Pilot Study on the Prevalence of Diamine Oxidase Gene Variants in Patients with Symptoms of Histamine Intolerance.

A retrospective pilot study was carried out to investigate the prevalence of four variants of the diamine oxidase (DAO) encoding gene (AOC1) in Caucasian adults with symptoms of histamine intolerance. In a cohort of 100 patients and 100 healthy individuals, DAO-encoding gene non-synonymous Single Nucleotide Variations (SNVs) were genotyped by multiplex single-nucleotide primer extension (SNPE) and capillary electrophoresis, and serum DAO activity was analyzed with a radio-extraction assay. The study found that 79% of individuals with symptoms of histamine intolerance harbored one or more of the four SNVs associated with reduced DAO activity. No significant differences were found in the prevalence of any variant between the group of patients and healthy controls. However, when considering the status of the alleles associated with DAO deficiency, more homozygous alleles were observed in histamine-intolerant patients. Moreover, a slightly but statistically higher percentage of patients had a high genetic risk score, reflecting the cumulative effect of carrying multiple DAO deficiency-associated gene variants and a high load of risk alleles (homozygous). A relationship between serum DAO activity and the genetic load of one specific SNV was observed, with DAO activity being significantly lower in patients homozygous for rs2052129. These results potentially support that carrying multiple DAO deficiency-associated gene variants and a high load of risk alleles (homozygous) is more relevant than the mere presence of one or more SNVs. Further studies are needed to determine the predictive value of these DAO-encoding gene variants.

Comparative Assessment of the Nutritional Profile of Meat Products and Their Plant-Based Analogues.

Vegetarian and vegan diets are increasingly being adopted in Spain, a trend mainly driven by ethical concerns for animal welfare and the environment. This has resulted in a growing market for plant-based substitutes of meat products. However, available data on the nutritional value of such meat analogues in Mediterranean countries are still limited. In this study, the labelling information of four categories of plant-based meat analogues (n = 100) and the corresponding conventional meat products (n = 48) available on the Spanish market was surveyed and compared. The nutrient content of plant-based meat analogues varied significantly, due to the wide range of ingredients used in their formulation. Some of these products were found to have a low protein content, which in others was enhanced by the addition of cereals and legumes. Compared to the meat products, the plant-based analogues contained lower levels of total fat as well as saturated fat, which ranged from 30% of total fat in burgers to less than 15% in meatballs, sausages, and nuggets; in contrast, they contained higher amounts of fiber and complex carbohydrates. Overall, the meat analogues cannot be considered as nutritionally equivalent substitutes to conventional meat products due to a high variability of protein content and other nutrients.

The dietary treatment of histamine intolerance reduces the abundance of some histamine-secreting bacteria of the gut microbiota in histamine intolerant women. A pilot study.

Restrictive diets for the treatment of different gastrointestinal disorders are reported to change the composition of intestinal microbiota. Recently, it has been proposed that individuals with histamine intolerance suffer from intestinal dysbiosis, having an overabundance of histamine-secreting bacteria, but how it is still unknown this state is affected by the usual dietary treatment of histamine intolerance [i.e., low-histamine diet and the supplementation with diamine oxidase (DAO) enzyme]. Thus, a preliminary study was carried out aiming to evaluate the potential changes on the composition of the intestinal microbiota in a group of five women diagnosed with histamine intolerance undergoing 9 months of the dietary treatment of histamine intolerance. After sequencing bacterial 16S rRNA genes (V3-V4 region) and analyzing the data using the EzBioCloud Database, we observed a reduction in certain histamine-secreting bacteria, including the genera Proteus and Raoultella and the specie Proteus mirabilis. Moreover, it was also observed an increase in Roseburia spp., a bacterial group frequently related to gut health. These changes could help to explain the clinical improvement experienced by histamine intolerant women underwent a dietary treatment.

1-methylhistamine as a potential biomarker of food histamine intolerance. A pilot study.

Efforts are currently being directed to identify a non-invasive marker that can serve as a solid and clinically irrefutable diagnostic criterion for histamine intolerance associated with diamine oxidase (DAO) deficiency. Accordingly, the identification of biomarkers of histamine (HA) metabolism in urine is proposed as a possible new diagnostic strategy. It is hypothesized that individuals with histamine intolerance could have a different urinary profile of HA and its metabolites in comparison with the healthy population. Thus, the aim of this study was to assess the urinary excretion of HA and 1-methylhistamine (MHA) in individuals diagnosed with histamine intolerance and in a control group. Levels of HA and MHA were compared between 24 h and first morning spot urine in a subgroup of 14 control individuals. Then, HA and MHA concentrations in spot urine of 32 histamine intolerant and 55 control individuals were determined by ultra-high performance liquid chromatography and fluorometric detection (UHPLC-FL) and normalized by creatinine. No differences were found between HA and MHA levels in 24 h and first morning samples. Overall, histamine intolerant patients presented a distinct urinary excretion profile compared to the control group due to lower levels of MHA. No differences in urinary MHA were observed related to serum DAO activity. Spot urine samples were thus validated as a reliable tool to determine the urinary excretion of HA and MHA. These results constitute a starting point for the study of HA metabolomics as a suitable and non-invasive approach to histamine intolerance diagnosis.

The Rate of Histamine Degradation by Diamine Oxidase Is Compromised by Other Biogenic Amines.

Nowadays, certain uncertainties related to the onset of histamine adverse effects remain unsolved and still require further research. Questions still to be resolved include the wide range of doses at which dietary histamine may trigger symptoms of intoxication (100-10,000 mg/kg) or the appearance of symptoms of histamine intolerance after the consumption of foods presumable without histamine. It seems feasible that other amines, by acting as competitive substrates, could interfere with histamine degradation by the intestinal enzyme diamine oxidase (DAO). Therefore, the aim of this study was to elucidate the interference of different amines on the rate of histamine degradation by DAO. A series of in vitro enzymatic assays were performed using histamine as the reaction substrate combined with different proportions of putrescine, cadaverine, tyramine, spermidine, and spermine (1:0.25, 1:1, 1:4, 1:20). Putrescine and cadaverine significantly delayed histamine degradation at all tested concentrations (p < 0.001). The greatest effect was observed when putrescine or cadaverine concentrations were 20-fold higher than that of histamine, its degradation being reduced by 70 and 80%, respectively, compared to histamine alone (28.16 ± 1.0 mU). In contrast, tyramine, spermidine and spermine significantly inhibited the histamine degradation rate only at the highest concentration (1:20), reducing it by 32-45%. These results demonstrate that other biogenic amines interfere with histamine metabolization by DAO in vitro, the extent depending on the substrate. These findings could explain why susceptibility to dietary histamine is so variable and account for the discrepancies in the scientific databases regarding the amount of histamine that triggers adverse health effects.

Intestinal Dysbiosis in Patients with Histamine Intolerance.

An underlying cause of histamine intolerance is diamine oxidase (DAO) deficiency, which leads to defective homeostasis and a higher systemic absorption of histamine. Impaired DAO activity may have a genetic, pharmacological or pathological origin. A recent proposal also suggests it can arise from an alteration in the gut microbiota, although only one study has explored this hypothesis to date. A greater abundance of histamine-secreting bacteria in the gut could lead to the development of histamine intolerance. Thus, the aim of this study was to characterize the composition of the intestinal microbiota of patients with histamine intolerance symptoms and compare it with that of healthy individuals. The study was performed by sequencing bacterial 16S rRNA genes (V3-V4 region) and analyzing the data using the EzBioCloud Database. Dysbiosis of the gut microbiota was observed in the histamine intolerance group who, in comparison with the healthy individuals, had a significantly lower proportion of Prevotellaceae, Ruminococcus, Faecalibacterium and Faecablibacterium prausnitzii, which are bacteria related to gut health. They also had a significantly higher abundance of histamine-secreting bacteria, including the genera Staphylococcus and Proteus, several unidentified genera belonging to the family Enterobacteriaceae and the species Clostridium perfringens and Enterococcus faecalis. A greater abundance of histaminogenic bacteria would favor the accumulation of high levels of histamine in the gut, its subsequent absorption in plasma and the appearance of adverse effects, even in individuals without DAO deficiency.

Differences in Polyamine Content between Human Milk and Infant Formulas.

Human milk is the gold standard for nutrition during the first months of life, but when breastfeeding is not possible, it may be replaced by infant formulas, either partially or totally. Polyamines, which play an important role in intestinal maturation and the development of the immune system, are found both in human milk and infant formulas, the first exogenous source of these compounds for the newborn. The aim of this study was to evaluate the occurrence and evolution of polyamines in human milk during the first semester of lactation and to compare the polyamine content with that of infant formulas. In total, 30 samples of human milk provided by six mothers during the first five months of lactation as well as 15 different types of infant formulas were analyzed using UHPLC-FL. Polyamines were detected in all human milk samples but with great variation among mothers. Spermidine and spermine levels tended to decrease during the lactation period, while putrescine remained practically unchanged. Considerable differences were observed in the polyamine contents and profiles between human milk and infant formulas, with concentrations being up to 30 times lower in the latter. The predominant polyamines in human milk were spermidine and spermine, and putrescine in infant formulas.

Influence of Breastfeeding Factors on Polyamine Content in Human Milk.

The polyamine content of human breast milk, which is the first exogenous source of polyamines for the newborn, can be affected by several factors associated with the mother, the infant, or breastfeeding itself. The aim of this study was to evaluate the influence of different breastfeeding factors on the polyamines found in human milk. For this study, a cohort of 83 mothers was considered for up to 4 months, and a subgroup of 33 mothers were followed during the first six months of breastfeeding. Two breast milk samples were collected at each sampling point (foremilk and hindmilk) and the polyamine content was determined by UHPLC-FL. Polyamine levels varied considerably between the mothers and tended to decrease over time. Putrescine was the minor polyamine, whereas spermidine and spermine contents were very similar. The concentrations of the three polyamines were significantly higher in hindmilk than foremilk (p < 0.001). Spermidine and spermine levels decreased significantly through the lactation progress (p < 0.05). Finally, slightly higher levels of polyamines were observed in the milk of mothers providing partial, rather than full, breastfeeding, although the differences were not significant. The polyamine content in human milk was found to change during a single feed (foremilk versus hindmilk) and as lactation progressed, mainly in response to the specific circumstances of the newborn.

Occurrence of Polyamines in Foods and the Influence of Cooking Processes.

Dietary polyamines are involved in different aspects of human health and play an important role in the prevention of certain chronic conditions such as cardiovascular diseases and diabetes. Different polyamines can be found in all foods in variable amounts. Moreover, several culinary practices have been reported to modify the content and profile of these bioactive compounds in food although experimental data are still scarce and even contradictory. Therefore, the aim of this study was to evaluate the occurrence of polyamines in a large range of foods and to assess the effect of different cooking processes on the polyamine content of a few of them. The highest level of polyamines was found in wheat germ (440.6 mg/kg). Among foods of a plant origin, high levels of total polyamines over 90 mg/kg were determined in mushrooms, green peppers, peas, citrus fruit, broad beans and tempeh with spermidine being predominant (ranging from 54 to 109 mg/kg). In foods of an animal origin, the highest levels of polyamines, above all putrescine (42-130 mg/kg), were found in raw milk, hard and blue cheeses and in dry-fermented sausages. Regarding the influence of different domestic cooking processes, polyamine levels in food were reduced by up to 64% by boiling and grilling but remained practically unmodified by microwave and sous-vide cooking.

[Lambert-Eaton myasthenic syndrome]. / Síndrome miasteniforme de Lambert-Eaton.

INTRODUCTION: Early diagnosis based on clinical findings, neurophysiological studies and serum antibody titres allows early initiation of symptomatic treatment and oncological screening. Reports of patients with LEMS in Latin America are scarce. AIM: This article aims to describe the characteristics of patients with LEMS from a private centre in Buenos Aires, Argentina, and to compare them with those of other series that have been published. PATIENTS AND METHODS: The medical records of 13 patients with LEMS with clinical findings, compatible electromyogram and/or positive antibodies were reviewed. Follow-up was performed until associated neoplasia was ruled out or confirmed according to the recommended algorithms. RESULTS: Four patients were diagnosed with T-LEMS, two of them with small-cell lung carcinoma. Of the nine patients with NT-LEMS, five had a DELTA-P score of 3 and 4. Nine patients presented with the classic clinical triad from the onset of the disease. All patients had electromyogram findings compatible with presynaptic neuromuscular plaque defect. Of the total, 70% improved symptomatically with pyridostigmine. CONCLUSIONS: The clinical findings, together with compatible neurophysiological studies, are sufficient for the diagnosis of LEMS. The relationship between the DELTA-P score and the risk of small-cell lung carcinoma could not be replicated. Symptomatic treatment with pyridostigmine represents an effective therapeutic alternative.

TITLE: Síndrome miasteniforme de Lambert-Eaton.Introducción. El síndrome miasteniforme de Lambert-Eaton (LEMS) es una patología paraneoplásica (T-LEMS) o idiopática autoinmunitaria (NT-LEMS) ocasionada por autoanticuerpos contra los canales de calcio dependientes del voltaje presinápticos de la unión neuromuscular. El 60% de los T-LEMS se asocia a carcinoma de pulmón de células pequeñas. Una puntuación Dutch-English LEMS Tumor Association Prediction (DELTA-P) mayor de 3 denota un riesgo elevado de dicha asociación. El diagnóstico precoz fundado en los hallazgos clínicos, estudios neurofisiológicos y dosificación de títulos de anticuerpos en el suero permite iniciar tempranamente el tratamiento sintomático y la búsqueda oncológica. Son escasos los informes de pacientes con LEMS en Latinoamérica. Objetivo. Describir las características de pacientes con LEMS de un centro privado de Buenos Aires, Argentina, y compararlas con las de otras series publicadas. Pacientes y métodos. Se revisaron historias clínicas de 13 pacientes con LEMS con hallazgos clínicos, electromiograma compatible y/o anticuerpos positivos. Se realizó seguimiento hasta descartar o confirmar una neoplasia asociada de acuerdo con los algoritmos recomendados. Resultados. Cuatro pacientes presentaron diagnóstico de T-LEMS, dos de ellos con carcinoma de pulmón de células pequeñas. De los nueve pacientes con NT-LEMS, cinco presentaron una puntuación DELTA-P de 3 y 4. Nueve pacientes presentaron la tríada clínica clásica desde el inicio. Todos los pacientes presentaron en el electromiograma hallazgos compatibles con defecto de placa neuromuscular presináptico. El 70% mejoró sintomáticamente con piridostigmina. Conclusiones. Los hallazgos clínicos, junto con los estudios neurofisiológicos compatibles, resultan suficientes para el diagnóstico de LEMS. No pudo replicarse la relación entre puntuación DELTA-P y riesgo de carcinoma de pulmón de células pequeñas. El tratamiento sintomático con piridostigmina representa una alternativa terapéutica eficaz.

Low-Histamine Diets: Is the Exclusion of Foods Justified by Their Histamine Content?

A low-histamine diet is currently the most advised strategy to prevent the symptomatology of histamine intolerance. Conceptually, these diets should be founded on the exclusion of histamine-containing foods, although a certain disparity is found within the list of excluded foods in accordance with the different low-histamine diets available in the literature. This study aimed to critically review low-histamine diets reported in the scientific literature, according to the histamine and other biogenic amine contents of the excluded foods. A total of ten scientific studies that provided specific recommendations on the foods that must be avoided within the framework of a low-histamine diet were found. Overall, the comparative review brought out the great heterogenicity in the type of foods that are advised against for histamine intolerant individuals. Excluded foods were, in most cases, different depending on the considered diet. Only fermented foods were unanimously excluded. The exclusion of 32% of foods could be explained by the occurrence of high contents of histamine. The presence of putrescine, which may interfere with histamine degradation by the DAO enzyme at the intestinal level, could partly explain the reason why certain foods (i.e., citrus fruits and bananas) were also frequently reported in low-histamine diets. Finally, there was a range of excluded foods with an absence or very low levels of biogenic amines. In this case, certain foods have been tagged as histamine-liberators, although the mechanism responsible has not yet been elucidated.

Influence of the Type of Breastfeeding and Human Milk Polyamines on Infant Anthropometric Parameters.

Feeding choices in the early months of life are key determinants of growth during infancy. Polyamines participate in cell proliferation and differentiation, and it has also been suggested that polyamine metabolism plays a role in adipogenesis. As the main exogenous source of polyamines in the infant is human milk, the aim of this work was to study if the type of breastfeeding received and the polyamine intake from human milk has an influence on infant anthropometric parameters. A cohort of 78 full-term healthy newborns was followed up until 4 months of age; 55 were fully and 23 partially breastfed. Anthropometric measurements were taken at 2 and 4 months, when human milk samples were also collected for analysis of polyamine content by UHPLC-FL. Fully breastfed infants had a better anthropometric profile than those partially breastfed (p < 0.05). Furthermore, polyamine intake in partially breastfed infants was significantly lower compared to those fully breastfed. However, only two of the 15 anthropometric indicators evaluated (triceps skinfold and mean upper arm circumference) showed a significant inverse association with polyamine content in human milk and intake (p < 0.05). Infant growth and body composition differ according to the type of breastfeeding received. Based on the weak associations between polyamines and anthropometric indicators, it is not possible to conclude the influence of polyamines in infant growth and body composition.

Vasculitic Peripheral Neuropathy, Differences Between Systemic and Non-Systemic Etiologies: A Case Series and Biopsy Report.

BACKGROUND: Vasculitic peripheral neuropathy (VPN) is caused by vessel inflammation leading to peripheral nerve injury of acute-to-subacute onset. When VPN occurs in the context of systemic disease it is classified as Systemic Vasculitic Neuropathy (SVN) and as Non-Systemic Vasculitic Neuropathy (NSVN) when restricted to the nerves. OBJECTIVE: This study aimed to compare the clinical characteristics, biopsy findings and disease outcome in patients with VPN. METHODS: Clinical records of adult patients with VPN diagnosed at our institution between June-2002 and June-2019 were retrospectively reviewed. Demographic characteristics, clinical manifestations, nerve conduction studies, nerve biopsies, treatment and clinical evolution were analyzed in all patients with at least 6 months follow-up. RESULTS: Twenty-five patients with VPN were included (SVN, n = 10; NSVN, n = 15). No significant differences in demographic or clinical features were found between groups. The median delay between symptom onset and nerve biopsy was significantly longer in NSVN patients (10 vs 5.5 months, p = 0.009). Erythrocyte sedimentation rate (ESR) values over 20 mm/h were significantly more common in SVN patients (100% vs. 60%, p = 0.024). Nerve biopsies showed active lesions more frequently in treatment-naive patients compared to those who had received at least 2 weeks of corticosteroids (92% vs 38%; p = 0.03), with a higher proportion of definite VPN cases (92 vs 46%; p = 0.04). CONCLUSIONS: Although the clinical manifestations are similar, ESR is an important tool to help distinguish between both conditions. Early nerve biopsy in untreated patients increases diagnostic accuracy, avoiding misdiagnosis.

In vitro determination of diamine oxidase activity in food matrices by an enzymatic assay coupled to UHPLC-FL.

Intestinal diamine oxidase (DAO) acts as a protective barrier against exogenous histamine. A deficit of DAO activity can lead to the appearance of histamine intolerance, a clinical condition that may be treated by a low-histamine diet and oral DAO supplementation to enhance intestinal histamine degradation. As sources of DAO, porcine kidneys and certain legume seedlings are suitable components for the formulation of a DAO supplement. The aim of this work was to develop a rapid and reliable methodology for the in vitro determination of DAO activity in food matrices based on an enzymatic assay coupled to UHPLC-FL. The proposed method showed a satisfactory linearity and sensitivity and provided a relative standard deviation lower than 3%, guaranteeing method precision, and a mean recovery greater than 99% both for lyophilized pea sprouts and porcine kidney protein extracts. A high specificity is a key attribute of this method due to the use of histamine as the reaction substrate and the direct quantification of its degradation. Moreover, the lack of interference of catalase and hydrogen peroxide is another advantage in comparison with previously published methods. Lyophilized pea sprouts showed the greatest histamine-degrading activity (0.40 ± 0.01 mU/mg), followed by porcine kidney protein extracts (0.23 ± 0.01 mU/mg) and commercial DAO supplements (0.09 ± 0.06 mU/mg). This technique could be used as a tool to validate the DAO activity of food matrices of potential interest for the treatment of histamine intolerance.

Atraumatic laparoscopic intraperitoneal mesh fixation using a new laparoscopic device: an animal experimental study.

PURPOSE: Laparoscopic ventral and incisional hernia repair (LVIHR) has become a common procedure because of its feasibility and safety, but it is not free of complications. Acute and chronic post-operative pain and bleeding caused by traumatic fixation of the mesh are frequently prolonging the hospital stay. The aim of this study was to analyze the behavior of n-butyl-cyanoacrylate (GLUBRAN® 2) as only mesh fixation METHODS: Ten female pigs were involved in the study and were divided into two groups of five (A and B). Animals in each group underwent a laparoscopic procedure in which two meshes were placed intraperitoneally and fixed with the same synthetic glue only. Animals in group A were sacrificed after 3 weeks, and those in group B were sacrificed after 12 weeks. We studied the morphological, biomechanical, and histological characteristics of the intraperitoneal mesh-tissue interface RESULTS: No disruption, migration or folding was observed in any of the pigs. In group A, the mean tensile strength was 1.4 N/cm (± 0.2) while in group B, the mean tensile strength was 2.5 N/cm (± 0.8). Histological analyses, in areas where mesh was fixed using the glue, showed a chronic lymphocytic inflammatory reaction with a granulomatous component and a marked desmoplastic reaction made up of immature collagen and numerous fibroblasts acquiring myofibroblastic characteristics. In some areas corresponding to fixation, the desmoplastic reaction originated from mature lamellar bone tissue with osteocytes and osteoblasts. CONCLUSION: Laparoscopic mesh fixation with only the synthetic comonomer glue GLUBRAN® 2 is feasible, effective, and safe in intraperitoneal incisional/ventral hernia repair in this animal model.

Polyamines in Food.

The polyamines spermine, spermidine, and putrescine are involved in various biological processes, notably in cell proliferation and differentiation, and also have antioxidant properties. Dietary polyamines have important implications in human health, mainly in the intestinal maturation and in the differentiation and development of immune system. The antioxidant and anti-inflammatory effect of polyamine can also play an important role in the prevention of chronic diseases such as cardiovascular diseases. In addition to endogenous synthesis, food is an important source of polyamines. Although there are no recommendations for polyamine daily intake, it is known that in stages of rapid cell growth (i.e., in the neonatal period), polyamine requirements are high. Additionally, de novo synthesis of polyamines tends to decrease with age, which is why their dietary sources acquire a greater importance in an aging population. Polyamine daily intake differs among to the available estimations, probably due to different dietary patterns and methodologies of data collection. Polyamines can be found in all types of foods in a wide range of concentrations. Spermidine and spermine are naturally present in food whereas putrescine could also have a microbial origin. The main polyamine in plant-based products is spermidine, whereas spermine content is generally higher in animal-derived foods. This article reviews the main implications of polyamines for human health, as well as their content in food and breast milk and infant formula. In addition, the estimated levels of polyamines intake in different populations are provided.

Increasing incidence of lentigo maligna and lentigo maligna melanoma in Catalonia.

BACKGROUND: Recent epidemiological studies suggest that past data where superficial spreading melanoma was by far the most common subtype of melanoma may not reflect current patterns of sun exposure or other risk factors more involved in other subtypes of melanoma as lentigo maligna (LM) or lentigo maligna melanoma (LMM). METHODS: In order to measure the current situation in our country, all cases of LM and LMM diagnosed in 23 hospitals in Catalonia, from 2000 to 2007, were recorded. RESULTS: Although for the global period LM/LMM represented only 8.4% of cases, an increasing trend in this percentage was observed throughout the study period (from 6.9% [27 cases] in 2000 to 13.1% [94 cases] in 2007). Also, an increasing incidence of LM/LMM was observed, especially in chronically sun-exposed areas (85.5% involving the head and neck region). During the 8 years of the registry, the mean Breslow thickness of LMM remained stable. However, the increase in the number of LM (in situ) cases was significantly higher than the increase of the invasive ones. CONCLUSIONS: An important observation from this data is that aging of population and current sun exposure patterns could keep increasing the incidence of LM/LMM, which may become an important public healthcare problem, over the other histological subtypes. In order to establish primary or secondary preventive measures to the LM/LMM risk-population, it is imperative to highlight the importance of chronic sun damage as a melanoma risk factor, and not only sunburn, most commonly addressed in melanoma prevention campaigns.

Biogenic Amines in Plant-Origin Foods: Are They Frequently Underestimated in Low-Histamine Diets?

Low-histamine diets are currently used to reduce symptoms of histamine intolerance, a disorder in histamine homeostasis that increases plasma levels, mainly due to reduced diamine-oxidase (DAO) activity. These diets exclude foods, many of them of plant origin, which patients associate with the onset of the symptomatology. This study aimed to review the existing data on histamine and other biogenic amine contents in nonfermented plant-origin foods, as well as on their origin and evolution during the storage or culinary process. The only plant-origin products with significant levels of histamine were eggplant, spinach, tomato, and avocado, each showing a great variability in content. Putrescine has been found in practically all plant-origin foods, probably due to its physiological origin. The high contents of putrescine in certain products could also be related to the triggering of the symptomatology by enzymatic competition with histamine. Additionally, high spermidine contents found in some foods should also be taken into account in these diets, because it can also be metabolized by DAO, albeit with a lower affinity. It is recommended to consume plant-origin foods that are boiled or are of maximum freshness to reduce biogenic amine intake.

A high-fat high-sucrose diet affects the long-term metabolic fate of grape proanthocyanidins in rats.

PURPOSE: Polyphenol metabolites are key mediators of the biological activities of polyphenols. This study aimed to evaluate the long-term effects of a high-fat high-sucrose (HFHS) diet on the metabolism of proanthocyanidins from grape seed extract (GSE). METHODS: Adult female Wistar-Kyoto rats were fed a standard (STD) or HFHS diet supplemented or not with GSE for 16 weeks. PA metabolites were determined by targeted HPLC-MS/MS analysis. RESULTS: A lower concentration of total microbial-derived PA metabolites was present in urine and the aqueous fraction of faeces in the HFHS + GSE group than in the STD + GSE group. In contrast, a tendency towards the formation of conjugated (epi)catechin metabolites in the HFHS + GSE group was observed. CONCLUSIONS: These results show that a HFHS diet significantly modifies PA metabolism, probably via: (1) a shift in microbial communities not counteracted by the polyphenols themselves; and (2) an up-regulation of hepatic enzymes.

New approach for the diagnosis of histamine intolerance based on the determination of histamine and methylhistamine in urine.

Histamine intolerance is a disorder in the homeostasis of histamine due to a reduced intestinal degradation of this amine, mainly caused by diamine oxidase (DAO) enzyme deficiency, which provokes its accumulation in plasma and the appearance of adverse health affects. A new approach for the diagnosis of this intolerance could be the determination of histamine and its metabolites in urine. The aim of this work was to develop and validate a rapid method to determine histamine and methylhistamine in human urine by Ultra High Performance Liquid Chromatography and Fluorimetric detection (UHPLC-FL). The proposed method is a consistent procedure to determine histamine and methylhistamine in less than 11min with adequate linearity and sensitivity. Relative standard deviation was always lower than 5.5%, ensuring method precision; and mean recovery was greater than 99% for both analytes. The structure of histamine and methylhistamine conjugated with OPA were confirmed by UHPLC-ITD-FTMS which enabled to unequivocally identify both analytes in standards and also in urine samples. The analysis of histamine and methylhistamine in urine samples could be a potential new approach for the routine diagnosis of histamine intolerance, more patient-friendly and with clear advantages in terms of equipment and personnel demand for sample collection in comparison with current plasmatic DAO activity determination.