Gastrointestinal Simulation Research Articles

Role, relevance, and possibilities of in vitro fermentation models in human dietary, and gut-microbial studies.

Dietary studies play a crucial role in determining the health-benefiting effects of most food substances, including prebiotics, probiotics, functional foods, and bioactive compounds. Such studies involve gastrointestinal digestion and colonic fermentation of dietary substances. In colonic fermentation, any digested food is further metabolized in the gut by the residing colonic microbiota, causing a shift in the gut microenvironment and production of various metabolites, such as short-chain fatty acids. These diet-induced shifts in the microbial community and metabolite production, which can be assessed through in vitro fermentation models using a donor's fecal microbiota, are well known to impact the health of the host. Although in vivo or animal experiments are the gold standard in dietary studies, recent advancements using different in vitro systems, like artificial colon (ARCOL), mini bioreactor array (MBRA), TNO in vitro model of the colon (TIM), Simulator of the Human Intestinal Microbial Ecosystem (SHIME), M-SHIME, Copenhagen MiniGut, and Dynamic Gastrointestinal Simulator,make it easy to study the dietary impact in terms of the gut microbiota and metabolites. Such a continuous in vitro system can have multiple compartments corresponding to different parts of the colon, that is, proximal, transverse, and distal colon, making the findings physiologically more significant. Furthermore, postfermentation samples can be analyzed using metagenomic, metabolomic, quantitative-polymerase chain reaction, and flow-cytometry approaches. Moreover, studies have shown that in vitro results are in accordance with the in vivo findings, supporting their relevance in dietary studies and giving confidence that shifts in metabolites are only due to microbes. This review meticulously describes the recent advancements in various fermentation models and their relevance in dietary studies.

Impact of Circular Brewer's Spent Grain Flour after In Vitro Gastrointestinal Digestion on Human Gut Microbiota.

Brewer’s spent grain (BSG) solid residues are constituted by dietary fibre, protein, sugars, and polyphenols, which can have potential effects on human health. In this study, for the first time, the flours obtained from solid residues of solid-liquid extraction (SLE) and ohmic heating extraction (OHE) were applied throughout the gastrointestinal digestion simulation (GID), in order to evaluate their prebiotic potential and in vitro human gut microbiota fermentation. The results showed that the digestion of BSG flours obtained by the different methods lead to an increase throughout the GID of total phenolic compounds (SLE: from 2.27 to 7.20 mg gallic acid/g BSG—60% ethanol:water (v/v); OHE: 2.23 to 8.36 mg gallic acid/g BSG—80% ethanol:water (v/v)) and consequently an increase in antioxidant activity (ABTS—SLE: from 6.26 to 13.07 mg ascorbic acid/g BSG—80% ethanol:water (v/v); OHE: 4.60 to 10.60 mg ascorbic acid/g BSG—80% ethanol:water (v/v)—ORAC—SLE: 3.31 to 14.94 mg Trolox/g BSG—80% ethanol:water (v/v); OHE: from 2.13 to 17.37 mg Trolox/g BSG—60% ethanol:water (v/v)). The main phenolic compounds identified included representative molecules such as vanillic and ferulic acids, vanillin and catechin, among others being identified and quantified in all GID phases. These samples also induced the growth of probiotic bacteria and promoted the positive modulation of beneficial strains (such as Bifidobacterium spp. and Lactobacillus spp.) present in human faeces. Moreover, the fermentation by human faeces microbiota also allowed the production of short chain fatty acids (acetic, propionic, and butyric). Furthermore, previous identified polyphenols were also identified during fecal fermentation. This study demonstrates that BSG flours obtained from the solid residues of SLE and OHE extractions promoted a positive modulation of gut microbiota and related metabolism and antioxidant environment associated to the released phenolic compounds.

Bioaccessibility of arsenic from contaminated soils and alteration of the gut microbiome in an in vitro gastrointestinal model

Arsenic exposure has been reported to alter the gut microbiome in mice. Activity of the gut microbiome derived from fecal microbiota has been found to affect arsenic bioaccessibility in an in vitro gastrointestinal (GI) model. Only a few studies have explored the relation between arsenic exposure and changes in the composition of the gut microbiome and in arsenic bioaccessibility. Here, we used simulated GI model system (GIMS) containing a stomach, small intestine, colon phases and microorganisms obtained from mouse feces (GIMS-F) and cecal contents (GIMS-C) to assess whether exposure to arsenic-contaminated soils affect the gut microbiome and whether composition of the gut microbiome affects arsenic bioaccessibility. Soils contaminated with arsenic did not alter gut microbiome composition in GIMS-F colon phase. In contrast, arsenic exposure resulted in the decline of bacteria in GIMS-C, including members of Clostridiaceae, Rikenellaceae, and Parabacteroides due to greater diversity and variability in microbial sensitivity to arsenic exposure. Arsenic bioaccessibility was greatest in the acidic stomach phase of GIMS (pH 1.5–1.7); except for GIMS-C colon phase exposed to mining-impacted soil in which greater levels of arsenic solubilized likely due to microbiome effects. Physicochemical properties of different test soils likely influenced variability in arsenic bioaccessibility (GIMS-F bioaccessibility range: 8–37%, GIMS-C bioaccessibility range: 2–18%) observed in this study.

Impact of protein oxidation induced by different cooking methods in channel fish (Ietalurus punetaus) on structure and in vitro digestion of protein

SummaryThis study was designed to evaluate the effect of different cooking methods on the protein digestion characteristics of channel fish (Ietalurus punetaus). The channel fish muscles were subjected to different cooking methods, namely boiling, steaming and roasting and were subjected to in vitro gastrointestinal digestion simulation using raw fish as a control. All the cooking methods increased the protein digestibility (1.60–8.28%) and decreased the protein particle size at the end of the gastrointestinal digestion. The highest protein digestibility (66.78%) and the smallest protein particle size values (600.7 nm) were observed for the steamed group. Samples which were steam cooked showed lowest β‐sheet content (9.63 ± 0.81%) and were accompanied with moderate protein oxidation. As the core temperature increased from 40°C to 90°C, protein oxidation increased significantly (P < 0.05) with the increase of carbonyl groups and Schiff bases and decrease of sulfhydryl groups in all cooked groups. Based on the results, steaming was recommended as the best methods of cooking channel fish for improved protein digestibility.

Effect Factors and Model Prediction of Soil Heavy Metal Bioaccessibility

The soil environmental pollution situation has been severe in recent years, but studies on evaluating with bioavailability testing and prediction models are lacking, which makes it difficult to accurately assess the ecological risks of contaminated soil. As an important indicator of bioavailability, the bioaccessibility of cadmium (Cd), arsenic (As), copper (Cu), zinc (Zn), and lead (Pb) in the soil was analyzed in this study. The bioaccessibility content and their corresponding soil property data were screened and systematically analyzed to explore the relationship between bioaccessibility content and soil properties. Furthermore, some testing methods for bioaccessibility were summarized to analyze the relationship between bioaccessibility content, test methods, and bioavailability content. Additionally, the bioaccessibility content prediction models were established. The results showed that there was a strong correlation between the bioaccessibility content and the total content of heavy metals (P<0.01) and a significant (P<0.05) correlation with the soil pH. Different test methods had obvious effects on bioavailability. The proportion of bioaccessibility content determined via various test methods was as follows:in vitro gastrointestinal tract simulation>chemical reagent extraction. The proportions of bioaccessibility content of Cd and Pb in natural soil were relatively high, with mean values of 42.12% and 37.33%, respectively, indicating that Cd and Pb had higher risks of being absorbed by soil organisms. Moreover, 30 bioaccessibility prediction models for five heavy metals were constructed, which involved the soil properties and test methods. The results of this study can provide scientific information and bioaccessibility prediction models that can help in accurately assessing the ecological risks of contaminated soil.

Antimicrobial bioactive peptides from goat Milk proteins: Insilico prediction and analysis.

The main goal of this study was to assess the potential proteins of goat milk (i.e. α-s1-casein, α-s2-casein, β-casein, κ-casein, α-lactoglobulin and β-lactalbumin) as precursors of antimicrobial peptides (AMPs). Bioinformatics tools such as BIOPEP-UWM (enzyme action) were used for the in silico gastrointestinal digestion via a cocktail of pepsin, trypsin, and chymotrypsin A. The antimicrobial activity of peptides was predicted by using four algorithms, including Random Forest, Support Vector Machines, Artificial Neural Network and Discriminant Analysis on CAMPR3 online server, which works on Hidden Markov Models. Different online tools predicted the physiochemical properties, allergenicity, and toxicity of peptides as well. In silico gastrointestinal digestion simulation of proteins by enzymes cocktail yielded a total of 83 potential AMPs, with thirteen peptides being confident by all four algorithms. More AMPs were released from β-casein (21) than from β-lactoglobulin (16), α-s1-casein (15), α-s2-casein (12), κ-casein (11) and α-lactalbumin (9). A total of 17 peptides were cationic, and the majority of the peptides were extended AMPs. These peptides were released from α-s1-casein (SGK, IQK), α-s2-casein (SIR, AIH, TQPK), β-casein (GPVR, AVPQR, AIAR, GVPK, SQPK, PVPQK, IH, VPK), k-casein (AIPPK, QQR, IAK, TVPAK). All of the AMPs were anticipated to be non-toxic, and 54 of the 83 peptides were confirmed to be non-allergic, with the remaining 29 suspected of being allergenic and 31 to be predicted to have good water solubility. Further the molecular docking was used to evaluate the potent dihydropteroate synthase (DHPS) inhibitors. On the basis of ligand binding energy, 17 predicted AMPs were selected and then analyzed by AutoDock tools. Among the 17 AMPs, 3 AMPs were predicted as high-potent antimicrobial. Based on these findings, in silico investigations reveal that proteins of goat milk are a potential source of AMPs. These peptides can be synthesized and improved for use in the food sector. PRACTICAL APPLICATIONS: Goat milk is regarded as a high-quality milk protein source. According to this study, goat milk protein is a possible source of AMPs, and therefore, most important AMPs can be synthesized and developed for use in the food sector.

Effect of the addition of the probiotic Bifidobacterium animalis subsp. Lactis (BB-12) in free and microencapsulated form and the prebiotic inulin to synbiotic dry coppa

The effect of the addition of the prebiotic inulin and free and microencapsulated Bifidobacterium animalis subsp. Lactis (BB-12) strains to synbiotic dry coppa formulations was evaluated during 45 days of ripening. The following formulations were made: control C without probiotic and prebiotic; PROB with free probiotic; SYNB with free probiotic and inulin; ENPROB with microencapsulated probiotic, and ENSYNB with microencapsulated probiotic and inulin. The incorporation of BB-12 with inulin provided adequate physicochemical characteristics (proximate composition, weight loss, pH, water activity (aw), and instrumental color). The treatments PRO and SYNB showed lower lipid and protein oxidation levels. The treatments PROB, SYNB, ENPROB, and ENSYNB had viable cell counts above 109 CFU/g and can be considered probiotic. In the in vitro gastrointestinal simulation, the BB-12 strain showed survival and growth capacity in saline solution and at low pH values for all treatments. The sample SYNB was the most accepted by the assessors in the sensory evaluation. Therefore, dry coppa can be used as a vehicle for the development of a synbiotic fermented meat product.

Effect of Oral Supplementation of Gordonibacter urolithinfaciens on Gut Microbiota and Bioavailability of Ellagic Acid and Urolithins in Mice

ObjectivesGordonibacter urolithinfaciens (GUro) is one of the three human bacteria that can convert ellagic acid (EA) to urolithins (Uros). Individuals deficient in Uro-producing bacteria may not benefit from EA-rich diets due to poor bioavailability of EA. Thus, GUro supplementation could be a solution. This work aims to examine 1) the viability of naked and protected GUro after gastrointestinal (GI) digestion; 2) colonization of GUro in vivo and the impact of GUro on gut microbiota; 3) the effect of GUro supplementation on the bioavailability of EA and Uros. MethodsIn vitro studies: Simulated GI digestion was conducted with GUro in naked (NG), alginate-chitosan encapsulated (ACG) or hydrogel protected (HGG) forms. Bacteria enumeration was performed by plate count. In vivo studies: Male C57BL/6J mice deficient in GUro were divided into 2 groups: Control (Ctrl, vehicle) and Experiment (Exp, GUro at 107 CFU/mouse). Mice received vehicle or GUro on days 1, 2, 3 and 7 by oral gavage, and then 20 mg/kg EA 12 h after the final dose of GUro or vehicle on D8. Feces were collected for gut microbiota analysis. Blood and tissues were collected at 0.5, 12, 24 and 36 h after EA intake. 36 h excretion of urine and feces were collected. The change in the main genera of gut microbiota was measured by qPCR. Colon tissue histology was examined by H&E staining. EA and Uros were extracted from biosamples and analyzed by UHPLC with triple quadrupole mass spectrometry. ResultsNG showed comparable viability as ACG and HGG after in vitro GI digestion indicating GUro’s suitability to be ingested without protection. For in vivo study, the level of GUro increased 8 folds 12 h after the last dose of GUro but returned to baseline in 24–36 h. For Ctrl group, Akkermansia (Akk) increased substantially at all time points. Similarly, Akk bloomed post-gavage of EA but most strikingly at 0.5 h in Exp group. GUro administration significantly enhanced the bioavailability of EA and Uros. Substantial amounts of Uro C, dimethyl Uro C, Uro A and methyl Uro A were excreted in the urine of Exp group, but barely detected in the Ctrl. ConclusionsSupplementation of GUro improved the bioavailability of EA and bioactive metabolites. Moreover, the high survival rate of naked GUro after GI digestion indicated its potential to serve as a probiotic. Funding SourcesNational Natural Science Foundation of China; PolyU Research Institute for Future Food.

Spray-Dried Microencapsulation of Oregano (Lippia graveolens) Polyphenols with Maltodextrin Enhances Their Stability during In Vitro Digestion

The effect of in vitro gastrointestinal digestion on the release of microencapsulated phenolic compounds was evaluated through an optimized spray drying process. A stock extract of oregano phenolic compounds was developed and microencapsulated in a spray dryer following a central composite rotatable design, controlling the variables, inlet temperature (111.7-168.2°C), and percentage of wall material (5.8-34.1%). Optimum drying conditions for spray drying were decided based on different yield percentages ( Y %) and encapsulated phenolic compounds (EPC). The analyzed physical properties were morphology measured by electron microscopy and humidity; other properties evaluated were the content of total phenolic compounds, antioxidant capacity determined by DPPH and ABTS assays, and phenolic profile by ultraperformance liquid chromatography coupled to mass spectrometry (UPLC-MS). During the gastrointestinal simulation, a stability of 85% was determined in the intestinal stage. Microencapsulation technology by spray drying is an excellent selection to stabilize and protect bioactive compounds of oregano and promote its use as a functional ingredient.

Determining the Relationship Between Clofazimine Gastrointestinal Levels and anti‐CryptosporidiumEfficacy in Mice

IntroductionCryptosporidiosis, the disease caused by parasitic infections with Cryptosporidium spp. can cause long‐term adverse impacts and even death in malnourished children and immunocompromised patients. The only FDA‐approved drug for treating cryptosporidiosis, nitazoxanide, has limited efficacy in the populations that are impacted most by the disease. A large‐scale phenotypic screening campaign identified clofazimine as active in both in vitro and in vivo preclinical models of Cryptosporidium infection. However, clofazimine was not effective in controlling Cryptosporidium infection in a subsequent Phase 2a clinical trial in HIV‐positive adults with cryptosporidiosis. Our recent pharmacokinetic/pharmacodynamic (PK/PD) modeling work demonstrated that plasma clofazimine levels observed in the Phase 2a clinical trial fell well below projected efficacious plasma concentrations estimated with preclinical in vivo data. Therefore, suboptimal clofazimine exposure in the Phase 2a trial likely contributed to the observed lack of efficacy. Nevertheless, plasma clofazimine levels may not represent local concentrations at the gastrointestinal (GI) tract, the site of action for treatment of Cryptosporidium infection. Thus, the objective of our current study is to build a physiologically based pharmacokinetic (PBPK) model of clofazimine in mice to simulate clofazimine GI pharmacokinetics (PK), estimate efficacious clofazimine concentrations at the tissue level, and explore important factors that can impact clofazimine exposure at the site of infection.MethodsC57BL/6 mice were administered a single oral dose of clofazimine at dose levels ranging 0.03‐300 mg/kg. Blood samples were collected up to 240 hours post‐dosing and GI samples were collected at 240 hours post‐dosing. In tandem, an efficacy study treated C. parvum‐infected IFN‐γ‐/‐ mice with equivalent clofazimine dosing and oocysts in fecal samples were quantified over time. GastroPlus (Simulations Plus) was used for modeling and simulation.ResultsThe final PBPK model captured clofazimine plasma PK in mice well across most doses (within a 2‐fold margin). The simulated clofazimine GI concentrations increased with increasing dose in a non‐proportional manner, similar to what was observed with the plasma PK. As expected for a drug with poor solubility, the non‐linearity was attributed to diminished drug dissolution at higher dose levels. The simulated clofazimine tissue concentrations were used to construct PK/PD models to predict efficacious tissue concentrations.ConclusionA clofazimine PBPK model was generated in mice to simulate clofazimine levels in plasma and the GI tract. By incorporating clofazimine efficacy data from a mouse model of Cryptosporidium infection, we identified a relationship between tissue drug concentrations and reduction in infection burden. Establishing a PK/PD relationship informed by GI drug levels will assist future drug development efforts for cryptosporidiosis.

Cápsulas de polvo de arándano como propuesta nutracéutica para mejorar la bioaccesibilidad de compuestos fenólicos

Blueberry (Vaccinium corymbosum L.) has a high content of phenolic compounds which have been studied mainly for their antioxidant, antiobesogenic, anti-inflammatory activity, among others. Objetive. The objective of the present study was to evaluate the effect of in vitro gastrointestinal digestion on the bioaccessibility of phenolic compounds and antioxidant activity of a nutraceutical formulation of blueberry (capsule), compared to fresh and powder blueberry. Materials and methods. Methanolic extracts of fresh and lyophilized blueberry were obtained and determined its total phenols, flavonoids, anthocyanins content, as well as antioxidant activity. A gastrointestinal digestion simulation test also was carried out to assess the bioaccessibility of the phenolic compounds found in samples. Results. The results showed that gastric digestion of powder and capsule blueberry promoted greater bioaccessibility of phenols (42% and 40%), flavonoids (52% and 33%) and anthocyanins (45% and 40%), compared to fresh blueberry digests. After intestinal digestion, the bioaccessibility of phenols (63%) and flavonoids (67%) was higher in the blueberry capsule compared to its powdered blueberry counterpart. The intestinal digestion conditions negatively affected the bioaccessibility of anthocyanins regardless of the type of sample evaluated. Conclusion. Gastric digestion conditions promote greater stability of phenolic compounds in powdered and capsule blueberries, which could be relevant for the maintenance of an antioxidant environment at this level. The intestinal digestion conditions particularly affected the phenolic compounds of fresh and lyophilized blueberry, but not the capsule, which may suggest that encapsulation protected the phenols present from alkaline conditions. Further studies on in vitro absorption of the remaining components in the intestine and their possible effects on oxidative stress biomarkers in in vivo models are suggested.

Response surface optimization of millet milk fermented by Lactobacillus kefir

Based on the amino acid score (AAS), chemical score (CS), and amino acid proportional coefficient score (SRCAA) as evaluation indicators, millet powder, whey protein isolate powder, and soybean protein isolate powder were mixed to make millet compound powder. After the millet compound powder and water were uniformly mixed at a material-to-liquid ratio of 1:20, the kefir fermented millet nutritional milk was prepared by beating, gelatinizing, liquefying, saccharifying, and fermenting. The protein content, polyphenol content, viable count and acidity of kefir millet fermented milk were significantly higher than those of the other two commercially available similar beverages. The scavenging rates of DPPH free radicals and hydroxyl radicals in the kefir millet fermented milk group at three stages (before undigested, after gastric digestion for 2.5 h, and after intestinal digestion for 2.5 h) were significantly higher than those in the unfermented millet pulp group. Novelty impact statement In this study, based on the amino acid pattern and amino acid nutrition evaluation methods (AAS, CS, SRCAA), millet flour and two protein powders with rich lysine content (whey protein isolate powder and soybean protein isolate powder) were rationally compounded as amino acid balanced millet compound powder. The millet compound powder is fermented by Lactobacillus kefir into millet nutritional fermented milk with unique flavor of probiotic fermentation. The antioxidant activity of millet nutritional fermented milk and millet pulp before fermentation was compared and analyzed by gastrointestinal digestion simulation in vitro, and it was determined that millet nutritional fermented milk had strong antioxidant activity.

Antioxidant Potential of Selected Wild Edible Leafy Vegetables of Sikkim Himalayan Region: Effects of Cooking Methods and Gastrointestinal Digestion on Activity.

Green leafy vegetables or GLVs are one of the main attractions in the local vegetable market and are widely consumed as the main course and side dish in the Sikkim Himalayan region (SHR). This study evaluated the total phenolic (TPC) and flavonoid contents (TFC) and antioxidant potential in different extracts such as methanolic (MeOH), ethyl acetate (EtOAC), and hexane extracts of selected GLVs followed by changes in the antioxidant activity on cooking and stimulated gastrointestinal (GI) digestion. The MeOH extracts of Urtica dioica L. (Sisnu), Nasturtium officinale W. T. Aiton (Simrayo), Diplazium esculentum Retz. Sw. (Ningro), and Chenopodium album L. (Bethu) were estimated to have higher TPC [22.73–45.84 μg gallic acid equivalent (GAE)/mg of extract]. In contrast, the plant extracts prepared using EtOAC (except for N. officinale, where TFC was found to be higher in hexane extract) were found to contain higher TFC (3.42–14.86 μg quercetin equivalent (QE)/mg of extract). The MeOH extracts also exhibited higher 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (9.55–18.67 μg ascorbic acid equivalent (AAE)/mg of extract), total antioxidant activity (TAA) (0.27–0.32 mg AAE/mg of extract), and reducing power potential (RPP) (1.6–9.9 μg AAE/mg of extract). Among the test MeOH extracts, U. dioica demonstrated relatively higher antioxidant activities and was selected for cooking experiments followed by simulated GI digestion. The findings revealed that the loss of antioxidant activity was minimal in steam-cooked leaves (3.5% in 40 min) as compared to the boiled ones (18% in 10 min). The simulated GI (simulated salivary, gastric, and intestinal) digestion performed on raw, steam cooked, and boiled U. dioica leaves showed substantial enhancement of antioxidant properties (by 64.63%) through steam cooking in comparison to the raw leaves. Overall the study concludes that higher antioxidant properties can be achieved on the consumption of steam-cooked U. dioica leaves.

Enhanced viability of microencapsulated lyophilized probiotics under in vitro simulated gastrointestinal conditions

The aim of the study was to investigate the impact of different encapsulation matrices on the viability and stability of probiotic. Probiotics were encapsulated by Lyophilization using different wall materials soy protein isolate (SPI), sodium alginate (SA), iota-carrageenan (I-CG), and starch (ST). The prepared microbeads were characterized in terms of size, encapsulation efficiency, and zeta potential. The viability of free and encapsulated probiotics was also assessed under In vitro gastrointestinal (GIT) conditions and in cow milk-based plain yoghurt. The encapsulation efficiency of SPI (95%) and SA (92%) microbeads were higher than I-CG (88%) and ST (79%). The zeta potentials of the microbeads were 35 mv for SPI), −11 mv for SA, −23 for I-CG, and −26 mv for ST. The statistical results support the practicability of employed wall materials for encapsulation of probiotics for improved viability under simulated GIT conditions as well in a food matrix. Practical applications Encapsulation is an effective approach for the delivery of sensitive core materials. Encapsulation with different wall materials is an economical technology to improve the viability of probiotics under hostile conditions. Soy protein isolate, sodium alginate are effective wall materials in ensuring the probiotic viability under stressed conditions.

Dual crosslinking of folic acid-modified pectin nanoparticles for enhanced oral insulin delivery

Pectin-based drug delivery systems hold great potential for oral insulin delivery, since they possess excellent gelling property, good mucoadhesion and high stability in the gastrointestinal (GI) tract. However, lack of enterocyte targeting ability and premature drug release in the upper GI tract of the susceptible ionic-crosslinked pectin matrices are two major problems to be solved. To address these issues, we developed folic acid (FA)-modified pectin nanoparticles (INS/DFAN) as insulin delivery vehicles by a dual-crosslinking method using calcium ions and adipic dihydrazide (ADH) as crosslinkers. In vitro studies indicated insulin release behaviors of INS/DFAN depended on COOH/ADH molar ratio in the dual-crosslinking process. INS/DFAN effectively prevented premature insulin release in simulated GI fluids compared to ionic-crosslinked nanoparticles (INS/FAN). At an optimized COOH/ADH molar ratio, INS/DFAN with FA graft ratio of 18.2% exhibited a relatively small particle size, high encapsulation efficiency and excellent stability. Cellular uptake of INS/DFAN was FA graft ratio dependent when it was at/below 18.2%. Uptake mechanism and intestinal distribution studies demonstrated the enhanced insulin transepithelial transport by INS/DFAN via FA carrier-mediated transport pathway. In vivo studies revealed that orally-administered INS/DFAN produced a significant reduction in blood glucose levels and further improved insulin bioavailability in type I diabetic rats compared to INS/FAN. Taken together, the combination of dual crosslinking and FA modification is an effective strategy to develop pectin nano-vehicles for enhanced oral insulin delivery.

Fungal digestive enzymes promote macronutrient hydrolysis in the INFOGEST static in vitro simulation of digestion

The objective of this study was to test the hydrolytic efficacy of 6 fungal enzymes in the INFOGEST static in vitro simulation of gastrointestinal (GI) digestion. First, the INFOGEST protocol was adapted for testing of exogenous enzymes. Second, a dose-response study of 3 individual fungal proteases, a lipase, and an amylase with glucoamylase demonstrated improved dietary protein, lipid, and carbohydrate hydrolysis, respectively, from an oral nutritional supplement (ONS) under simulated gastric or GI conditions, compared to pepsin and pancreatin-based control conditions. Third, a combination of the 6 enzymes (BC-006) improved macronutrient digestion, including enhanced release of individual amino acids from ONS and mixed meal substrates. Finally, we validated digestive models of aging and proton pump inhibitor (PPI) use, and showed that BC-006 improved gastric digestion under these compromised digestive conditions. The INFOGEST static simulation is a feasible tool to rapidly screen and profile exogenous enzymes for digestive efficacy in vitro.

Gravitational and microwave-assisted multi-stages block freeze concentration process to obtain enriched concentrated beet (Beta vulgaris L.) by-products extract: bioactive compounds and simulated gastrointestinal profile

Gravitational (GC) and microwave-assisted (MWC) block freeze cryoconcentration was carried out to obtain extracts rich in phenolic compounds from beet leaves extract. The performance of both processes was evaluated and cryoconcentrated and ice fractions were analyzed for physicochemical properties, bioactive compounds content, and in vitro gastrointestinal simulation. After four concentration cycles using GC, the total and soluble solids were approximately 6 and 5 times higher the initial condition, whilst MWC allowed to 4 and 4.5, respectively. GC and MWC presented an increase in the bioactive compound concentration, reaching an efficiency process of 90% (stage 4) and 80% (stage 3), respectively. Consequently an increase in the antioxidant activity was observed. Comparing GC and MWC was observed a reduction in the processing time from several hours (GC) to only a few minutes (MWC), besides the high retention of bioactive compounds, as well as notabl values in terms of solutes and process parameter.

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.

Design and implementation of a highly integrated dual hemisphere capsule robot.

To achieve cancer screening in any appointed position in 3D regions of the gastrointestinal (GI) tract such as esophagus, stomach and colon, a highly integrated dual hemisphere capsule robot (DHCR) with a novel three-layer nested structure is proposed. Based on tracking effect, in which the robotic axis is likely to be approximately coincident with the orientation of thespace universal rotating magnetic field (SURMF) using the gyroscope dynamic balance, the dual hemisphere structure realizes the observation at a fixed-point in the passive mode and the rolling locomotion in the active mode by the dynamic posture control of the SURMF manipulation. The image acquisition module, wireless transmission module and driving actuator are tuned in a spherical structure, making the DHCR more compact and less invasive. To verify the maneuverability of the innovative DHCR both for observation at a fixed-point and navigation in curved intestine by aid of image, experiments are conducted in the simulated GI tract environment. The results show that the DHCR achieves effective conversion between posture adjustment and rolling locomotion, which lays a foundation for all-over inspection and medical operation inside 3D regions of the GI tract of human body.

Screening and bioavailability evaluation of anti-oxidative selenium-containing peptides from soybeans based on specific structures.

Our previous study has evaluated the antioxidant capacity and identified the sequences of soybean selenium-containing peptides. Herein, pharmacophore screening, gastrointestinal simulation and in vivo pharmacokinetics were performed to predict the potentials of selenium-containing peptides in terms of antioxidant activity, safety and bioavailability. A pharmacophore model with 6 structure features was constructed for virtual screening to determine the potential activities of 85 selenium sequences from soybean peptides. Strong reversing effects (p < 0.05) of the targeted sequences were observed in tumor necrosis factor-α (TNF-α)-induced inflammatory cytokines and adhesion factors burst in EA·hy926/Caco-2 co-culture cell models. Ser-Phe-Gln-SeMet (SFQSeM), a promising peptide selected from both virtual screening and cell models, was proved to be stable in the gastrointestinal tract and could be transported across the Caco-2 monolayer via the paracellular pathway. Additionally, SFQSeM showed a long residence time (89.42 ± 1.34 min) and half-life (81.60 ± 11.88 min) after consumption, and it induced lower liver alanine/aspartate transaminase (ALT/AST) and serum nitric oxide (NO) levels compared to Na2SeO3 and SeMet (p < 0.05). The potency of SFQSeM against oxidative stress as well as its oral bioavailability and low risk highlight its potential utility as an effective Se nutritional supplement.