Associations of Plasma Erythritol with Dietary Factors, Cardiometabolic, Inflammatory, and Gut Health Markers in People with and without HIV: A Cross-Sectional Study.

BACKGROUND: Recently, elevated levels of plasma erythritol have been associated with major adverse cardiovascular events (MACE). It is known that people with HIV (PWH) have a higher cardiovascular disease burden. Whether PWH have higher levels of plasma erythritol has not been evaluated. This study aimed to assess if blood erythritol levels are elevated in PWH and to examine relationships between erythritol and dietary, cardiometabolic, inflammatory, and gut health markers. METHODS: Plasma erythritol levels were measured using frozen samples from 162 participants, including 109 PWH and 53 people without HIV (PWoH) in a parent study. General linear models were used to assess the linear relationship between characteristics, cardiovascular measures, markers of body composition, inflammation, and gut integrity with plasma erythritol. Logistic regression was used to assess risk factors associated with PWH, and cumulative logit models were used to investigate which factors were associated with having the highest plasma erythritol levels among PWH. RESULTS: Compared to PWoH, PWH had higher plasma erythritol levels (p = 0.03). Every 10% increase in VLDL (p = 0.01), visceral adipose tissue (p < 0.0001), or TNFrI (p = 0.01) was associated with an approximately 1% increase in plasma erythritol. Among PWH, HgbA1c (p = 0.003), TNFrI (p = 0.002), and IFAB-P (p = 0.004) were associated with having the highest tertile of plasma erythritol (≥3.6 µM). Compared to PWoH, PWH were more than two times as likely (p = 0.03) to have plasma erythritol ≥ 3.6 µM. CONCLUSIONS: We identified positive associations between plasma erythritol levels and several factors, including HIV status, BMI, adipose tissue, TNFr1, HbA1c, and VLDL. These results underscore the importance of further investigating the role of elevated plasma erythritol levels in people with HIV, particularly in light of their increased vulnerability to cardiovascular and metabolic diseases.

Disruption of Erythritol Catabolism via the Deletion of Fructose-Bisphosphate Aldolase (Fba) and Transaldolase (Tal) as a Strategy to Improve the Brucella Rev1 Vaccine.

Brucellosis is a bacterial zoonosis caused by the genus Brucella, which mainly affects domestic animals. In these natural hosts, brucellae display a tropism towards the reproductive organs, such as the placenta, replicating in high numbers and leading to placentitis and abortion, an ability also exerted by the B. melitensis live-attenuated Rev1 strain, the only vaccine available for ovine brucellosis. It is broadly accepted that this tropism is mediated, at least in part, by the presence of certain preferred nutrients in the placenta, particularly erythritol, a polyol that is ultimately incorporated into the Brucella central carbon metabolism via two reactions dependent on transaldolase (Tal) or fructose-bisphosphate aldolase (Fba). In the light of these remarks, we propose that blocking the incorporation of erythritol into the central carbon metabolism of Rev1 by deleting the genes encoding Tal and Fba may impair the ability of the vaccine to proliferate massively in the placenta. Therefore, a Rev1ΔfbaΔtal double mutant was generated and confirmed to be unable to use erythritol. This mutant exhibited a reduced intracellular fitness both in BeWo trophoblasts and THP-1 macrophages. In the murine model, Rev1ΔfbaΔtal provided comparable protection to the Rev1 reference vaccine while inducing fewer adverse reproductive events in pregnant animals. Altogether, these results postulate the Rev1ΔfbaΔtal mutant as a reproductively safer Rev1-derived vaccine candidate to be studied in the natural host.

Rubisco supplies pyruvate for the 2-C-methyl-D-erythritol-4-phosphate pathway.

RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE/OXYGENASE (Rubisco) produces pyruvate in the chloroplast through ß-elimination of the aci-carbanion intermediate1. Here we show that this side reaction supplies pyruvate for isoprenoid, fatty acid and branched-chain amino acid biosynthesis in photosynthetically active tissue. 13C labelling studies of intact Arabidopsis plants demonstrate that the total carbon commitment to pyruvate is too large for phosphoenolpyruvate to serve as a precursor. Low oxygen stimulates Rubisco carboxylase activity and increases pyruvate production and flux through the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, which supplies the precursors for plastidic isoprenoid biosynthesis2,3. Metabolome analysis of mutants defective in phosphoenolpyruvate or pyruvate import and biochemical characterization of isolated chloroplasts further support Rubisco as the main source of pyruvate in chloroplasts. Seedlings incorporated exogenous,13C-labelled pyruvate into MEP pathway intermediates, while adult plants did not, underscoring the developmental transition in pyruvate sourcing. Rubisco ß-elimination leading to pyruvate constituted 0.7% of the product profile in in vitro assays, which translates to 2% of the total carbon leaving the Calvin-Benson-Bassham cycle. These insights solve the "pyruvate paradox"4, improve the fit of metabolic models for central metabolism and connect the MEP pathway directly to carbon assimilation.

Effect of low frequency alternating magnetic field for erythritol production in Yarrowia lipolytica.

Numerous works have reported that magnetic fields serve as signals capable of influencing microbial metabolism. However, little is known about the effect of magnetic field on erythritol production by the model microorganism Yarrowia lipolytica (Y. lipolytica). Therefore, we investigated the effect of low-frequency alternating magnetic fields (LF-AMF) with different magnetic field intensities (0-1.5 mT) and different magnetic field treatment times (1-10 days) on the production of erythritol by Y. lipolytica -JZ204. The optimal treatment condition was 0.5 mT for 8 days. As a result, a maximal erythritol yield was achieved 63.74 g/L, the biomass was reached 37 g/L, and the specific erythritol yield per unit of biomass was 1.7227 g/g, which were 60.72%, 32.09%, and 24.85% higher than the control, respectively. We investigated the internal mechanism of magnetic fields impact by using transcriptomics and RT-qPCR technology. This study demonstrated the effectiveness of LF-AMF in enhancing erythritol production by Y. lipolytica JZ-204, providing insights for the application of magnetic field in assisting microbial fermentation and improving the synthesis of beneficial products.

Improving an Alternative Glycerol Catabolism Pathway in Yarrowia lipolytica to Enhance Erythritol Production.

Engineering the glycerol-3-phosphate pathway could enhance erythritol production by accelerating glycerol uptake. However, little work has been conducted on the alternative dihydroxyacetone (DHA) pathway in Yarrowia lipolytica. Herein, this route was identified and characterized in Y. lipolytica by metabolomic and transcriptomic analysis. Moreover, the reaction catalyzed by dihydroxyacetone kinase encoded by dak2 was identified as the rate-limiting step. By combining NHEJ-mediated insertion mutagenesis with a push-and-pull strategy, Y. lipolytica strains with high-yield erythritol synthesis from glycerol were obtained. Screening of a library of insertion mutants allows the identification of a mutant with fourfold increased erythritol production. Overexpression of DAK2 and glycerol dehydrogenase GCY3 together with gene encoding transketolase and transaldolase from the nonoxidative part of the pentose phosphate pathway led to a strain with further increased productivity with a titer of 53.1 g/L and a yield 0.56 g/g glycerol, which were 8.1- and 4.2-fold of starting strain.

Targeting Plasmodium falciparum IspD in the Methyl-d-erythritol Phosphate Pathway: Urea-Based Compounds with Nanomolar Potency on Target and Low-Micromolar Whole-Cell Activity.

The methyl-d-erythritol phosphate (MEP) pathway has emerged as an interesting target in the fight against antimicrobial resistance. The pathway is essential in many human pathogens, including Plasmodium falciparum (Pf), but is absent in human cells. In the present study, we report on the discovery of a new chemical class targeting IspD, the third enzyme in the pathway. Exploration of the structure-activity relationship yielded inhibitors with potency in the low-nanomolar range. Moreover, we investigated the whole-cell activity, mode of inhibition, metabolic, and plasma stability of this compound class, and conducted in vivo pharmacokinetic profiling on selected compounds. Lastly, we disclosed a new mass spectrometry (MS)-based enzymatic assay for direct IspD activity determination, circumventing the need for auxiliary enzymes. In summary, we have identified a readily synthesizable compound class, demonstrating excellent activity and a promising profile, positioning it as a valuable tool compound for advancing research on IspD.

Serum Erythritol and Risk of Overall and Cause-Specific Mortality in a Cohort of Men.

Erythritol occurs naturally in some fruits and fermented foods, and has also been used as an artificial sweetener since the 1990s. Although there have been questions and some studies regarding its potential adverse health effects, the association between serum erythritol and long-term mortality has not been evaluated. To examine the association between serum erythritol's biochemical status and risk of overall and cause-specific mortality, a prospective cohort analysis was conducted using participants in the ATBC Study (1985-1993) previously selected for metabolomic sub-studies. The analysis included 4468 participants, among whom 3377 deaths occurred during an average of 19.1 years of follow-up. Serum erythritol was assayed using an untargeted, global, high-resolution, accurate-mass platform of ultra-high-performance liquid and gas chromatography. Cause-specific deaths were identified through Statistics Finland and defined by the International Classification of Diseases. After adjustment for potential confounders, serum erythritol was associated with increased risk of overall mortality (HR = 1.50 [95% CI = 1.17-1.92]). We found a positive association between serum erythritol and cardiovascular disease mortality risk (HR = 1.86 [95% CI = 1.18-2.94]), which was stronger for heart disease mortality than for stroke mortality risk (HR = 3.03 [95% CI = 1.00-9.17] and HR = 2.06 [95% CI = 0.72-5.90], respectively). Cancer mortality risk was also positively associated with erythritol (HR = 1.54 [95% CI = 1.09-2.19]). The serum erythritol-overall mortality risk association was stronger in men ≥ 55 years of age and those with diastolic blood pressure ≥ 88 mm Hg (p for interactions 0.045 and 0.01, respectively). Our study suggests that elevated serum erythritol is associated with increased risk of overall, cardiovascular disease, and cancer mortality. Additional studies clarifying the role of endogenous production and dietary/beverage intake of erythritol in human health and mortality are warranted.

Ingestion of the Non-Nutritive Sweetener Erythritol, but Not Glucose, Enhances Platelet Reactivity and Thrombosis Potential in Healthy Volunteers-Brief Report.

BACKGROUND: Although artificial and non-nutritive sweeteners are widely used and generally recognized as safe by the US and European Union regulatory agencies, there have been no clinical trials to assess either long-term cardiovascular disease risks or short-term cardiovascular disease-relevant phenotypes. Recent studies report that fasting plasma levels of erythritol, a commonly used sweetener, are clinically associated with heightened incident cardiovascular disease risks and enhance thrombosis potential in vitro and in animal models. Effects of dietary erythritol on thrombosis phenotypes in humans have not been examined. METHODS: Using a prospective interventional study design, we tested the impact of erythritol or glucose consumption on multiple indices of stimulus-dependent platelet responsiveness in healthy volunteers (n=10 per group). Erythritol plasma levels were quantified with liquid chromatography tandem mass spectrometry. Platelet function at baseline and following erythritol or glucose ingestion was assessed via both aggregometry and analysis of granule markers released. RESULTS: Dietary erythritol (30 g), but not glucose (30 g), lead to a >1000-fold increase in erythritol plasma concentration (6480 [5930-7300] versus 3.75 [3.35-3.87] µmol/L; P<0.0001) and exhibited acute enhancement of stimulus-dependent aggregation responses in all subjects, agonists, and doses examined. Erythritol ingestion also enhanced stimulus-dependent release of the platelet dense granule marker serotonin (P<0.0001 for TRAP6 [thrombin activator peptide 6] and P=0.004 for ADP) and the platelet α-granule marker CXCL4 (C-X-C motif ligand-4; P<0.0001 for TRAP6 and P=0.06 for ADP). In contrast, glucose ingestion triggered no significant increases in stimulus-dependent release of either serotonin or CXCL4. CONCLUSIONS: Ingestion of a typical quantity of the non-nutritive sweetener erythritol, but not glucose, enhances platelet reactivity in healthy volunteers, raising concerns that erythritol consumption may enhance thrombosis potential. Combined with recent large-scale clinical observational studies and mechanistic cell-based and animal model studies, the present findings suggest that discussion of whether erythritol should be reevaluated as a food additive with the Generally Recognized as Safe designation is warranted. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04731363.

Comparative transcriptomics analysis-guided metabolic engineering of Yarrowia lipolytica for improved erythritol and fructooligosaccharides production.

Currently, fructooligosaccharides (FOS) are converted from sucrose by purified enzymes or fungal cells, but these methods are costly and time-consuming. Here, the optimal fermentation conditions for strain E326 were determined through fermentation optimization: initial glucose 200 g/L, NaCl 25 g/L, inoculum volume 20 %, dissolved oxygen 20-30 %, pH 3, and glucose feeding concentration 100 g/L, which increased erythritol titer by 1.5 times. The co-expression of HGT1 and APC11 genes alleviated the erythritol synthesis stagnation, shorten the fermentation time by 16.7 %, and increased the erythritol productivity by 17.2 %. The episomal plasmids based on yeast mitochondrial replication origins (mtORIs) were constructed to surface display fructosyltransferase, effectively utilizing waste yeast cells generated during erythritol fermentation. Under the conditions of 60℃ and pH 6, the FOS yield reached 65 %, which to our best of knowledge is so-far the highest yield of FOS obtained. These findings will contribute to the industrial production of erythritol and FOS.

Using Euf1 transcription factor as a titrator of erythritol-inducible promoters in Yarrowia lipolytica; insight into the structure, splicing, and regulation mechanism.

Controllable regulatory elements, like inducible, titratable promoters, are highly desired in synthetic biology toolboxes. A set of previously developed erythritol-inducible promoters along with an engineered Yarrowia lipolytica host strain were shown to be a very potent expression platform. In this study, we push the previously encountered limits of the synthetic promoters' titratability (by the number of upstream motifs) by using a compatible transcription factor, Euf1, as the promoter titrator. Overexpression of spliced EUF1 turned out to be very efficient in promoting expression from the compatible promoter, however, the erythritol-inducible character of the promoter was then lost. Analysis of the EUF1's splicing pattern suggests that the intron removal is promoted in the presence of erythritol, but is not dependent on it. The 3D structures of spliced versus unspliced Euf1 were modeled, and ligand-binding strength was calculated and compared. Furthermore, the EUF1-dependent expression profile under different chemical stimulants was investigated. Depletion of carbon source was identified as the significant factor upregulating the expression from the Euf1-dependent promoter (2-10-fold). Considering these findings and transcriptomics data, a new mechanism of the Euf1-regulated promoter action is proposed, involving a 'catabolite repression' transcription factor-Adr1, both acting on the same ERY-inducible promoter.

Development and application of a multi-sugar assay to assess intestinal permeability.

Aim: Bioanalytical assays to measure rhamnose, erythritol, lactulose and sucralose in human urine and plasma were developed to support an indomethacin challenge study for intestinal permeability assessment in healthy participants.Methods: The multi-sugar assays utilized 5-µl sample matrix and a simple chemical derivatization with acetic anhydride, followed by RPLC-MS/MS detection.Results: Rhamnose and erythritol quantification was established between 1.00-1,000 µg/ml in urine and 250-250,000 ng/ml in plasma. For lactulose and sucralose, dynamic ranges of 0.1-100 µg/ml (urine) and 25-25,000 ng/ml (plasma) were applied for biological measurements.Conclusion: This work helped overcome some of the common analytical challenges associated with the bioanalysis of mono- and disaccharides and achieved improved limits of quantification.

[Box: see text].

Protein rational design and modification of erythrose reductase for the improvement of erythritol production in Yarrowia lipolytica.

Erythritol is a natural non-caloric sweetener, which is produced by fermentation and extensively applied in food, medicine and chemical industries. The final step of the erythritol synthesis pathway is involved in erythritol reductase, whose activity and NADPH-dependent become the limiting node of erythritol production efficiency. Herein, we implemented a strategy combining molecular docking and thermal stability screening to construct an ER mutant library. And we successfully obtained a double mutant ERK26N/V295M (ER*) whose catalytic activity was 1.48 times that of wild-type ER. Through structural analysis and MD analysis, we found that the catalytic pocket and the enzyme stability of ER* were both improved. We overexpressed ER* in the engineered strain ΔKU70 to obtain the strain YLE-1. YLE-1 can produce 39.47 g/L of erythritol within 144 h, representing a 35% increase compared to the unmodified strain, and a 10% increase compared to the strain overexpressing wild-type ER. Considering the essentiality of NADPH supply, we further co-expressed ER* with two genes from the oxidative phase of PPP, ZWF1 and GND1. This resulted in the construction of YLE-3, which exhibited a significant increase in production, producing 47.85 g/L of erythritol within 144 h, representing a 63.90% increase compared to the original chassis strain. The productivity and the yield of the engineered strain YLE-3 were 0.33 g/L/h and 0.48 g/g glycerol, respectively. This work provided an ER mutation with excellent performance, and also proved the importance of cofactors in the process of erythritol synthesis, which will promote the industrial production of erythritol by metabolic engineering of Y. lipolytica.

A picomolar inhibitor of the Plasmodium falciparum IPP pathway.

We identified MMV026468 as a picomolar inhibitor of blood-stage Plasmodium falciparum. Phenotyping assays, including isopentenyl diphosphate rescue of parasite growth inhibition, demonstrated that it targets MEP isoprenoid precursor biosynthesis. MMV026468-treated parasites showed an overall decrease in MEP pathway intermediates, which could result from inhibition of the first MEP enzyme DXS or steps prior to DXS such as regulation of the MEP pathway. Selection of MMV026468-resistant parasites lacking DXS mutations suggested that other targets are possible. The identification of MMV026468 could lead to a new class of antimalarial isoprenoid inhibitors.

The efficacy of diode laser and subgingival air polishing with erythritol in treatment of periodontitis (clinical and microbiological study).

BACKGROUND: There is insufficient clinical and microbiological evidence to support the use of diode laser and air-polishing with erythritol as supplements to scaling and root planning(SRP). The aim of the current study is to evaluate the clinical and microbiologic efficacy of erythritol subgingival air polishing and diode laser in treatment of periodontitis. METHODS: The study encompassed twenty-four individuals seeking periodontal therapy and diagnosed with stage I and stage II periodontitis. Eight patients simply underwent SRP. Eight more patients had SRP followed by erythritol subgingival air polishing, and eight patients had SRP followed by diode laser application. At baseline and six weeks, clinical periodontal parameters were measured, including Plaque Index (PI), Gingival Index (GI), periodontal Probing Depth (PPD), and Clinical Attachment Level (CAL). The bacterial count of Aggregatibacter actinomycetemcomitans(A.A), Porphyromonas gingivalis (P.G) was evaluated at different points of time. RESULTS: The microbiological assessment revealed significant differences in the count of A.A. between the laser and erythritol groups immediately after treatment, indicating a potential impact on microbial levels. However, the microbial levels showed fluctuations over the subsequent weeks, without statistically significant differences. Plaque indices significantly decreased post-treatment in all groups, with no significant inter-group differences. Gingival indices decreased, and the laser group showed lower values than erythritol and control groups. PPD and CAL decreased significantly across all groups, with the laser group exhibiting the lowest values. CONCLUSION: The supplementary use of diode laser and erythritol air polishing, alongside SRP, represents an expedited periodontal treatment modality. This approach leads to a reduction in bacteria and improvement in periodontal health. TRIAL REGISTRATION: This clinical trial was registered on Clinical Trials.gov (Registration ID: NCT06209554) and released on 08/01/2024.

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.

The methylerythritol phosphate pathway as an oxidative stress sense and response system.

The methylerythritol phosphate (MEP) pathway is responsible for biosynthesis of the precursors of isoprenoid compounds in eubacteria and plastids. It is a metabolic alternative to the well-known mevalonate pathway for isoprenoid production found in archaea and eukaryotes. Recently, a role for the MEP pathway in oxidative stress detection, signalling, and response has been identified. This role is executed in part through the unusual cyclic intermediate, methylerythritol cyclodiphosphate (MEcDP). We postulate that this response is triggered through the oxygen sensitivity of the MEP pathway's terminal iron-sulfur (Fe-S) cluster enzymes. MEcDP is the substrate of IspG, the first Fe-S cluster enzyme in the pathway; it accumulates under oxidative stress conditions and acts as a signalling molecule. It may also act as an antioxidant. Furthermore, evidence is emerging for a broader and highly nuanced role of the MEP pathway in oxidative stress responses, implemented through a complex system of differential regulation and sensitivity at numerous nodes in the pathway. Here, we explore the evidence for such a role (including the contribution of the Fe-S cluster enzymes and different pathway metabolites, especially MEcDP), the evolutionary implications, and the many questions remaining about the behaviour of the MEP pathway in the presence of oxidative stress.

Multidimensional combinatorial screening for high-level production of erythritol in Yarrowia lipolytica.

Yarrowia lipolytica was successfully engineered to synthesize erythritol from crude glycerol, a cheap by-product of biodiesel production, but the yield remained low. Here, a biosensor-guided adaptive evolution screening platform was constructed to obtain mutant strains which could efficiently utilize crude glycerol to produce erythritol. Erythrose reductase D46A (M1) was identified as a key mutant through whole-genome sequencing of the strain G12, which exhibited higher catalytic activity (1.6-fold of the wild-type). M1 was further modified to obtain a combinatorial mutant with 4.1-fold enhancement of catalytic activity. Finally, the metabolic network was reconfigured to redirect carbon fluxes toward erythritol synthesis. The erythritol titer of the engineered strain G31 reached 220.5 g/L with a productivity of 1.8 g/L/h in a 5-L bioreactor. The study provides valuable guidance for biosensor-based ultra-high-throughput screening strategies in Y. lipolytica, as well as presenting a new paradigm for the sustainable valorization of crude glycerol.

Research progress on biosynthesis of erythritol and multi-dimensional optimization of production strategies.

Erythritol, as a new type of natural sweetener, has been widely used in food, medical, cosmetics, pharmaceutical and other fields due to its unique physical and chemical properties and physiological functions. In recent years, with the continuous development of strategies such as synthetic biology, metabolic engineering, omics-based systems biology and high-throughput screening technology, people's understanding of the erythritol biosynthesis pathway has gradually deepened, and microbial cell factories with independent modification capabilities have been successfully constructed. In this review, the cheap feedstocks for erythritol synthesis are introduced in detail, the environmental factors affecting the synthesis of erythritol and its regulatory mechanism are described, and the tools and strategies of metabolic engineering involved in erythritol synthesis are summarized. In addition, the study of erythritol derivatives is helpful in expanding its application field. Finally, the challenges that hinder the effective production of erythritol are discussed, which lay a foundation for the green, efficient and sustainable production of erythritol in the future and breaking through the bottleneck of production.

Reviving resilience: MEcPP-mediated ASK1-IMPα-9-TRP2 stress-responsive module.

Chloroplasts are not only critical photosynthesis sites in plants, but they also participate in plastidial retrograde signaling in response to developmental and environmental signals. MEcPP (2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate) is an intermediary in the methylerythritol phosphate (MEP) pathway in chloroplasts. It is a critical precursor for the synthesis of isoprenoids and terpenoid derivatives, which play crucial roles in plant growth and development, photosynthesis, reproduction, and defense against environmental constraints. Accumulation of MEcPP under stressful conditions triggers the expression of IMPα-9 and TPR2, contributing to the activation of abiotic stress-responsive genes. In this correspondence, we discuss plastidial retrograde signaling in support of a recently published paper in Molecular Plant (Zeng et al. 2024). We hope that it can shed more insight on the retrograde signaling cascade.

Modulation of the glycaemic index value of shortbread cookies by the use of erythritol and fruit pomace.

Fruit pomace, as a by-product of fruit and vegetable processing, is a cheap and easily accessible material for further processing that can replace selected recipe ingredients, most often flour. In addition, their advantage is their high health-promoting potential. The aim of this study was to evaluate the effect of the simultaneous use of erythritol (100% sucrose substitution) and the addition of varying amounts of blackcurrant, chokeberry and apple pomace (0%, 10%, 30% and 50% by weight of flour) on the glycaemic response after consumption of shortbread cookies in an in vivo study with humans (ISO 26642:2010). It was shown that an increase in the addition of each type of pomace reduced the glycaemic index value of the cookies. The pomace and sucrose-sweetened cookies were classified in the medium and low GI group. For each type of pomace, an increase in its share in the recipe of cookies was associated with a reduction in GI values (pomace: apple 49.1-37.2%, blackcurrant 56.4-41.0%, chokeberry 59.4-35.5%). Similar correlations were shown for the use of erythritol (pomace: apple 39.5-29.1%, blackcurrant 43.9-31.9%, chokeberry 34.6-20.7%). A significant effect of pomace addition on the GI values of shortbread cookies, was only observed for sucrose-sweetened products. The results obtained allow the conclusion that there is potential for the use of waste raw materials in the production of functional foods.