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26 result(s) for "Witthöft, Cornelia M."
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Simultaneous quantification of trimethylamine N-oxide, trimethylamine, choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine in clinical and food samples using HILIC-LC-MS
Trimethylamine-N-oxide (TMAO), a microbiome-derived metabolite from the metabolism of choline, betaine, and carnitines, is associated to adverse cardiovascular outcomes. A method suitable for routine quantification of TMAO and its precursors (trimethylamine (TMA), choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine) in clinical and food samples has been developed based on LC-MS. TMA was successfully derivatized using iodoacetonitrile, and no cross-reactions with TMAO or the other methylamines were detected. Extraction from clinical samples (plasma and urine) was performed after protein precipitation using acetonitrile:methanol. For food samples (meatballs and eggs), water extraction was shown to be sufficient, but acid hydrolysis was required to release bound choline before extraction. Baseline separation of the methylamines was achieved using a neutral HILIC column and a mobile phase consisting of 25 mmol/L ammonium formate in water:ACN (30:70). Quantification was performed by MS using external calibration and isotopic labelled internal standards. The assay proved suitable for both clinical and food samples and was linear from ≈ 0.1 up to 200 μmol/L for all methylamines except for TMA and TMAO, which were linear up to 100 μmol/L. Recoveries were 91–107% in clinical samples and 76–98% in food samples. The interday (n=8, four duplicate analysis) CVs were below 9% for all metabolites in clinical and food samples. The method was applied successfully to determine the methylamine concentrations in plasma and urine from the subjects participating in an intervention trial (n=10) to determine the effect of animal food ingestion on methylamine concentrations.
Characterization of Flavonoid Compounds in Common Swedish Berry Species
Berries are considered an ideal source of polyphenols, especially from the flavonoid group. In this study, we examined the flavonoid content in 16 varieties of Swedish lingonberry, raspberry, blueberry, and strawberry. Nineteen flavonoids were simultaneously quantified using external standards. An additional 29 flavonoids were tentatively identified using MS as no standards were available. Quantification was done using HPLC-UV after optimization of chromatographic and extraction procedures. The method showed high linearity within the range of 2–100 μg/mL (correlation co-efficient >0.999), intra- and inter-day precision of 1.7–7.3% and average recovery above 84% for all compounds. Blueberries and lingonberries were found to contain higher contents of flavonoids (1100 mg/100 g dry weight) than raspberries and strawberries (500 mg/100 g dry weight). Anthocyanins were the dominant flavonoids in all berries. The tentatively characterized compounds contribute 18%, 29%, 61%, and 67% of the total flavonoid content in strawberries, lingonberries, raspberries, and blueberries, respectively. Overall, Swedish berries were shown to be good sources of polyphenols.
Development and Application of a UPLC–MRM–MS Method for Quantifying Trimethylamine, Trimethylamine-N-Oxide, and Related Metabolites in Individuals with and Without Metabolic Syndrome
Trimethylamine-N-oxide (TMAO) is associated with various chronic diseases. TMAO is a downstream oxidative metabolite of trimethylamine (TMA) that is generated by the gut microbiota from dietary choline, carnitine, and betaine. Current analytical methods predominantly target TMAO only, due to the challenge of efficiently extracting and quantifying TMA. The present study demonstrates a simple and rapid UPLC–MRM–MS method for concurrent quantification of TMAO, TMA, and related precursors (choline, betaine, and various carnitines) following a methanol extraction from plasma and derivatization using iodoacetonitrile (IACN). Pure methanol resulted in a higher extractability of TMA (up to two-fold) compared to both pure acetonitrile and various methanol/acetonitrile mixtures. The quantification method showed high linearity within the tested range of 0.0625–100 μmol/L (determination coefficient > 0.999) and an intra- (n = 3) and inter-day (n = 9) precision of 2–8% along with an average recovery of above 94% for all metabolites (TMAO, TMA, choline, betaine, L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine). The method’s applicability was confirmed through a comparison of TMAO and its precursor concentrations in plasma samples of overnight-fasted subjects with (n = 12) and without (n = 21) metabolic syndrome.
Folate content in faba beans (Vicia faba L.)—effects of cultivar, maturity stage, industrial processing, and bioprocessing
Faba beans are an important source of folate and commonly consumed in Egypt. This study examined the effects of Egyptian industrial food processing (e.g., canning and freezing), germination, cultivar, and maturity stages on folate content, with the aim to develop a candidate functional canned faba bean food with increased folate content. The folate content in four cultivars of green faba beans ranged from 110 to 130 μg 100 g−1 fresh weight (535–620 μg 100 g−1 dry matter [DM]), which was four‐ to sixfold higher than in dried seeds. Industrial canning of dried seeds resulted in significant folate losses of ~20% (P = 0.004), while industrial freezing had no effect. Germination of faba beans increased the folate content by >40% (P < 0.0001). A novel industrial canning process involving pregermination of dried faba beans resulted in a net folate content of 194 μg 100 g−1 DM, which is 52% more than in conventional canned beans. The consumption of green faba beans should be recommended, providing ~120 μg dietary folate equivalents per 100 g/portion. Folate content in green faba beans was approximately four‐ to sixfold higher than in dried beans. Industrial canning resulted in significant folate losses, while industrial freezing had no effect. Germination produced a functional faba bean product with increased folate content.
Plasma metabolite profiles in healthy women differ after intervention with supplemental folic acid v. folate-rich foods
Public health authorities recommend all fertile women to increase their folate intake to 400 µg/d by eating folate-rich foods or by taking a folic acid supplement to protect against neural tube defects. In a previous study it was shown that folate-rich foods improved folate blood status as effectively as folic acid supplementation. The aim of the present study was to investigate, using NMR metabolomics, the effects of an intervention with a synthetic folic acid supplement v. native food folate on the profile of plasma metabolites. Healthy women with normal folate status received, in parallel, 500 µg/d synthetic folic acid from a supplement (n 18), 250 µg/d folate from intervention foods (n 19), or no additional folate (0 µg/d) through a portion of apple juice (n 20). The metabolic profile of plasma was measured using 1H-NMR in fasted blood drawn at baseline and after 12 weeks of intervention. Metabolic differences between the groups at baseline and after intervention were assessed using a univariate statistical approach (P ≤ 0·001, Bonferroni-adjusted significance level). At baseline, the groups showed no significant differences in measured metabolite concentrations. After intervention, eight metabolites, of which six (glycine, choline, betaine, formate, histidine and threonine) are related to one-carbon metabolism, were identified as discriminative metabolites. The present study suggests that different folate forms (synthetic v. natural) may affect related one-carbon metabolites differently.
Plasma TMAO Concentrations and Gut Microbiota Composition in Subjects with and Without Metabolic Syndrome: Results from Pilot Study
Background/Objectives: Trimethylamine N-oxide (TMAO) is a gut microbiota-dependent metabolite considered as a risk metabolite for various non-communicable diseases. This study aims to identify differences in the gut microbiota composition and concentrations of TMAO and related metabolites in subjects with and without metabolic syndrome (MetS). Methods: Plasma samples were collected following an overnight fast on two occasions from subjects with (n = 12) and without (n = 21) MetS. Feces samples were collected on the day before the first blood sampling. The gut microbiota was profiled using 16S rRNA full-gene amplification sequencing. TMAO and related methylamines were quantified using UPLC-MSMS. The fasted plasma glucose, plasma lipid profile, and HbA1c were determined, and blood pressure, circumference, height, and weight were measured. Results: A divergent gut microbiota composition was observed in feces samples from both groups. In contrast to subjects without MetS, subjects with MetS had a reduced microbial diversity, with lower Blautia glucerasea and higher Ruminococcus torques—a pattern associated with (increased) inflammation. Trimethylamine (TMA)-producing bacteria were low in abundance across both groups. While plasma TMAO and related methylamines displayed no significant differences between both groups, L-carnitine was elevated (p = 0.0191) in subjects with MetS. A strong positive correlation was detected between TMAO and TMA (r = 0.439, p = 0.003), with a tendency to correlate with carnitine (r = 0.212, p = 0.087). Conclusions: Subjects with MetS were characterized by gut microbiota favoring inflammation-associated species but not TMA producers. This suggests that TMAO may not play a role in MetS subjects without overt comorbidities, e.g., CVD or T2D. The influence of the gut microbiota on early MetS is likely mediated through inflammatory mechanisms driven by specific bacterial shifts rather than TMAO production.
Plasma and Urinary TMAO and Methylamine Responses to Meat and Egg Ingestion: Links to Gut Microbiota Composition in Subjects With and Without Metabolic Syndrome
Background/Objectives: Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite from L-carnitine and choline (abundant in meat and eggs), is linked to CVD and T2D. This study investigated whether TMAO responses to animal-based foods differ between individuals with and without metabolic syndrome (MetS), in relation to their gut microbiota composition. Subjects/Methods: In a randomized crossover trial, 12 MetS (≥3 criteria according to the Adult Treatment Panel III: elevated waist circumference, fasting glucose, triglycerides, and blood pressure or reduced HDL cholesterol) and 21 non-MetS subjects consumed two test meals (3 hard-boiled eggs or 170 g meat balls) after overnight fasting, with ≥1-week washout. Blood was collected at baseline and 0.5, 1, 2, 4, and 6 h postprandially; urine was collected over 6 h. Fecal samples (collected pre-first day of intervention) underwent 16S rRNA sequencing. Plasma and urinary TMAO, TMA, choline, and carnitine were quantified using UPLC-MS/MS. Results: MetS subjects exhibited a non-significant trend towards higher incremental AUCs for plasma TMA, TMAO, choline, and carnitine after consuming both foods, with a 30–50% higher urinary TMAO excretion (but similar for TMA) versus non-MetS subjects. This exploratory analysis also indicated that MetS subjects had reduced gut microbial diversity, featuring decreased Blautia glucerasea (butyrate producer) and increased Ruminococcus torques (pro-inflammatory), a profile associated with inflammation but not TMA production. Conclusion: No significant increase in plasma methylamines after choline and carnitine challenge was observed in subjects with MetS compared with non-MetS. In MetS subjects (without CVD and T2D), gut microbiota composition was characterized by increased pro-inflammatory bacteria rather than TMAO-generating bacteria. The lack of statistical significance with regard to plasma TMAO response could be due to an insufficient sample size rather than the absence of an effect. Nevertheless, the observed elevation might still be clinically relevant, supported by concurrent differences in microbiota composition. These preliminary findings warrant validation in larger cohorts due to sample size limitations.
Effects of Whole Brown Bean and Its Isolated Fiber Fraction on Plasma Lipid Profile, Atherosclerosis, Gut Microbiota, and Microbiota-Dependent Metabolites in Apoe−/− Mice
The health benefits of bean consumption are widely recognized and are largely attributed to the dietary fiber content. This study investigated and compared the effects of whole brown beans and an isolated bean dietary fiber fraction on the plasma lipid profile, atherosclerotic plaque amount, gut microbiota, and microbiota-dependent metabolites (cecal short-chain fatty acids (SCFAs) and plasma methylamines) in Apoe−/− mice fed high fat diets for 10.5 weeks. The results showed that both whole bean and the isolated fiber fraction had a tendency to lower atherosclerotic plaque amount, but not plasma lipid concentration. The whole bean diet led to a significantly higher diversity of gut microbiota compared with the high fat diet. Both bean diets resulted in a lower Firmicutes/Bacteroidetes ratio, higher relative abundance of unclassified S24-7, Prevotella, Bifidobacterium, and unclassified Clostridiales, and lower abundance of Lactobacillus. Both bean diets resulted in higher formation of all cecal SCFAs (higher proportion of propionic acid and lower proportion of acetic acid) and higher plasma trimethylamine N-oxide concentrations compared with the high fat diet. Whole beans and the isolated fiber fraction exerted similar positive effects on atherosclerotic plaque amount, gut microbiota, and cecal SCFAs in Apoe−/− mice compared with the control diets.
Diet and nutrient status of legume consumers in Sweden: a descriptive cross-sectional study
Background Legumes are nutrient-dense foods and can be an environmentally sustainable alternative to meat consumption. Data on legume intake are scarce and data on legume consumption in Sweden are lacking. This study investigated dietary intake and dietary patterns, together with iron, vitamin D, and folate status, in relation to legume consumption in Sweden. Methods Cross-sectional dietary and biomarker data (n 1760) from the 2011 Riksmaten national survey were analyzed. All legume foods (including soy) were identified from 4-day dietary records and ferritin, folate, and vitamin D status in a subgroup (n 280). Participants were classified into non-consumers and quartiles of legume intake. Principal Component Analysis (PCA) was performed to uncover dietary patterns associated with legume intake. Partial Least Square (PLS) regression was used to identify variables associated with variations in legume consumption. Results Legumes were consumed by 44% of the population, with mean (SD) intake of 138 (84) g/d in the highest and 11 (5) g/d in the lowest quartiles. Among consumers, 6% reported being vegetarian, compared with 0.9% among non-consumers. Legume consumers drank less alcohol, but had higher intakes of energy, dietary fiber, folate, thiamin, and several minerals, and more often met recommended intake levels for folate and fiber, critical nutrients in Sweden. Biomarker status did not differ with legume intake. PCA revealed multiple loadings on legumes that generally reflected healthier eating habits for legume-consuming women. PLS revealed that vegetarianism was most influential for high legume intake. Other influential variables were high fruit, tea, nut, and seed intakes. High intake of meat, sodas, fast foods, and sweet foods, together with omnivorism, were influential for low legume intake. The associations were similar for men and women. Conclusions This study supports dietary recommendations on inclusion of legumes in a healthy diet. Greater focus on assessment of legume intake is necessary to explore the population-wide health effects of legumes as sustainable meat alternatives, and to reinforce national nutritional guidelines.
High-Moisture Meat Analogues Produced from Yellow Pea and Faba Bean Protein Isolates/Concentrate: Effect of Raw Material Composition and Extrusion Parameters on Texture Properties
Yellow pea and faba bean are potential candidates to replace soybean-based ingredients due to their suitability for cultivation in the northern hemisphere, non-genetically modified organisms cultivation practice and low risk of allergenicity. This study examined the functionality of local yellow pea and faba bean protein isolates/concentrate as meat analogue products. The most critical factors affecting the texture properties of meat analogue were also determined. Extrusion was used to produce high-moisture meat analogues (HMMAs) from yellow pea and faba bean protein isolates/concentrates and HMMAs with fibrous layered structures was successfully produced from both imported commercial and local sources. The texture properties of the HMMA produced were mainly affected by the ash, fiber and protein content and water-holding capacity of the source protein. Three extrusion process parameters (target moisture content, extrusion temperature, screw speed), also significantly affected HMMA texture. In conclusion, functional HMMA can be produced using protein isolates derived from locally grown pulses.