Synbiotic Combination between Lactobacillus paracasei VL8 and Mannan-Oligosaccharide Repairs the Intestinal Barrier in the Dextran Sulfate Sodium-Induced Colitis Model by Regulating the Intestinal Stem Cell Niche.

Previously, Lactobacillus paracasei VL8, a lactobacillus strain isolated from the traditional Finnish fermented dairy product Viili, demonstrated immunomodulatory and antibacterial effects. The prebiotic mannan-oligosaccharide (MOS) further promoted its antibacterial activity and growth performance, holding promise for maintaining intestinal health. However, this has not been verified in vivo. In this study, we elucidated the process by which L. paracasei VL8 and its synbiotc combination (SYN) with MOS repair the intestinal barrier function in dextran sodium sulfate (DSS)-induced colitis mice. SYN surpasses VL8 or MOS alone in restoring goblet cells and improving the tight junction structure. Omics analysis on gut microbiota reveals SYN's ability to restore Lactobacillus spp. abundance and promote tryptophan metabolism. SYN intervention also inhibits the DSS-induced hyperactivation of the Wnt/ß-catenin pathway. Tryptophan metabolites from Lactobacillus induce intestinal organoid differentiation. Co-housing experiments confirm microbiota transferability, replicating intestinal barrier repair. In conclusion, our study highlights the potential therapeutic efficacy of the synbiotic combination of Lactobacillus paracasei VL8 and MOS in restoring the damaged intestinal barrier and offers new insights into the complex crosstalk between the gut microbiota and intestinal stem cells.

Amino acid regulated citrus pectin-based emulsion stability mediated by pH.

BACKGROUND: Citrus residuals are rich in nutrients like pectin, essential oil, and amino acids, which are wasted in the food industry. Moreover, citrus components often coexist with amino acids during emulsion preparation and application. RESULTS: Adding glutamic or arginine after emulsification resulted in a stable emulsion compared with adding them before emulsification. Adding glycine before or after emulsification had no effect on the emulsion stability. Emulsion stability was improved by adding glutamic acid at pH 6. Ionic interaction and hydrogen bonding were the main forms of bonding. The rhamnogalacturonan II domain was the potential binding site for the amino acids. CONCLUSIONS: The emulsions prepared by adding acidic amino acids or basic amino acids after emulsification were stable relative to those in which the amino acids were added before emulsification. However, the order in which neutral amino acids were added did not affect the emulsion stability after storage for 7 days. With an increase in the pH level, droplet size increased and emulsion stability decreased. All the results could be attributed to changes in the structure and properties of citrus pectin, as well as the interaction between citrus pectin and amino acids. This study may expand the application of citrus-derived emulsions in the food industry. © 2023 Society of Chemical Industry.

Pear pomace soluble dietary fiber ameliorates the negative effects of high-fat diet in mice by regulating the gut microbiota and associated metabolites.

The gut microbiota and related metabolites are positively regulated by soluble dietary fiber (SDF). In this study, we explored the effects of SDF from pear pomace (PP) on the regulation of gut microbiota and metabolism in high-fat-diet-fed (HFD-fed) C57BL/6J male mice. The results showed that PP-SDF was able to maintain the HFD disrupted gut microbiota diversity with a significant increase in Lachnospiraceae_UCG-006, Akkermansia, and Bifidobacterium spp. The negative effects of high-fat diet were ameliorated by PP-SDF by regulating lipid metabolisms with a significant increase in metabolites like isobutyryl carnitine and dioscoretine. Correlation analysis revealed that gut microbiota, such as Akkermansia and Lachnospiraceae_UCG-006 in the PP-SDF intervention groups had strong positive correlations with isobutyryl carnitine and dioscoretin. These findings demonstrated that PP-SDF interfered with the host's gut microbiota and related metabolites to reduce the negative effects caused by a high-fat diet.

Effects of four cooking methods on flavor and sensory characteristics of scallop muscle.

This work aimed to explore the influence of four different cooking methods (Boiling, roasting, frying, and microwaving) on the sensory characteristics of scallop muscles. Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and electronic nose (e-nose) were combined to analyze the aroma of scallops. Combined with the results of free amino acids and electronic tongue (e-tongue), the taste changes of different samples were analyzed. Furthermore, texture profile and microstructure analysis jointly showed the influence of cooking methods on texture. The results showed that frying was the most suitable cooking method for scallop muscle because it resulted the best tasted products, boiled scallops retain the highest similarity to fresh scallops. Besides, a higher level of lipid oxidation and Maillard reaction resulted in significant increase in aldehydes, ketones, furans, umami, and sweet amino acid. For the boiled sample, the loss of water-soluble compounds and less fat oxidation resulted in fewer flavor substances and free amino acids, along with looser organizational structure and poorer sensory quality. The research showed that besides the texture of scallop muscle, volatile organic compounds and free amino acids as well as their mutual roles in taste and smell were also important to sensory receptivity.

Comparison of structural characteristics and bioactivity of Tricholoma mongolicum Imai polysaccharides from five extraction methods.

Tricholoma mongolicum Imai is an edible fungus rich in various health-promoting compounds, such as polysaccharides, polypeptides, polyunsaturated fatty acids, etc., and among them, polysaccharides have gotten more attention in recent research trends. This study explored the extraction of polysaccharides from T. mongolicum Imai by five extraction methods, including hot water extraction, ultrasound extraction, enzyme-assisted extraction, 0.1 M HCL extraction, and 0.1 M NaOH extraction. The effects of these extraction methods on the yield, chemical structure, apparent morphology, and the antioxidant activities of Tricholoma mongolicum Imai polysaccharides (TMIPs) were investigated in this study. The data showed that 0.1 M NaOH extraction produced the highest extraction yield compared to the other extraction methods. The results of high-performance gel permeation chromatography (HPGPC) and scanning electron microscopy (SEM) showed that different extraction methods had significant effects on the molecular weight and morphology of TMIPs. The results of Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis showed that the extraction methods had no significant difference in functional groups, crystal structure, and thermal stability of TMIPs. The antioxidant activity of TMIPs extracted by ultrasound extraction was more prominent among the five polysaccharides, which might be related to a large number of low-molecular-weight components in molecular weight distribution.

Application of stable isotopic and mineral elemental fingerprints in identifying the geographical originof concentrated apple juice in China.

Food traceability is an important component of food safety and quality. Currently, there is no authentic established technique to identify the origin of concentrated apple juice (CAJ) in China. In this study, the isotopes of δ13C, δ18O and the contents of 32 elements in CAJ from five production areas (BHB, NWR, SCH, LP and YRAR) were determined. The δ13C, δ18O and 28 elements were significantly different (P < 0.05: post-hoc Duncan's test) in the five production areas. PCA, PLS-DA and OPLS-DA were employed for regional classification of samples. The results show that ten key variables (Tl, Se, δ18O, B, Mg, Sr, Nd, Mo, As, and Na) are more relevant for discrimination of the samples. These findings contribute to understanding the variations of stable isotopic and element compositions in Chinese CAJ depending on geographic origins and offer valuable insight into the control of fraudulent labeling regarding the geographic origins of CAJ.

Physicochemical Properties and in vitro Digestibility of Myofibrillar Proteins From the Scallop Mantle (Patinopecten yessoensis) Based on Ultrahigh Pressure Treatment.

The utilization of myofibrillar proteins (MPs) from the scallop mantle was limited due to its poor digestibility in vitro. In this study, structural properties and in vitro digestibility of MP were evaluated after modified by ultra-high pressure (UHP) at different pressures (0.1, 100, 200, 300, 400, and 500 MPa). The results showed that high pressure could significantly increase the ordered structure content like α-helix, inhibit the formation of disulfide bonds, and decrease surface hydrophobicity. Moreover, MP possessed the optimal solubility and in vitro digestibility properties at 200 MPa due to the minimum particle size and turbidity, relatively dense and uniform microstructure. The results indicated that the UHP treatment was an effective method to improve the digestibility of MP from scallop mantle and lay a theoretical basis for the functional foods development of poor digestion people and comprehensive utilization of scallop mantles.

Structural characterization and immunomodulatory effects of extracellular polysaccharide from Lactobacillus paracasei VL8 obtained by gradient ethanol precipitation.

In this study, gradient ethanol precipitation method was applied to obtain the extracellular polysaccharides of Lactobacillus paracasei VL8 (VL8-EPS). The yields, physicochemical properties, and immunomodulatory effects of VL8-EPS obtained by precipitation at different ethanol concentrations (30%, 50%, and 70%, v/v) were compared. The results showed that VL8-EPSs were high molecular weight sulfated heteropolysaccharides, composed mainly of glucose and galactose, and the alteration of ethanol concentration had an effect on their chemical compositions, molecular weight distributions, monosaccharide composition, and surface structure, while the primary structure remained the same. Among the three polysaccharide fractions, VL8-EPS50 displayed better immunomodulatory activities compared with VL8-EPS30 and VL8-EPS70. VL8-EPS50 was found to exert immunomodulatory effects by enhancing the phagocytic activity of RAW264.7 cells and to promote their secretion of more nitric oxide; it also showed stronger thermal and solution stability. In summary, there was a correlation between the structural characteristics of polysaccharides and their immunomodulatory activity, and VL8-EPS50 was preferentially used for in vivo immunomodulatory activity. Practical Application This study opens up the source of raw materials for functional foods, which can provide some theoretical basis for the research and development of extracellular polysaccharides of lactic acid bacteria and promote their application in the future development of food industry.

Characteristics of surface layer protein from Lactobacillus kefiri HBA20 and the role in mediating interactions with Saccharomyces cerevisiae Y8.

In this study, the surface layer protein (SLP) from Lactobacillus kefiri HBA20 was characterized. The SLP was extracted by 5M LiCl. The molecular mass of the SLP was approximately 64 kDa as analyzed via SDS-PAGE. The surface morphology and the adhesion potential of L. kefiri HBA20 in the absence and presence of SLP were measured by AFM. Moreover, the protein secondary structure was evaluated by using circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), respectively. SLP had high ß-sheet contents and low content of α-helix. Thermal analysis of SLP of Lactobacillus kefiri HBA20 exhibited one transition peak at 129.64 °C. Furthermore, SEM measurements were showed that after the SLP were removed from the cell surface, the coaggregation ability with Saccharomyces cerevisiae Y8 of the strain was significantly reduced. In conclusion, the SLP of Lactobacillus kefiri HBA20 has a stable structure and the ability of adhesion to yeast. Molecular docking study revealed that mannan bind with the hydrophobic residues of SLP. Our results will help further understanding of the new surface layer protein and the interaction between L. kefiri and S. cerevisiae.

Effect of ultrasonic treatment on the structure and functional properties of mantle proteins from scallops (Patinopecten yessoensis).

In this study, scallop mantle protein was treated by ultrasound at different powers, and then analyzed by ANS fluorescent probes, circular dichroism spectroscopy, endogenous fluorescence spectrum, DNTB colorimetry and in-vitro digestion model to elucidate the structure-function relationship. The results indicated that ultrasound can significantly affect the secondary structure of scallop mantle protein like enhancing hydrophobicity, lowering the particle size, increasing the relative contents of α-helix and decreasing contents of ß-pleated sheet, ß-turn and random coil, as well as altering intrinsic fluorescence intensity with blue shift of maximum fluorescence peak. But ultrasound had no effect on its primary structure. Moreover, the functions of scallop mantle protein were regulated by modifying its structures by ultrasound. Specifically, the protein had the highest performance in foaming property and in-vitro digestibility under ultrasonic power of 100 W, oil binding capacity under 100 W, water binding capacity under 300 W, solubility and emulsification capacity under 400 W, and emulsion stability under 600 W. These results prove ultrasonic treatment has the potential to effectively improve functional properties and quality of scallop mantle protein, benefiting in comprehensive utilization of scallop mantles.

Tibet Kefir Milk Regulated Metabolic Changes Induced by High-Fat Diet via Amino Acids, Bile Acids, and Equol Metabolism in Human-Microbiota-Associated Rats.

This study aimed to confirm the effects of Tibet kefir milk (TKM) on gut microbiota and metabolism. An obesity model was established by feeding a high-fat diet (HFD) to human-microbiota-associated rats. Next-generation sequencing and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry were applied for gut microbiota and untargeted metabolomics, respectively. After 8 weeks of feeding, the enterotype in the HFD group was switched from ET1 (Prevotella/Akkermansia-dominant) to ET2 (Bacteroides/Akkermansia-dominant). Branched-chain amino-acids- and aromatic amino-acids-metabolism increased, and taurine-conjugated bile acids decreased in the HFD group. Compared with the HFD group, taurocholic acid increased in the TKM1 group, while l-threonine decreased, and equol, taurochenodeoxycholate, and taurodeoxycholic acid increased in the TKM2 group. The metabolite alteration suggested restorative bile acid metabolism, modified metabolic pattern of amino acids, and elevation of anti-obesity factors in the TKM-intervened animals. It can be deduced that changes by TKM intervention in the host gut metabolites are the major contributors to reducing fat deposition.

Bifidobacterium animalis subsp. lactis BB-12 Has Effect Against Obesity by Regulating Gut Microbiota in Two Phases in Human Microbiota-Associated Rats.

Bifidobacterium animalis subsp. lactis BB-12 (BB-12) is an extensively studied probiotics species, which has been reported to improve the human gut microbiota. This study aimed to confirm the effects of BB-12 on high-fat diet (HFD)-induced gut microbiota disorders. The probiotic BB-12 was consumed by human microbiota-associated rats and changes in gut microbiota were compared using next generation sequencing of the fecal samples collected from the normal chow group, the HFD group, and the BB-12-supplemented group. The enterotypes switched from Prevotella dominant to Akkermansia dominant as a result of switching diet from normal chow to HFD. BB-12 conferred protection on the gut microbiota composition of the rats by increasing the abundance of Prevotella and decreasing the abundance of Clostridium, Blautia, and Bacteroides in 0-3 weeks. In addition, Prevotella-dominant enterotype was maintained, which provides improve obesity effects. A decrease in body weight and the Firmicutes/Bacteroidetes ratio were also observed at week 3. While in 4-8 weeks, the enrichment of short-chain fatty acids-producing bacteria such as Eubacterium and Parabacteroides and probiotics such as Bifidobacterium was observed. The results revealed that BB-12 against obesity by regulating gut microbiota in two phases. After a short-term intervention, BB-12 supplementation suppressed the transition from the healthy to obesity state by protecting Prevotella-dominant enterotype, whereas after a long-term intervention, BB-12 ameliorates obesity by enriching beneficial bacteria in the gut.

Antioxidant and α-glucosidase inhibitory capacity of nonextractable polyphenols in Mopan persimmon.

This study was to evaluate and compare the polyphenols contents, antioxidant capacities, and α-glucosidase inhibitory abilities of extractable and nonextractable polyphenols (EP and NEP) in Mopan persimmon. The results showed that total phenols content of NEP was 5 times higher than that of EP, and the hydrolyzed NEP compounds displayed higher antioxidant capacity than EP in vitro by DPPH, ORAC assays. Meanwhile, NEP also exhibited inhibition capacity of α-glucosidase and were higher than that of acarbose. In addition, an in vitro model of gastrointestinal digestion was used for the release of NEP, the polyphenols content and ORAC values were obviously increased in gastric digestion stage. The result indicated that NEP in Mopan persimmon, which has often been overlooked and discarded in the past, possessed higher polyphenols content and antioxidant capacity than EP.