Amino acid intake and plasma concentrations and their interplay with gut microbiota in vegans and omnivores in Germany

Purpose It has been estimated that most vegans meet the total protein requirements, but whether this is also true for individual essential amino acids (AAs) is unclear. Furthermore, a shift in protein intake is suggested to alter microbiota composition, but this association is unknown in terms of veganism or individual AAs. This cross-sectional study compared vegans and omnivores regarding dietary intake and plasma concentration of AAs. The prevalence of insufficient intake of essential AAs among vegans was determined using estimated average requirements (EAR) of WHO. Moreover, correlations between AAs intake and gut microbiota were investigated. Methods Data of 36 vegans and 36 omnivores (30–60 years) were analysed. AA intake, AA plasma concentrations and gut microbiota were ascertained by three-day weighed food protocols, gas/liquid chromatography-tandem mass spectrometry and 16S rRNA sequencing, respectively. Results At almost the same energy intake, the intake of 9 AAs in vegans was significantly lower than in omnivores, with median differences of − 27.0% to − 51.9%. However, only one female vegan showed total protein and lysine intake below the EAR. Vegans showed lower lysine (− 25.0%), but higher glycine (+ 25.4%) and glutamate (+ 13.1%) plasma concentrations than omnivores. Correlation patterns between AA intake and bacterial microbiota differed between vegans and omnivores. In vegans 19 species and in omnivores 5 species showed correlations with AA intake. Conclusion Vegans consumed apparently sufficient but lower AAs than omnivores. In addition, the different AAs intake seems to influence the microbiota composition. The use of short-term dietary data without considering usual intake limits these findings.

Psychiatric Comorbidities and Liver Injury Are Associated With Unbalanced Plasma Bile Acid Profile During Methamphetamine Withdrawal

BackgroundThe pathogenesis of methamphetamine usedisorders (MUDs) remains largely unknown; however, bile acids may play arole as potential mediators of liver injury and psychiatric comorbidities.The aim of this study was to characterize bile acid (BA) profiles in plasmaof patients with MUDs undergoing withdrawal.MethodsLiver functions and psychiatric symptoms wereevaluated in a retrospective cohort (30 MUDs versus 30 control subjects) andan exploratory cohort (30 MUDs including 10 subjects each at the 7-day,3-month, and 12-month withdrawal stages versus 10 control subjects). BAcompositions in plasma samples from MUD patients in the exploratory cohortwere determined by gas-liquid chromatography.ResultsBoth psychiatric comorbidities andmethamphetamine-induced liver injury were observed in patients in both MUDcohorts. The plasma concentrations of the total BA, cholic acid (CA), andchenodeoxycholic acid (CDCA) were lower in MUD patients relative tocontrols. The maximum decline was observed at the 3-month stage, withgradual recovery at the 12-month stage. Notably, the ratios of deoxycholicacid (DCA)/CA and lithocholic acid (LCA)/CDCA were statistically significantat the 3-month stage comparing with controls. Significant correlations werefound between the LCA/CDCA and taurolithocholic acid (TLCA)/CDCA ratios andthe levels of alanine transaminase and aspartate aminotransferase, andbetween the LCA/CDCA ratio and the HAM-A score.ConclusionBA profile during METH withdrawal weremarkedly altered, with these unbalanced BAs being associated with liverinjury. The associations between BA profiles and psychiatric symptomssuggest an association between specific BAs and disease progression,possibly through the liver-brain axis.

Metabolomics of meat color: Practical implications

Objective: Meat is biochemically active, and the various pre-and post-harvest processes can affect meat quality. Metabolomics is a valuable tool to elucidate metabolite changes in meat. The overall goal of this study was to provide an overview of various techniques, data analysis, and application of metabolomics in meat color research. Results: Both targeted and non-targeted approaches have been used to determine metabolite profiles in meat. Researchers use gas-, liquid-chromatography, and nuclear magnetic resonance platforms to separate molecules. Metabolomics is used to characterize muscle-specific differences in color stability, meat tenderness, the impact of aging on meat color, and to determine metabolite profile differences between normal-pH and dark-cutting beef. Color stable muscles have more glycolytic metabolites than color labile muscles. Conclusion: The use of metabolomics has greatly enhanced our understanding of metabolites' role in meat quality. There are challenges in data analysis; thus, there is a need for multiple platforms in order to obtain comprehensive metabolite libraries specific to food. Metabolomics in combination with wet-laboratory techniques can provide novel insights on the relationship between postmortem metabolism and meat color.

Substantiation of technological parameters of the oil extract obtained from Urtica dioica roots based on the yield determination of phytosterols using capillary gas chromatography method

Due to the content of phytosterols, extractive preparations of Urtica dioica roots are able to show antiandrogenic effect in the case of external therapy of men and women with androgenic alopecia. Oil extracts (OE) are characterized by several advantages when applied to the skin of the scalp compared to water-alcohol extracts. For the development of OE technology from Urtica dioica roots, it is important to choose the optimal extraction parameters, which are based on the quantitative determination of phytosterols in the extractant and the studied samples of extracts. The aim of the work is to choose the optimal parameters for obtaining OE from Urtica dioica roots based on quantitative determination of phytosterols content in experimental samples of OE by gas capillary chromatography. Materials and methods. Objects of the research – Urtica dioica root, refined corn oil, refined sunflower oil, samples of oil extracts. Determination of phytosterol content in experimental samples was carried out by gas capillary chromatography (chromatograph “Crystal 2000”, manufacturer – research and production company “Analytics”). Results. 5 different compounds of steroid structure (stigmasterol, β-sitosterol, etc.) were identified in sunflower oil by gas liquid chromatography, and 10 (campesterol, 2-α stigmasterol, β-sitosterol, Δ5-avenosterol, etc.) were identified in sunflower oil. The quantitative content of β-sitosterol in the sum of sterols of corn oil was significantly higher compared to the content of this substance in sunflower oil and amounted to 59.33 %. Optimal technological parameters were established considering the peculiarities of extraction with oil extractant and quantitative determination of the amount of phytosterols and β-sitosterol in experimental samples of OE. The total content of plant sterols in OE, including considering their amount in the extractant, was in the range of 7880 mg/kg; the amount of β-sitosterol was 4638 mg/kg. Conclusion. The choice of optimal parameters for obtaining OE from UDR based on determination of phytosterol yield by gas capillary chromatography was experimentally substantiated, namely: extractant – corn oil, raw material-extract ratio – 1: 5, extraction time – 6 h, extraction method – maceration

Inhibition of Fenton Reaction of Glucose by Alcohols and Tetrahydrofuran in Catalytic Concentrations. Calculation of the Stability Constants of ROH/Fe2+ Complexes

Background: The Fenton reaction is of growing interest due to its primary function in bodily processes and industrial waste disposal. However, the effects of alcohol on this reaction have not been addressed. Therefore, we analyze for the first time the role that catalytic concentrations of alcohols play in the Fenton reaction. Methods: The Fenton reaction was carried out by measuring oxidation-reduction potential and pH monitoring under dark conditions to avoid photochemical reactions. The reaction end point was established using the first derivative of plotting potential versus time. This point was also checked by the dichromate test for hydrogen peroxide detection. Gas-liquid chromatography was used to measure alcohol content. The Fenton reaction of glucose was performed first, and then each alcohol, including ethanol, methanol, iso-propanol, and ter-butanol, was added separately in catalytic amounts, as well as the cyclic ether tetrahydrofuran. The reaction rate constants and the stability constants of each complex formed were measured. Results : Alcohols were shown to inhibit the Fenton reaction by forming iron-alcohol complexes. An iron-tetrahydrofuran complex was also formed. The crucial oxygen role in the functional group of alcohols and ethers is supported by a reaction with tetrahydrofuran. These results also explain the difficulties in the disposal of sugar-enriched alcoholic industrial effluents. Conclusion: Our findings show that alcohols, such as ethanol, methanol, iso-propanol, and ter-butanol at catalytic concentrations, slow down the Fenton reaction due to decreased iron availability by forming iron(II)-alcohol complexes. The method is also useful for calculating stability constants for iron-alcohol and iron-tetrahydrofuran complexes, which are not otherwise easy to assess.

Methodology for studying the combustion products composition from various materials

Изложены методология и принципы лабораторного исследования состава продуктов горения различных материалов с использованием таких инструментов, как газовая и газожидкостная хроматография, масс-эффузио-спетрометрия. Большое внимание уделено применяемым в хроматографических колонках сорбентам и их температурным режимам, а также способам приготовления образцов для исследований. Рассмотрены вопросы детектирования различных компонентов в смеси продуктов горения. Результаты исследований продуктов горения разных материалов представлены в табличной форме, при этом в скобках указаны рассчитанные индексы токсичности С, оцененные по литературным данным (смертельная для человека концентрация при получасовой экспозиции). The article discusses the issues of determining the qualitative and quantitative composition of the combustion products from synthetic and natural materials. Multicomponent mixtures of volatile combustion products contain compounds of inorganic and organic origin. To determine the composition of the combustion products from various materials there is proposed the methodology and principles of laboratory research using such instruments as gas and gas-liquid chromatography, mass spectrometry, infrared and ultraviolet spectroscopy, and visible-field spectroscopy. These methods make it possible to identify certain chemicals. For example, organic compounds are analyzed by chromatography. Inorganic substances are determined by converting them into colored compounds and by analyzing their spectrum in the visible and ultraviolet regions. When developing methods of chromatographic and spectrophotometric studies, it is proposed first of all to identify the qualitative composition of combustion products based on information about the composition of polymer molecules of the studied natural or synthetic materials. Such an assessment, as an example, was made by studying the combustion products of polyethylene. The molecular weights were determined using the MX-1312 chromatomassefusiometer. To determine the molecular weight of a substance, a mathematic formula was obtained based on mathematical processing of experimental data. A special method has been developed to reduce the processing time of effusiograms (by 10-15 times). Much attention is paid to the sorbents used in chromatographic columns, their temperature conditions, and methods of preparing samples for research. Methods of identification of various components in a mixture of combustion products using various detectors are considered. The results of studies of the combustion products from different materials are presented in tabular form, with the calculated toxicity indices, С, estimated according to the literature data (lethal concentration for humans at half-hour exposure) are indicated in parentheses.

Modern methods for vegetable oils from various raw materials identification

Продукты масложировой промышленности играют важную роль в формировании рациона питания человека. При этом особое внимание отводится растительным маслам ввиду их высокой физиологической ценности. На сегодняшний день достаточно остро стоит вопрос о способах их идентификации. В связи с тем, что стоимость растительного масла в значительной степени обуславливается выбором сырья, наиболее распространенным видом фальсификации является внесение недобросовестными производителями в готовую продукцию более дешевых видов масел. Приведен анализ современных способов идентификации растительных масел из различного сырья. До настоящего времени метод газожидкостной хроматографии являлся основным при выявлении примесей посторонних жиров в продукции по ее жирнокислотному составу. Также для выявления фальсификатов могут быть использованы такие инструментальные методы, как ЯМР-спектроскопия, ИК-спектроскопия, а также метод изотопной масс-спектрометрии, который является наиболее перспективным. Особый научный интерес представляет идентификация растительных масел по их географическому месту происхождения. Основываясь на анализе литературы, показано, что наибольшее распространение при установлении региональной принадлежности масел получили исследования, направленные на изучение изотопных характеристик углерода (13С/12С), кислорода (18O/16O) и водорода (2H/1H) элементов, входящих в состав продукта, а также его жирнокислотного состава. Описаны преимущества комплексного подхода исследований, включающего в себя создание массива данных, состоящего из значений различных показателей, и его глубокий анализ с использованием статистических методов анализа. Математическая модель может быть усилена данными элементного профиля масла, изотопных характеристик отдельно взятых жирных кислот или содержанием фенольных соединений. Products of the fat and oil industry play an important role in shaping human diet. At the same time, special attention is paid to vegetable oils in view of their high physiological value. Today, the question of how to identify them is quite acute. Due to the fact that the cost of vegetable oil is largely determined by the choice of raw materials, the most common falsification type is the introduction of cheaper oils types into finished products by unscrupulous manufacturers. The authors provide an analysis of modern methods for identifying vegetable oils from various raw materials. It has been shown that the gas-liquid chromatography method is the main one in identifying products by their fatty acid composition and makes it possible to establish the presence of foreign fats impurities. Also, methods of isotope mass spectrometry, NMR spectroscopy, IR spectroscopy and electrophysical methods of analysis can be used to detect counterfeits. Of particular scientific interest is the vegetable oils identification by their geographical place of origin, which is very important for some countries of the European Union. Based on the analysis of literature, it has been shown that the most widespread in the regional oils affiliation establishing are researches aimed at researching the isotopic characteristics of carbon (13C/12C), oxygen (18O/16O) and hydrogen (2H/1H) of the elements that make up the product, and also its fatty acid composition. The advantages of an integrated research approach are described, including the creation of a data array consisting of the values of various indicators and its in-depth analysis using statistical analysis methods. The mathematical model can be strengthened by data on the elemental profile of the oil, isotopic characteristics of individual fatty acids, or the content of phenolic compounds.

Physical development and its relationship to the metabolic activity of the intestinal microbiota in young children

Introduction. The metabolic activity of the intestinal microbiota is an important indicator of the functioning of the digestive tract, one of the main functions of which is the absorption of nutrients.The aim of the study was to analyze the content of short chain fatty acids in feces and assess their relationship with the indicators of physical development in children 3 years of age.Materials and methods. A prospective cohort study was conducted in 89 children 3rd year of life. The 1st observation group included children of the I and II health groups, the children of the 2nd group underwent surgical treatment on the intestine in the first months of life, the children of the3rd group are with atopic dermatitis. FD assessment was carried out in accordance with WHO recommendations (2017) the spectrum of FGC in feces was determined by gas-liquid chromatography.Results. It was determined the features of the rates of FD in healthy children, children with a history of intestinal resection and children with atopy in relation to the indicators of metabolic activity of the intestinal microbiota. The percentile distribution of the values of FGC in feces and their comparative assessment in the observation groups are given.Discussion. The content of FGM in feces has differences depending on the health status of children of the 3rd year of life. Different level of FGC shows a close relationship with the indicators of FD. Conclusions. A decrease in growth rates (body length SD: from -1 to -2) was revealed at low values (<25%) of the amount of acids, with an increase in propionate (25%) in feces. Reduced nutrition (body weight SD: from -1 to -2) it was associated with low values of the sum of isoacids and AI(-) (<25%); by 3rd year of life, the risk of low nutrition decreased in 4 times with high values (75%) of the sum of acids in feces (OR=4.33[1.09-17.71]). The multidirectionality of the content of fecal matter in young children and their influence on the indicators of FD emphasizes the versatility of the functions of the intestinal microbiota, which has a local and systemic effect on the human body.