Effects of aluminum (Al) stress on the isoprenoid metabolism of two Citrus species differing in Al-tolerance.

Isoprenoid metabolism and its derivatives took part in photosynthesis, growth regulation, signal transduction, and plant defense to biotic and abiotic stresses. However, how aluminum (Al) stress affects the isoprenoid metabolism and whether isoprenoid metabolism plays a vital role in the Citrus plants in coping with Al stress remain unclear. In this study, we reported that Al-treatment-induced alternation in the volatilization rate of monoterpenes (α-pinene, ß-pinene, limonene, α-terpinene, γ-terpinene and 3-carene) and isoprene were different between Citrus sinensis (Al-tolerant) and C. grandis (Al-sensitive) leaves. The Al-induced decrease of CO2 assimilation, maximum quantum yield of primary PSII photochemistry (Fv/Fm), the lower contents of glucose and starch, and the lowered activities of enzymes involved in the mevalonic acid (MVA) pathway and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway might account for the different volatilization rate of isoprenoids. Furthermore, the altered transcript levels of genes related to isoprenoid precursors and/or derivatives metabolism, such as geranyl diphosphate (GPP) synthase (GPPS) in GPP biosynthesis, geranylgeranyl diphosphate synthase (GGPPS), chlorophyll synthase (CHS) and GGPP reductase (GGPPR) in chlorophyll biosynthesis, limonene synthase (LS) and α-pinene synthase (APS) in limonene and α-pinene synthesis, respectively, might be responsible for the different contents of corresponding products in C. grandis and C. sinensis. Our data suggested that isoprenoid metabolism was involved in Al tolerance response in Citrus, and the alternation of some branches of isoprenoid metabolism could confer different Al-tolerance to Citrus species.

Neural responses to oral administration of erythritol vs. sucrose and sucralose explain differences in subjective liking ratings.

INTRODUCTION: High sugar intake is associated with many chronic diseases. However, non-caloric sweeteners (NCSs) might fail to successfully replace sucrose due to the mismatch between their rewarding sweet taste and lack of caloric content. The natural NCS erythritol has been proposed as a sugar substitute due to its satiating properties despite being non-caloric. We aimed to compare brain responses to erythritol vs. sucrose and the artificial NCS sucralose in a priori taste, homeostatic, and reward brain regions of interest (ROIs). METHODS: We performed a within-subject, single-blind, counterbalanced fMRI study in 30 healthy men (mean ± SEM age:24.3 ± 0.8 years, BMI:22.3 ± 0.3 kg/m2). Before scanning, we individually matched the concentrations of both NCSs to the perceived sweetness intensity of a 10% sucrose solution. During scanning, participants received 1 mL sips of the individually titrated equisweet solutions of sucrose, erythritol, and sucralose, as well as water. After each sip, they rated subjective sweetness liking. RESULTS: Liking ratings were significantly higher for sucrose and sucralose vs. erythritol (both pHolm = 0.0037); water ratings were neutral. General Linear Model (GLM) analyses of brain blood oxygen level-depended (BOLD) responses at qFDR<0.05 showed no differences between any of the sweeteners in a priori ROIs, but distinct differences were found between the individual sweeteners and water. These results were confirmed by Bayesian GLM and machine learning-based models. However, several brain response patterns mediating the differences in liking ratings between the sweeteners were found in whole-brain multivariate mediation analyses. Both subjective and neural responses showed large inter-subject variability. CONCLUSION: We found lower liking ratings in response to oral administration of erythritol vs. sucrose and sucralose, but no differences in neural responses between any of the sweeteners in a priori ROIs. However, differences in liking ratings between erythritol vs. sucrose or sucralose are mediated by multiple whole-brain response patterns.

The use of blackcurrant pomace and erythritol to optimise the functional properties of shortbread cookies.

As a result of the production of blackcurrant juice, pomace is produced, which is a cheap, easy to further process raw material with high health benefits. The aim of the research was to develop a recipe for shortbread cookies based on blackcurrant pomace (0, 10, 30, 50%) and erythritol, and to assess their nutritional value (content of proteins, fats, sugars, dietary fibre, selected minerals and energy value), pro-health properties (antioxidant and anti-diabetic capacity) and sensory evaluation. The energy value of products with 50% of pomace sweetened with erythritol was nearly 30% lower compared to traditional cookies, while the content of dietary fibre was 10 times higher in products with the highest percentage of pomace. The antioxidant capacity and the total content of polyphenolic compounds increased with the increase in pomace content. The ability to inhibit α-amylase by shortbread cookies without pomace was about 400 times lower than those with 50% pomace. The results of the sensory evaluation showed that erythritol-sweetened cookies have more desirable characteristics compared to sucrose-sweetened cookies. Finally, it was proved that the proposed products are an excellent proposal for people struggling with food-dependent diseases, as well as being an opportunity to manage waste from the fruit industry.

Evaluation of the adjunctive use of Er:YAG laser or erythritol powder air-polishing in the treatment of peri-implant mucositis: A randomized clinical trial.

AIM: To assess the efficacy of Er:YAG laser (ERL) and erythritol powder air-polishing (AP) in addition to the submarginal instrumentation in the non-surgical treatment of peri-implant mucositis (PM). MATERIALS AND METHODS: Patients with at least one implant diagnosed with PM were included in the present 6-month randomized clinical trial (RCT). Implants were randomly assigned to one of the three treatment groups after submarginal instrumentation: AP (test 1 group), ERL (test 2 group) or no adjunctive methods (control group). The primary and secondary outcomes were, respectively, bleeding on probing (BoP) reduction and, complete disease resolution (total absence of BoP) and probing pocket depth (PPD) changes. The patient and the implant were considered the statistical unit. A multivariate logistic regression analysis was performed. RESULTS: A total of 75 patients were enrolled in the study. At each time point, significant BoP and PPD reductions were observed within each group. Intergroup analysis did not show statistically significant differences. Complete disease resolution ranged between 29% and 31%. The logistic regression showed that supramucosal restoration margin, PPD < 4 mm and vestibular keratinized mucosa (KM) significantly influenced the probability to obtain treatment success. CONCLUSION: The adjunctive use of AP and ERL in PM non-surgical therapy does not seem to provide any significant or clinically relevant benefit in terms of BoP and PPD reductions and complete disease resolution, over the use of submarginal instrumentation alone. Baseline PPD < 4 mm, presence of buccal KM and supramucosal restoration margin may play a role in the complete resolution of PM.

Erythritol Can Inhibit the Expression of Senescence Molecules in Mouse Gingival Tissues and Human Gingival Fibroblasts.

Oral aging causes conditions including periodontal disease. We investigated how the sugar alcohol erythritol, which has anti-caries effects, impacts aging periodontal tissues and gingival fibroblasts in mice and humans in vivo and in vitro. Mice were classified into three groups: control groups of six-week-old (YC) and eighteen-month-old mice (AC) and a group receiving 5% w/w erythritol water for 6 months (AE). After rearing, RNA was extracted from the gingiva, and the levels of aging-related molecules were measured using PCR. Immunostaining was performed for the aging markers p21, γH2AX, and NF-κB p65. p16, p21, γH2AX, IL-1ß, and TNFα mRNA expression levels were higher in the gingiva of the AC group than in the YC group, while this enhanced expression was significantly suppressed in AE gingiva. NF-κB p65 expression was high in the AC group but was strongly suppressed in the AE group. We induced senescence in cultured human gingival fibroblasts using H2O2 and lipopolysaccharide before erythritol treatment, which reduced elevated senescence-related marker (p16, p21, SA-ß-gal, IL-1ß, and TNFα) expression levels. Knockdown of PFK or PGAM promoted p16 and p21 mRNA expression, but erythritol subsequently rescued pyruvate production. Overall, intraoral erythritol administration may prevent age-related oral mucosal diseases.

Evaluation of Solutions Containing Fluoride, Sodium Trimetaphosphate, Xylitol, and Erythritol, Alone or in Different Associations, on Dual-Species Biofilms.

Although the association of polyols/polyphosphates/fluoride has been demonstrated to promote remarkable effects on dental enamel, little is known on their combined effects on biofilms. This study assessed the effects of solutions containing fluoride/sodium trimetaphosphate (TMP)/xylitol/erythritol on dual-species biofilms of Streptococcus mutans and Candida albicans. Biofilms were grown in the continuous presence of these actives alone or in different associations. Quantification of viable plate counts, metabolic activity, biofilm biomass, and extracellular matrix components were evaluated. Overall, fluoride and TMP were the main actives that significantly influenced most of the variables analyzed, with a synergistic effect between them for S. mutans CFUs, biofilm biomass, and protein content of the extracellular matrix (p < 0.05). A similar trend was observed for biofilm metabolic activity and carbohydrate concentrations of the extracellular matrix, although without statistical significance. Regarding the polyols, despite their modest effects on most of the parameters analyzed when administered alone, their co-administration with fluoride and TMP led to a greater reduction in S. mutans CFUs and biofilm biomass compared with fluoride alone at the same concentration. It can be concluded that fluoride and TMP act synergistically on important biofilm parameters, and their co-administration with xylitol/erythritol significantly impacts S. mutans CFUs and biomass reduction.

Liquid chromatography-mass spectrometry analyses of polyprenyl phosphates in Escherichia coli cells in which genes for isoprenoid synthesis are amplified.

Overproduction of isopentenyl diphosphate by the amplification of the genes for the methylerythritol 4-phosphate pathway, dxs and dxr, is known to be deleterious for the growth of Escherichia coli. We hypothesized that overproduction of one of the endogenous isoprenoids, in addition to isopentenyl diphosphate itself, might be the cause of the reported reduced growth rate and attempted to identify the causative agent. In order to analyze polyprenyl phosphates, they were methylated by the reaction with diazomethane. The resulting dimethyl esters of polyprenyl phosphates with carbon numbers from 40 to 60 were quantitated by high-performance liquid chromatography-mass spectrometric analysis detecting ion peaks of the sodium ion adducts. The E. coli was transformed by a multi-copy plasmid carrying both the dxs and dxr genes. Amplification of dxs and dxr significantly increased the levels of polyprenyl phosphates and 2-octaprenylphenol. The levels of Z,E-mixed polyprenyl phosphates with carbon numbers of 50-60 in the strain in which ispB was co-amplified with dxs and dxr were lower than those in the control strain where only dxs and dxr were amplified. The levels of (all-E)-octaprenyl phosphate and 2-octaprenylphenol in the strains in which ispU/rth or crtE was co-amplified with dxs and dxr were lower than those in the control strain. Although the increase in the level of each isoprenoid intermediate was blocked, the growth rates of these strains were not restored. Neither polyprenyl phosphates nor 2-octaprenylphenol can be determined to be the cause of the growth rate reduction seen with dxs and dxr amplification.

The gibberellic acid derived from the plastidial MEP pathway is involved in the accumulation of Bamboo mosaic virus.

A gene upregulated in Nicotiana benthamiana after Bamboo mosaic virus (BaMV) infection was revealed as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (NbDXR). DXR is the key enzyme in the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway that catalyzes the conversion of 1-deoxy-d-xylulose 5-phosphate to 2-C-methyl-d-erythritol-4-phosphate. Knockdown and overexpression of NbDXR followed by BaMV inoculation revealed that NbDXR is involved in BaMV accumulation. Treating leaves with fosmidomycin, an inhibitor of DXR function, reduced BaMV accumulation. Subcellular localization confirmed that DXR is a chloroplast-localized protein by confocal microscopy. Furthermore, knockdown of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase, one of the enzymes in the MEP pathway, also reduced BaMV accumulation. The accumulation of BaMV increased significantly in protoplasts treated with isopentenyl pyrophosphate. Thus, the metabolites of the MEP pathway could be involved in BaMV infection. To identify the critical components involved in BaMV accumulation, we knocked down the crucial enzyme of isoprenoid synthesis, NbGGPPS11 or NbGGPPS2. Only NbGGPPS2 was involved in BaMV infection. The geranylgeranyl pyrophosphate (GGPP) synthesized by NbGGPPS2 is known for gibberellin synthesis. We confirmed this result by supplying gibberellic acid exogenously on leaves, which increased BaMV accumulation. The de novo synthesis of gibberellic acid could assist BaMV accumulation.

The efficacy of the adjunct use of subgingival air-polishing therapy with erythritol powder compared to conventional debridement alone during initial non-surgical periodontal therapy.

AIM: To assess the efficacy of the adjunct use of a subgingival erythritol powder air-polishing device (EPAP) in comparison to conventional subgingival instrumentation alone during initial non-surgical periodontal therapy. MATERIALS AND METHODS: Twenty-one patients with generalized Stages 2 and 3 grade B periodontitis were included in this single centre, single blinded, split-mouth, randomized clinical trial. Teeth on the control side were treated with conventional hand and ultrasonic instrumentation, while those on the contralateral test side was treated using EPAP as adjunct to conventional subgingival instrumentation with hand and ultrasonic instruments. Three months after initial instrumentation, persisting pockets of ≥4 mm were re-treated, in both control and test sides, again with the respective treatment approach-subgingival instrumentation alone on control, and subgingival instrumentation + EPAP on test side. Clinical parameters such as probing pocket depth (PPD), bleeding on probing, and relative attachment level were recorded at baseline and 3 and 6 months following the initial instrumentation. Subgingival plaque samples were collected at baseline, immediately post surgery, as well as at 1 week, 1 month, 3 months, and 6 months after initial instrumentation. RESULTS: In the test group after 6 months, a significantly larger number of initially deep pockets (PPD ≥ 5.5 mm) were reduced to shallow (PPD ≤ 3.4 mm), and a larger attachment gain was observed. No statistically significant microbiological differences could be found between test and control group. CONCLUSIONS: The results of the present study indicate that the adjunct use of subgingival airflow therapy with EPAP during initial non-surgical periodontal therapy might be beneficial in initially deep pockets (PPD ≥ 5.5 mm).

YdfD, a Lysis Protein of the Qin Prophage, Is a Specific Inhibitor of the IspG-Catalyzed Step in the MEP Pathway of Escherichia coli.

Bacterial cryptic prophage (defective prophage) genes are known to drastically influence host physiology, such as causing cell growth arrest or lysis, upon expression. Many phages encode lytic proteins to destroy the cell envelope. As natural antibiotics, only a few lysis target proteins were identified. ydfD is a lytic gene from the Qin cryptic prophage that encodes a 63-amino-acid protein, the ectopic expression of which in Escherichia coli can cause nearly complete cell lysis rapidly. The bacterial 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is responsible for synthesizing the isoprenoids uniquely required for sustaining bacterial growth. In this study, we provide evidence that YdfD can interact with IspG, a key enzyme involved in the MEP pathway, both in vivo and in vitro. We show that intact YdfD is required for the interaction with IspG to perform its lysis function and that the mRNA levels of ydfD increase significantly under certain stress conditions. Crucially, the cell lysis induced by YdfD can be abolished by the overexpression of ispG or the complementation of the IspG enzyme catalysis product methylerythritol 2,4-cyclodiphosphate. We propose that YdfD from the Qin cryptic prophage inhibits IspG to block the MEP pathway, leading to a compromised cell membrane and cell wall biosynthesis and eventual cell lysis.

Erythritol air polishing in the surgical treatment of peri-implantitis: A randomized controlled trial.

OBJECTIVES: To compare erythritol air polishing with implant surface cleansing using saline during the surgical treatment of peri-implantitis. MATERIAL AND METHODS: During a resective surgical intervention, implant surfaces were randomly treated with either air polishing (test group n = 26 patients/53 implants) or saline-soaked cotton gauzes (control group n = 31 patients/ 40 implants). Primary outcome was change in mean bleeding on probing (BoP) from baseline to 12 months follow-up. Secondary outcomes were changes in mean suppuration on probing (SoP), plaque score (Plq), probing pocket depth (PPD), marginal bone loss (MBL), periodontal full-mouth scores (PFMS), and levels of 8 classical periodontal pathogens. Clinical and radiographical parameters were analyzed using multilevel regression analyses. Microbiological outcomes were analyzed using the Mann-Whitney U test. RESULTS: No differences between the test and control group were found for BoP over 12 months of follow-up, nor for the secondary parameters Plq, PPD, and MBL. Between both groups, a significant difference was found for the levels of SoP (p = 0.035). No significant effect on microbiological levels was found. A total number of 6 implants were lost in the test group and 10 in the control group. At 1-year follow-up, a successful treatment outcome (PPD<5 mm, max 1 out of 6 sites BoP, no suppuration and no progressive bone loss >0.5 mm) was achieved for a total of 18 implants (19.2%). CONCLUSIONS: Erythritol air polishing as implant surface cleansing method was not more effective than saline during resective surgical treatment of peri-implantitis in terms of clinical, radiographical, and microbiological parameters. Both therapies resulted in low treatment success. TRIAL REGISTRY: https://www.trialregister.nl/ Identifier: NL8621.

Erythritol modulates the polarization of macrophages: Potential role of tumor necrosis factor-α and Akt pathway.

Low-calorie sweeteners are substitutes for sugar and frequently used by patients with cardiometabolic diseases. Erythritol, a natural low-calorie sugar alcohol, was linked to cardiometabolic diseases in several recent metabolomics studies. However, the characterization of its role in disease development is lacking. Macrophage polarization orchestrates the immune response in various inflammatory conditions, most notably cardiometabolic disease. Therefore, the physiological effects of Erythritol on THP-1 macrophages were investigated. We observed an increased cellular abundance of proinflammatory M1 macrophages, characterized by CD11c, TNF-α, CD64, CD38, and HLA-DR markers and decreased anti-inflammatory M2 macrophages, characterized by mannose receptor CD206. The, Erythritol increased ROS generation, and the activation of the AKT pathway, cytosolic calcium overload, and cell cycle arrest at the G1 phase. Concomitantly, an increased population of necroptotic macrophages was observed. In conclusion, we provide evidence that Erythritol induced the proinflammatory phenotype in THP-1 macrophages and this was associated with an increased population of necroptotic macrophages. PRACTICAL APPLICATIONS: This assessment provides evidence of the effects of Erythritol on macrophages, particularly THP-1-derived macrophages. Our results support the role of Erythritol in driving the inflammation that is associated with cardiometabolic diseases and provide insights in the role of Erythritol as an inducer of necroptosis in THP-1 derived macrophages that could be associated the disease.

Microbiological and clinical evaluation of ultrasonic debridement with/without erythritol air polishing during supportive periodontal therapy in arches with full-arch fixed implant-supported prostheses: protocol for a randomised controlled trial.

INTRODUCTION: Implant-supported prostheses are often successfully used in edentulous patients. However, the incidences of peri-implant mucositis and peri-implantitis increase over time. The accumulation of pathogenic bacteria adjacent to prostheses can induce peri-implant disease. Plaque removal is recommended to prevent and manage peri-implant diseases. The purpose of this study is to compare the plaque removal efficacy of ultrasonic debridement with/without erythritol air-polishing powder around implants and bridges in patients with full-arch fixed implant-supported prostheses as well as the effects of these two methods on the rates of peri-implant mucositis and peri-implantitis, and the submucosal microbiota composition over 5 years in patients undergoing supportive periodontal therapy. METHODS AND ANALYSIS: We plan to enrol 10 edentulous (maxilla and/or mandible) patients seeking full-arch fixed implant-supported prostheses. The study will use a split-mouth model in which contralateral quadrants are randomly assigned to two groups. Group 1: one contralateral quadrant of full-arch fixed implant-supported prostheses will undergo ultrasonic debridement combined with erythritol air-polishing powder. Group 2: a separate contralateral quadrant of full-arch fixed implant-supported prostheses will undergo ultrasonic debridement. The 5-year trial will involve a total of 10 re-examinations per participant. The mucosal conditions around the implants will be recorded at 6-month intervals after restoration. Peri-implant submucosal plaque will be collected at each re-examination, and the bacterial flora will be analysed by 16s ribosomal RNA gene sequencing. X-ray examinations will be conducted at 12-month intervals to evaluate the marginal bone level around implants. ETHICS AND DISSEMINATION: This prospective single-centre, randomised controlled trial (PKUSSIRB-202054045) has been approved by the Ethics Committee of Stomatology School and Hospital of Peking University. Data will be registered with the International Clinical Trials Registry Platform. Additionally, we will disseminate the results via publication in scientific journals. TRIAL REGISTRATION NUMBER: ChiCTR-2000032431.

Erythritol Improves Nonalcoholic Fatty Liver Disease by Activating Nrf2 Antioxidant Capacity.

Nonalcoholic fatty liver disease (NAFLD) is a kind of serious fat disorder that has become a critical problem to human society. Therefore, finding drugs that are safe and effective has become more and more important. Erythritol (Ery) is a polyol sweetener with a variety of biological functions. However, whether Ery has a relieving effect on NAFLD has not been reported yet. Therefore, we induced HepG2 cells with oleic acid and palmitic acid as our in vitro model. Moreover, we choose wild-type mice with tyloxapol and high-fat diet and nuclear factor E2-related factor 2 (Nrf2) knockout mice with high-fat diet as our in vivo model. We found that Ery could reverse the lipid accumulation, oxidative stress, and endoplasmic reticulum stress caused by the NAFLD model. The mechanism studies showed that Ery promoted the translocation of Nrf2 from cytoplasm to nucleus, and the molecular simulation docking results of Ery and Nrf2 showed that there was a hydrogen bond between them. Moreover, Ery could promote the production of HO-1 and NQO1 antioxidant proteins and inhibit the expression of endoplasmic reticulum stress proteins GPR78, p-PERK, and CHOP. On the contrast, when Nrf2 was knocked out in mice, Ery lost its protective effect on NAFLD. In conclusion, we found that the potential mechanism of Ery's protective effect is that it plays an antioxidant role by activating the Nrf2 signaling pathway, thereby inhibiting endoplasmic reticulum stress and lipid accumulation in NAFLD.

Conferring thermotolerant phenotype to wild-type Yarrowia lipolytica improves cell growth and erythritol production.

In microbial engineering, heat stress is an important environmental factor modulating cell growth, metabolic flux distribution and the synthesis of target products. Yarrowia lipolytica, as a GARS (generally recognized as safe) nonconventional yeast, has been widely used in the food industry, especially as the host of erythritol production. Biomanufacturing economics is limited by the high operational cost of cooling energy in large-scale fermentation. It is of great significance to select thermotolerant Y. lipolytica to reduce the cooling cost and elucidate the heat-resistant mechanism at molecular level. For this purpose, we performed adaptive evolution and obtained a thermotolerant strain named Y. lipolytica BBE-18. Transcriptome analysis allows us to identify four genes in thiamine metabolism pathway that are responsible for the complicated thermotolerant phenotype. The heat-resistant phenotype was validated with the model strain Y. lipolytica Po1f by overexpression of single and combined genes. Then, conferring the thermotolerant phenotype to the wild-type Y. lipolytica BBE-17 enable the strain to produce three-times more erythritol of the control strain with 3°C higher than optimal cultivation temperature. To our knowledge, this is the first report on engineering heat-resistant phenotype to improve the erythritol production in Y. lipolytica. However, due to the increase of culture temperature, a large amount of adenosine triphosphate is consumed to ensure the life activities of Y. lipolytica which limits the potential of cell synthetic products to a certain extent. Even so, this study provides a reference for Y. lipolytica to produce other products under high temperature.

Erythritol-enriched powder and oral biofilm regrowth on dental implants: an in vitro study.

BACKGROUND: Peri-implant mucositis and peri-implantitis are the main biological complications associated with dental implants. Since most authors agree that bacteria play a major etiological role, the main aims of this study were to determine if a formulation of erythritol and chlorhexidine applied with an air polishing system inhibits biofilm regrowth over dental implants and to compare the decontamination capacity of this therapy with that of mechanical removal by saline and gauze. MATERIAL AND METHODS: A multispecies biofilm (P. gingivalis, A. actinomycetemcomitans, F. nucleatum, A. naeslundii, V. parvula and S. oralis) was grown for 14 days on 52 dental implants in an artificial mouth. These implants were divided into three groups according to the applied treatment: 14 negative control (CON), 19 erythritol-chlorhexidine (ERY) and 19 gauze with saline (GAU) samples. Twelve dental implants from the ERY and GAU groups and 8 implants from the CON group were re-incubated for 7 additional days after treatment. The bacterial count was performed by quantitative polymerase chain reaction (qPCR) using propidium monoazide (PMA). A descriptive and bivariate analysis of the data was performed. RESULTS: The erythritol and chlorhexidine formulation significantly inhibited biofilm regrowth in comparison with the mechanical treatment (GAU), since a significant decrease in all the species was observed in the ERY group (except for Aggregatibacter actinomycetemcomitans). The antibiofilm and antibacterial capacity of the two active treatment groups (ERY and GAU) was similar for a 14 days multispecies in vitro biofilm, except for the lower count of A. naeslundii in the GAU group. CONCLUSIONS: The use of erythritol powder with chlorhexidine applied with an air polishing system reduces biofilm regrowth over dental implants when compared with mechanical removal by saline and gauze. This effect might be beneficial for patients included in peri-implant maintenance programs.

Gastric emptying of solutions containing the natural sweetener erythritol and effects on gut hormone secretion in humans: A pilot dose-ranging study.

AIM: To determine whether a dose-dependent effect in the stimulation of gut hormone release (plasma cholecystokinin [CCK], active glucagon-like peptide-1 [aGLP-1] and peptide tyrosine tyrosine [PYY]) is found for the natural sweetener erythritol. MATERIALS AND METHODS: Twelve healthy, lean volunteers received solutions with 10, 25 or 50 g erythritol, or tap water enriched with 13 C-sodium acetate on four study days via a nasogastric tube in this randomized (active treatments), placebo-controlled, double-blind, cross-over trial. Blood samples and breath samples (13 C-sodium acetate method for measurement of gastric emptying [GE]) were taken at regular intervals, and sensations of appetite and gastrointestinal symptoms were rated. RESULTS: We found (a) a dose-dependent stimulation of CCK, aGLP-1 and PYY, and slowing of GE, (b) no effect on blood glucose, insulin, motilin, glucagon or glucose-dependent insulinotropic polypeptide, (c) no effect on blood lipids and uric acid, and (d) no abdominal pain, nausea or vomiting. CONCLUSIONS: Solutions with 10 and 50 g of erythritol stimulated gut hormone release. Emptying of erythritol-containing solutions from the stomach was slower compared with placebo. There was no effect on plasma glucose, insulin, glucagon, blood lipids or uric acid. All doses were well tolerated.

The eukaryotic MEP-pathway genes are evolutionarily conserved and originated from Chlaymidia and cyanobacteria.

BACKGROUND: Isoprenoids are the most ancient and essential class of metabolites produced in all organisms, either via mevalonate (MVA)-and/or methylerythritol phosphate (MEP)-pathways. The MEP-pathway is present in all plastid-bearing organisms and most eubacteria. However, no comprehensive study reveals the origination and evolutionary characteristics of MEP-pathway genes in eukaryotes. RESULTS: Here, detailed bioinformatics analyses of the MEP-pathway provide an in-depth understanding the evolutionary history of this indispensable biochemical route, and offer a basis for the co-existence of the cytosolic MVA- and plastidial MEP-pathway in plants given the established exchange of the end products between the two isoprenoid-biosynthesis pathways. Here, phylogenetic analyses establish the contributions of both cyanobacteria and Chlamydiae sequences to the plant's MEP-pathway genes. Moreover, Phylogenetic and inter-species syntenic block analyses demonstrate that six of the seven MEP-pathway genes have predominantly remained as single-copy in land plants in spite of multiple whole-genome duplication events (WGDs). Substitution rate and domain studies display the evolutionary conservation of these genes, reinforced by their high expression levels. Distinct phenotypic variation among plants with reduced expression levels of individual MEP-pathway genes confirm the indispensable function of each nuclear-encoded plastid-targeted MEP-pathway enzyme in plant growth and development. CONCLUSION: Collectively, these findings reveal the polyphyletic origin and restrict conservation of MEP-pathway genes, and reinforce the potential function of the individual enzymes beyond production of the isoprenoids intermediates.

Transcriptomics Integrated with Free and Bound Terpenoid Aroma Profiling during "Shine Muscat" (Vitis labrusca × V. vinifera) Grape Berry Development Reveals Coordinate Regulation of MEP Pathway and Terpene Synthase Gene Expression.

Terpenes and their derivatives are important biomarkers of grape quality as they contribute to the flavor and aroma of grapes. However, the molecular basis of terpene biosynthesis throughout the grapevine phenological developmental cycle remains elusive. Our current study investigates the free and bound terpene biosynthesis of berries at different phenological stages from preveraison to harvest. Detailed gene expression (transcriptomics) analysis, terpenoid volatile production by gas chromatography-mass spectrometry (GC-MS), and in planta transient expression were employed. Our results show that concentrations of most individual terpenes at different stages are distinctive and increase from preveraison to the veraison stage followed by a decrease from veraison to maturity. The combined transcriptomic analysis and terpene profiling revealed that 22 genes belonging to the MEP pathway and multiple classes of transcription factor family members including bHLH and several hormone biosynthesis- or signaling-related genes likely participate in the regulation of terpenoid biosynthesis according to their specific expression patterns in berries. Quantitative real-time polymerase chain expression analysis of 8 key differentially expressed genes in MEP pathways and further 12 randomly selected genes was performed during 8 sampling stages and validated the RNA-seq-derived expression profiles. To further confirm the function of a subset of the differentially expressed genes, we investigated the effects of combined overexpression of 1-deoxy-d-xylulose-5-phosphate synthase (VvDXS1-LOC100249323), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (VvDXR-LOC100248516), and terpene synthase (VvTPS56-LOC100266449) on the production of terpenes by transient overexpression in Nicotiana benthamiana leaves. The overall developmental patterns of total terpenes and gene expression profiles will help guide the functional analyses of further candidate genes important for terpene biosynthesis of grape as well as identifying the master transcriptional and hormonal regulators of this pathway in the future.

Clinical outcomes following periodontal surgery and root surface decontamination by erythritol-based air polishing. A randomized, controlled, clinical pilot study.

AIM: To evaluate the outcomes following surgical periodontal treatment and root surface decontamination by means of air polishing using an erythritol powder or conventional mechanical root debridement. MATERIAL AND METHODS: Thirty systemically healthy patients (44.38 ± 8.2 years old, 11 smokers, 19 women) diagnosed with periodontitis stages III-IV were included. Each patient, with one single-rooted tooth, with one probing pocket depth (PD) ≥ 6 mm associated with horizontal bone loss, was treated by means of simplified papilla preservation flap (SPPF) and randomized to either test treatment (careful removal of the calculus with the tip of a blade, air polishing of the root surfaces with erythritol) or to the control group (scaling and root planing with hand curettes, ultrasonic instruments). PD, clinical attachment (CAL), bone sounding (BS), and radiographic bone level (BL) were evaluated at baseline and 12 months postsurgically. RESULTS: Twenty-seven patients completed the 12-month follow-up (test: n = 14, control: n = 13). In both groups, statistically significant improvements were obtained (p < 0.05, mean CAL gain/PD reduction: test, 2.50 ± 1.60 mm/3.00 ± 0.96 mm; control, 2.85 ± 1.21 mm/3.38 ± 1.12 mm). No statistically significant differences were observed between the groups for any of the investigated parameters (p < 0.05). CONCLUSION: Within their limits, the present results indicate that the use of air polishing with an erythritol powder during periodontal surgery may represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus. CLINICAL RELEVANCE: The use of air polishing with an erythritol powder during periodontal surgery appears to represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus.