Ramulus mori has been widely used in traditional Chinese medicine because of its physiological activities, including antibacterial, anti-inflammatory, and antioxidant activities. Antimicrobial properties of Ramulus mori extract have been well described. However, no information is available regarding on Ramulus mori oligosaccharides (RMOS). The aim of this study was to investigate the effects of RMOS on the growth and virulence properties of the cariogenic bacterium Streptococcus mutans. The effects of RMOS on the biofilm structure and virulence gene expression of S. mutans were also evaluated, and the results were compared with the effects of commercial prebiotic galactooligosaccharides. RMOS were found to have an antibacterial effect against S. mutans, resulting in significant reductions in acid production, lactate dehydrogenase activity, adhesion, insoluble extracellular polysaccharide production, glucosyltransferase activity, and biofilm formation in a dose-dependent manner. Moreover, the biofilm structure was visibly damaged. A quantitative real-time PCR assay revealed downregulation of virulence gene-regulated acid production, polysaccharide production, adhesion, biofilm formation, and quorum sensing. These findings suggest that RMOS may be a promising natural product for the prevention of dental caries.

Human milk oligosaccharides (HMOs) are the third most abundant solid component of breast milk. However, the newborn cannot assimilate them as nutrients. They are recognized prebiotic agents (the first in the newborn diet) that stimulate the growth of beneficial microorganisms, mainly the genus Bifidobacterium, dominant in the gut of breastfed infants. The structures of the oligosaccharides vary mainly according to maternal genetics, but also other maternal factors such as parity and mode of delivery, age, diet, and nutritional status or even geographic location and seasonality cause different breast milk oligosaccharides profiles. Differences in the profiles of HMO have been linked to breast milk microbiota and gut microbial colonization of babies. Here, we provide a review of the scope of reports on associations between HMOs and the infant gut microbiota to assess the impact of HMO composition.

Three mannan polysaccharides and their oligosaccharides were investigated in terms of physicochemical characteristics and effects on gut microbiota. Oligosaccharides from guar gum had the fastest fermentation kinetics for SCFAs generation at the initial stage, while the locust bean of both polymers and oligosaccharides demonstrated the lowest SCFAs through the whole fermentation process. In contrast, konjac gum steadily increased SCFAs and reached its maximum level at 24 h fermentation, indicating its fermentation character may be associated with its rheological properties. Compared to their corresponding polysaccharides, all the oligosaccharides demonstrated a faster fermentation kinetics, followed by an enriched abundance of propionate-producing bacterial Prevotella and a decreased abundance of Megamonas and Collinsella. Meanwhile, oligosaccharides reduced the Firmicutes/Bacteroidota ratio as well as the abundance of Bacteroidetes and Escherichia-Shigella. The fermentation of konjac substrate significantly promoted the abundance of butyrate-producing bacterial Faecalibacterium. In contrast, although the fermentation of locust bean and guar gum substrates benefited Bifidobacterium abundance due to their similar structure and monosaccharides composition, the fermentation of locust bean gum led to greater Bifidobacterium than the others, which may be associated with its higher mannose composition in the molecules. Interestingly, the partial hydrolysis of the three polysaccharides slightly reduced their prebiotic function.

A novel and green procedure consisting of high hydrostatic pressure (HHP) aided by a commercial cellulase (Celluclast®) has been applied to valorise the apple by-product, a valuable source of dietary fibre but mainly composed by insoluble fibre. Optimal conditions for solubilisation of dietary fibre were first determined at atmospheric pressure as 2% (w/v) of substrate concentration and 20 Endo-Glucanase Units of cellulase. Monitoring of polysaccharides and oligosaccharides released from apple by-product was carried out by means of a newly validated HPLC method with refractive index detector. A synergistic effect was observed when the combined HHP plus cellulase treatment was used. Thus, the application of 200 MPa at 50 °C for 15 min enabled a significant increase in the release of water-soluble polysaccharides (1.8-fold) and oligosaccharides (3.8-fold), as well as a considerable decrease in the time required (up to 120-fold), compared to control at 0.1 MPa. Therefore, this technology could be a promising alternative approach to transform an industrial by-product into a novel rich-in-oligosaccharide food ingredient and a step forward into shaping the world of prebiotics.

This study set out to identify the composition and the biological activity of pectin-derived oligosaccharides (POS) generated from mild acid or enzymatic hydrolysis of apple pomace (AP). The effect of the polymerization of the structural units of POS contained in the AP hydrolysate on the growth and metabolism of microbiota from the human gastrointestinal tract and the adhesion of lactic acid bacteria (LAB) or pathogens to human gut epithelial cells was investigated in vitro. Mild acid hydrolysis followed by pectinolysis with Rohapect MaPlusT yielded the highest concentration of POS. In contrast, pure enzymatic processing of the AP performed with a mixed preparation of cellulase and Rohapect MaPlusT resulted in 1.8-fold lower overall POS. The concentration of higher-order oligosaccharides (degree of polymerization (DP) 7-10), however, was 1.7-fold higher. The increased ratio of higher-order oligosaccharides caused an increase in the bifidogenic effect, as well as affecting the amount and nature of short-chain fatty acid produced. Inhibition of Enterobacteriaceae was also observed. The strongest stimulation of LAB adhesion to the human epithelial cells occurred in the presence of the preparation containing the highest concentration of higher-order oligosaccharides. The fecal bacteria and pathogens showed much weaker adhesion to intestinal cells in the presence of all the tested AP hydrolysates. Both of the tested POS preparations, containing structurally different oligosaccharides (DPs 2-10 with different ratios of higher-order oligosaccharides), have the potential to be used as prebiotics for humans and animals. They stimulate bowel colonization with lactic acid bacteria and inhibit the development of infections caused by pathogens.

Mannan oligosaccharides (MOSs) have been implicated in the animal growth rate, health indices, and lipid oxidative stability. MOSs have been indicated to maintain intestinal health and anti-inflammatory effects via modulation of gut microbiota. Furthermore, the role of MOSs in modulating skeletal muscle function is largely unknown. Here, this study aimed to investigate the effects of MOS supplementation on muscle function and muscle mass in mice. Additionally, the possible underlying mechanisms, including the contributions of gut microbiota and microbial metabolites, were explored. In our study, 3-week-old C57BL/6J male mice (body weight of approximately 10.7 ± 1.1 g) were given pure water or pure water with 1% MOS. To study the effect of MOSs on gut-microbiota-derived metabolites, serum metabolic profiles were analyzed through untargeted metabolomic profiling. Moreover, we detected the downstream signals of differential metabolites, and decanoic acid (DA) was selected as our target spot. Then, DA was used to treat C2C12 cells, and we found that DA promotes C2C12 cell differentiation via the GPR84 and PI3K/AKT signaling pathways. In conclusion, these results showed that MOS supplementation improves muscle function and muscle mass. Additionally, gut microbiome and microbial metabolites were regulated by MOSs, and DA may be one of the most important links between the gut microbiome and skeletal muscle function regulation.

Alginate lyase has been demonstrated as an efficient tool in the preparation of functional oligosaccharides (AOS) from alginate. The high viscosity resulting from the high concentration of alginate poses a limiting factor affecting enzymatic hydrolysis, particularly in the preparation of the fragments with low degrees of polymerization (DP). Herein, a PL7 family alginate lyase Algt from Microbulbifer thermotolerans DSM 19189 was developed and expressed in Pichia pastoris. The recombinant alginate lyase Algt1 was constructed by adopting the structural domain truncation strategy, and the enzymatic activity towards the alginate was improved from 53.9 U/mg to 212.86 U/mg compared to Algt. Algt1 was stable when incubated at 40 °C for 90 min, remaining with approximately 80.9% of initial activity. The analyses of thin-layer chromatography (TLC), fast protein liquid chromatography (FPLC), and electrospray ionization mass spectrometry (ESI-MS) demonstrated that the DP of the minimum identifiable substrate of Algt1 was five, and the main hydrolysis products were AOS with DP 1-4. Additionally, 1-L the enzymatic hydrolysis system demonstrated that Algt1 exhibited an effective degradation at alginate concentrations of up to 20%, with the resulting products of monosaccharides (14.02%), disaccharides (21.10%), trisaccharides (37.08%), and tetrasaccharides (27.80%). These superior properties of Algt1 make it possible to efficiently generate functional AOS with low DP in industrial processing.

Melon by-products, that currently lack high value-added applications, could be a sustainable source of bioactive compounds such as polysaccharides and antioxidants. In this work, melon peels were extracted with water to remove free sugars, and the water-insoluble solids (WISs) were subjected to hydrothermal processing. The effect of temperature on the composition of the obtained liquors and their total phenolic content was evaluated. The selected liquors were also characterized by matrix assisted laser desorption/ionization-time of flight mass spectroscopy (MALDI-TOF MS), fourier transform infrared spectroscopy (FTIR) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), and its phenolic compounds were identified and quantified by high-performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC-DAD-MS/MS). In addition, the spent solids from the hydrothermal treatment were characterized and their potential use was assessed. At the optimal conditions of 140 °C (severity 2.03), the total oligosaccharide yield accounted for 15.24 g/100 g WIS, of which 10.07 g/100 g WIS were oligogalacturonides. The structural characterization confirmed the presence of partially methyl esterified oligogalacturonides with a wide range of polymerization degrees. After precipitation, 16.59 g/100 g WIS of pectin were recovered, with a galacturonic acid content of 55.41% and high linearity.

This study explored the Maillard reaction process during the glycation of soy protein isolate (SPI) with galacto-oligosaccharides (GOSs) under high-pressure homogenization (HPH) and its effects on the emulsifying properties of SPI. SPI-GOS glycation under moderate pressure (80 MPa) significantly inhibited the occurrence and extent of the Maillard reaction (p < 0.05), but homogenization pressures in the range of 80−140 MPa gradually promoted this reaction. HPH caused a decrease in the surface hydrophobicity of the glycated protein, an increase in the abundance of free sulfhydryl groups, unfolding of the protein molecular structure, and the formation of new covalent bonds (C=O, C=N). Additionally, the particle size of emulsions created with SPI-GOS conjugates was reduced under HPH, thus improving the emulsifying properties of SPI. A reduction in particle size (117 nm), enhanced zeta potential (−23 mV), and uniform droplet size were observed for the emulsion created with the SPI-GOS conjugate prepared at 120 MPa. The conformational changes in the glycated protein supported the improved emulsification function. All results were significantly different (p < 0.05). The study findings indicate that HPH provides a potential method for controlling glycation and improving the emulsifying properties of SPI.

Alginate oligosaccharides are degradation products of alginate and have attracted increasing attention due to their versatile biological functions. In the present study, C57BL/6 mice were used to assess the ameliorative effects and mechanisms of guluronate oligosaccharides (GAOS), mannuronic oligosaccharides (MAOS), and heterozygous alginate oligosaccharides (HAOS), which are the three alginate oligosaccharides of dextran sulfate sodium (DSS)-induced ulcerative colitis. The study showed that alginate oligosaccharides alleviated pathological histological damage by slowing down weight loss, inhibiting colonic length shortening, and reducing disease activity index (DAI) and histopathological scores. Alginate oligosaccharides modulated the colonic inflammatory response by reducing colonic MPO levels and downregulating the expression of IL-6 and IL-1β. Alginate oligosaccharides reduced intestinal permeability and reversed intestinal barrier damage by increasing the number of goblet cells, decreasing LPS levels, downregulating Bax protein levels, upregulating Bcl-2 protein levels, and enhancing the expression of the E-cadherin. Furthermore, alginate oligosaccharides modulated the composition of the gut microbiota and restored the production of short-chain fatty acids (SCFAs), especially acetate and butyrate. In conclusion, our study provides a scientific basis for the role of alginate oligosaccharides in relieving ulcerative colitis.

Functional oligosaccharides exert obesity-reducing effects by acting at various pathological sites responsible for the development of obesity. In this study, tamarind xyloglucan oligosaccharides (TXOS) were used to attenuate metabolic disorders via the gut-liver axis in mice with high-fat-diet (HFD)-induced obesity, as determined through LC/MS-MS and 16S rRNA sequencing technology. A TXOS dose equivalent to 0.39 g/kg/day in humans restored the gut microbiota in obese mice, which was in part supported by the key microflora, particularly Bifidobacterium pseudolongum. Moreover, TXOS reduced the abundance of opportunistic pathogen species, such as Klebsiella variicola and Romboutsia ilealis. The bodyweight and weight gain of TXOS-treated (4.8 g/kg per day) mice began to decrease at the 14th week, decreasing by 12.8% and 23.3%, respectively. Sixteen fatty acids were identified as potential biomarkers in the liver, and B. pseudolongum and caprylic acid were found to tightly regulate each other. This was associated with reduced inflammation in the liver, circulation, and adipose tissue and protection from metabolic disorders. The findings of this study indicate that TXOS can significantly increase the gut microbiota diversity of obese mice and restore the HFD-induced dysbiosis of gut microbiota.

High-fat diets (HFD) can promote the development of hepatic steatosis by altering the structure and composition of gut flora. In this study, the potential therapeutic mechanism of Lycium barbarum oligosaccharide (LBO) against hepatic steatosis was investigated by analyzing the changes in the intestinal flora and metabolites in mice. Mice on an HFD were administered LBO by gavage once daily for a continuous period of eight weeks. Compared with the HFD group, the levels of triglyceride (TG), alanine aminotransferase (ALT) in the serum, and hepatic TG were significantly reduced in the LBO group, and liver lipid accumulation was obviously improved. In addition, LBO could regulate the HFD-induced alteration of intestinal flora. The HFD increased the proportion of Barnesiellaceae, Barnesiella, and CHKCI001. LBO increased the proportion of Dubosiella, Eubacterium, and Lactobacillus. LBO also altered the fecal metabolic profile. Significantly different metabolites between LBO and the HFD, such as taurochenodeoxycholate, taurocholate, fluvastatin, and kynurenic acid, were related to the cholesterol metabolism, bile acid metabolism, and tryptophan metabolic pathways. In light of the above, LBO can alleviate HFD-induced NAFLD by modulating the components of the intestinal flora and fecal metabolites.

Bifidobacteria are known to inhibit, compete with and displace the adhesion of pathogens to human intestinal cells. Previously, we demonstrated that goat milk oligosaccharides (GMO) increased the attachment of Bifidobacterium longum subsp. infantis ATCC 15697 to intestinal cells in vitro. In this study, we aimed to exploit this effect as a mechanism for inhibiting pathogen association with intestinal cells. We examined the synergistic effect of GMO-treated B. infantis on preventing the attachment of a highly invasive strain of Campylobacter jejuni to intestinal HT-29 cells. The combination decreased the adherence of C. jejuni to the HT-29 cells by an average of 42% compared to the control (non-GMO treated B. infantis). Increasing the incubation time of the GMO with the Bifidobacterium strain resulted in the strain metabolizing the GMO, correlating with a subsequent 104% increase in growth over a 24 h period when compared to the control. Metabolite analysis in the 24 h period also revealed increased production of acetate, lactate, formate and ethanol by GMO-treated B. infantis. Statistically significant changes in the GMO profile were also demonstrated over the 24 h period, indicating that the strain was digesting certain structures within the pool such as lactose, lacto-N-neotetraose, lacto-N-neohexaose 3'-sialyllactose, 6'-sialyllactose, sialyllacto-N-neotetraose c and disialyllactose. It may be that early exposure to GMO modulates the adhesion of B. infantis while carbohydrate utilisation becomes more important after the bacteria have transiently colonised the host cells in adequate numbers. This study builds a strong case for the use of synbiotics that incorporate oligosaccharides sourced from goat's milk and probiotic bifidobacteria in functional foods, particularly considering the growing popularity of formulas based on goat milk.

In this work, Lactiplantibacillus plantarum (L. plantarum) isolated from mice feces (LP-M) and pickles (LP-P) were chosen as the endogenous and exogenous L. plantarum, respectively, which were separately combined with chitosan oligosaccharides (COS) to be synbiotics. The anti-inflammatory activity of LP-M, LP-P, COS, and the synbiotics was explored using dextran-sodium-sulfate (DSS)-induced acute colitis mice, as well as by comparing the synergistic effects of COS with LP-M or LP-P. The results revealed that L. plantarum, COS, and the synbiotics alleviated the symptoms of mice colitis and inhibited the changes in short-chain fatty acids (SCFAs), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-10, and myeloperoxidase (MPO) caused by DSS. In addition, the intervention of L. plantarum, COS, and the synbiotics increased the relative abundance of beneficial bacteria Muribaculaceae and Lactobacillus and suppressed the pathogenic bacteria Turicibacter and Escherichia-Shigella. There was no statistically difference between LP-M and the endogenous synbiotics on intestinal immunity and metabolism. However, the exogenous synbiotics improved SCFAs, inhibited the changes in cytokines and MPO activity, and restored the gut microbiota more effectively than exogenous L. plantarum LP-P. This indicated that the anti-inflammatory activity of exogenous LP-P can be increased by combining it with COS as a synbiotic.

Soy molasses is rich in oligosaccharides like sucrose, stachyose, and raffinose, with stachyose and raffinose being functional oligosaccharides. Harnessing soy molasses for the production of functional soy oligosaccharides (FSO) can significantly elevate its value. Biological purification, a method leveraging the selective utilization of different carbon sources by microorganisms, allows for the specific removal of sucrose from soy molasses while preserving stachyose and raffinose, thereby increasing the FSO content. This research identified a yeast named YT312 with strong purification capabilities for soy molasses and optimized the purification conditions. The study revealed that yeast YT312 was Wickerhamomyces anomalus, exhibiting a broad range of growth temperatures and pH levels alongside a high tolerance to glucose, sucrose, and NaCl. Through single-factor and orthogonal experiments, it was established that under specific conditions-0.375% inoculum size, 30 °C fermentation temperature, 150 rpm shaking speed, 10-fold dilution ratio, pH of 7, and 12 h of fermentation-sucrose was completely removed from soy molasses, while functional raffinose and stachyose were retained at rates of 96.1% and 90.2%, respectively. Consequently, W. anomalus YT312 displayed exceptional characteristics for the biological purification of soy molasses and the production of FSO.

Historically, honey is known for its anti-bacterial and anti-fungal activities and its use for treatment of wound infections. Although this practice has been in place for millennia, little information exists regarding which manuka honey components contribute to the protective nature of this product. Given that sugar accounts for over 80% of honey and up to 25% of this sugar is composed of oligosaccharides, we have investigated the anti-infective activity of manuka honey oligosaccharides against a range of pathogens. Initially, oligosaccharides were extracted from a commercially-available New Zealand manuka honey-MGO™ Manuka Honey (Manuka Health New Zealand Ltd)-and characterized by High pH anion exchange chromatography coupled with pulsed amperiometric detection. The adhesion of specific pathogens to the human colonic adenocarcinoma cell line, HT-29, was then assessed in the presence and absence of these oligosaccharides. Manuka honey oligosaccharides significantly reduced the adhesion of Escherichia coli O157:H7 (by 40%), Staphylococcus aureus (by 30%), and Pseudomonas aeruginosa (by 52%) to HT-29 cells. This activity was then proven to be concentration dependent and independent of bacterial killing. This study identifies MGO™ Manuka Honey as a source of anti-infective oligosaccharides for applications in functional foods aimed at lowering the incidence of infectious diseases.

Herein, we applied the Illumina MiSeq pyrosequencing platform to amplify the V3-V4 hypervariable regions of the 16 S rRNA gene of the gut microbiota (GM) and a gas chromatograph-mass spectrometer to detect the metabolites after supplementation with pumpkin oligosaccharides (POSs) to determine the metabolic markers and mechanisms in rats with type 2 diabetes (T2D). The POSs alleviated glucolipid metabolism by decreasing the serum low-density lipoprotein (LDL), total cholesterol (TC), and glucose levels. These responses were supported by a shift in the gut microbiota, especially in the butyric-acid-producing communities. Meanwhile, elevated total short-chain fatty acid (SCFA), isovaleric acid, and butyric acid levels were observed after supplementation with POSs. Additionally, this work demonstrated that supplementation with POSs could reduce TNF-α and IL-6 secretion via the FFA2-Akt/PI3K pathway in the pancreas. These results suggested that POSs alleviated T2D by changing the SCFA-producing gut microbiota and SCFA receptor pathways.

The importance of cereals and pulses in the diet is widely recognized, and consumers are seeking for ways to balance their diet with plant-based options. However, the presence of antinutritional factors reduces their nutritional value by decreasing the bioavailability of proteins and minerals. This study's aim was to select microbes and fermentation conditions to affect the nutritional value, taste, and safety of products. Single lactic acid bacteria (LAB) strains that reduce the levels of antinutrients in faba bean and pea were utilized in the selection of microbes for two starter mixtures. They were studied in fermentations of a faba bean-oat mixture at two temperatures for 24, 48, and 72 h. The levels of antinutrients, including galacto-oligosaccharides and pyrimidine glycosides (vicine and convicine), were determined. Furthermore, a sensory evaluation of the fermented product was conducted. Fermentations with selected single strains and microbial mixtures showed a significant reduction in the content of antinutrients, and vicine and convicine decreased by up to 99.7% and 96.1%, respectively. Similarly, the oligosaccharides were almost completely degraded. Selected LAB mixtures were also shown to affect the product's sensory characteristics. Microbial consortia were shown to perform effectively in the fermentation of protein-rich materials, resulting in products with improved nutritional value and organoleptic properties.

Rice (Oryza sativa L.) is a staple food that is consumed worldwide, and hybrid rice has been widely employed in many countries to greatly increase yield. However, the frequency of extreme temperature events is increasing, presenting a serious challenge to rice grain quality. Improving hybrid rice grain quality has become crucial for ensuring consumer acceptance. This study compared the differences in milling quality, appearance quality, and physical and chemical starch properties of rice grains of five restorer lines (the male parent of hybrid rice) when they encountered naturally unfavorable temperatures during the filling period under field conditions. High temperatures (HTs) and low temperatures (LTs) had opposite effects on grain quality, and the effect was correlated with rice variety. Notably, R751, R313, and Yuewangsimiao (YWSM) were shown to be superior restorer lines with good resistance to both HT and LT according to traits such as head rice rate, chalkiness degree, chalky rice rate, amylose content, alkali spreading value, and pasting properties. However, Huazhan and 8XR274 were susceptible to sub-optimal temperatures at the grain-filling stage. Breeding hybrid rice with adverse-temperature-tolerant restorer lines can not only ensure high yield via heterosis but also produce superior grain quality. This could ensure the quantity and taste of rice as a staple food in the future, when extreme temperatures will occur increasingly frequently.

Ultra-high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to study the diversity of tea polysaccharides and the dynamic changes in the physicochemical indexes of tea samples. FT-IR spectra and the free radical scavenging ability of tea polysaccharides, during pile-fermentation of post-fermented tea, were analyzed. The results showed that 23 saccharide co mponents in tea polysaccharides were identified: these belonged to 11 monosaccharides, 5 oligosaccharides, and 6 derivatives of monosaccharides and oligosaccharides. The abundance of oligosaccharides decreased gradually, while monosaccharides, and derivatives of monosaccharides and oligosaccharides increased gradually with the development of pile-fermentation. According to the differences in polysaccharide composition and their abundance, the tea polysaccharide samples extracted from different pile-fermentation stages could be clearly classed into three groups, W-0, W-1~W-4 and W-5~C-1. The pile-fermentation process affected the yield, the content of each component, FT-IR spectra, and the DPPH free radical scavenging ability of tea polysaccharides. Correlation analysis showed that microorganisms were directly related to the changes in composition and the abundance of polysaccharides extracted from different pile-fermentation stages. The study will further help to reveal the function of tea polysaccharides and promote their practical application as a functional food.