Simulated Intestinal Juice Research Articles

Seleksi Bakteri Asam Laktat dari Nira Aren [(Arenga pinnata (Wurmb)] Asal Papua Sebagai Kandidat Probiotik

Palm sap has several nutrients which are suitable to support the growth of lactic acid bacteria (LAB). As a probiotic, LAB have been intensively studied to promote gastrointestinal health in humans and animals. This study aimed to assess the probiotic properties of LAB isolated form [(Arenga pinnata (Wurmb)] palm sap originated from Papua. Several probiotic property test were performed, including antimicrobial activity against Escherichia coli InaCC B5 and Bacillus cereus InaCC B9, resistance to bile salts (0.1%, 0.2%, 0.3%), to low pH (pH 2.5), simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Further antimicrobial activity was conducted against 12 pathogenic bacteria, followed by characterisation of enzymatic properties, genetic profiles (RAPD-PCR M13 and ERIC-PCR) and molecular identification based on 16S rDNA sequences. The results show that 6 out of 52 isolates obtained from palm sap originated Papua were fulfilled the criteria as probiotic candidates, including able to produce antimicrobial activity (inhibiting 12 pathogenic bacteria) and able to survive when exposured in low pH, bile salt, simulated gastric juice and simulated intestinal juice. Further biochemical test indicate that isolates NP29 and NP34 produce protease and amylase enzymes while isolates NP29, NP33, NP44, NP46, NP57 produce phytase enzymes. Genetic profiling and molecular identification confirm that all isolates classified into three groups, including group 1 (NP29, NP33, NP46, NP57) identified as Lactobacillus plantarum, group 2 (NP34) identified as Lactobacillus casei and group 3 (NP44) identified as Lactobacillus paracasei.

Seleksi Bakteri Asam Laktat dari Nira Aren [(Arenga pinnata (Wurmb)] Asal Papua Sebagai Kandidat Probiotik

ABSTRACT Palm sap has several nutrients which are suitable to support the growth of lactic acid bacteria (LAB). As a probiotic, LAB have been intensively studied to promote gastrointestinal health in humans and animals. This study aimed to assess the probiotic properties of LAB isolated form [(Arenga pinnata (Wurmb)] palm sap originated from Papua. Several probiotic property test were performed, including antimicrobial activity against Escherichia coli InaCC B5 and Bacillus cereus InaCC B9, resistance to bile salts (0.1%, 0.2%, 0.3%), to low pH (pH 2.5), simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Further antimicrobial activity was conducted against 12 pathogenic bacteria, followed by characterisation of enzymatic properties, genetic profiles (RAPD-PCR M13 and ERIC-PCR) and molecular identification based on 16S rDNA sequences. The results show that 6 out of 52 isolates obtained from palm sap originated Papua were fulfilled the criteria as probiotic candidates, including able to produce antimicrobial activity (inhibiting 12 pathogenic bacteria) and able to survive when exposured in low pH, bile salt, simulated gastric juice and simulated intestinal juice. Further biochemical test indicate that isolates NP29 and NP34 produce protease and amylase enzymes while isolates NP29, NP33, NP44, NP46, NP57 produce phytase enzymes. Genetic profiling and molecular identification confirm that all isolates classified into three groups, including group 1 (NP29, NP33, NP46,NP57) identified as Lactobacillus plantarum, group 2 (NP34) identified as Lactobacillus casei and group 3 (NP44) identified as Lactobacillus paracasei. Keywords: Lactic acid bacteria, palm sap, Papua, probiotic.

The Effect of Encapsulated Powder of Goji Berry (Lycium barbarum) on Growth and Survival of Probiotic Bacteria.

The aim of the present work was to investigate the potential prebiotic action of Goji berry powder on selected probiotic bacteria grown in a nutritive synthetic substrate and in simulated gastric and intestinal juices. Different probiotic strains of Bifidobacterium and Lactobacillus were grown in these substrates with or without the addition of encapsulated goji berry extracts of different polysaccharide and polyphenol contents. The results proved that the addition of the extracts promoted the proliferation of probiotic strains and, in particular, increased the number of bacterial colonies of Bifidobacterium animalis subsp. lactis (Bb12), Bifidobacterium longum (Bb46), and Lactobacillus casei by 2, 0.26, and 1.34 (log cfu/mL), respectively. Furthermore, the prebiotic effect seems to be correlated to Goji berry polysaccharides and/or polyphenols, higher contents of which (under the tested concentrations) could increase the stress tolerance of B. lactis and B. longum in a simulated gastrointestinal environment. According to the findings of the present research, it can be suggested that the Goji berry encapsulated extracts could be used as prebiotic additives in food or nutraceuticals, in order to stimulate growth or protect the viability of probiotic strains of Bifidobacterium and Lactobacillus.

Degradation of polysaccharides from Sargassum fusiforme using UV/H2O2 and its effects on structural characteristics

The depolymerization effect of UV/H2O2 on the polysaccharides from Sargassum fusiforme (PSF), a brown algae, were studied. The structural changes of PSF before and after UV/H2O2 treatment were analyzed, and molecular weight changes during in vitro digestion were determined. Results indicated that the molecular weight of PSF was reduced from ∼289 to ∼12.6 kDa within 2 h with UV/150 mmol/L H2O2, and the depolymerization effect of UV/H2O2 was significantly higher than that of UV or H2O2 alone. In addition, the UV/H2O2 treatment had a high recovery rate of total sugar (93.54 %) and clearance rate of protein (76.34 %). The monosaccharide composition showed that UV/H2O2 treatment could increase the mole percentage of mannose (37.44 %) and decrease the mole percentage of fucose (14.88 %). The helix-coil transition, X-ray diffraction (XRD) and atomic force microscopy (AFM) imaging showed that the UV/H2O2 treatment depolymerized PSF. Rheological studies indicated that PSF with UV/H2O2 treatment had lower viscosity. In vitro digestion showed that PSF was minimally digested with the in vitro gastrointestinal tract simulation, but PSF with UV/H2O2 treatment could be digested in the low acid environment in the simulated gastric juice, but was minimally digested with the simulated intestinal juice. This studied suggested that the preparation and application of functional PSF with low molecular weight might be beneficial.

Optimization of Alginate-Whey Protein Isolate Microcapsules for Survivability and Release Behavior of Probiotic Bacteria.

The present study aimed to improve the survivability of L. acidophilus encapsulated in alginate-whey protein isolate (AL-WPI) biocomposite under simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Microcapsules were prepared based on emulsification/internal gelation technique. Optimal compositions of AL and WPI and their ratio in the aqueous phase were evaluated based on minimizing mean diameter (MD) of the microcapsules and maximizing encapsulation efficiency (EE), survivability of cells under SGJ (Viability), and release of viable cells under SIJ (Release) using Box-Behnken experimental design. Optimal composition comprising 4.54% (w/v) AL, 10% (w/v) WPI, and 10% (v/v) AL-WPI gum in the aqueous phase was determined statistically. Physicochemical characteristics of the optimized matrix were investigated by SEM, FTIR, and XRD analysis to determine surface morphology, molecular bonds, and crystalline nature of such hydrocolloid. It could be concluded that the proposed biocomposite is a good promise for nutrients encapsulation in the food industry.

Effect on Viability of Microencapsulated Lactobacillus rhamnosus with the Whey Protein-pullulan Gels in Simulated Gastrointestinal Conditions and Properties of Gels.

Lactobacillus rhamnosus GG (LGG) has low resistance to low pH and bile salt in the gastrointestinal juice. In this study, the gel made from whey protein concentrate (WPC) and pullulan (PUL) was used as the wall material to prepare the microencapsulation for LGG protection. The gelation process was optimized and the properties of gel were also determined. The results showed the optimal gel was made from 10% WPC and 8.0% PUL at pH 7.5, which could get the best protective effect; the viable counts of LGG were 6.61 Log CFU/g after exposure to simulated gastric juice (SGJ) and 9.40 Log CFU/g to simulated intestinal juice (SIJ) for 4 h. Sodium dodecyl sulphite polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that the WPC-PUL gel had low solubility in SGJ, but dissolved well in SIJ, which suggested that the gel can protect LGG under SGJ condition and release probiotics in the SIJ. Moreover, when the gel has highest hardness and water-holding capacity, the viable counts of LGG were not the best, suggesting the relationship between the protection and the properties of the gel was non-linear.

Isolation and characterization of potential probiotic Lactobacilli from leaves of food plants for possible additives in pellet feeding

Bacteria strains isolated from plant leaves of papaya, cassava, sugarcane, yam, and taro, were investigated for their potential probiotic properties. Four isolates from food crop plant leaves were identified as Lactobacillus plantarum, Enterococcus faecalis, Lactobacillus paraplantarum, and Weissella paramesenteroides by sequence of 16S rDNA. The five isolates exhibited tolerance to simulated intestinal juices, and these were selected to evaluate their probiotic properties by biochemical characterization and in vivo testing as a pelleted feed additive. All 5 strains were susceptible to Streptomycin, Penicillin, Chloramphenicol, Ampicillin, and Tetracycline, and exhibited antimicrobial activity against Gram-positive Bacilus cereus, Listeria monocytogenes, Staphylococcus aureus, and the Gram-negative Escherichia coli pathogen. Furthermore, the lactobacilli isolates W. paramesenteroides C02, E. faecalis S04, L. paraplantarum P01, L. plantarum T03, and W. paramesenteroides Y05 exhibited rapid growth in skimmed milk with no nutritional supplement to 108 cfu·mL−1 after 24 h incubation. In vivo analysis of swine feeds after granulation exhibited 109–1010 cfu·kg−1 of L. plantarum, E faecalis, and W. paramesenteroides, which confirmed the probiotic potential and application of the lactobacilli strains isolated from plant leaves in granulated or pelleted feed as additives.

Characterization and embedding potential of bovine serum albumin cold-set gel induced by glucono-δ-lactone and sodium chloride

Bovine serum albumin (BSA) was induced to form cold-set gel by using glucono-δ-lactone (GDL) and sodium chloride (NaCl), and characteristics of the gel and its embedding potential to bioactive molecules were investigated. The results from texture analyzer indicated that hardness and springiness of BSA cold-set gel were improved by increasing GDL or NaCl, but the gel with lower concentration of GDL (1.0%) and NaCl (0.2 M) had better water holding capacity (WHC). GDL had a significant influence on storage modulus (G’) and loss modulus (G″) but it did not appear to be applicable to NaCl. Light transmittance at 500 nm and average particle size were used to characterize formation of BSA cold-set gel as pH values decreased, and the results suggested that BSA molecules had aggregated at the pH value of the gel point. Microstructure and fractal analysis from confocal laser scanning microscope (CLSM) further suggested that electrostatic and hydrophobic interaction played important roles in the formation of the cold-set gel and it could be deduced that structure and properties of the gel were closely related to the forces. BSA cold-set gel showed an excellent embedding performance to encapsulate bioactive molecules (used quercetin as representative), and achieved effective slow-release action, especially in simulated intestinal juice of pH 7.5. BSA cold-set gel may have important potential application in encapsulation, protection, delivery and controlled-release of some fragile bioactive components, so the research provides a theoretical basis for its application.

Growth and survival of microencapsulated probiotics prepared by emulsion and internal gelation

Efficient microencapsulation of probiotics by most existing methods is limited by low throughput. In this work, Saccharomyces boulardii and Enterococcus faecium were microencapsulated by a method based on emulsion and internal gelation. The growth and survival of microencapsulated microbes under different stressors were investigated using free non-encapsulated ones as a control. The results showed that the prepared micro-beads by emulsion and internal gelation exhibited a spherical and smooth shape, with sizes between 300 and 500 μm. Both S. boulardii and E. faecium grew well and survived better when encapsulated in micro-beads. The survival rates were increased 25% and 40% for microencapsulated S. boulardii and E. faecium respectively when compared with non-encapsulated controls under high temperature and high humidity. The increases of survival rates were 60% for microencapsulated S. boulardii and 25% for E. faecium in simulated gastric juice. And the increases were 15% and 20% respectively when the survival rates of the microencapsulated S. boulardii and E. faecium were determined in simulated intestinal juice. The microencapsulation by emulsion and internal gelation offers an effective way to protect microbes in adverse in vitro and in vivo conditions and is promising for the large-scale production of probiotics microencapsulation.

Microencapsulation of Lactobacillus acidophilus NCFM incorporated with mannitol and its storage stability in mulberry tea

ABSTRACT Lactobacillus acidophilus NCFM (L-NCFM) was microencapsulated via co-extrusion technique with mannitol. Optimization of coating material, locust bean gum (0% to 2%, w/v) and prebiotic, mannitol (0% to 5%, w/v) was tested on bead size and microencapsulation efficiency. L-NCFM cells microencapsulated in three different forms were tested in simulated gastric juice (pH 2.0) and simulated intestinal juice (pH 7.5) and storage test at 4 °C and 25 °C for 4 weeks. 0.5% (w/v) locust bean gum and 3% (w/v) of mannitol are the optimal concentrations to produce bead size of 570 µm, microencapsulation efficiency of 96.81% and cell count 8.92 log CFU/mL. Microencapsulation of L-NCFM with mannitol protect cells better in acidic environment. The viability of encapsulated L-NCFM with mannitol at 4 °C throughout the storage period for 30 days ranged from 8.62 log cfu/mL to 6.80 log cfu/mL, which met the minimum required for probiotic (106CFU/mL).

Oligosaccharides as co-encapsulating agents: effect on oral Lactobacillus fermentum survival in a simulated gastrointestinal tract.

Four kinds of oligosaccharides were used as co-encapsulating agents to test the effect of extrusion-based microencapsulation on protection of Lactobacillus fermentum L7 against exposure to simulated gastric and intestinal juices as well as long-term refrigeration storage at 4°C. The combination of alginate with galacto-oligosaccharides, isomalto-oligosaccharides, fructo-oligosaccharides, and xylo-oligosaccharides, or alginate alone exhibited good properties of the beads. The diameters of the cell beads co-encapsulated with oligosaccharides and encapsulated with alginate alone were similar, in the range of 2.34-2.51mm. However, the encapsulation yield of L. fermentum cells co-encapsulated with oligosaccharides, which was in the range of 79.52-89.75%, was significantly higher than that of cells encapsulated with alginate alone. The capsules were stable in gastric conditions and can disintegrated when exposed to intestinal conditions. Additionally, the viability of microencapsulated cells after exposure to the simulated gastric and intestinal juices as well as long-term refrigeration storage was better than that of free cells, and the viability of cells co-encapsulated with oligosaccharides was better than that of cells encapsulated with alginate alone. Furthermore, fructo-oligosaccharides used as co-encapsulating agent showed the best performance. Microencapsulating L. fermentum with oligosaccharides protected cells well at a low temperature and offered effective gastrointestinal delivery of probiotics, and thus has the potential to maintain bacterial survival in probiotic products and will provide the research basis for design of effective probiotic-prebiotic combinations to maximize host benefit.

The Prebiotic Activity of Simulated Gastric and Intestinal Digesta of Polysaccharides from the Hericium erinaceus.

Hericium erinaceus (HE) is a well-known edible and medicinal fungus widely grown in Asian countries. Polysaccharides from the Hericium erinaceus (HEP) are major biological macromolecules. It has been reported that HEP has multiple biological activities, such as antioxidant activity, immunomodulatory effects, anti-inflammatory effect, anti-chronic gastritis activity, and so on. In the current study, we investigated the biological property of HEP during gastrointestinal digestion. The results indicated that both simulated gastric and small intestinal digesta of HEP has better stimulation of probiotics growth than HEP alone, especially for Lactobacillus plantarum BG112. The prebiotic activity was the strongest when HEP was treated by simulated gastric juice for 2 h and by simulated small intestinal juice for 4 h. The molecular weight (Mw) of HEP decreased from 1.68 × 106 Da and 2.32 × 104 Da to 529.3 ± 7.2 Da, as digestion time increased. Meanwhile, the reducing sugar content was significantly increased from 0.610 ± 0.007 to 22.698 ± 0.752 mg/ml, suggesting that the decrease of Mw was likely due to the breakdown of glycosidic bonds. Considerable mannose and galactopyranose were released throughout the gastrointestinal digestion period, indicating that the gastrointestinal digestion resulted in production of free monosaccharides. After fermentation of L. plantarum BG112, the Mw of HEP was decreased and short chain fatty acids (SCFAs) including acetic acid, isovaleric acid, lactic acid, and butyric acid were produced. We speculated that the release of free monosaccharides during gastrointestinal digestion and utilization of HEP, by the probiotics, contributed to the prebiotic activity of HEP’s gastric and intestinal digesta. These results unveiled some mechanisms on the close relationship between the structure and bioactivity of polysaccharides, during digestion.

In vitro digestibility and prebiotic potential of a novel polysaccharide from Rosa roxburghii Tratt fruit

In the present study, the digestion properties of a polysaccharide from Rosa roxburghii fruit (RTFP-3) under saliva, simulated gastric and small intestinal conditions were studied for the first time. The results indicated that human saliva had no effect on RTFP-3. RTFP-3 was slightly degraded in simulated gastric and small intestinal juices. The molecular weight (Mw) of RTFP-3 was decreased from 67.59 to 44.22 kDa. Meanwhile, the reducing sugars were increased from 0.503 to 1.744 mM. Then, the prebiotic effects of RTFP-3 were examined by in vitro fermentation model. RTFP-3 could significantly increase the production of total short-chain fatty acids from 23.49 to 44.29 mM, and 60.28% of total carbohydrate was consumed after 48 h fermentation. Furthermore, RTFP-3 could significantly modulate the microbial structure by lowering the ratio of Firmicutes to Bacteroidetes from 14.89 to 4.68 after 48 h fermentation, and improving the relative abundances of some beneficial gut microbiota.

Lactobacillus fermentum strains from human breast milk with probiotic properties and cholesterol-lowering effects.

The study aimed to identify two lactic acid bacteria from human breast milk and evaluate for their probiotic potential. Lactobacillus fermentum strains showed various degree of antibiotic susceptibility profile to clinical commercial antibiotics. The MA-7 and MA-8 strains have never lost their vitality at pH 2 and 3. Lactobacillus fermentum MA-8 exhibited more resistance to 0.3 and 1% bile concentrations than MA-7 strain. Both of the L. fermentum strains can tolerate the simulated gastric and intestinal juices. The strains showed high auto-aggregation percentages varied from 95 to 98%. Both isolates also exhibited gamma hemolytic activity. The cholesterol lowering activity of MA-7 and MA-8 strains was varied from 34.84 to 91.15%. The supernatants showed higher anti-cholesterol activity compared to pellets. The results demonstrated that both L. fermentum strains maybe good probiotic candidates and may have potential as health biotherapeutic with cholesterol-lowering effects.

Screening of lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluation of probiotic function

To screen the lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluate their probiotic function. By plate separating, cholesterol-lowering and triglyceride-lowering activity in vitro were determined; and by evaluating the probiotic functions, including tolerances to simulated gastric and intestinal juice, the antibacterial spectrum, and the adhesion ability to Caco-2 cells, the probiotic strains with cholesterol-lowering and triglyceride-lowering activity in vitro were screened, and then were identified by phenotypical and physiological tests and 16Sr DNA. Finally, the cholesterol-lowering and triglyceride-lowering activity in vivo of the strains were evaluated using male Sprague-Dawley rats. Two strains L2-16 and L2-73 with stronger cholesterol-lowering and triglyceride-lowering activity in vitro, stronger tolerance to simulated gastric and intestinal juice and adhesion ability to Caco-2 cells, and wider antibacterial spectrum were screened from traditional Chinese fermented cucumber and were identified as Lactobacillus acidophilus and Enterococcus faecalis, respectively. Compared with a hyperlipidemia diet without lactic acid bacteria, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly reduced serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels, and liver total cholesterol and triglyceride levels in rats (P < 0.05). Moreover, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly increased the fecal elimination of bile acids (P < 0.05). Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 may have application prospect in the production of some fermented foods such as fermented vegetables, milk, or meat, and probiotic preparations with the function to lower the serum lipid and liver lipid levels.

Preliminary test on the distribution, hydrolyzation and excretion of aluminum dialkyl phosphinate flame retardants in rats

Aluminum dialkyl phosphinates (ADPs) are a promising class of chemicals offering superior flame retardance. However, knowledge on their behavior in vivo is scarce. Hydrolysis has been suggested as one of the major routes of environmental degradation of ADPs. Herein, aluminum methylcyclohexyl phosphinic (AMHP), a kind of ADPs with industrial production in China, and its hydrolysate methyl cyclohexyl phosphinic acid (MHPA) were continuously exposed to Sprague Dawley (SD) rats for 28 days in this study. The same ratio of MHPA in organs to serum and the same daily excretion of MHPA were observed for AMHP exposure group and MHPA exposure group, suggesting the hydrolysis of AMHP in vivo. The hydrolysis of AMHP to MHPA was further confirmed by in vitro simulated human gastric intestinal juice. Therefore, both AMHP and MHPA distributed in liver, kidney and even brain in the form of MHPA. More than 80% of AMHP and MHPA could be excreted by feces and urine. Feces are the main route of excretion of AMHP and MHPA. The denseness of the inflammatory cell in the hepatic portal area and biochemical indexes showed the obvious dose-effect relationship. However, the toxicity of AMHP and MHPA was quite low even with exposure level up to 100 mg/kg dw/day. The low cumulative ability and mild toxicity indicated AMHP as a promising substitute for brominated flame retardant.

Effects of polymerised whey protein-based microencapsulation on survivability of Lactobacillus acidophilus LA-5 and physiochemical properties of yoghurt

Lactobacillus acidophilus LA-5 has poor survivability in yoghurts. This study aims to microencapsulate L. acidophilus LA-5 using polymerised whey protein as wall material and evaluate its survivability and effects on physiochemical properties of yoghurts. The microencapsulation yield was 92.90% and average beads size was 744 μm. Microencapsulated L. acidophilus LA-5 showed higher survival at simulated gastrointestinal conditions. Microencapsulated L. acidophilus LA-5 had improved survivability (∼106 cfu/mL) than free cells (∼104 cfu/mL) after digesting by simulated intestinal juice (6 h) in yoghurts during 10-week storage. Microencapsulated L. acidophilus LA-5 improved the firmness and protein content and decreased the spontaneous whey separation and synaeresis of yoghurts significantly (p < 0.01). Changes in pH and free microorganism population of yoghurts during storage were not affected by adding microencapsulated L. acidophilus LA-5. Microencapsulation of L. acidophilus LA-5 using polymerised whey protein as wall material improved its survivability and the physiochemical properties of the yoghurt.

Probiotic Potential of Enterococcus faecium Isolated from Chicken Cecum with Immunomodulating Activity and Promoting Longevity in Caenorhabditis elegans.

Probiotics, including Enterococcus faecium, confer a health benefit on the host. An Enterococcus strain was isolated from healthy chicken cecum, identified as E. faecium by 16S rDNA gene sequence analysis, and designated as E. faecium L11. To evaluate the potential of E. faecium L11 as a probiotic, the gastrointestinal tolerance, immunomodulatory activity, and lifespan extension properties of the strain were assayed. E. faecium L11 showed >66% and >62% survival in artificial gastric juice (0.3% pepsin, pH 2.5) and simulated small intestinal juice (0.5% bile salt and 0.1% pancreatin), respectively. Heat-killed E. faecium L11 significantly (p < 0.05) increased immune cell proliferation compared with controls, and stimulated the production of cytokines (IL-6 and TNF-α) by activated macrophages obtained from ICR mice. In addition, E. faecium L11 showed a protective effect against Salmonella Typhimurium infection in Caenorhabditis elegans. In addition, feeding E. faecium L11 significantly (p < 0.05) extended the lifespan of C. elegans compared with the control. Furthermore, genes related to aging and host defense were upregulated in E. faecium L11-fed worms. In conclusion, E. faecium L11, which prolongs the lifespan of C. elegans, may be a potent probiotic supplement for livestock.

Effects of a homogeneous polysaccharide from Sijunzi decoction on human intestinal microbes and short chain fatty acids in vitro

Ethnopharmacological relevanceSijunzi decoction (SJZD) is a classic recipe in traditional Chinese medicine (TCM) to strengthen the spleen and replenish Qi. It is well known for treating disorders of gastrointestinal function manifested in poor appetite, reduced food intake and loose stools. Polysaccharide is the most abundant constituent and the major effective component in SJZD. Aim of the studyThe present study aimed to understand the immunomodulatory mechanism of S-3–1, a homogeneous polysaccharide purified from SJZD with immune-enhancement activity, by investigating its effects on human intestinal microbes and short chain fatty acids. Materials and methodsS-3–1 was incubated with simulated gastric juice, intestinal juice, and human fecal microflora independently and sequentially. The concentrations of total polysaccharide and reducing sugar were measured to identify the stability of independently and sequentially incubated S-3–1 in three in vitro fermentation models. Gas chromatograph (GC) analysis was used to measure the short chain fatty acid (SCFA) contents in human fecal samples. The human gut microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region). ResultsS-3–1 was degraded in three in vitro fermentation models separately and sequentially. Both S-3–1 and incubated S-3–1 could regulate the abundances of Lactobacillus, Pediococcus, Streptococcus, Bacteroides, Enterococcus, Clostridium and Dorea in human intestinal microflora samples. Specifically, S-3–1 could only regulate the abundances of Paraprevotella and Oscillospira, while the influenced flora changed to Butyricimonas, Coprococcus, Dialister, Sutterella, Ruminococcus and Parabacteroides after sequential incubation of S-3–1. In contrast to S-3–1 showing no influence on the content of SCFA, incubated S-3–1 showed increased contents of acetic acid and total acid that were associated with its effects on the abundances of Enterococcus, Sutterella, Butyricimonas and Streptococcus. ConclusionS-3–1 plays an immunomodulatory role by regulating the abundances of 9 intestinal bacteria genera. Incubated S-3–1 can regulate more bacteria genera, a total of 13 kinds, and can adjust the SCFA content to affect immunomodulation. Incubation with gastric and intestinal juices enhanced S-3–1′s capability of modulating the intestinal flora composition and decreased the bacteria’s need for a carbon source. This study could provide new insights for studies on the pharmacological mechanisms of polysaccharides in vitro.

Study of Factors Influencing the Bioaccessibility of Triazolone in Cherry Tomatoes Using a Static SHIME Model.

Estimating the influence of bioaccessibility of pesticide residues in fruits and vegetables on dietary exposure is a challenge for human health risk assessment. This study investigated the bioaccessibility of pesticide residues in cherry tomatoes and contributing factors (digestion time, pH, solid/liquid ratio, and dietary nutrition) using an in vitro test simulating the human gastrointestinal tract. pH had the largest effect on triazolone precipitation in the simulated gastric intestinal juice, which had a significant impact on the bioaccessibility. The bioaccessibility of triazolone in the intestinal stage was slightly higher than that in the stomach stage, owing to bile salts and pancreatic enzymes present in the intestinal juice. The bioaccessibility of triazolone did not change significantly with digestion time. In the gastric stage, there was a logarithmic relationship between the bioaccessibility and solid/liquid ratio (R2 = 0.9941). The addition of oil significantly changed the bioaccessibility in the gastrointestinal stage. Protein and dietary fiber only affected bioaccessibility in the stomach stage. Dietary nutrition can reduce the release of pesticides from fruits and vegetables into the stomach, sharply reducing the bioaccessibility, and the dietary exposure of pesticide residues in fruits and vegetables can be properly evaluated.