Hydrogen Excretion Research Articles

Added Value of 13C Analysis in Breath Tests in H2-Negative Subjects to Diagnose Lactose Malabsorption: A Proof of Concept Study.

Diagnosing lactose malabsorption is usually based on hydrogen excretion in breath after a lactose challenge. However, a proportion of subjects with lactose malabsorption will not present a rise in hydrogen. Measuring excretion of methane or stable isotope labeled 13CO2 after ingestion of 13C-lactose has been proposed to mitigate this problem. The aim of the study was to assess the performance of measuring methane and 13CO2 in individuals with normal hydrogen excretion compared to a genetic lactase non-persistence test. Individuals referred for lactose breath testing and healthy controls were included. Participants received 13C-enriched lactose, performed breath testing, and underwent genotyping for a marker of lactase non-persistence (13910C*T). Using genotype as gold standard, the performance of measuring methane and 13CO2 excretion was assessed. 151 subjects participated in the study, 50 of which presented a lactase non-persistent genotype. Of these, 72% were correctly diagnosed through hydrogen excretion of ≥ 20ppm above baseline. In subjects with normal hydrogen excretion, cumulative 13C excretion had an area under the curve (AUC) of the receiver operating characteristics (ROC) curve of 0.852. Sensitivity was 93% and specificity was 51% for the current cutoff of 14.5%. The optimal cutoff was 12.65% (sensitivity 93%, specificity 70%). The ROC curve of peak methane had an AUC of 0.542 (sensitivity of 14%, specificity of 91% for cutoff ≥ 10ppm). In individuals with genetically demonstrated lactase non-persistence and negative hydrogen breath test, the use of 13C-lactose with measurement of 13CO2 excretion and hydrogen is a well-performing test to detect the lactose malabsorption and performs better than methane in our cohort.

2'-fucosyllactose alone or combined with resistant starch increases circulating short-chain fatty acids in lean men and men with prediabetes and obesity.

Infusion of short-chain fatty acids (SCFA) to the distal colon beneficially affects human substrate and energy metabolism. Here, we hypothesized that the combination of 2'-fucosyllactose (2'-FL) with resistant starch (RS) increases distal colonic SCFA production and improves metabolic parameters. In this randomized, crossover study, 10 lean (BMI 20-24.9 kg/m2) and nine men with prediabetes and overweight/obesity (BMI 25-35 kg/m2) were supplemented with either 2'-FL, 2'-FL+RS, or placebo one day before a clinical investigation day (CID). During the CID, blood samples were collected after a overnight fast and after intake of a liquid high-fat mixed meal to determine plasma SCFA (primary outcomes). Secondary outcomes were fasting and postprandial plasma insulin, glucose, free fatty acid (FFA), glucagon-like peptide-1, and peptide YY concentrations. In addition, fecal SCFA and microbiota composition, energy expenditure and substrate oxidation (indirect calorimetry), and breath hydrogen excretion were determined. In lean men, supplementation with 2'-FL increased postprandial plasma acetate (P = 0.017) and fasting H2 excretion (P = 0.041) compared to placebo. Postprandial plasma butyrate concentration increased after 2'-FL and 2'-FL+RS as compared to placebo (P < 0.05) in lean men and men with prediabetes and overweight/obesity. Additionally, 2'-FL+RS decreased fasting and postprandial plasma FFA concentrations compared to placebo (P < 0.05) in lean men. Supplementation of 2'-FL with/without RS the day before investigation increased systemic butyrate concentrations in lean men as well as in men with prediabetes and obesity, while acetate only increased in lean men. The combination of 2'-FL with RS showed a putatively beneficial metabolic effect by lowering plasma FFA in lean men, indicating a phenotype-specific effect. nr. NCT04795804.

Resistant Starch Decreases Serum Total Cholesterol and Triacylglycerol Concentrations in Rats

Rats were meal-fed semipurified diets containing a low (0.8 g/MJ) and a high (9.6 g/MJ) amount of resistant starch (RS) or various amounts of RS (0.8 to 9.6 g/MJ) and guar gum (0 to 8.8 g/MJ). In one experiment, rats were fed the low and high RS diets in three dietary regimens (ad libitum consuming, 12 h ad libitum/12 h food deprived, and meal fed). Effects of RS and guar gum on serum postprandial and postabsorptive concentrations of total cholesterol (TC) and triacylglycerol (TAG), growth, hydrogen excretion, tissue weights and contents of small intestine and cecum, and pH of cecal contents were investigated. In addition, effects of RS on food intake, de novo hepatic synthesis of fatty acids and neutral sterols, and on lipoprotein lipase activity and weight of epididymal fat pads were investigated. Compared with feeding the low RS diet, the high RS diet reduced the serum TC and TAG concentrations, with these effects observed after 1 and 2 wk of feeding, respectively. The dietary regimen did not influence the effect of RS on the serum TC and TAG concentrations, but it did affect the serum TAG concentration. Resistant starch had no effect on the hepatic synthesis of fatty acids and neutral sterols or on the lipoprotein lipase activity in epididymal fat pads. Guar gum also reduced the serum TC concentration, but it had no effect on serum TAG concentration. The tissue weights and contents of small intestine and cecum as well as hydrogen excretion increased with increasing amounts of dietary RS and guar gum, whereas the pH of cecal contents decreased. No effects of RS on food intake and total body weight gain were found, whereas guar gum decreased weight gain. Feeding the high RS diet also led to a lower weight of the epididymal fat pads. We conclude that dietary RS can reduce serum TC and TAG concentrations and fat accretion.

Impact of Saccharomyces boulardii CNCM I-745 on Bacterial Overgrowth and Composition of Intestinal Microbiota in Diarrhea-Predominant Irritable Bowel Syndrome Patients: Results of a Randomized Pilot Study

Background: Small intestinal bacterial overgrowth (SIBO) is associated with diarrhea-predominant irritable bowel syndrome (IBS-D). Probiotics like Saccharomyces boulardii CNCM I-745 (Sb) may be efficacious in balancing the microbiota. This randomized open label study assessed the effect of Sb in patients with bacterial overgrowth associated with IBS-D and its impact on the intestinal microbiota. Methods: Patients were randomized to receive Sb + dietary advice (Sb + DA) or dietary advice (DA) only for 15 days. SIBO was assessed by the lactulose hydrogen breath test (LHBT). Symptoms were assessed with the IBS Symptom Severity Scale (IBS-SSS) and stool consistency with the Bristol Stool Form Scale. Microbiota and mycobiota were analyzed by 16S rDNA and ITS2. Results: 54 patients were included, among whom 48 (27 Sb + DA, 21 DA) were evaluated. Decrease of hydrogen excretion was slightly higher in Sb + DA group, 41% versus 29% in DA group, and IBS-SSS total score were reduced by −134 and −93, respectively. The proportion of patients with diarrhea was lower in the Sb + DA group than in the DA group (25.9% compared to 47.6%). Bacterial and fungal microbiota showed that Sb treatment was associated with several modifications. Interestingly, F. prausnitzii was more abundant in Sb-treated patients with marked clinical improvement. The safety of S. boulardii CNCM I-745 was excellent. Conclusions: In patients with SIBO, S. boulardii CNCM I-745 associated with dietary advice reduced bacterial overgrowth and improved digestive symptoms while restoring the intestinal microbiota. The increased abundance of F. prausnitzii coupled with symptom improvement merits further research.

In Vivo Digestibility of Carbohydrate Rich in Isomaltomegalosaccharide Produced from Starch by Dextrin Dextranase.

Slowly digestible carbohydrates are needed for nutritional support in diabetic patients with malnutrition. They are a good source of energy and have the advantage that their consumption produces a low postprandial peak in blood glucose levels because they are slowly and completely digested in the small intestine. A high-amount isomaltomegalosaccharide containing carbohydrate (H-IMS), made from starch by dextrin dextranase, is a mixture of glucose polymers which has a continuous linear structure of α-1,6-glucosidic bonds and a small number of α-1,4-glucosidic bonds at the reducing ends. It has a broad degree of polymerization (DP) distribution with glucans of DP 10－30 as the major component. In our previous study, H-IMS has been shown to exhibit slow digestibility in vitro and not to raise postprandial blood glucose to such levels as that raised by dextrin in vivo. This marks it out as a potentially useful slowly digestible carbohydrate, and this study aimed to evaluate its in vivo digestibility. The amount of breath hydrogen emitted following oral administration of H-IMS was measured to determine whether any indigestible fraction passed through to and was fermented in the large intestine. Total carbohydrate in the feces was also measured. H-IMS, like glucose and dextrin, did not result in breath hydrogen excretion. Carbohydrate excretion with dietary H-IMS was no different from that of glucose or water. These results show that the H-IMS is completely digested and absorbed in the small intestine, indicating its potential as a slowly digestible carbohydrate in the diet of diabetic patients.

A cytosolic ferredoxin-independent hydrogenase possibly mediates hydrogen uptake in Trichomonas vaginalis

Trichomonads, represented by the highly prevalent sexually transmitted human parasite Trichomonas vaginalis, are anaerobic eukaryotes with hydrogenosomes in the place of the standard mitochondria. Hydrogenosomes form indispensable FeS-clusters, synthesize ATP, and release molecular hydrogen as a waste product. Hydrogen formation is catalyzed by [FeFe] hydrogenase, the hallmark enzyme of all hydrogenosomes found in various eukaryotic anaerobes. Eukaryotic hydrogenases were originally thought to be exclusively localized within organelles, but today few eukaryotic anaerobes are known that possess hydrogenase in their cytosol. We identified a thus-far unknown hydrogenase in T.vaginalis cytosol that cannot use ferredoxin as a redox partner but can use cytochrome b5 as an electron acceptor. Trichomonads overexpressing the cytosolic hydrogenase, while maintaining the carbon flux through hydrogenosomes, show decreased excretion of hydrogen and increased excretion of methylated alcohols, suggesting that the cytosolic hydrogenase uses the hydrogen gas as a source of reducing power for the reactions occurring in the cytoplasm and thus accounts for the overall redox balance. This is the first evidence of hydrogen uptake in a eukaryote, although further work is needed to confirm it. Assembly of the catalytic center of [FeFe] hydrogenases (H-cluster) requires the activity of three dedicated maturases, and these proteins in T.vaginalis are exclusively localized in hydrogenosomes, where they participate in the maturation of organellar hydrogenases. Despite the different subcellular localization of cytosolic hydrogenase and maturases, the H-cluster is present in the cytosolic enzyme, suggesting the existence of an alternative mechanism of H-cluster assembly.

European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus.

IntroductionMeasurement of breath hydrogen (H2) and methane (CH4) excretion after ingestion of test‐carbohydrates is used for different diagnostic purposes. There is a lack of standardization among centers performing these tests and this, together with recent technical developments and evidence from clinical studies, highlight the need for a European guideline.MethodsThis consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of H2‐CH4‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 44 experts from 18 European countries. Eighty eight statements and recommendations were drafted based on a review of the literature. Consensus (≥80% agreement) was reached for 82. Quality of evidence was evaluated using validated criteria.ResultsThe guideline incorporates new insights into the role of symptom assessment to diagnose carbohydrate (e.g., lactose) intolerances and recommends that breath tests for carbohydrate malabsorption require additional validated concurrent symptom evaluation to establish carbohydrate intolerance. Regarding the use of breath tests for the evaluation of oro‐cecal transit time and suspected small bowel bacterial overgrowth, this guideline highlights confounding factors associated with the interpretation of H2‐CH4‐breath tests in these indications and recommends approaches to mitigate these issues.ConclusionThis clinical practice guideline should facilitate pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, it identifies areas of future research needs to clarify diagnostic and therapeutic approaches.

Evaluation of the relative available energy of cyclic nigerosylnigerose using breath hydrogen excretion in healthy humans.

Cyclic nigerosylnigerose (CNN) is a cyclic tetrasaccharide with properties distinct from those of other conventional cyclodextrins. We investigated the relative available energy of CNN in healthy humans. CNN digestibility was determined using brush border membrane vesicles from the small intestines of rats. CNN was not hydrolyzed by rat intestinal enzymes. To investigate breath hydrogen excretion, 13 human subjects were included in a double-blind cross-over, randomized, placebo-controlled study. The effects of CNN on hydrogen excretion were compared with those of a typical nondigestible, fermentable fructooligosaccharide (FOS). In the study participants, hydrogen excretion hardly increased upon CNN and was remarkably lower than for FOS. The available energy value was determined using the fermentability based on breath hydrogen excretion and was evaluated as 0 kcal/g for CNN. CNN was hardly metabolized and hence may be used as a low-energy dietary fiber.

Acute effects of increased gut microbial fermentation on the hypoxic ventilatory response in humans

What is the central question of this study? Is there a link between gut microbial fermentation and ventilatory responsiveness to hypoxia in humans? What is the main finding and its importance? Increased gut microbial fermentation is associated with augmented ventilatory (but not haemodynamic) responses to transient hypoxia. These findings imply a capacity for gut microbiota to modulate the peripheral chemoreflex response to hypoxia in humans. Recent animal data indicate the presence of a bidirectional link between gut microbial activity and respiratory control. Nevertheless, the presence of a similar association between gut microbiota and peripheral chemoreceptor responsiveness to hypoxia in humans has not been reported to date. Therefore, we performed a within subject, placebo-controlled study in a group of 16 healthy individuals (eight men; mean±SD age 25.9±5.2years). Participants underwent two tests (in a random order), receiving lactulose, which stimulates gut fermentation, or placebo. Ventilatory and haemodynamic responses to transient hypoxia were evaluated before and 2h after the test meal. The magnitude of these responses was related to the net hydrogen content in the exhaled air, reflecting gut fermentation intensity. A lactulose meal, compared to placebo, caused an increase in the minute ventilation (Hyp-VI; l/min/ ) and breathing rate (Hyp-BR; breaths/min/ ) responses to hypoxia (for Hyp-VI, mean±SD -0.03±0.059 in placebo test vs. 0.05±0.116 in lactulose test, P=0.03; for Hyp-BR, -0.015±0.046 vs. 0.034±0.054, P=0.01). The magnitude of these responses was positively correlated with the lactulose-induced hydrogen excretion (for Hyp-VI, r=0.62, P=0.01; for Hyp-BR, r=0.73, P=0.001). Changes in the resting parameters during normoxia did not differ significantly between the tests. Our results demonstrate that the increased gut microbial fermentation is associated with augmented ventilatory (but not haemodynamic) responses to the transient hypoxia, which implies a capacity for gut microbiota to modulate the peripheral chemoreflex in humans.

How the North American Consensus Protocol Affects the Performance of Glucose Breath Testing for Bacterial Overgrowth Versus a Traditional Method

The North American Consensus guidelines for glucose breath testing (GBT) for small intestinal bacterial overgrowth (SIBO) incorporated changes in glucose dosing and diagnostic cutoffs. We compared GBT positivity based on hydrogen and methane excretion and quantified symptoms during performance of the North American vs older modified Rome Consensus protocols. GBT was performed using the North American protocol (75 g glucose, cutoffs >20 parts per million [ppm] hydrogen increase after glucose and >10 ppm methane anytime) in 3,102 patients vs modified Rome protocol (50 g glucose, >12 ppm hydrogen and methane increases after glucose) in 3,193 patients with suspected SIBO. Positive GBT were more common with the North American vs modified Rome protocol (39.5% vs 29.7%, P < 0.001). Overall percentages with GBT positivity using methane criteria were greater and hydrogen criteria lower with the North American protocol (P < 0.001). Peak methane levels were higher for the North American protocol (P < 0.001). Times to peak hydrogen and methane production were not different between protocols. With the North American protocol, gastrointestinal and extraintestinal symptoms were more prevalent after glucose with both positive and negative GBT (P < 0.04) and greater numbers of symptoms (P < 0.001) were reported. GBT performed using the North American Consensus protocol was more often positive for SIBO vs the modified Rome protocol because of more prevalent positive methane excretion. Symptoms during testing were greater with the North American protocol. Implications of these observations on determining breath test positivity and antibiotic decisions for SIBO await future prospective testing.

Revaluation of the available energy of difructose anhydride III and maltobionic acid based on the fermentability of breath hydrogen excretion in healthy humans

ABSTRACT The relative available energy (RAE) based on the fermentability of breath hydrogen excreted by gut microbiota was assessed using a method accepted by the Japanese Society for Dietary Fiber Research. The purpose of this study was to evaluate RAE of difructose anhydride III (DFA III) and maltobionic acid (MA). In this study, which had a within-subject, repeated measures design, 11 healthy female participants ingested 5 g of DFA III, MA, and fructooligosaccharide, which has RAE of 2 kcal/g. Breath hydrogen was collected 12 times up to 14 h after meal consumption and measured using gas chromatography, and the area under the curves (AUCs) was calculated 0–14 h after ingestion. Compared with the AUCs of breath hydrogen excretion related to the ingested fructooligosaccharide for 14 h, those of DFA III and MA were 40.5% and 23.1%, respectively. RAE was 0.81 kcal/g for DFA III and 0.46 kcal/g for MA, respectively.

Diagnosis of the Syndrome of Excessive Bacterial Growth of the Small Intestine in Patients with Bauhinia Insufficiency and After its Surgical Correction (First Results)

Objective: To determine the syndrome of excessive bacterial growth in the small intestine (SIBO) in patients with insufficiency of the bauhinia valve (NBZ) and after its surgical correction. Methods of examination: Patients of the studied groups were examined using direct and indirect methods of diagnosis of SIBO. Bacteriological examination of ileal aspirate and other surgical material was performed. All patients underwent a hydrogen respiratory test with a load of lactulose and performed a qualitative reaction of urine to indican. Characteristics of the material: 50 patients were examined, of which 30 were included in the main group, who underwent surgical correction of NBZ - Bauginoplasty; 20 patients are included in the control group in which the ileocecal valve is consistent. Patients of the main group were examined before surgery and on the 7th and 45th day after Bauhinoplasty. Main results: All patients of the main group had SIBS of varying severity, in 80% of patients SIBS was localized in the distal small intestine. Patients with normal function of ileocecal valve syndrome of excessive bacterial growth did not suffer. Intraoperatively, 76% of patients showed signs of mesenteric mesentery of the small intestine, and the fact of bacterial translocation in SIBO was also confirmed. After 7 days after surgical correction of the Bauhinia valve, the normalization of peak and background excretion of hydrogen was observed in 37% of patients. For 45 days in all patients the hydrogen curve corresponded to the norm. Conclusions: the deficiency of the bauhinia valve is obligately accompanied by the syndrome of excessive bacterial growth in the small intestine, surgical correction is an effective method for correcting the syndrome of excessive bacterial growth in patients with NBD.

Early hydrogen excretion peaks during breath tests. Small intestinal bacterial overgrowth or accelerated transit?

BackgroundSmall intestinal bacterial overgrowth (SIBO) has been reported with varying prevalence, depending upon the criteria used for diagnosis. Lactulose and glucose breath tests are the most used in clinical settings. Early rises of hydrogen excretion during a lactose breath test suggest SIBO, but the finding could result from accelerated mouth-to-caecum transit time. AimsDefining the prevalence of early hydrogen peaks during lactose breath tests and assessing the proportion of patients affected by SIBO. MethodsAn early (≤ 60′) hydrogen excretion peak was observed in 120/663 patients with positive lactose hydrogen breath test. Eighty-one of them underwent a 50 g-9sample-glucose hydrogen breath test to diagnose SIBO. ResultsThe glucose breath test proved positive in 11/81 (13.6%) patients. The positivity rate was 18.2% (2/11) in those with the first peak detected at 30′ and 12.8% (9/70) in those with the peak occurring at 60′. ConclusionsEarly hydrogen excretion peaks are rarely associated with SIBO. The low positive predictive value indicates that the finding does not help identifying patients at high risk for this condition. Indirectly, the present data support the opinion that the prevalence of SIBO diagnosed by standard lactulose breath tests is much lower than reported, and the reliability of the test is low.

Trial of Available Energy Evaluation of Highly Cross-linked Starch and Modified Cellulose Based on Breath H2 Excretion

Background: The energy value of a substance is essential in nutritional labeling. However, the available energy of newly developed highly cross-linked phosphate starch (HCPS-N) and modified cellulose (MC) are unknown. Objective: To evaluate the available energy of HCPS-N and MC, an indirect and simple method which was applied as an indicator of the fermentability based on the breath hydrogen excretion, was used. Methods: HCPS-N was made from tapioca starch by polymerization in the presence of 0.5% phosphoric acid. MC was made from microcrystalline cellulose, maltodextrin, and karaya gum to attain a highly stable suspension. The present study was carried out using a within-subject, repeatedmeasures design. Blood was collected at 30 min intervals for 3 h after the ingestion of 30 g of a test substance. The end-respiratory gas was collected for 14 h after ingestion of 5 g of a test substance to evaluate the available energy. Results and Discussion: Plasma glucose and insulin levels did not elevate after the ingestion of HCPS-N, although they increased significantly after glucose ingestion. In the experiments to evaluate the available energy, breath hydrogen excretion after ingesting HCPS-N did not increase distinctly during the experiment. Breath hydrogen excretion after preceding HCPS-P (0 kcal) ingestion was also markedly smaller compared with the peak value at 4 h after FOS ingestion. For the ingestion of MC, breath hydrogen excretion increased scarcely, and the basal level remained until the end of the experiment. Conclusion: The available energies were evaluated to be 0 kcal/g for HCPS-N and 1 kcal/g for MC in healthy humans.

Highly Cross-linked Starch and Modified Cellulose as Dietary Fibers, and their Acclimation Effect on Hydrogen Excretion in Rats

Background: Highly cross-linked phosphate starch (HCPS) and modified cellulose (MC) were newly developed and modified dietary fiber materials to prevent lifestyle-related diseases. Objective: We investigated the physiological property of HCPS and MC to be a dietary fiber. Methods: HCPS was made from tapioca starch by polymerization in the presence of 0.5% phosphoric acid, and MC was made from cellulose, maltodextrin and karaya gum by high-speed mixing. In the present study, rats were raised on a diet containing 10% or 15% HCPS, or 10% MC for four weeks, and physical effects such as growth, organ weights, blood biomedical parameters, fecal weight, and hydrogen excretion were recorded. Results: Growth was normal among all groups, and there was no significant difference in total body weight gain. Some organ weights including the adipose tissues differed slightly among groups, but no difference based on diet composition was observed. Blood biomedical parameters were normal and not significantly different among groups. Cecum tissue and content weights were significantly greater in the 15% HCPS, 10% MC, and 10% fructooligosaccharide (FOS) groups than in the control group, and fecal weight was significantly increased in the 10% and 15% HCPS, and 10% MC groups compared with the control group. Hydrogen excretion over 24 h was negligible when HCPS was administered orally to rats non-acclimatized to HCPS but increased significantly in rats acclimatized to 10% HCPS diet for one week. Conclusion: We conclude that both HCPS and MC could be suitable for use as low energy bulking materials.

Metabolic fate of newly developed nondigestible oligosaccharide, maltobionic acid, in rats and humans.

Maltobionic acid (MA), formed by a gluconic acid and glucose linked by an α‐1,4 bond, may have the properties of a nondigestible oligosaccharide. The objective of this study was to elucidate the bioavailability of MA in rats and humans by observing digestion of MA by small intestinal enzymes, the fermentation of MA by gut microbiota, and the effect of adaptation following prolonged ingestion of MA. MA digestion was assessed using brush border membrane vesicles (BBMV) from rat small intestine. A within‐subject repeated measures design was used for ingestion experiments in 10 healthy female participants. After MA ingestion, postprandial plasma glucose and insulin levels, breath hydrogen excretion, and urinary MA were measured. The effect of adaptation following prolonged MA ingestion was investigated in rats. MA was minimally hydrolyzed by BBMV. Ingestion of 10 g of MA by healthy females did not elevate postprandial plasma glucose and insulin levels. Breath hydrogen and urinary MA were negligibly excreted over 8 hr following ingestion. Adaptation to prolonged MA ingestion produced no significant difference in exhaled hydrogen levels over 8 hr following administration compared with controls. MA is a new food material that is highly resistant to digestion and fermentation. It expresses the characteristics of a nondigestible oligosaccharide, including being low energy, improving the flavor of food and juice, and mineral solubilization.

PECULIARITIES OF UNITIOL INFLUENCE ON THE KIDNEY FUNCTIONING IN RATS OF THE JUVENILE AGE

This investigation shows an influence of different dosages of unitiol (sodium2,3-dimercaptopropanesulfonate) on the kidney functioning in juvenile rats.Purpose of the work is to study unitiol influence upon the kidney excretion function insexually mature rats at single and repeated injections.Material and methods. This investigation was performed on the juvenile male rats withthe body weight 95.0±8.5 g. The kidney functioning was determined for the single andrepeated (10, 20 and 30 days) injections of 5 % unitiol solution (50 mg/kg, subcutaneously)against a background of the additional water load realized through introduction of warmwater into the stomach in the volume of 5 % of the animal’s body weight. The concentrationOriginal research53Клінічна та експериментальна патологія. 2020. Т.19, №1(71) ISSN 1727-4338 https://www.bsmu.edu.uaof sodium, potassium ions, creatinine, proteins, ammonium, titratable acids and pH weredetermined in the rat’s urine and then compared with the corresponding values obtainedfrom the control and previous groups under study.Results. No significant changes were determined in the excretion and acid-regulationfunctions of the rat’s kidney in 2.5 hours after unitiol single injection against a backgroundof the water load. However, the concentration of sodium increased 1.7 times as large andthe concentration of potassium decreased correspondingly. No changes were registeredin diuresis while excretion of sodium increased 1.9 times as large, kaliuresis decreased1.6 times, sodium/potassium urine coefficient increased 2.6 times.After daily untiol injection during 10 days, concentration of sodium in the urine became3.2 times less in comparison with animal’s reaction to the single injection of the drugand 1.9 times less than that in the control group. Against a background of the 20 and30 days of the drug injection, the concentration of sodium has decreased almost thricecomparing to the control group value. Natriuresis decreased by 4 times comparing tothe value achieved after a single drug injection, decreased twice in comparison withthe control group and then it remained unchanged throughout the following 20- or 30-days long injections. No significant deviations from the control value were found in thepotassium concentration after the repeated injections of the drug. Kaliuresis decreasedafter the single injection but then it increased to its control value following the injection ofthe drug during 20 days. The urine sodium/potassium coefficient decreased 1.7-2.5 timescomparing to the control value after the repeated injections. No significant changes wereregistered throughout the entire experiment in the endogenous creatinine excretion andconcentration. The protein concentration decreased by 2.2 times comparing to its controllevel after unitiol application during 10 days and then it remained unchanged after 20-or 30-days long courses of injections. The indices of titratable acids and ammoniumexcretion became in 1.8 times less than those in the control group, then they increasedafter the 20th day and on the 30th day of injection they didn’t significantly differ fromthe control indices. The hydrogen excretion increased 2.4 and 2.8 times as large after20 and 30 days of the drug injection respectively at urine pH decrease. Unlike the singleinjection, the repeated unitiol injections significantly decrease natriuresis and the proteinexcretion with urine. Some age-related features of unitiol influence on the kidneys can beaccounted at different types of its administration as a chemical antidote.Conclusions. 1. Unitiol influence on the kidney functioning combined with the water loadin juvenile rats depends on the duration of application.2. The natriuretic effect increases and the kaliuretic effect decreases after a singleinjection of the drug when there is no significant influence on diuresis, excretion andacid-regulating parameters of the kidney. 3. A prolonged (10, 20, 30 days) application ofunitiol causes some intensification of sodium-retaining and hypoproteinuretic activitiescombined with some increase in the urine pH.

Comparison of utilisation and fermentation of highly cross-linked phosphate starches produced from two different plant origins, potato and tapioca in rats and humans

The utilisation and fermentation of highly cross-linked phosphate starches made from two different origins, potato (HXL-P) and tapioca (HXL-T) were investigated in rats and humans. HXL-P and HXL-T were highly resistant to digestion by carbohydrate enzymes and were also resistant to fermentation by gut microbiota in rats. The postprandial blood glucose scarcely increased after administration of HXL-P or HXL-T in healthy humans. Incremental AUC of both HXL-P and HXL-T for 180 min was significantly lower than that of glucose (p < .05). Breath hydrogen excretion was very low after oral administration of HXL-P or HXL-T, and AUCs of breath hydrogen excretion for 13 h after administration were significantly lower than that of fructooligosaccharide as a reference of fermentation (p < .05). These results show that HXL-P and HXL-T were hardly digested and were highly resistant to fermentation. In conclusion, HXL-P and HXL-T could be good low-energy bulking ingredients to replace wheat flour.

Evaluation of lactulose, lactose, and fructose breath testing in clinical practice: A focus on methane.

Background and AimBreath testing (BT) is used to identify carbohydrate malabsorption and small intestine bacterial overgrowth. Measuring methane alongside hydrogen is advocated to reduce false‐negative studies, but the variability of methane production is unknown. The aim of this study is to examine the effect of high methane production on hydrogen excretion after ingesting lactulose, fructose, or lactose.MethodsA retrospective audit was performed of patients with gastrointestinal symptoms who underwent BT. Following a low fermentable carbohydrate diet for 24‐h, a fasting BT before consuming 35 ml lactulose, 35 g fructose, or lactose in 200 ml water, followed by BT every 10–15 min for up to 3‐h, was performed. A positive test was defined as a ≥20 ppm rise of hydrogen or methane from baseline. A high methane producer had an initial reading of ≥5 ppm. Breath hydrogen and methane production were measured as area under the curve. Chi‐squared tests were used to compare proportions of those meeting the cut‐off criteria.ResultsOf patients, 26% (28/106) were high methane producers at their initial lactulose test. The test–retest repeatability of methane production was high, with the same methane production status before ingesting lactose in all (70/70) and before ingesting fructose in most (71/73). Methane production was highly variable during testing, with 38% (10/26) having ≥1 reading lower than baseline. Hydrogen produced by high or low methane producers did not differ (1528 [960–3645] ppm min vs 2375 [1810–3195] ppm min [P = 0.11]). Symptoms and breath test results were not positively related.ConclusionThe validity of including an increase of ≥20 ppm methane to identify carbohydrate malabsorption or small intestine bacterial overgrowth should be questioned due to the variability of readings during testing.

Preventing explosions of hydrogen gas inhalers.

Production and excretion of hydrogen (H2) gas in human was reported in 1969, since then it has been regarded as non-toxic molecule. For preventive and therapeutic medical uses, a possible treatment for cancer was reported and another article was published on how H2 acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. A variety of H2 gas inhalers have been available in the market for hospital and home uses. However, H2 is odorless and flammable or explosive ignited by static electricity. We have examined the safety of a variety of H2 gas concentrations from the viewpoint of flammability and explosion. We have also measured concentrations of H2 gas inhalers in the market respectively. This paper also details how to control H2 gas concentration for preventing explosions.