of acetic, butyric and propionic acids. Ammonium concentrations increased during the supplementation period.Conclusions: Results showed that the major effect of E. faecium CRL 183 was found in the ascendant and transverse colon. Key words: Gut microbiota, Enterococcus, Gastrointestinal resource management, Simulator of Human Intestinal Microbial Ecosystem (SHIME)

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The efficacy and effect on gut microbiota of an aflatoxin binder and a fumonisin esterase using an in vitro simulator of the human intestinal microbial ecosystem (SHIME®)

Food Research International ◽

10.1016/j.foodres.2021.110395 ◽

2021 ◽

pp. 110395

Author(s):

Kaat Neckermann ◽

Gregor Claus ◽

Siegrid De Baere ◽

Gunther Antonissen ◽

Sarah Lebrun ◽

...

Keyword(s):

Gut Microbiota ◽

Microbial Ecosystem

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Mucin as a Functional Niche is a More Important Driver of in Vitro Gut Microbiota Composition and Functionality than Supplementation of Akkermansia muciniphila

Applied and Environmental Microbiology ◽

10.1128/aem.02647-20 ◽

2020 ◽

Author(s):

Florence Van Herreweghen ◽

Kim De Paepe ◽

Massimo Marzorati ◽

Tom Van de Wiele

Keyword(s):

Gut Microbiota ◽

Microbial Community Composition ◽

Microbiota Composition ◽

Gut Health ◽

Microbial Ecosystem ◽

Ongoing Research ◽

Akkermansia Muciniphila ◽

The Impact

IMPORTANCE SECTION Research into identification of biomarkers for gut health and ways to modulate the microbiota composition and activity to improve health, has put Akkermansia muciniphila in the spotlight. As a mucin degrader, A. muciniphila colonizes the interesting but not-fully described host-glycan degradation niche., . Plenty of research concerning A. muciniphila has been done, but little is known about its behavior in the complex microbial ecosystem in the colon, about the potential role of mucins to influence A. muciniphila behavior and the impact of its probiotic administration on the microbial ecosystem. This study aimed at investigating the impact of A. muciniphila administration on the endogenous community while also taking into account its nutritional specificity. As such, the effect of A.mucinihpila administration was investigated with and without addition of mucin. This allowed us to elucidate the importance of mucin presence to modulate the efficiency of the probiotic supplementation with A. muciniphila. Akkermansia muciniphila is an abundantly present commensal mucin degrading gut bacterium (1 – 4%) , widely distributed among healthy individuals. It has been positioned as a health biomarker and is currently explored as a biotherapeutic agent and next generation probiotic. Preliminary and ongoing research is mostly based on in vivo mouse models and human intervention trials. While these allow the assessment of physiologically relevant endpoints, the analysis of fecal samples presents limitations with respect to the in-depth mechanistic characterization of Akkermansia effects at the level of the microbiome. We aimed to evaluate the effect of A. muciniphila treatment on the endogenous community from four different donors in a validated, controlled in vitro model of the gut microbial ecosystem (SHIME). Taking into account the nutritional specificity of A. muciniphila, and the prebiotic-like action of mucins in the colon environment, the interplay between mucin, A. muciniphila and the endogenous community was investigated. The effects on the microbial community composition and functionality of A. muciniphila supplementation without mucin were limited, whereas mucin addition successfully induced compositional and metabolic changes in the gut microbiota. Indeed, mucin addition resulted in significantly higher acetate, propionate and butyrate production for all four donors, and the increase of several species, including A. muciniphila, Ruminococcus, Clostridium cluster XIVa, and Lachnospiraceae. This study revealed that the supplementation of A. muciniphila together with mucin limited the observed prebiotic-like effect of mucin in inducing compositional changes.

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In vitro study of the interaction between human gut microbiota and herbal extracts using willow bark extract as an example

Planta Medica ◽

10.1055/s-0036-1596386 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

EM Pferschy-Wenzig ◽

K Koskinen ◽

C Moissl-Eichinger ◽

R Bauer

Keyword(s):

Gut Microbiota ◽

In Vitro Study ◽

Vitro Study ◽

Bark Extract ◽

Herbal Extracts ◽

Human Gut ◽

Human Gut Microbiota ◽

Willow Bark

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Metabolization of the herbal combination STW-5 by human gut microbiota in vitro

10.1055/s-0037-1608399 ◽

2017 ◽

Author(s):

EM Pferschy-Wenzig ◽

A Roßmann ◽

K Koskinen ◽

H Abdel-Aziz ◽

C Moissl-Eichinger ◽

...

Keyword(s):

Gut Microbiota ◽

Human Gut ◽

Human Gut Microbiota

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Preservation of Human Gut Microbiota Inoculums for In Vitro Fermentations Studies

Fermentation ◽

10.3390/fermentation7010014 ◽

2021 ◽

Vol 7 (1) ◽

pp. 14

Author(s):

Nelson Mota de Carvalho ◽

Diana Luazi Oliveira ◽

Mayra Anton Dib Saleh ◽

Manuela Pintado ◽

Ana Raquel Madureira

Keyword(s):

Gut Microbiota ◽

Metabolic Profile ◽

Bacterial Count ◽

Glycerol Solution ◽

Metabolic Profiles ◽

Human Gut ◽

Colonic Fermentation ◽

In Vitro Fermentation ◽

Fecal Samples

The use of fecal inoculums for in vitro fermentation models requires a viable gut microbiota, capable of fermenting the unabsorbed nutrients. Fresh samples from human donors are used; however, the availability of fresh fecal inoculum and its inherent variability is often a problem. This study aimed to optimize a method of preserving pooled human fecal samples for in vitro fermentation studies. Different conditions and times of storage at −20 °C were tested. In vitro fermentation experiments were carried out for both fresh and frozen inoculums, and the metabolic profile compared. In comparison with the fresh, the inoculum frozen in a PBS and 30% glycerol solution, had a significantly lower (p < 0.05) bacterial count (<1 log CFU/mL). However, no significant differences (p < 0.05) were found between the metabolic profiles after 48 h. Hence, a PBS and 30% glycerol solution can be used to maintain the gut microbiota viability during storage at −20 °C for at least 3 months, without interfering with the normal course of colonic fermentation.

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Wheat cell walls and constituent polysaccharides induce similar microbiota profiles upon in vitro fermentation despite different short chain fatty acid end-product levels.

Food & Function ◽

10.1039/d0fo02509g ◽

2021 ◽

Author(s):

Shiyi Lu ◽

Deirdre Mikkelsen ◽

Hong Yao ◽

Barbara Williams ◽

Bernadine Flanagan ◽

...

Keyword(s):

Fatty Acid ◽

Gut Microbiota ◽

Plant Cell ◽

Cell Walls ◽

Short Chain Fatty Acid ◽

Chain Fatty Acid ◽

Plant Cell Walls ◽

Human Gut ◽

In Vitro Fermentation

Plant cell walls as well as their component polysaccharides in foods can be utilized to alter and maintain a beneficial human gut microbiota, but it is not known whether the...

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The use of an in-vitro batch fermentation (human colon) model for investigating mechanisms of TMA production from choline, l-carnitine and related precursors by the human gut microbiota

European Journal of Nutrition ◽

10.1007/s00394-021-02572-6 ◽

2021 ◽

Author(s):

Priscilla Day-Walsh ◽

Emad Shehata ◽

Shikha Saha ◽

George M. Savva ◽

Barbora Nemeckova ◽

...

Keyword(s):

Gut Microbiota ◽

Metabolic Diseases ◽

Human Colon ◽

Human Studies ◽

Bacterial Strains ◽

Increased Risk ◽

Carnitine Metabolism ◽

Registration Number ◽

Vitro Model

Abstract Purpose Plasma trimethylamine-N-oxide (TMAO) levels have been shown to correlate with increased risk of metabolic diseases including cardiovascular diseases. TMAO exposure predominantly occurs as a consequence of gut microbiota-dependent trimethylamine (TMA) production from dietary substrates including choline, carnitine and betaine, which is then converted to TMAO in the liver. Reducing microbial TMA production is likely to be the most effective and sustainable approach to overcoming TMAO burden in humans. Current models for studying microbial TMA production have numerous weaknesses including the cost and length of human studies, differences in TMA(O) metabolism in animal models and the risk of failing to replicate multi-enzyme/multi-strain pathways when using isolated bacterial strains. The purpose of this research was to investigate TMA production from dietary precursors in an in-vitro model of the human colon. Methods TMA production from choline, l-carnitine, betaine and γ-butyrobetaine was studied over 24–48 h using an in-vitro human colon model with metabolite quantification performed using LC–MS. Results Choline was metabolised via the direct choline TMA-lyase route but not the indirect choline–betaine-TMA route, conversion of l-carnitine to TMA was slower than that of choline and involves the formation of the intermediate γ-BB, whereas the Rieske-type monooxygenase/reductase pathway for l-carnitine metabolism to TMA was negligible. The rate of TMA production from precursors was choline > carnitine > betaine > γ-BB. 3,3-Dimethyl-1-butanol (DMB) had no effect on the conversion of choline to TMA. Conclusion The metabolic routes for microbial TMA production in the colon model are consistent with observations from human studies. Thus, this model is suitable for studying gut microbiota metabolism of TMA and for screening potential therapeutic targets that aim to attenuate TMA production by the gut microbiota. Trial registration number NCT02653001 (http://www.clinicaltrials.gov), registered 12 Jan 2016.

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