BACKGROUND: Alpha-glucosidase inhibitors or dipeptidyl peptidase-4 inhibitors are both hypoglycemia agents that specifically impact on postprandial hyperglycemia. We compared the effects of acarbose and sitagliptin add on to metformin on time in range (TIR) and glycemic variability (GV) in Chinese patients with type 2 diabetes mellitus through continuous glucose monitoring (CGM). METHODS: This study was a randomized, open-label, active-con-trolled, parallel-group trial conducted at 15 centers in China from January 2020 to August 2022. We recruited patients with type 2 diabetes aged 18-65 years with body mass index (BMI) within 19-40 kg/m 2 and hemoglobin A1c (HbA1c) between 6.5% and 9.0%. Eligible patients were randomized to receive either metformin combined with acarbose 100 mg three times daily or metformin combined with sitagliptin 100 mg once daily for 28 days. After the first 14-day treatment period, patients wore CGM and entered another 14-day treatment period. The primary outcome was the level of TIR after treatment between groups. We also performed time series decomposition, dimensionality reduction, and clustering using the CGM data. RESULTS: A total of 701 participants received either acarbose or sitagliptin treatment in combination with metformin. There was no statistically significant difference in TIR between the two groups. Time below range (TBR) and coefficient of variation (CV) levels in acarbose users were significantly lower than those in sitagliptin users. Median (25th percentile, 75th percentile) of TBR below target level <3.9 mmol/L (TBR 3.9 ): Acarbose: 0.45% (0, 2.13%) vs . Sitagliptin: 0.78% (0, 3.12%), P = 0.042; Median (25th percentile, 75th percentile) of TBR below target level <3.0 mmol/L (TBR 3.0 ): Acarbose: 0 (0, 0.22%) vs . Sitagliptin: 0 (0, 0.63%), P = 0.033; CV: Acarbose: 22.44 ± 5.08% vs . Sitagliptin: 23.96 ± 5.19%, P <0.001. By using time series analysis and clustering, we distinguished three groups of patients with representative metabolism characteristics, especially in GV (group with small wave, moderate wave and big wave). No significant difference was found in the complexity of glucose time series index (CGI) between acarbose users and sitagliptin users. By using time series analysis and clustering, we distinguished three groups of patients with representative metabolism characteristics, especially in GV. CONCLUSIONS: Acarbose had slight advantages over sitagliptin in improving GV and reducing the risk of hypoglycemia. Time series analysis of CGM data may predict GV and the risk of hypoglycemia. TRIAL REGISTRATION Chinese Clinical Trial Registry: ChiCTR2000039424.
Humans ; Metformin/therapeutic use* ; Sitagliptin Phosphate/therapeutic use* ; Acarbose/therapeutic use* ; Diabetes Mellitus, Type 2/blood* ; Middle Aged ; Male ; Female ; Adult ; Blood Glucose/drug effects* ; Hypoglycemic Agents/therapeutic use* ; Aged ; Glycated Hemoglobin/metabolism* ; Adolescent ; Young Adult ; China ; East Asian People

OBJECTIVES: To investigate the therapeutic effects of inulin-type oligosaccharides of Morinda officinalis (IOMO) in a murine model of Streptococcus pneumoniae meningitis (SPM) and explore its possible mechanisms. METHODS: A total of 120 male C57BL/6J mice were randomly assigned into Sham, SPM+Saline, SPM+IOMO (25 mg/kg), and SPM+IOMO (50 mg/kg) groups. After modeling, the mice received daily gavage of saline or IOMO at the indicated doses for 7 consecutive days, and the changes in symptom scores and mortality of the mice were monitored. Brain pathology and neuronal injury of the mice were assessed using HE and Nissl staining, and qRT-PCR was performed to detect mRNA levels of the inflammatory mediators. Brain edema and blood-brain barrier (BBB) permeability of the mice were evaluated by measuring brain water content and Evans blue (EB) staining; Western blotting was used to analyze the expressions of BBB-associated proteins, and flow cytometry was employed to detect IFN‑γ expression level in the infiltrating lymphocytes. Open-field test (OFT) and novel object recognition test (NORT) were conducted to assess learning and memory ability of the mice on day 21 after modeling. RESULTS: IOMO treatment at 50 mg/kg significantly reduced the symptom scores and mortality rate of SPM mice, alleviated brain damage, and downregulated mRNA levels of IL-6, TNF‑α, IL-1β, IL-18, IFN‑γ, iNOS, NLRP3, ASC, caspase-1 and GSDMD in the brain tissue. IOMO treatment also decreased brain water content and EB leakage, upregulated VE-cadherin and occludin expressions, and suppressed AQP4, iNOS, and IFN‑γ levels of the mice. IOMO-treated mice exhibited improved learning and memory compared with the saline-treated mice on day 21 after SPM modeling. CONCLUSIONS IOMO alleviates SPM symptoms, reduces mortality, and mitigates cognitive deficits in mice possibly by suppressing cerebral inflammation and protecting BBB functions.
Animals ; Morinda/chemistry* ; Mice, Inbred C57BL ; Male ; Mice ; Meningitis, Pneumococcal/drug therapy* ; Blood-Brain Barrier/metabolism* ; Inulin/therapeutic use* ; Oligosaccharides/therapeutic use* ; Disease Models, Animal ; Interferon-gamma/metabolism* ; Brain Edema

The caries-preventive effects of arginine have been attributed to its impact on biofilm composition and pH. Recent in vitro studies suggest that arginine also affects the production of biofilm matrix components that contribute to virulence, but this mechanism has not been investigated clinically. This randomized, placebo-controlled, triple-blind, split-mouth in situ trial assessed arginine's impact on the microbial composition, matrix architecture, and microscale pH of biofilms from caries-active patients (N = 10). We also examined whether individual differences in the pH response to arginine were related to biofilm composition and matrix structure. Biofilms were grown for four days on carriers attached to intraoral splints. Three times daily, the biofilms were treated extraorally with sucrose (5 min), followed by arginine or placebo (30 min), in a split-mouth design. After growth, the microscale biofilm pH response to sucrose was monitored by pH ratiometry. Microbial biofilm composition and carbohydrate matrix architecture were analyzed by 16S rRNA gene sequencing and fluorescence lectin-binding analysis, respectively. Arginine treatment significantly mitigated sucrose-induced pH drops, reduced total carbohydrate matrix production, and altered the spatial distribution of fucose- and galactose-containing carbohydrates. Both arginine- and placebo-treated biofilms were dominated by streptococci and Veillonella spp. Paired analyses showed a significant reduction in mitis/oralis group streptococci and a non-significant increase in several arginine metabolizers in arginine-treated biofilms. Individual pH responses were not significantly associated with the abundance of specific bacterial taxa or carbohydrate matrix components. In conclusion, arginine reduced the virulence of biofilms from caries-active patients through multiple mechanisms, including suppressing matrix carbohydrate production.
Biofilms/drug effects* ; Humans ; Arginine/pharmacology* ; Hydrogen-Ion Concentration ; Dental Caries/prevention & control* ; Male ; Female ; Adult ; Double-Blind Method ; Sucrose/pharmacology*

The high content of sucrose and raffinose reduces the prebiotic value of soybean oligosaccharides. Fructan sucrases can catalyze the conversion of sucrose and raffinose to high-value products such as fructooligosaccharides and melibiose. To obtain a fructan sucrase that can efficiently convert soybean oligosaccharides, we first mined the fructan sucrase gene from microorganisms in the coastal areas of Xisha Islands and Bohai Bay and then characterized the enzymatic and catalytic properties of the enzyme. Finally, recombinant extracellular expression of this gene was carried out in Bacillus subtilis. The results showed that a novel fructan sucrase, BhLS 39, was mined from Bacillus halotolerans. With sucrose and raffinose as substrates, BhLS 39 showed the optimal temperatures of 50 ℃ and 55 ℃, optimal pH 5.5 for both, and K_cat/K_m ratio of 3.4 and 6.6 L/(mmol·s), respectively. When 400 g/L raffinose was used as the substrate, the melibiose conversion rate was 84.6% after 30 min treatment with 5 U BhLS 39. Furthermore, BhLS 39 catalyzed the conversion of sucrose to produce levan-type-fructooligosaccharide and levan. Then, the recombinant extracellular expression of BhLS 39 in B. subtilis was achieved. The co-expression of the intracellular chaperone DnaK and the extracellular chaperone PrsA increased the extracellular activity of the recombinant BhLS 39 by 5.2 folds to 17 U/mL compared with that of the control strain. BhLS 39 obtained in this study is conducive to improving the quality and economic benefits of soybean oligosaccharides. At the same time, the strategy used here to enhance the extracellular expression of BhLS 39 will also promote the efficient recombinant expression of other proteins in B. subtilis.
Oligosaccharides/metabolism* ; Glycine max/metabolism* ; Bacillus subtilis/metabolism* ; Sucrase/biosynthesis* ; Raffinose/metabolism* ; Fructans/metabolism* ; Sucrose/metabolism* ; Bacillus/genetics* ; Recombinant Proteins/biosynthesis* ; Bacterial Proteins/biosynthesis*

The gut microbiota is closely related to human health, and various gut microbiota health indices have been developed to assist in evaluating the health of the gut microbiota and even the overall health of the human body. Diets are one of the main factors that regulate the gut microbiota, while there is still no good method for evaluating the regulatory effects of dietary factors. To assess the regulatory effects of dietary factors on the gut microbiota of overweight individuals, we conducted an in vitro fermentation experiment based on 17 dietary factors, and developed an evaluation method for the regulatory effects of dietary factors based on the health index with principal component analysis (hiPCA). The results showed that most dietary factors had positive regulatory effects on the gut microbiota of overweight individuals. Galactooligosaccharides (GOS) and puerarin were the most significant dietary factors in regulating the gut microbiota of overweight individuals. The analysis of the contribution of species to the hiPCA indicated that GOS and puerarin might inhibit the activities of bacteria associated with overweight by regulating Eubacterium dolichum, Lactobacillus salivarius, Clostridium clostridioforme, Clostridium citroniae, and Lachnospiraceae bacterium 9_1_43BFAA. In addition, GOS may further enhance the inhibition of these activities by regulating Lachnospiraceae bacterium 6_1_63FAA, thereby reducing the gut health risks in overweight individuals. In summary, this study evaluated the health effects of dietary factors based on the hiPCA and specifically analyzed the role of different dietary factors in regulating the gut microbiota of overweight individuals. This provides new ideas and methods for improving gut microbiota health and has potential applications in the field of precision nutrition.
Humans ; Gastrointestinal Microbiome/physiology* ; Isoflavones/pharmacology* ; Overweight/microbiology* ; Diet ; Fermentation ; Oligosaccharides/pharmacology* ; Principal Component Analysis

α-amylase is an endonucleoside hydrolase that hydrolyzes the α-1, 4-glycosidic bonds inside polysaccharides, such as starch, to generate oligosaccharides, dextrins, maltotriose, maltose and a small amount of glucose. Due to the importance of α-amylase in food industry, human health monitoring and pharmaceuticals, detection of its activity is widely required in the breeding of α-amylase producing strains, in vitro diagnosis, development of diabetes drugs, and the control of food quality. In recent years, many new α-amylase detection methods have been developed with improved speed and sensitivity. This review summarized recent processes in the development and applications of new α-amylase detection methods. The major principle of these detection methods were introduced, and their advantages and disadvantages were compared to facilitate future development and applications of α-amylase detection methods.
Humans ; alpha-Amylases/chemistry* ; Polysaccharides ; Oligosaccharides ; Starch ; Maltose

Chitosanases represent a class of glycoside hydrolases with high catalytic activity on chitosan but nearly no activity on chitin. Chitosanases can convert high molecular weight chitosan into functional chitooligosaccharides with low molecular weight. In recent years, remarkable progress has been made in the research on chitosanases. This review summarizes and discusses its biochemical properties, crystal structures, catalytic mechanisms, and protein engineering, highlighting the preparation of pure chitooligosaccharides by enzymatic hydrolysis. This review may advance the understandings on the mechanism of chitosanases and promote its industrial applications.
Chitosan/chemistry* ; Chitin ; Glycoside Hydrolases/genetics* ; Protein Engineering ; Oligosaccharides/chemistry* ; Hydrolysis

L-arabinose isomerase (L-AI) is the key enzyme that isomerizes D-galactose to D-tagatose. In this study, to improve the activity of L-arabinose isomerase on D-galactose and its conversion rate in biotransformation, an L-arabinose isomerase from Lactobacillus fermentum CGMCC2921 was recombinantly expressed and applied in biotransformation. Moreover, its substrate binding pocket was rationally designed to improve the affinity and catalytic activity on D-galactose. We show that the conversion of D-galactose by variant F279I was increased 1.4 times that of the wild-type enzyme. The K_m and k_cat values of the double mutant M185A/F279I obtained by superimposed mutation were 530.8 mmol/L and 19.9 s^-1, respectively, and the catalytic efficiency was increased 8.2 times that of the wild type. When 400 g/L lactose was used as the substrate, the conversion rate of M185A/F279I reached a high level of 22.8%, which shows great application potential for the enzymatic production of tagatose from lactose.
Galactose/metabolism* ; Limosilactobacillus fermentum/genetics* ; Lactose ; Hexoses/metabolism* ; Aldose-Ketose Isomerases/genetics* ; Hydrogen-Ion Concentration

We prepared 15 batches of Kaixin Powder benchmark samples with the decoction pieces of different batches. Further, we established the specific chromatograms and index component content determination method of Kaixin Powder benchmark samples and analyzed the peaks and similarity of the chromatograms. With sibiricose A5, sibiricose A6, polygalaxanthone Ⅲ, 3,6'-disinapoyl sucrose, ginsenoside Rb_1, β-asarone, α-asarone, and dehydropachymic acid as index components, the index component content determination method was established and 70%-130% of the mean content of each component was set as the range. The chromatograms of 15 batches of Kaixin Powder benchmark samples had a total of 22 characteristic peaks, among which 8 peaks were identified, which represented sibiricose A5, sibiricose A6, polygalaxanthone Ⅲ, 3,6'-disinapoyl sucrose, ginsenoside Rb_1, β-asarone, α-asarone, and dehydropachymic acid, respectively. The chromatograms shared the similarity of 0.992-0.999. The 15 batches of benchmark samples had sibiricose A5 of 0.34-0.55 mg·g~(-1), sibiricose A6 of 0.43-0.57 mg·g~(-1), polygalaxanthone Ⅲ of 0.12-0.19 mg·g~(-1), 3,6'-disinapoyl sucrose of 1.08-1.78 mg·g~(-1), ginsenoside Rb_1 of 0.33-0.62 mg·g~(-1), β-asarone of 2.34-3.72 mg·g~(-1), α-asarone of 0.11-0.22 mg·g~(-1), and dehydropachymic acid of 0.053-0.079 mg·g~(-1). This study established the specific chromatograms and index component content determination method of Kaixin Powder benchmark samples, and the method was simple, feasible, reproducible, and stable. This study provides a scientific basis for further research on the key chemical properties of the benchmark samples and preparations of Kaixin Powder.
Powders ; Ginsenosides ; Benchmarking ; Drugs, Chinese Herbal/chemistry* ; Sucrose ; Chromatography, High Pressure Liquid/methods*

Soluble cello-oligosaccharide with 2-6 oligosaccharide units is a kind of oligosaccharide with various biological functions, which can promote the proliferation of intestinal probiotics such as Bifidobacteria and Lactobacillus paracei. Therefore, it has a regulatory effect on human intestinal microbiota. In this study, a Cc 01 strain was constructed by expressing cellodextrin phosphorylase (CDP) in Escherichia coli. By combining with a previously constructed COS 01 strain, a three-enzyme cascade reaction system based on strains COS 01 and Cc 01 was developed, which can convert glucose and sucrose into cello-oligosaccharide. After optimization, the final titer of soluble cello-oligosaccharides with 2-6 oligosaccharide units reached 97 g/L, with a purity of about 97%. It contained cellobiose (16.8 wt%), cellotriose (49.8 wt%), cellotetrose (16.4 wt%), cellopentaose (11.5 wt%) and cellohexose (5.5 wt%). When using inulin, xylo-oligosaccharide and fructooligosaccharide as the control substrate, the biomass (OD₆₀₀) of Lactobacillus casei (WSH 004), Lactobacillus paracei (WSH 005) and Lactobacillus acidophilus (WSH 006) on cello-oligosaccharides was about 2 folds higher than that of the control. This study demonstrated the efficient synthesis of cello-oligosaccharides by a three-enzyme cascade reaction and demonstrated that the synthesized cello-oligosaccharides was capable of promoting intestinal microbial proliferation.
Humans ; Oligosaccharides ; Biomass ; Escherichia coli/genetics* ; Gastrointestinal Microbiome ; Glucose