Simulated gastrointestinal digestion of beer using the simgi® model. Investigation of colonic phenolic metabolism and impact on human gut microbiota.

Beer is a source of bioactive compounds, mainly polyphenols, which can reach the large intestine and interact with colonic microbiota. However, the effects of beer consumption in the gastrointestinal function have scarcely been studied. This paper reports, for the first time, the in vitro digestion of beer and its impact on intestinal microbiota metabolism. Three commercial beers of different styles were subjected to gastrointestinal digestion using the simgi® model, and the digested fluids were further fermented in triplicate with faecal microbiota from a healthy volunteer. The effect of digested beer on human gut microbiota was evaluated in terms of microbial metabolism (short-chain fatty acids (SCFAs) and ammonium ion), microbial diversity and bacterial populations (plate counting and 16S rRNA gene sequencing). Monitoring beer polyphenols through the different digestion phases showed their extensive metabolism, mainly at the colonic stage. In addition, a higher abundance of taxa related to gut health, especially Bacteroides, Bifidobacterium, Mitsuokella and Succinilasticum at the genus level, and the Ruminococcaceae and Prevotellaceae families were found in the presence of beers. Regarding microbial metabolism, beer feeding significantly increased microbial SCFA production (mainly butyric acid) and decreased ammonium content. Overall, these results evidence the positive actions of moderate beer consumption on the metabolic activity of colonic microbiota, suggesting that the raw materials and brewing methods used may affect the beer gut effects.

Deciphering the interactions between lipids and red wine polyphenols through the gastrointestinal tract.

This paper investigates the mutual interactions between lipids and red wine polyphenols at different stages of the gastrointestinal tract by using the simgi® dynamic simulator. Three food models were tested: a Wine model, a Lipid model (olive oil + cholesterol) and a Wine + Lipid model (red wine + olive oil + cholesterol). With regard to wine polyphenols, results showed that co-digestion with lipids slightly affected the phenolic profile after gastrointestinal digestion. In relation to lipid bioaccessibility, the co-digestion with red wine tended to increase the percentage of bioaccessible monoglycerides, although significant differences were not found (p > 0.05). Furthermore, co-digestion with red wine tended to reduce cholesterol bioaccessibility (from 80 to 49 %), which could be related to the decrease in bile salt content observed in the micellar phase. For free fatty acids, almost no changes were observed. At the colonic level, the co-digestion of red wine and lipids conditioned the composition and metabolism of colonic microbiota. For instance, the growth [log (ufc/mL)] of lactic acid bacteria (6.9 ± 0.2) and bifidobacteria (6.8 ± 0.1) populations were significantly higher for the Wine + Lipid food model respect to the control colonic fermentation (5.2 ± 0.1 and 5.3 ± 0.2, respectively). Besides, the production of total SCFAs was greater for the Wine + Lipid food model. Also, the cytotoxicity of the colonic-digested samples towards human colon adenocarcinoma cells (HCT-116 and HT-29) was found to be significantly lower for the Wine and Wine + Lipid models than for the Lipid model and the control (no food addition). Overall, the results obtained using the simgi® model were consistent with those reported in vivo in the literature. In particular, they suggest that red wine may favourably modulate lipid bioaccessibility - a fact that could explain the hypocholesterolemic effects of red wine and red wine polyphenols observed in humans.

The gut microbiota, a key to understanding the health implications of micro(nano)plastics and their biodegradation.

The effects of plastic debris on the environment and plant, animal, and human health are a global challenge, with micro(nano)plastics (MNPs) being the main focus. MNPs are found so often in the food chain that they are provoking an increase in human intake. They have been detected in most categories of consumed foods, drinking water, and even human feces. Therefore, oral ingestion becomes the main source of exposure to MNPs, and the gastrointestinal tract, primarily the gut, constantly interacts with these small particles. The consequences of human exposure to MNPs remain unclear. However, current in vivo studies and in vitro gastrointestinal tract models have shown that MNPs of several types and sizes impact gut intestinal bacteria, affecting gut homeostasis. The typical microbiome signature of MNP ingestion is often associated with dysbiosis and loss of resilience, leads to frequent pathogen outbreaks, and local and systemic metabolic disorders. Moreover, the small micro- and nano-plastic particles found in animal tissues with accumulated evidence of microbial degradation of plastics/MNPs by bacteria and insect gut microbiota raise the issue of whether human gut bacteria make key contributions to the bio-transformation of ingested MNPs. Here, we discuss these issues and unveil the complex interplay between MNPs and the human gut microbiome. Therefore, the elucidation of the biological consequences of this interaction on both host and microbiota is undoubtedly challenging. It is expected that microbial biotechnology and microbiome research could help decipher the extent to which gut microorganisms diversify and MNP-determinant species, mechanisms, and enzymatic systems, as well as become important to understand our response to MNP exposure and provide background information to inspire future holistic studies.

Nano- and microplastics: a comprehensive review on their exposure routes, translocation, and fate in humans.

Contamination of the environment with nano-and microplastic particles (NMPs) and its putative adverse effects on organisms, ecosystems, and human health is gaining increasing scientific and public attention. Various studies show that NMPs occur abundantly within the environment, leading to a high likelihood of human exposure to NMPs. Here, different exposure scenarios can occur. The most notable exposure routes of NMPs into the human body are via the airways and gastrointestinal tract (GIT) through inhalation or ingestion, but also via the skin due to the use of personal care products (PCPs) containing NMPs. Once NMPs have entered the human body, it is possible that they are translocated from the exposed organ to other body compartments. In our review article, we combine the current knowledge on the (1) exposure routes of NMPs to humans with the basic understanding of the potential (2) translocation mechanisms into human tissues and, consequently, their (3) fate within the human body. Regarding the (1) exposure routes, we reviewed the current knowledge on the occurrence of NMPs in food, beverages, personal care products and the air (focusing on indoors and workplaces) and found that the studies suggest an abundant presence of MPs within the exposure scenarios. The overall abundance of MPs in exposure matrices relevant to humans highlights the importance of understanding whether NMPs have the potential for tissue translocation. Therefore, we describe the current knowledge on the potential (2) translocation pathways of NMPs from the skin, GIT and respiratory systems to other body compartments. Here, particular attention was paid to how likely NMPs can translocate from the primary exposed organs to secondary organs due to naturally occurring defence mechanisms against tissue translocation. Based on the current understanding, we conclude that a dermal translocation of NMPs is rather unlikely. In contrast, small MPs and NPs can generally translocate from the GIT and respiratory system to other tissues. Thus, we reviewed the existing literature on the (3) fate of NMPs within the human body. Based on the current knowledge of the contamination of human exposure routes and the potential translocation mechanisms, we critically discuss the size of the detected particles reported in the fate studies. In some cases, the particles detected in human tissue samples exceed the size of a particle to overcome biological barriers allowing particle translocation into tissues. Therefore, we emphasize the importance of critically reading and discussing the presented results of NMP in human tissue samples.

Gastrointestinal co-digestion of wine polyphenols with glucose/whey proteins affects their bioaccessibility and impact on colonic microbiota.

Interactions between food components during their gastrointestinal digestion are constant and could affect compounds digestibility and bioaccessibility. These interactions could have a key role in the bioactivity of dietary polyphenols. This study aimed to investigate the food matrix effects during the co-digestion of red wine with glucose and whey proteins using the gastrointestinal dynamic simulator simgi®. Bioaccessibility of wine polyphenols and nutrients and the effect of co-digestion on colonic microbiota composition and metabolism were evaluated. Co-digestion with red wine led to a reduction of over 50% of glucose bioaccessibility and lowered α-lactalbumin gastric degradation. Still, co-digestion with the food matrices modified polyphenols profiles, including their bioaccessible and non-bioaccessible fractions. For instance, the (-)-epicatechin bioaccessible fraction increased 70% when the wine was co-digested with glucose. Hence, the combined feeding of wine and each food matrix affected microbiota composition and functionality at colonic level. Glucose and whey proteins reduced bacterial diversity, but homogenization of beta-diversity by wine was observed. Moreover, wine presence favoured intestinal health-related taxa as Akkermansia or Bifidobacterium, and the co-digestion of wine and food matrices significantly increased total short- and medium-chain fatty acids production, especially butyric acid. Overall, this study provides evidence of the convenience of the simgi® system to evaluate the effects of co-digestion and highlights the importance of food matrix effects on our understanding of polyphenol bioactivity.

PET microplastics affect human gut microbiota communities during simulated gastrointestinal digestion, first evidence of plausible polymer biodegradation during human digestion.

Microplastics (MPs) are a widely recognized global problem due to their prevalence in natural environments and the food chain. However, the impact of microplastics on human microbiota and their possible biotransformation in the gastrointestinal tract have not been well reported. To evaluate the potential risks of microplastics at the digestive level, completely passing a single dose of polyethylene terephthalate (PET) through the gastrointestinal tract was simulated by combining a harmonized static model and the dynamic gastrointestinal simgi model, which recreates the different regions of the digestive tract in physiological conditions. PET MPs started several biotransformations in the gastrointestinal tract and, at the colon, appeared to be structurally different from the original particles. We report that the feeding with microplastics alters human microbial colonic community composition and hypothesize that some members of the colonic microbiota could adhere to MPs surface promoting the formation of biofilms. The work presented here indicates that microplastics are indeed capable of digestive-level health effects. Considering this evidence and the increasing exposure to microplastics in consumer foods and beverages, the impact of plastics on the functionality of the gut microbiome and their potential biodegradation through digestion and intestinal bacteria merits critical investigation.

Simulated gastrointestinal digestion of cranberry polyphenols under dynamic conditions. Impact on antiadhesive activity against uropathogenic bacteria.

This study is the first dynamic simulation of gastrointestinal digestion of cranberry polyphenols [1 g cranberry extract per day (206.2 mg polyphenols) for 18 days]. Samples from the simulated ascending, transverse, and descending colon of the dynamic gastrointestinal simulator simgi® were analyzed. Results showed that 67% of the total cranberry polyphenols were recovered after simulated gastrointestinal digestion. Specifically, benzoic acids, hydroxycinnamic acids, phenylpropionic acids, phenylacetic acids, and simple phenols were identified. Cranberry feeding modified colonic microbiota composition of Enterococcaceae population significantly. However, increments in microbial-derived short-chain fatty acids, particularly in butyric acid, were observed. Finally, the simgi® effluent during cranberry feeding showed significant antiadhesive activity against uropathogenic Escherichia coli (13.7 ± 1.59 % of inhibition). Understanding the role that gut microbiota plays in cranberry metabolism could help to elucidate its interaction with the human body and explain cranberry protective effects against urinary tract infections.

Gastrointestinal Digestion of a Grape Pomace Extract: Impact on Intestinal Barrier Permeability and Interaction with Gut Microbiome.

Grape pomace (GP) is a winemaking by-product rich in polyphenols and fibre. Supplementation with GP extracts has shown potential benefits against oxidative stress- and inflammation-related pathologies. As a new nutritional target, this paper explores the impact of the ingestion of a grape pomace extract on intestinal barrier functionality. A GP extract was sequentially subjected to gastrointestinal and colonic digestion using the dynamic gastrointestinal simulator (simgi®). This generated two simulated fluids: intestinal-digested extract (IDE) and colonic-digested extract (CDE). The effects of these two fluids on paracellular permeability and the expression of tight junction (TJ) proteins (i.e., zonula occludens-1 (ZO-1) and occludin) were assessed in Caco-2-cell monolayers grown in Transwell® inserts. The IDE fluid significantly (p < 0.001) reduced the paracellular transport of FITC-dextran with respect to the control, whereas no significant differences (p > 0.05) were found for CDE, which could be due, at least partially, to the pro-leaky effect of the colonic digestion medium. Accordant slight increases in the mRNA levels of both ZO-1 and occludin were observed for IDE, but without statistical significance. Additionally, the colonic fermentation of the GP extract promoted the production of short-chain fatty acids (SCFA) and phenolic metabolites and led to changes in the relative abundance of some bacteria that might affect paracellular permeability. Overall, this paper reports first trends about the effects of grape pomace extracts on intestinal permeability that would require further confirmation in future experiments.

Effects of Wine and Its Microbial-Derived Metabolites on Intestinal Permeability Using Simulated Gastrointestinal Digestion/Colonic Fermentation and Caco-2 Intestinal Cell Models.

This paper explores the effects of wine polyphenols on intestinal permeability in in vitro conditions. A red wine (2500 mg/L of gallic acid equivalents) was sequentially subjected to gastrointestinal and colonic digestion in the Dynamic Gastrointestinal Simulator (simgi®) to obtain two simulated fluids: intestinal-digested wine (IDW) and colonic-digested wine (CDW). The two fluids were incubated with Caco-2 cell monolayers grown in Transwell® inserts, and paracellular permeability was measured as transport of FITC-dextran. Non-significant decreases (p > 0.05) in paracellular permeability were found, which was attributed to the relatively low phenolic concentration in the solutions tested (15.6 and 7.8 mg of gallic acid equivalents/L for IDW and CDW, respectively) as quercetin (200 µM) and one of its microbial-derived phenolic metabolites, 3,4-dihydroxyphenylacetic acid (200 µM), led to significant decreases (p < 0.05). The expression of tight junction (TJ) proteins (i.e., ZO-1 and occludin) in Caco-2 cells after incubation with IDW and CDW was also determined. A slight increase in mRNA levels for occludin for both IDW and CDW fluids, albeit without statistical significance (p > 0.05), was observed. Analysis of the microbiome and microbial activity during wine colonic fermentation revealed relevant changes in the relative abundance of some families/genera (i.e., reduction in Bacteroides and an increase in Veillonella, Escherichia/Shigella and Akkermansia) as well as in the microbial production of SCFA (i.e., a significant increase in propionic acid in the presence of IDW), all of which might affect paracellular permeability. Both direct and indirect (microbiota-mediated) mechanisms might be involved in the protective effects of (wine) polyphenols on intestinal barrier integrity. Overall, this paper reinforces (wine) polyphenols as a promising dietary strategy to improve gut functionality, although further studies are needed to evaluate the effect on the intestinal barrier under different conditions.

A multi-omics approach for understanding the effects of moderate wine consumption on human intestinal health.

The human gut is a highly diverse microbial ecosystem. Although showing a well-defined core of dominant taxa, an interindividual variability exists in microbiome arrangement patterns, and the presence and proportion of specific species, determining individual metabolic features-metabotypes-which govern the health effects of dietary interventions (i.e. polyphenol consumption). Starting with a 19-volunteer human intervention study, divided into low, medium, and high wine-polyphenol-metabolizers, we detected interindividual discrepancies on the effect of wine consumption in gut bacterial alpha-diversity, but a significant homogenization of beta-diversity among moderate wine consumers, independently of their metabotype. In addition, the abundance of key health-related taxa such as Akkermansia sp. increased after moderate wine intake in the group of high polyphenol-metabolizers. Regarding the metabolic activity, significant (p < 0.05) positive correlations in the production of SCFAs were observed after wine intake. Finally, we were able to correlate the microbiome and the metabolome of the three metabotypes, and to identify some metabolites-biomarker species, highlighting the genera Phascolarctobacterium, Pelotomaculum and Prevotella, as positively correlated with polyphenol concentration, and Prevotella, Zymophilus and Eubacterium as positively correlated with SCFAs concentration in faeces. Our results contribute to the evidence of the need of including the microbiome variable in personalized nutrition programs, as different metabotyes respond differently to dietary interventions.

Intake of soluble fibre from chia seed reduces bioaccessibility of lipids, cholesterol and glucose in the dynamic gastrointestinal model simgi®.

The role of soluble fibres on hypoglycemic and hypocholesterolemic effects has been widely documented, but the effect on glucose and cholesterol binding capacity of soluble fibre extracted from chia seed mucilage has not been studied until now. In the present research, dynamic gastrointestinal model simgi® combined with absorption static techniques have been used to explore the effect of chia seed mucilage at 0.75 and 0.95% w/w on the bioaccessibility of glucose, dietary lipids and cholesterol along the gastrointestinal tract. Glucose bioaccessibility was reduced when 0.95% of chia mucilage was present in sugar food models. The total reduction of glucose bioaccessibility reached a maximum of 66.7% while glucose dialysis retardation index presented its maximum of 53.4% at the end of small intestine digestion. The in vitro studies with lipid food models, showed that the presence of both, 0.75 and 0.95% of chia seed mucilage caused substantial reductions on the bioaccessibility of free fatty acids (16.8 and 56.1%), cholesterol (18.2 and 37.2% respectively) and bile salts (4.8 and 64.6%), revealing a clear dependence on fibre concentration. These innovative results highlight the potential functionality of the soluble fibre extracted from chia seeds to improve lipid and glycemic profiles and suggest the dietary health benefits of this new soluble fibre source as an ingredient in functional foods designed to reduce the risk of certain non-communicable diseases.

Moderate Wine Consumption Reduces Faecal Water Cytotoxicity in Healthy Volunteers.

There are some studies that suggest that moderate consumption of wine, as part of a healthy and balanced diet, has a favourable effect on intestinal health. This study evaluates the effect of moderate wine consumption on faecal water (FW) cytotoxicity as a parameter of gut health. To that end, faecal samples before and after a red wine intervention study (250 mL of wine/day, 4 weeks) in healthy volunteers (n = 8) and in a parallel control group (n = 3) were collected and assayed for in vitro FW cytotoxicity. Two reference compounds, phenol and p-cresol, were used for assessing the cytotoxicity assays using two colon epithelial cell lines (HT-29 and HCT 116) and different assay conditions (FW dilution and incubation time). For the two cell lines and all assay conditions, the means of percentage cell viability were higher (lower cytotoxicity) for samples collected after the red wine intervention than for those collected before, although significant (p < 0.05) differences were only found in certain assay conditions for both cell lines. Significant positive correlations between the percentage cell viability and the contents of some faecal metabolites (short-chain fatty acids (SCFA) and phenolic acids (PA)) were found for the more resistant cell line (HCT 116), suggesting that the reduction in FW cytotoxicity observed after moderate red wine consumption was related to the production of microbial-derived metabolites such as SCFA and PA, whose faecal contents have been shown to increase after wine consumption. FW cytotoxicity can be deemed as a holistic biomarker that involves diet, gut microbiota and host.

Application of the dynamic gastrointestinal simulator (simgi®) to assess the impact of probiotic supplementation in the metabolism of grape polyphenols.

In this paper, the Dynamic Gastrointestinal Simulator (simgi®) is used as a model to the study the metabolic activity of probiotics at the intestinal level, and in particular, to assess the impact of probiotic supplementation in the microbial metabolism of grape polyphenols. Two independent simulations using fecal samples from two healthy volunteers were carried out. Changes in microbiota composition and in metabolic activity were assessed by qPCR and 16S rRNA gene sequencing and by analyses of phenolic metabolites and ammonium ions (NH4+). The strain Lactobacillus plantarum CLC 17 was successfully implanted in the colon compartments of the simgi® after daily feeding of 2 × 1010 CFU/day for 7 days. Overall, no changes in bacterial diversity were observed after probiotic implantation. In comparison to the digestion of the grape polyphenols on their own, the inclusion of L. plantarum CLC 17 in the simgi® colon compartments led to a greater formation of phenolic metabolites such as benzoic acids, probably by the breakdown of high-molecular-weight procyanidin polymers. These results provide evidence that the probiotic strain Lactobacillus plantarum CLC 17 may improve the metabolism of dietary polyphenols when used as a food ingredient.

In Vitro Colonic Fermentation of Saponin-Rich Extracts from Quinoa, Lentil, and Fenugreek. Effect on Sapogenins Yield and Human Gut Microbiota.

In vitro colonic fermentation of saponin-rich extracts from quinoa, lentil, and fenugreek was performed. Production of sapogenins by human fecal microbiota and the impact of extracts on representative intestinal bacterial groups were evaluated. The main sapogenins were found after fermentation (soyasapogenol B for lentil; oleanolic acid, hederagenin, phytolaccagenic acid, and serjanic acid for quinoa; and sarsasapogenin, diosgenin, and neotigogenin acetate for fenugreek). Interindividual differences were observed, but the highest production of sapogenins corresponded to quinoa (90 µg/mL) and fenugreek (70 µg/mL) extracts, being minor for lentil (4 µg/mL). Lentil and quinoa extracts showed a general antimicrobial effect, mainly on lactic acid bacteria and Lactobacillus spp. Significant increases of Bifidobacterium spp. and Lactobacillus spp. were observed for fenugreek in one volunteer. Thus, the transformation of saponin-rich extracts of quinoa, lentil, and fenugreek to sapogenins by human gut microbiota is demonstrated, exhibiting a modulatory effect on the growth of selected intestinal bacteria.

Gastrointestinal digestion of food-use silver nanoparticles in the dynamic SIMulator of the GastroIntestinal tract (simgi®). Impact on human gut microbiota.

The increasing use of silver nanoparticles (AgNPs) in consumer products has led to concern about their impact on human health. This paper aims to provide new scientific evidence about the modifications and potential effects of AgNPs with food applications during their passage through the digestive tract. For that, two types of AgNPs [solid polyethylene glycol-stabilised silver nanoparticles (PEG-AgNPs 20) and liquid glutathione-stabilised silver nanoparticles (GSH-AgNPs)] were initially subjected to gut-microbial digestion simulation in an in vitro static model. Based on these experiments, digestion of GSH-AgNPs was carried out in a dynamic model (simgi®) that simulated the different regions of the digestive tract (stomach, small intestine and the ascending, transverse and descending colon) in physiological conditions. Dynamic transport of GSH-AgNPs in the simgi® was similar to that observed for the inert compound Cr-EDTA, which discarded any alterations in the intestinal fluid delivery due to the AgNPs. Also, feeding the simgi® with GSH-AgNPs seemed not to induce significant changes in the composition and metabolic activity (i.e., proteolytic activity) of the gut microbiota. Concerning monitoring of AgNps, it was observed that the GSH-AgNPs underwent several transformations in the gastrointestinal fluids and appeared to expose the intestine in ways that were structurally different from the original forms. In compliance with European guidelines, the simgi® model can be considered a useful in vitro tool to evaluate the effects of nanoparticles at the digestive level, prior to human studies, and, therefore, minimising animal testing.

Physical effects of dietary fibre on simulated luminal flow, studied by in vitro dynamic gastrointestinal digestion and fermentation.

During the transit through the gastrointestinal tract, fibre undergoes physical changes not usually included in in vitro digestion studies even though they influence nutrient diffusion and might play a role in gut microbiota growth. The aim of this study was to evaluate how physical fibre properties influence the physical properties of gastrointestinal fluids using a gastrointestinal model (stomach, small intestine, ascending colon, transverse colon, and descending colon) (simgi®). Analysis by rheological and particle size characterisation, microbiota composition and short-chain fatty acid (SCFA) determination allows the achievement of this goal. First, the water-holding capacity (WHC), microstructure, and viscosity of eight different fibres plus agar were tested. Based on the results, potato fibre, hydroxypropyl methylcellulose (HPMC), psyllium fibres, and agar (as a control) were selected for addition to a medium growth (GNMF) that was used to feed the stomach/small intestine and colon compartments in the simgi®. During gastrointestinal digestion, GNMF was collected at 5, 30 and 55 minutes of processing at the gastric stage and after the intestinal stage. Then, samples of GNMF with faecal slurry were collected at 0, 24 and 48 h of colonic fermentation. Results showed fibre-dependence on apparent viscosity. Although psyllium was partially broken down in the stomach (decrease in particle size), it was the most viscous at the colonic stage, opposite to the potato fibre, but both led to the highest total SFCA and acetic acid production profile. On a microbiological level, the most relevant increase of bacterial growth was observed in the faecal Lactobacillus species, especially for HPMC and potato fibre, that were not digested until reaching the colon. Besides fibre fermentability, viscosity also influenced microbial growth, and it is necessary to characterise these changes to understand fibre functionality.

Simulador gastrointestinal dinámico (simgi): una herramienta potencialmente útil en nutrición clínica / The dynamic gastrointestinal simulator (simgi): a useful tool for clinical nutrition

Dentro de la microbiota humana, el tracto gastrointestinal alberga el ecosistema más complejo y abundante del cuerpo humano, siendo el colon donde se encuentra la concentración más alta de microorganismos (1012 cél/g). La microbiota intestinal desempeña funciones metabólicas, tróficas y de protección que son de gran importancia para el hospedador. Durante las últimas décadas, son numerosos los estudios que han tratado de aportar evidencias científicas acerca de los factores que, a través de cambios en la composición de la microbiota intestinal, influyen en la salud humana. Sin embargo, esta aproximación está cambiando, y son cada vez más los expertos que apuestan por evaluar cambios a nivel de funcionalidad de la microbiota. Si aplicamos este enfoque dual al papel desempeñado por la dieta, resulta obvia la necesidad de disponer de modelos dinámicos de simulación gastrointestinal, como es el simgi, que permitan evaluar las transformaciones que sufren los alimentos y/o ingredientes alimentarios durante el tránsito por el tracto gastrointestinal, así como para determinar los posibles cambios en la composición y funcionalidad de la microbiota intestinal derivados de la ingesta de alimentos. Los estudios llevados a cabo hasta el momento con el simgi constatan sus potenciales aplicaciones en el área de los alimentos como paso previo a su aplicación en nutrición clínica, para prevenir y/o tratar enfermedades asociadas a disbiosis intestinal, así como trastornos metabólicos. Asimismo, esta revisión recoge posibles perspectivas de utilización del simgi en la investigación clínica relativa a enfermedades vinculadas con disfunciones de la microbiota intestinal (AU)

The human gastrointestinal tract harbours the most complex and abundant community of the human body, the colon being where the highest microbial concentration is found (1012 cell/g). The intestinal microbiota exerts metabolic, trophic and protective functions which are important in the maintenance of the host health. Over recent decades, numerous studies have attempted to provide scientific evidence about the environmental factors that can impact on human health through the modulation of the intestinal microbiota composition. However, this approach is changing, and a new focus on assessing changes at functional level is being developed. If we apply this dual approach to the role played by the diet, it is obvious the need of dynamic gastrointestinal simulation models such as simgi, that allow to evaluate the transformations undergone by food and/or food ingredients during their transit through the gastrointestinal tract, as well as to determine potential changes in the composition and functionality of the intestinal microbiota after food ingestion. So far the studies using the simgi have confirmed its potential applications in the area of food as a prior step to its application in clinical nutrition to prevent and/or treat diseases associated with intestinal dysbiosis and metabolic disorders. Likewise, this review includes feasible perspectives of the use of simgi in clinical research concerning to diseases related to the intestinal microbiota (AU)