Absolute abundance values reveal microbial shifts and co-occurrence patterns during gut microbiota fermentation of dietary fibres in vitro

AbstractAlterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. The present study tested the hypothesis that obese individuals subjected for 12 weeks to an inulin-enriched v. inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received a fructan-rich diet for 3 weeks produces more gas and total SCFA compared with the microbiota taken from the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared with the treated group. The present study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favours the production of specific bioactive metabolites.

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The effects of fermentation products of prebiotic fibres on gut barrier and immune functions in vitro

PeerJ ◽

10.7717/peerj.5288 ◽

2018 ◽

Vol 6 ◽

pp. e5288 ◽

Cited By ~ 13

Author(s):

Van T. Pham ◽

Nicole Seifert ◽

Nathalie Richard ◽

Daniel Raederstorff ◽

Robert Steinert ◽

...

Keyword(s):

Gut Microbiota ◽

Gut Barrier ◽

Mucus Production ◽

Fermentation Products ◽

Barrier Integrity ◽

Positive Effects ◽

Dietary Fibres ◽

Chicory Root ◽

Luminex Technology

The beneficial effects of prebiotic fibres on human health have been related to their capacities to alter the gut microbiota and modify the growth of beneficial microorganisms. It is long appreciated that bacterial metabolites affect the host’s physiology. The inner lining of the intestinal tract is the first level of interaction between the host and bacteria and their metabolites. Therefore, we set out to test the effects of five common dietary fibres (oat β-glucan 28%; oat β-glucan 94%; dried chicory root containing inulin 75%; xylo-oligosaccharide; inulin 90%) and maltodextrin, after fermentation by human gut microbiota in vitro, on measures of gut barrier integrity using a Caco-2/HT29-MTX co-culture as well as mucus production and immune parameters using HT29-MTX and HT29 cell models, respectively. Our data show that all fibres, fermentation products increased the tightness of the gut barrier with oat β-glucan 28% having the largest effect. Fermentation supernatants were tested also in models of the compromised gut barrier (leaky gut). After the addition of ethanol as basolateral stressor, only fermentation supernatant of oat β-glucan 28%, oat β-glucan 94% and maltodextrin improved the gut barrier integrity, while oat β-glucan 28% and dried chicory root containing inulin 75% significantly improved the gut barrier integrity after addition of rhamnolipids as apical stressor. Using the Luminex Technology, we demonstrated an important role of oat β-glucan fermentation products in modulating cytokine and chemokine productions. Furthermore, treating the goblet cells with effluent from xylo-oligosaccharide fermentation significantly increased mucus production. In summary, our data emphasize the potential positive effects of fermentation supernatant of dietary fibres on gut-related physiological outcomes and show that prebiotic fibres may have promising potential to induce specific gut health benefits.

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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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