Physiological effects, mechanisms of action and application of lactulose
The discovery of lactulose as a bifidogenic factor became the background for the appearance of the prebiotics concept. Currently, lactulose is the most studied in terms of medical use oligosaccharide with a high prebiotic index. The exact mechanisms of action of lactulose remain largely unknown despite a number of new researches based on modern methods of molecular biology, genetics, and bioinformatics.
The aim of this review to summarize and analyze the actual information about biological activity, probable mechanisms of action, and possible uses of lactulose in human nutrition.
Results. The structure of lactulose, methods for its determination and preparation are briefly described. Promising methods for producing lactulose include enzymatic synthesis from lactose using β-galactosidase or epimerase. Information on the physiological effects of lactulose and the mechanisms of its action on the human organism is presented. The works confirming the ability of lactulose to stimulate the growth of bifidobacteria and to influence the metabolism of the intestinal microbiota are summarized. The results of studies of the ability of lactulose to have antitoxic and anticarcinogenic effects are presented. The mechanisms of the positive effect of the prebiotic on the absorption of minerals, increased absorption of Ca and Mg in the human organism are described. The effect of lactulose on immunity and the possibility of its use to reduce the glucose blood level in patients with type 2 diabetes mellitus are shown. The main directions of the use of lactulose in food production are systematized. The data confirming the possibility of using lactulose as a growth factor for probiotics, as well as a protective agent to increase the survival of some starter cultures, are presented. Brief information on the doses and forms of lactulose apply in medicine is presented. The dependence of the effects of lactulose on the dose, health condition and age of patients has been established.
Conclusion. Perspective directions of lactulose using in combination with probiotics, other prebiotics, and as an encapsulating ingredient for vitamins and other functional nutrition ingredients are determined. In this regard, the study of lactulose interaction with the components of complex products is relevant.
Gluten-free diet in the treatment of extra-intestinal forms of gluten intolerance
Following a gluten-free diet is recommended by clinical guidelines in the presence of gluten intolerance. However, due to the variety of clinical picture of various forms of intolerance, the elimination of gluten occurs not always timely. There are also diseases that classic treatment regimen does not include diet therapy, however, studies have confirmed the effectiveness of its use.
The aim of the research - to study current data on the effectiveness of a gluten-free diet for extra-intestinal manifestations of gluten intolerance.
Material and methods. Literature data concerning the effectiveness of including a gluten-free diet in the treatment of various diseases according to the PubMed and eLIBRARYportal were studied.
Results. Modern data on the forms of gluten intolerance and their clinical manifestations are presented. The results of both randomized studies and individual clinical cases of gluten intolerance that occurred under the guise of other diseases are presented. A clinical case of an acute onset of the disease - celiac crisis, accompanied by acute diarrheal syndrome with subsequent malabsorption and progressive loss of body weight, anasarca and electrolyte disorders is considered. Neurological and psycho-neurological manifestations of celiac disease are described, including current data on the results of including a gluten-free diet in the treatment of autism spectrum disorders. The question of using dietary therapy for autism remains controversial to nowadays. The article outlines the arguments of supporters and opponents of excluding gluten in this pathology. Particular attention is paid to the diagnosis of gluten intolerance in patients with hematological disorders. The significance of a complete survey to identify celiac disease and timely diet therapy of the disease under stunted growth in children, after excluding other causes of malabsorption and even in the presence of negative serological markers of celiac disease is shown. The article also contains information on the pathology of kidneys and reproductive system, which were leveled only after the exclusion of gluten from the diet.
Conclusion. The presented cases demonstrate a wide variety of clinical forms of gluten intolerance, examples of diagnostic search and dynamics of the clinical picture with the timely appointment of a gluten-free diet are given.
The content of essential and toxic microelements in the organs of mice of various lines receiving a high-carb high-fat diet and supplemented with quercetin
Quercetin (Q) is known to be a powerful chelating agent for metal ions. Due to this property, Q, when ingested, is able to intervene actively in microelement homeostasis. The assessment of the possible significance of these effects for the dietary use of Q in obesity is complicated by the fact that in obese patients there are numerous changes in mineral metabolism and microelement homeostasis due to the pathogenesis of the disease. Thus, it is of considerable interest to identify the systemic effects of biologically active substances, including Q, on mineral metabolism in biological in vivo models (due to the limited choice of biosubstrates in clinical observations - blood plasma, urine, hair).
The aim was to study the possible effects of Q on the levels of essential, non-essential and toxic elements in mice of three lines: db/db with knockout of the leptin receptor gene, prone to spontaneous development of obesity, inbred line C57Bl/6J, relatively resistant to the development of nutritional obesity, and complex hybrid of the 2nd generation DBCB, genetically more prone to developing obesity and fatty hepatosis when consuming diets with an excess quota of fat and simple carbohydrates.
Material and methods. The content of 16 chemical elements (Fe, Mg, Cu, Mn, Co, Se, Zn, Cr, Al, Cd, As, Pb, Ni, Ag, V, Cs) was determined by mass spectrometry with inductively coupledplasma in the liver, kidneys, brain of genetically obese db/db mice (8-10 weeks old) receiving standard semisynthetic ration (SSD) and Q for 47 days at doses of 25 and 100 mg/kg body weight, C57Bl/6J mice treated with SPR or a high-fat high-carb diet (HFCD - 30% fats and20% fructose solution instead of water) and Q supplementation at the same doses, DBCB tetrahybrid mice treated with SSD, HFCD and HFCD supplemented with Q for 63 days (25 mg/kg body weight). The compounds of Fe, Zn, Cu, Mn, Mg, Cr, Ni, Se, and V were included in the salt mixture in the form of inorganic salts or oxides in amounts close to physiological needs; Al, Cd, As, Pb, Ag, Cs, Co - were present in the diets in background amounts.
Results and discussion. In db/db mice, in comparison with C57Bl/6J, a decreased content of Pb in the liver and increased in the kidneys and brain, decreased Co in the kidneys, increased Cs and As in the brain, which could not be explained by differences in the consumption of these elements with feed. The consumption of Q decreased the content of Mn, Cs, V, Ni, As in the liver in db/db mice and increased Cu and did not significantly affect the level of trace elements in the liver in animals C57Bl/6J. In kidneys of C57Bl/ 6J receiving Q, the content of As and Al increased. In brain of db/db mice, Q supplementation caused a decrease in the content of As, Pb, Cs and Se. In tetrahybrids DBCB, Q increased Pb levels in liver and brain and decreased in kidneys; increased the level of V in liver and brain; decreased As content in kidneys and increased in liver. Multiple correlations were noted between the organ content of elements in various valence forms, as well as between the content of trace elements and biochemical indicators of the intensity of catabolic and anabolic processes.
Conclusion. Quercetin has an effect on the homeostasis of microelements, depending both on the animal genotype and on the diet, and not having unambiguous physiological significance. Indicators of the status of essential and toxic trace elements are recommended to be included in the protocols of preclinical trials of the efficacy and safety of minor biologically active food substances.
Influence of high-fructose diet on fibronectin level in rat blood serum
In recent years, the consumption of diets containing a large amount of fructose has increased sharply, which is associated with the observed increase in the incidence of obesity, diabetes mellitus, metabolic syndrome, and cardiovascular diseases. Changes in lipid and carbohydrate metabolism due to increased consumption of fructose are one of the causes of destructive processes in the tissues and cells of the organism. Fibronectin, which is an adhesive and regulatory protein of the intercellular matrix, can serve as one of the markers of these processes.
The aim of the research was to study the effect of a high-fructose diet on rat serum fibronectin level.
Material and methods. The experiment was performed on 50 outbred male rats aged 5-6 months. Rats from the control group (n=25) received a balanced diet of vivarium. Animals of the experimental group (n=25) for 35 days were fed a diet containing 60% fructose, 20% protein, 14% fiber, 6% fat. From the 36th to the 60th day, all rats were fed usual vivarium diet. On the 60th day, the formation of metabolic changes in the long-term period was evaluated. The animals of each group were weighed before and when removed from the experiment on the 21st, 35th and 60th day. Serum was obtained from blood samples collected during decapitation on an empty stomach under short-term ether anesthesia. The concentration of cholesterol, high and low density lipoproteins, triglycerides, glucose, insulin and fibronectin were determined in serum. The atherogenic index and insulin resistance indices were calculated using the corresponding formulas.
Results and discussion. The experiment revealed a significant increase in glucose concentration from 6.52±0.35 (in control) to 7.74±0.73, 7.97±1.91 and 7.87±0.65 mmol/l and in insulin level from 1.6±0.6 to 2.3±0.4,2.6±0.6 and 3.1±0.9 pU/ml on the 21nd, 35th and 60th days of the experiment, respectively, in animals of the experimental group, which is possibly associated with a sharp rise in the concentration of free fatty acids due to the special metabolism of fructose and the occurring oxidative stress, which causes cell damage and the formation of insulin resistance. This is reflected by insulin resistance indices that are different from the control: HOMA by 42.3, 49.2 and 81.3% higher, CARO by 13.3, 16.0 and 28.8% less than the control in the dynamics of the experiment. There was a tendency to an increase in cholesterol level with a significant rise on the 35th day of the experiment by 58.9% relative to the control. A statistically significant increase in the content of low-density lipoproteins was also observed by 158, 141 and229% compared with the control. Such a rise can be associated with both increased formation of free fatty acids and lipogenetic activity of insulin. In addition, we revealed a significant increase in the content of fibronectin on days 21,35 and 60 of the experiment, respectively, from 56.5±2.8 (in control) to 74±8.1, 79±3.8 and 98±2.1 pg/ml. Fibronectin plays a significant role in tissue repair processes, providing cell migration and adhesion. Its blood level can correlate with the degree of destructive and reparative processes in the cells of liver and vascular endothelium.
Conclusion. A high-fructose diet in rats causes an increase in the studied biochemical parameters of carbohydrate and lipid metabolism, as well as an increase in blood level of the main regulatory protein of the intercellular matrix - fibronectin.
Age and gender peculiarities of body composition in pupils according to bioelectrical impedance analysis
The study is relevant due to insufficient diagnostic sensitivity of the body mass index to assess the risk of nutrition disorders and determine the range and the content of preventive measures.
The aim of the research was to investigate age and gender characteristics of body composition indicators in schoolchildren according to bioimpedance analysis.
Material and methods. 136 students of the city secondary school divided in four age groups (7-8, 10-11, 12-14, 15-17 years old) were examined, each group was divided into gender subgroups. All children underwent bio-impedance research using the analyzer ABC-01 «Medass». A comparative analysis of anthropometric data, absolute and relative average values of the main parameters of bio-impedance analysis and the frequency of deviation of the parameter from standard values was carried out.
Results and discussion. Boys in the age group of 7-8 years showed a tendency to more frequent registration of both deficiency and excess body fat relative to girls (36 vs 8% and 36 vs 15%). The body composition of girls in this age group was characterized by higher values of the indicators of the development of musculoskeletal system. Children aged 10-11 years, demonstrated less sexual differentiation between indicators of fat metabolism; adipose tissue deficiency was detected with a frequency up to 13-20%, an excess - up to 40-47%. Girls were also characterized by higher parameters of skeletal muscle mass. In boys of the 12-14 year old age group, the average values of the phase angle, active cell mass and its proportion were statistically significantly lower than the similar indicators for girls. The most pronounced gender differences were found in children in the age group of 15-17 years. The average height and body weight of boys exceeded that of girls. The average values of the phase angle, lean mass, active cell mass, musculoskeletal mass and their proportion were statistically significantly higher in boys, against the background of lower parameters of fat metabolism relative to similar indicators of girls. A direct relationship of age with the proportion of skeletal muscle mass and the relative value of active cell mass in boys, and the proportion of fat mass in girls has been shown. It is noteworthy that the frequency of high values of the proportion of fat mass was up to 2.2 fold higher than the percentage of high values of the body mass index.
Conclusion. In boys in the period from 7 to 17 years, there was observed an increase in indicators characterizing the level of motor activity and overall physical development, and in girls the prevalence of the adipose tissue excess and obesity increased.
Study on the development of measures to manage the risks associated with the food produced using microbial synthesis
In order to increase the efficiency of food production, micro-organisms are used whose genetic material has been modified by directed mutagenesis or by transgenesis. Such products belong to a new type of products, the mandatory condition for the use of which is to confirm its safety when used in food.
The aim of the article - justification of the need to improve the system for assessing the safety of foods obtained by microbial synthesis.
Material and methods. The analysis and generalization of current scientific researches published in the databases Scopus, Web of Science, PubMed, RSCI, as well as national and international regulatory and legislative documents have been carried out.
Results and conclusion. The analysis of scientific data, legislative and regulatory documents of international legislation, the European Union, as well as other economically developed countries, has shown that a mandatory element of assessing the possibility of safe use of food produced by microbial synthesis is the study of the sequence of transgenic insert nucleotides in the producer strain in order to analyze the presence of pathogenicity determinants, antibiotic resistance, and the ability to produce toxic metabolites. The data obtained in vitro on the absence of risks of using both producer strains and the enzyme preparations and other ingredients synthesized by them in the food industry should be confirmed in experiments in vivo. Currently, the need to comply with these requirements, as well as the main criteria for assessing the risks of such food, are mainly provided by legislation and regulations of the Russian Federation. At the same time, the system of sanitary and hygienic assessment of the safety of producer strains and food ingredients produced by them needs to be updated.
Evaluation of the diet based on the variability of the food composition data
Nutrient composition is a necessary part in the assessing of nutritional value of diets and new foods. According to the results of comparison of nutrient value of the diet with daily requirements the judgment on compliance of the diet (or product) to norm or deviation from the standard is taken out. In the interpretation of the term “value corresponds to the norm” in modern practice, only average values are used, while the content of nutrients in food is not described by fixed values, but has a statistical nature, which creates difficulties in the conscientious development of diets and their harmonization in sanitary authorities. Specifying a range of normative values (±5-10%) does not provide a valid solution.
The aim of the research was to assess the size of the spread of nutrient content for the diet as a whole and to use this estimate in relation to the task of "comparing the actual value and the norm".
Material and methods. In this work, we used the method of mathematical modeling of recipes, the calculation of nutrient content based on that of ingredients, and reference publications on the nutrient composition of products and collections of recipes were used as starting materials.
Results and discussion. The calculation of nutrient composition according to the recipe is described, taking into account not only average values, but also scatter indicators (error) of nutrient content values, which makes it possible to reasonably make judgments about the compliance of the actual value with the established reference value. The calculation of estimates of the spread of nutrient composition values using the information about the error of the initial data on the nutrient composition of the products, the output of the absolute and relative error in the formulation and the whole diet was described. Examples of calculations of scatter estimates are given: for one recipe/ nutrient (primary); calculation for days and mealtimes; for a day of a cyclic menu and for a 4-week cycle of school meals menus (primary and secondary school age). The mapping of the variables having a statistical nature has been graphically showed, the measure of estimating the proximity of the values of the statistical nature has been proposed discrete and continuous. Comparison of indicators of variability of domestic and foreign reference databases, mapping information about variation in the types of meals, differences in the extent of variation in the nutrients has been given.
Conclusions. The conclusions are formulated on the need for statistical presentation of consumption reference values for research for various reasons of variability, on the need to take statistics into account for the system of accumulating data on nutrient composition in databases.
Dynamics of indicators of vitamin D status in children with cystic fibrosis of the Moscow region for 2016-2018
Vitamin D deficiency is widespread in patients with cystic fibrosis (CF). From 2016 to 2018, prophylactic doses of vitamin D were prescribed for the patients of the Russian cystic fibrosis Center in accordance with the National cystic fibrosis consensus and they were informed about the role of vitamin D deficiency.
The aim of the study was to conduct a comparative analysis of the frequency of deficiency and insufficiency of vitamin D in children with CF of different ages in Moscow region in 2016 and 2018.
Material and methods. The study involved 115 patients with CF at the age of 0-18 in 2016 and 211 children of the same age in 2018. All children underwent determination of 25(OH)D in blood serum by ELISA.
Results and discussion. The frequency of vitamin D deficiency and insufficiency [25(OH)D level <30 ng/ml] in CF patients in 2016 was 64.3%, and in 2018 - 48.7%. Among children of 0-3 years normal serum 25(OH)D levels (>30 ng/ml) were registered in 62.5% in 2016 and in 62.2% in 2018, in children of 4-11 years - 28.8% in 2016 and 58.1% in 2018, among adolescents (11-18 years) - 11.8 and 30.2%, respectively.
Conclusion. Comparative analysis showed a positive dynamics in reducing the proportion of CF patients with vitamin D deficiency and insufficiency against the background of continuous use of prophylactic doses of cholecalciferol and educational work for the period from 2016 to 2018. However, in a significant proportion of patients (48.7%), vitamin D level did not reach the norm in 2018 that requires the correction of preventive doses and increase in patient compliance.
Spinach and quinoa - prospective food sources of biologically active substances
Formally, phytoadaptogens extracted mainly from medicinal plants are not food substances, and their use in preventive nutrition is significantly limited. However, screening studies can detect phytoadaptogens in food plants, however in much smaller quantities. For example, phytoecdysteroids are biologically active substances (BAS), used to relieve chronic fatigue syndrome, reduce nervous and muscle fatigue, improve memory and attention processes. Phytoecdysteroids can be isolated not only from various medicinal plants, but also from food plants like spinach (Spinacia oleracea) and quinoa (Chenopōdium quīnoa). Researchers show interest in possible synergies in the manifestation of a wide range of pharmacological effects, determined by a combination of phytoecdysteroids and other biologically active substances of these food plants.
The aim of this research is a brief analytical review of publications characterizing the spectrum of minor biologically active substances of spinach and quinoa, as well as those devoted to the experimental assessment of their pharmacological activity in experiments on laboratory animals.
Results. An analysis of the publications presented in the review indicates that spinach and its extracts are promising food sources of phytoadaptogens, carotenoids, phenolic compounds, in particular quercetin, kempferol, phenolic acids (p-coumaric, ferulic), as well as lignans metabolized into biologically active phytoestrogens (enterolactone and enterodiol). The possible prophylactic effect of spinach is being actively studied in vivo in laboratory animals when modeling diseases such as diabetes mellitus, cardiovascular and cancer diseases. Numerous adaptogenic effects and the neuroprotective effect of spinach and its extracts are shown, expressed in improving the memory and learning of animals. Publications of the last decade indicate an increased interest in such a promising food source of high-grade protein and a wide spectrum of biologically active substances, including phytoecdysteroids, as quinoa grains. More than 20 phenolic compounds in free or conjugated forms were found in quinoa grains; tannins, saponins, sterols, phytic acid, and ecdysteroids are present in small quantities. The consumptionof quinoa can have a beneficial effect on the organism, normalizing carbohydrate and lipid metabolism, reducing body weight and preventing excessive lipid peroxidation. The anti-inflammatory effects and antioxidant effects of quinoa are widely discussed.
Conclusion. Spinach, quinoa and their extracts are promising food sources of biologically active substances, their pharmacological action is confirmed from the standpoint of evidence-based medicine by in vivo experimental studies. Accordingly, it is advisable to expand the use of these food plants for inclusion in biologically active dietary supplements, functional food ingredients and specialized food products for various purposes.
Clinical efficacy of probiotic strains of the Bifidobacterium and Lactobacillus
The article analyzes the effectiveness of the most studied probiotic strains that are used for prophylactic or therapeutic purposes. The requirements for probiotic microorganisms are described, depending on the form in which they are used. However, their scope most often covers both prevention and treatment of various functional disorders and diseases of the gastrointestinal tract. At the same time, a lot of data has been accumulated on the effectiveness of probiotics for the treatment and prevention of diseases of other organs and organism systems. Most strains are successfully used as dietary supplements, and some of them have found their application in food industry.
Content of vitamins and mineral substancеs in enriched milk
The enrichment of food products of industrial production in order to replenish vitamin and mineral deficiency is an actual trend in optimizing the diet of adults and children. Enriched milk as a healthy food is in constant demand. In this regard, monitoring the content of nutrients declared by the manufacturer in fortified milk and identification of its assortment is an important task.
The aim of the research was assessment of the content of vitamins and mineral substances as micronutrients that form a balanced diet, in enriched milk marketed in Kemerovo.
Material and methods. The content of micronutrients declared by the manufacturer in the information on the individual product label has been determined: vitamins C and B1; mineral substances (calcium, iron, iodine, zinc) in 10 samples of fortified drinking milk with a fat content of 2.5% from different manufacturers. Iron was determined by colorimetric method based on measuring the color intensity of red solution of a complex compound of divalent iron with ortho-phenanthroline. The content of zinc and iodine was determined by inversion voltammetry, the content of calcium and ascorbic acid by titrimetric method, the content of thiamine by the voltammetric method.
Results and discussion. The actual content of ascorbic acid in fortified milk was in the range from 6 to 12 mg/100 g, thiamine - from 0.10 to 0.20 mg/100 g, which corresponded to their declared amount. The content of calcium varied from 99 to 155 mg per 100 g, iron - from 1.4 to 1.7 mg per 100 g, zinc - from 0.7 to 1.5 mg per 100 g, iodine - from 94.0 up to 151.0 mcg/kg. The compliance of the declared mineral substances in fortified milk has been confirmed. It has been shown that due to the consumption of200 ml of product, the daily physiological requirement for the analyzed vitamins and minerals for adults will be: for vitamins C and B1 on average 13-26%; calcium - 18-31%; iron - from 14-18% for women to 28-34% for men; zinc - 12-25%; iodine - 12-20%.
Conclusion. It was found that all samples of fortified milk corresponded to the declared characteristics for the content of vitamins and mineral substances. Regular consumption of fortified milk will improve the supply with essential micronutrients in the residents of the Kuzbass region.
A review on the monograph of N.R. Efimochkina «Bacterial food pathogens of the genus Campylobacter»
In the presented review of the book N.R. Efimochkina “Bacterial food pathogens of the Campylobacter genus” (Moscow, 2019) attention is drawn to the safety of food products and food raw materials, especially poultry products for consumers. In general, the problematic issues of campylobacteriosis and its causative agent are highlighted in a new way: the main reservoirs, sources and factors of pathogen transmission are indicated, theoretical issues are analyzed and generalized data of screening studies of food products and environmental objects in the poultry industry for bacteria of the genus Campylobacter are presented. Particular attention is paid to laboratory diagnostics of the pathogen for the presence of uncultivated forms of these pathogens, the existence of Campylobacter in biofilms, and the resistance of isolated cultures to antibiotics. Laboratory methods that improve the detection of these pathogens are proposed. The developed methodological documents that accelerate the processes of Campylobacter isolation and antibiotic resistance assessment are relevant, which is important for the efficiency of production control and sanitary inspections of poultry and meat processing enterprises at control critical points. The introduction of the methods described in the monograph for analyzing the content of Campylobacter in food products, on the surface of equipment and inventory will help to effectively manage the risks associated with contamination of food products by these pathogens. The monograph will be of great importance for improving the knowledge of a number of medical staff, including sanitary and hygienic profile, that is important for environmental protection, the prevention of food poisoning and intestinal infections with alimentary transmission factor.