scholarly journals Intestinal fermentation in vitro models to study food-induced gut microbiota shift: an updated review

2020 ◽  
Vol 367 (12) ◽  
Author(s):  
Lorenzo Nissen ◽  
Flavia Casciano ◽  
Andrea Gianotti

ABSTRACT In vitro gut fermentation models were firstly introduced in nutrition and applied microbiology research back in the 1990s. These models have improved greatly during time, mainly over the resemblance to the complexity of digestion stages, the replication of experimental conditions, the multitude of ecological parameters to assay. The state of the science is that the most competitive models shall include a complex gut microbiota, small working volumes, distinct interconnected compartments and rigorous bio-chemical and ecological settings, controlled by a computer, as well as a free-hands accessibility, not to contaminate the mock microbiota. These models are a useful tool to study the impact of a given diet compound, e.g. prebiotics, on the human gut microbiota. The principal application is to focus on the shift of the core microbial groups and selected species together with their metabolites, assaying their diversity, richness and abundance in the community over time. Besides, it is possible to study how a compound is digested, which metabolic pathways are triggered, and the type and quantity of microbial metabolites produced. Further prospective should focus on challenges with pathogens as well as on ecology of gut syndromes. In this minireview an updated presentation of the most used intestinal models is presented, basing on their concept, technical features, as well as on research applications.

2021 ◽  
pp. 1-16
Author(s):  
M.E. Arnal ◽  
S. Denis ◽  
O. Uriot ◽  
C. Lambert ◽  
S. Holowacz ◽  
...  

Health benefits of probiotics in humans essentially depend on their ability to survive during gastrointestinal (GI) transit and to modulate gut microbiota. To date, there is few data on the impact of galenic formulations of probiotics on these parameters. Even if clinical studies remain the gold standard to evaluate the efficacy of galenic forms, they stay hampered by technical, ethical and cost reasons. As an alternative approach, we used two complementary in vitro models of the human gut, the TNO gastrointestinal (TIM-1) model and the Artificial Colon (ARCOL), to study the effect of three oral formulations of a Lactobacillus salivarius strain (powder, capsule and sustained-release tablet) on its viability and interactions with gut microbiota. In the TIM-1 stomach, no or low numbers of bacteria were respectively released from the capsule and tablet, confirming their gastro-resistance. The capsule was disintegrated in the jejunum on average 76 min after administration while the core of sustained-release tablet was still intact at the end of digestion. Viability in TIM-1 was significantly influenced by the galenic form with survival percentages of 0.003±0.004%, 2.8±0.6% and 17.0±1.8% (n=3) for powder, capsule and tablet, respectively. In the ARCOL, the survival of the strain tended to be higher in the post-treatment phase with the tablet compared to capsule, but gut microbiota composition and activity were not differently modulated by the two formulations. In conclusion, the sustained-release tablet emerged as the formulation that most effectively preserved viability of the tested strain during GI passage. This study highlights the usefulness of in vitro gut models for the pre-screening of probiotic pharmaceutical forms. Their use could also easily be extended to the evaluation of the effects of food matrices and age on probiotic survival and activity during GI transit.


2019 ◽  
Vol 25 (37) ◽  
pp. 4946-4967 ◽  
Author(s):  
Anna K. Kiss ◽  
Jakub P. Piwowarski

The popularity of food products and medicinal plant materials containing hydrolysable tannins (HT) is nowadays rapidly increasing. Among various health effects attributable to the products of plant origin rich in gallotannins and/or ellagitannins the most often underlined is the beneficial influence on diseases possessing inflammatory background. Results of clinical, interventional and animal in vivo studies clearly indicate the antiinflammatory potential of HT-containing products, as well as pure ellagitannins and gallotannins. In recent years a great emphasis has been put on the consideration of metabolism and bioavailability of natural products during examination of their biological effects. Conducted in vivo and in vitro studies of polyphenols metabolism put a new light on this issue and indicate the gut microbiota to play a crucial role in the health effects following their oral administration. The aim of the review is to summarize the knowledge about HT-containing products’ phytochemistry and their anti-inflammatory effects together with discussion of the data about observed biological activities with regards to the current concepts on the HTs’ bioavailability and metabolism. Orally administered HT-containing products due to the limited bioavailability of ellagitannins and gallotannins can influence immune response at the level of gastrointestinal tract as well as express modulating effects on the gut microbiota composition. However, due to the chemical changes being a result of their transit through gastrointestinal tract, comprising of hydrolysis and gut microbiota metabolism, the activity of produced metabolites has to be taken into consideration. Studies regarding biological effects of the HTs’ metabolites, in particular urolithins, indicate their strong and structure-dependent anti-inflammatory activities, being observed at the concentrations, which fit the range of their established bioavailability. The impact of HTs on inflammatory processes has been well established on various in vivo and in vitro models, while influence of microbiota metabolites on silencing the immune response gives a new perspective on understanding anti-inflammatory effects attributed to HT containing products, especially their postulated effectiveness in inflammatory bowel diseases (IBD) and cardiovascular diseases.


Author(s):  
Leonardo Mancabelli ◽  
Walter Mancino ◽  
Gabriele Andrea Lugli ◽  
Chiara Argentini ◽  
Giulia Longhi ◽  
...  

Amoxicillin-Clavulanic acid (AMC) is one of the most frequently prescribed antibiotic formulations in the Western world. Extensive oral use of this antimicrobial combination influences the gut microbiota. One of the most abundant early colonizers of the human gut microbiota is represented by different taxa of the Bifidobacterium genus, which include many members that are considered to bestow beneficial effects upon their host. In the current study, we investigated the impact of AMC administration on the gut microbiota composition, comparing the gut microbiota of 23 children that had undergone AMC antibiotic therapy to that of 19 children that had not been treated with antibiotics during the preceding six months. Moreover, we evaluated AMC sensitivity by Minimal Inhibitory Concentration (MIC) test of 261 bifidobacterial strains, including reference strains for the currently recognized 64 bifidobacterial (sub)species, as well as 197 bifidobacterial isolates of human origin. These assessments allowed the identification of four bifidobacterial strains, which exhibit a high level of AMC insensitivity, and which were subjected to genomic and transcriptomic analyses to identify the putative genetic determinants responsible for this AMC insensitivity. Furthermore, we investigated the ecological role of AMC-resistant bifidobacterial strains by in vitro batch-cultures. Importance Based on our results, we observed a drastic reduction in gut microbiota diversity of children treated with antibiotics, also affecting the abundance of Bifidobacterium, a bacterial genus commonly found in the infant gut. MIC experiments revealed that more than 98% of bifidobacterial strains tested were shown to be inhibited by the AMC antibiotic. Isolation of four insensitive strains and sequencing of their genome revealed the identity of possible genes involved in AMC resistance mechanisms. Moreover, gut-simulating in-vitro experiments revealed that one strain, i.e. B. breve PRL2020, is able to persist in the presence of a complex microbiota combined with AMC antibiotic.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245922
Author(s):  
Faye Lanni ◽  
Neil Burton ◽  
Debbie Harris ◽  
Susan Fotheringham ◽  
Simon Clark ◽  
...  

Optimised pre-clinical models are required for TB drug development to better predict the pharmacokinetics of anti-tuberculosis (anti-TB) drugs to shorten the time taken for novel drugs and combinations to be approved for clinical trial. Microdialysis can be used to measure unbound drug concentrations in awake freely moving animals in order to describe the pharmacokinetics of drugs in the organs as a continuous sampling technique. The aim of this work was to develop and optimise the microdialysis methodology in guinea pigs to better understand the pharmacokinetics of rifampicin in the lung. In vitro experiments were performed before progressing into in vivo studies because the recovery (concentration of the drug in the tissue fluid related to that in the collected dialysate) of rifampicin was dependent on a variety of experimental conditions. Mass spectrometry of the dialysate was used to determine the impact of flow rate, perfusion fluid and the molecular weight cut-off and membrane length of probes on the recovery of rifampicin at physiologically relevant concentrations. Following determination of probe efficiency and identification of a correlation between rifampicin concentrations in the lung and skeletal muscle, experiments were conducted to measure rifampicin in the sacrospinalis of guinea pigs using microdialysis. Lung concentrations of rifampicin were estimated from the rifampicin concentrations measured in the sacrospinalis. These studies suggest the potential usefulness of the microdialysis methodology to determine drug concentrations of selected anti-TB drugs to support new TB drug development.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2806 ◽  
Author(s):  
Evdokia K. Mitsou ◽  
Georgia Saxami ◽  
Emmanuela Stamoulou ◽  
Evangelia Kerezoudi ◽  
Eirini Terzi ◽  
...  

Alterations of gut microbiota are evident during the aging process. Prebiotics may restore the gut microbial balance, with β-glucans emerging as prebiotic candidates. This study aimed to investigate the impact of edible mushrooms rich in β-glucans on the gut microbiota composition and metabolites by using in vitro static batch culture fermentations and fecal inocula from elderly donors (n = 8). Pleurotus ostreatus, P. eryngii, Hericium erinaceus and Cyclocybe cylindracea mushrooms derived from various substrates were examined. Gut microbiota composition (quantitative PCR (qPCR)) and short-chain fatty acids (SCFAs; gas chromatography (GC)) were determined during the 24-h fermentation. P. eryngii induced a strong lactogenic effect, while P. ostreatus and C. cylindracea induced a significant bifidogenic effect (p for all <0.05). Furthermore, P. eryngii produced on wheat straw and the prebiotic inulin had comparable Prebiotic Indexes, while P. eryngii produced on wheat straw/grape marc significantly increased the levels of tested butyrate producers. P. ostreatus, P. eryngii and C. cylindracea had similar trends in SCFA profile; H. erinaceus mushrooms were more diverse, especially in the production of propionate, butyrate and branched SCFAs. In conclusion, mushrooms rich in β-glucans may exert beneficial in vitro effects in gut microbiota and/or SCFAs production in elderly subjects.


Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3819
Author(s):  
Carlos Poveda ◽  
Dora I. A. Pereira ◽  
Marie C. Lewis ◽  
Gemma E. Walton

Ferrous iron supplementation has been reported to adversely alter the gut microbiota in infants. To date, the impact of iron on the adult microbiota is limited, particularly at low supplementary concentrations. The aim of this research was to explore the impact of low-level iron supplementation on the gut microbiota of healthy and Irritable Bowel Syndrome (IBS) volunteers. Anaerobic, pH-controlled in vitro batch cultures were inoculated with faeces from healthy or IBS donors along with iron (ferrous sulphate, nanoparticulate iron and pea ferritin (50 μmol−1 iron)). The microbiota were explored by fluorescence in situ hybridisation coupled with flow cytometry. Furthermore, metabolite production was assessed by gas chromatography. IBS volunteers had different starting microbial profiles to healthy controls. The sources of iron did not negatively impact the microbial population, with results of pea ferritin supplementation being similar to nanoparticulate iron, whilst ferrous sulphate led to enhanced Bacteroides spp. The metabolite data suggested no shift to potentially negative proteolysis. The results indicate that low doses of iron from the three sources were not detrimental to the gut microbiota. This is the first time that pea ferritin fermentation has been tested and indicates that low dose supplementation of iron is unlikely to be detrimental to the gut microbiota.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1560-1560
Author(s):  
Inah Gu ◽  
Wing Shun Lam ◽  
Daya Marasini ◽  
Cindi Brownmiller ◽  
Brett Savary ◽  
...  

Abstract Objectives Arabinoxylan is a non-starch polysaccharide and rich in wheat, rice and many other cereal grains. Diets high in fiber help promoting gut health in obesity. The objective of this study was to investigate the impact of arabinoxylan from rice bran on the gut microbiota and short chain fatty acids (SCFA) in normal weight (NW) and overweight/obese (OO) subjects through in vitro fecal fermentation. Methods Arabinoxylan was extracted from rice bran fiber. For in vitro fecal fermentation, each fecal sample from NW (n = 6, 3 males and 3 females) and OO (n = 7, 3 males and 4 females) was diluted into anaerobic medium with three treatments: control (no substrates), fructooligosaccharides (FOS, a well-known prebiotic), and arabinoxylan. Samples were incubated at 37˚C and aliquots were taken at 0, 4, 8, 12 and 24 h. SCFA content from samples at all timepoints was analyzed using HPLC. Samples at 0 and 24 h were used for gut microbiota analysis through 16S rRNA gene sequencing. Statistical analyses were performed for the randomized complete block design, where the weight classes are confounded with blocks (subjects). Friedman test was used to determine the difference at 5% level of significance. Results As a result, arabinoxylan treatment significantly increased total SCFA concentration in both NW and OO subjects than control (P &lt; 0.05), comparable to FOS treatment. Between weight classes under arabinoxylan treatment, OO group showed a significantly higher total SCFA content than NW group (P &lt; 0.05). Arabinoxylan changed gut microbial population at the genus level, stimulating Bifidobacterium, Collinsella and Blautia and decreasing Clostridium XIVa and b, Dorea and Oscillibacter (P &lt; 0.05). In addition, different microbiome population was shown in weight classes with three treatments, showing higher Bacteroides in NW and higher Prevotella in OO. Conclusions These results showed that arabinoxylan from rice bran modified gut microbiota in both weight classes, increasing total SCFA content. This study suggests that arabinoxylan from rice bran may have a potential impact on microbial gut health in obesity with prebiotic activities. Funding Sources University of Arkansas.


mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Payal Joglekar ◽  
Hua Ding ◽  
Pablo Canales-Herrerias ◽  
Pankaj Jay Pasricha ◽  
Justin L. Sonnenburg ◽  
...  

ABSTRACT Gut-derived immunoglobulin A (IgA) is the most abundant antibody secreted in the gut that shapes gut microbiota composition and functionality. However, most of the microbial antigens targeted by gut IgA remain unknown, and the functional effects of IgA targeting these antigens are currently understudied. This study provides a framework for identifying and characterizing gut microbiota antigens targeted by gut IgA. We developed a small intestinal ex vivo culture assay to harvest lamina propria IgA from gnotobiotic mice, with the aim of identifying antigenic targets in a model human gut commensal, Bacteroides thetaiotaomicron VPI-5482. Colonization by B. thetaiotaomicron induced a microbe-specific IgA response that was reactive against diverse antigens, including capsular polysaccharides, lipopolysaccharides, and proteins. IgA against microbial protein antigens targeted membrane and secreted proteins with diverse functionalities, including an IgA specific against proteins of the polysaccharide utilization locus (PUL) that are necessary for utilization of fructan, which is an important dietary polysaccharide. Further analyses demonstrated that the presence of dietary fructan increased the production of fructan PUL-specific IgA, which then downregulated the expression of fructan PUL in B. thetaiotaomicron, both in vivo and in vitro. Since the expression of fructan PUL has been associated with the ability of B. thetaiotaomicron to colonize the gut in the presence of dietary fructans, our work suggests a novel role for gut IgA in regulating microbial colonization by modulating their metabolism. IMPORTANCE Given the significant impact that gut microbes have on our health, it is essential to identify key host and environmental factors that shape this diverse community. While many studies have highlighted the impact of diet on gut microbiota, little is known about how the host regulates this critical diet-microbiota interaction. In our present study, we discovered that gut IgA targeted a protein complex involved in the utilization of an important dietary polysaccharide: fructan. While the presence of dietary fructans was previously thought to allow unrestricted growth of fructan-utilizing bacteria, our work shows that gut IgA, by targeting proteins responsible for fructan utilization, provides the host with tools that can restrict the microbial utilization of such polysaccharides, thereby controlling their growth.


2020 ◽  
Vol 10 (20) ◽  
pp. 7343
Author(s):  
Malwina Brożyna ◽  
Anna Żywicka ◽  
Karol Fijałkowski ◽  
Damian Gorczyca ◽  
Monika Oleksy-Wawrzyniak ◽  
...  

Herein, we present a new test, dubbed AntiBioVol, to be used for the quantitative evaluation of antibiofilm activity of volatile compounds in vitro. AntiBioVol is performed in two 24-well plates using a basic microbiological laboratory equipment. To demonstrate AntiBioVol usability, we have scrutinized the activity of volatilized eucalyptus, tea tree, thyme essential oils, and ethanol (used for method suitability testing) against biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. We have also compared AntiBioVol with the standard disc volatilization method, placing a special stress on evaluating the impact of various technical parameters on the outcomes of the latter method. The obtained results indicate that AntiBioVol allows analyzing the antibiofilm activity of volatile compounds in a high number of repeats and provides semi-quantitative or quantitative results of high repeatability. In comparison to disc volatilization, AntiBioVol is a more space- and cost-effective method that allows analyzing various types of microbial aggregates. Moreover, we have indicated that the possible reasons for the discrepancies in the results obtained by means of the standard disc volatilization method may be related to various parameters of the testing dishes used (height, volume, diameter) and to various volumes of the agar medium applied. In turn, the application of a 24-well plate and a strictly defined AntiBioVol protocol provide a higher control of experimental conditions. Therefore, the application of AntiBioVol may enable an optimization of and introduction of volatile compounds to the fight against infective biofilms.


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