The role of biomarkers in evaluating human health concerns from fungal contaminants in food

Assessing aflatoxin exposure in the United Arab Emirates (UAE): Biomonitoring AFM1 levels in urine samples and their association with dietary habits

BACKGROUND

Aflatoxins, known for their carcinoginc properties and produced by Aspergillus fungi, pose a substantial threat to public health, particularly in regions with hot and humid climates, where individuals are exposed to these toxins through contaminated food. The primary objective of this study was to assess the extent of aflatoxin exposure in the Emirate of Sharjah employing Aflatoxin M1 (AFM1) as a biomarker in urine samples from adult participants. Furthermore, this study aimed to explore the relationship between dietary habits and AFM1 levels in order to establish a potential link.

METHODS

In a cross-sectional study design, a total of 144 adults (73 females and 71 males) were recruited for participation. The urine samples obtained from participants were subjected to analysis for AFM1 concentrations utilizing the enzyme-linked immunosorbent assay (ELISA) method. Additionally, structured questionnaires were administered to collect information on the dietary and lifestyle habits of the participants. To explore the relationship between dietary factors and AFM1 levels, various statistical analyses, including linear regression and the Mann-Whitney U test, were performed.

RESULTS

AFM1 was detected in 69 % of the samples under invstigation, wherein males exhibited a higher mean level (0.912 ng/mg creatinine) in comparison to females (0.676 ng/mg creatinine). The overall mean concentration of AFM1 was determined to be 0.792 ng/mg creatinine. It is worth noting that there was a significant correlation between rice consumption and heightened AFM1 exposure among males, while no such correlation was observed among females.

CONCLUSION

This study conducted in the UAE provides novel perspectives on aflatoxin exposure, shedding light on the gender-specific correlation between rice consumption and aflatoxin levels among males. These findings hold significant implications for guiding public health interventions and underscore the pivotal role of ongoing surveillance and stringent food safety regulations in mitigating the hazards associated with aflatoxin contamination.

Aflatoxin B1-induced hepatotoxicity through mitochondrial dysfunction, oxidative stress, and inflammation as central pathological mechanisms: A review of experimental evidence

Aflatoxin B1 (AFB1) is a class of mycotoxin known to contaminate agricultural products, animal feed and animal food products, subsequently causing detrimental effects on human and animal health. AFB1 is the most common and potent aflatoxin found in food and contributes significantly to liver injury as well as the development of hepatocellular carcinoma. Although the liver is a primary target organ for AFB1 toxicity and biotransformation, underlying mechanisms implicated in liver injuries induced by these mycotoxins remain to be fully elucidated for therapeutic purposes. This review aims to dissect the complexities of the pathophysiological and molecular mechanisms implicated in hepatotoxicity induced by AFB1, including mitochondrial dysfunction, oxidative stress and hepatic inflammation. Mechanistically, AFB1 disrupt mitochondrial bioenergetics and membrane potential, promotes mitochondrial cholesterol trafficking and induces mitophagy. Moreover, mitochondrial dysfunction may lead to hepatic oxidative stress as a consequence of uncontrolled production of reactive oxygen species and defects in the antioxidant defense system. Retrieved experimental evidence also showed that AFB1 may lead to hepatic inflammation through gut microbiota dysbiosis, the release of DAMPs and cytokines, and immune cell recruitment. Overall, these mechanisms could be utilized as potential targets to extrapolate treatment for liver injury caused by AFB1.

Level of exposure to aflatoxins during pregnancy and its association with adverse birth outcomes in Africa: a meta-analysis

BACKGROUND

Aflatoxins are various poisonous carcinogens and mutagens produced by Aspergillus species. Exposure to aflatoxins during pregnancy results in adverse birth outcomes. This meta-analysis was carried out to determine the estimates of how much aflatoxin is harmful to the pregnancy and its outcome, including birthweight, birth length, low birthweight (LBW), small for gestational age (SGA), stunting, poverty, food insecurity, income, pesticides and stillbirth, in an African context.

METHODS

Both published and unpublished studies in Africa were searched on MEDLINE, PubMed, Embase, SCOPUS, Web of Science and Google Scholar. Stata version 18.2 software was used for cleaning and analysis. The prevalence with a 95% confidence interval (CI) was estimated using the random effects model and a forest plot was used to present the findings. In addition, the heterogeneity of the study was assessed using Cochrane I2 statistics and publication bias was assessed using Egger's intercept and funnel plot.

RESULTS

This review included 28 studies with a total of 6283 pregnant women and newborns. The analysis showed the overall level of exposure to aflatoxins was 64% (95% CI 48 to 78, τ2=0.66, I2=99.34%, p=0.001). In the subgroup analysis by publication year, the highest level of exposure to aflatoxins (82% [95% CI 69 to 92]) was observed among studies published from 2020 to 2023. This study also found that exposure to aflatoxins during pregnancy had an association with prematurity, LBW, SGA and stillbirth.

CONCLUSIONS

The data analysed in this study indicated that three of every five pregnant women had exposure to aflatoxins in Africa. Moreover, pregnant women exposed to aflatoxins had a higher likelihood of having a LBW and SGA newborn. Thus governments and all stakeholders should initiate policies that mitigate the toxicity of aflatoxins in pregnant women, foetuses and newborns.

Alginate Oligosaccharides Enhance Gut Microbiota and Intestinal Barrier Function, Alleviating Host Damage Induced by Deoxynivalenol in Mice

BACKGROUND

Alginate oligosaccharides (AOS) exhibits notable effects in terms of anti-inflammatory, antibacterial, and antioxidant properties. Deoxynivalenol (DON) has the potential to trigger intestinal inflammation by upregulating pro-inflammatory cytokines and apoptosis, thereby compromising the integrity of the intestinal barrier function and perturbing the balance of the gut microbiota.

OBJECTIVES

We assessed the impact of AOS on mitigating DON-induced intestinal damage and systemic inflammation in mice.

METHODS

After a 1-wk acclimatization period, the mice were divided into 4 groups. For 3 wk, the AOS and AOS + DON groups were gavaged daily with 200 μL of AOS [200 mg/kg body weight (BW)], whereas the CON and DON groups received an equivalent volume of sterile Phosphate-Buffered Saline (PBS). Subsequently, for 1 wk, the DON and AOS + DON groups received 100 μL of DON (4.8 mg/kg BW) daily, whereas the control (CON) and AOS groups continued receiving PBS.

RESULTS

After administering DON via gavage to mice, there was a significant decrease (P < 0.05) in body weights compared with the CON group. Interestingly, AOS exhibited a tendency to mitigate this weight loss in the AOS + DON group. In the feces of mice treated with both AOS and DON, the concentration of DON significantly increased (P < 0.05) compared with the DON group alone. Histological analysis revealed that DON exposure caused increased intestinal damage, including shortened villi and eroded epithelial cells, which was ameliorated by presupplementation with AOS, alleviating harm to the intestinal barrier function. In both jejunum and colon tissues, DON exposure significantly reduced (P < 0.05) the expression of tight junction proteins (claudin and occludin in the colon) and the mucin protein mucin 2, compared with the CON group. Prophylactic administration of AOS alleviated these reductions, thereby improving the expression levels of these key proteins. Additionally, AOS supplementation protected DON-exposed mice by increasing the abundance of probiotics such as Bifidobacterium, Faecalibaculum, and Romboutsia. These gut microbes are known to enhance (P < 0.05) anti-inflammatory responses and the production of short-chain fatty acids (SCFAs), including total SCFAs, acetate, and valerate, compared with the DON group.

CONCLUSIONS

This study unveils that AOS not only enhances gut microbiota and intestinal barrier function but also significantly mitigates DON-induced intestinal damage.

Synthetic biology for Monascus: From strain breeding to industrial production

Traditional Chinese food therapies often motivate the development of modern medicines, and learning from them will bring bright prospects. Monascus, a conventional Chinese fungus with centuries of use in the food industry, produces various metabolites, including natural pigments, lipid-lowering substances, and other bioactive ingredients. Recent Monascus studies focused on the metabolite biosynthesis mechanisms, strain modifications, and fermentation process optimizations, significantly advancing Monascus development on a lab scale. However, the advanced manufacture for Monascus is lacking, restricting its scale production. Here, the synthetic biology techniques and their challenges for engineering filamentous fungi were summarized, especially for Monascus. With further in-depth discussions of automatic solid-state fermentation manufacturing and prospects for combining synthetic biology and process intensification, the industrial scale production of Monascus will succeed with the help of Monascus improvement and intelligent fermentation control, promoting Monascus applications in food, cosmetic, agriculture, medicine, and environmental protection industries.

Evaluating the human neurotoxicity and toxicological interactions impact of co-occurring regulated and emerging mycotoxins

Mycotoxins can inflict harmful effects on diverse organs, and mounting evidence indicates their potential involvement in human neurodegenerative diseases. Given the common occurrence of these toxins in food, there is an increasing demand for a comprehensive assessment of their combined toxicity to enhance our understanding of their potential hazards. This research investigates mycotoxin exposure from widely consumed cereal-based products, including enniatin B (ENNB), sterigmatocystin (STG), aflatoxin B1 (AFB1), cyclopiazonic acid (CPZ), citrinin (CIT), and ochratoxin A (OTA). Employing the median-effect equation based on Chou and Talalay's mass-action law, we assessed their cytotoxicity in human SH-SY5Y neuronal cells. Notably, ENNB displayed the highest neurotoxicity (IC50 = 3.72 µM), followed by OTA (9.10 µM) and STG (9.99 µM). The combination of OTA + STG exhibited the highest toxicity (IC50 = 3.77 µM), while CPZ + CIT showed the least detrimental effect. Approximately 70 % of tested binary combinations displayed synergistic or additive effects, except for ENNB + STG, ENNB + AFB1, and CPZ + CIT, which showed antagonistic interactions. Intriguingly, the senary combination displayed moderate antagonism at the lowest exposure and moderate synergism at higher doses. OTA exhibited predominantly synergistic interactions, comprising approximately 90 %, a noteworthy finding considering its prevalence in food. Conversely, ENNB interactions tended to be antagonistic. The most remarkable synergy occurred in the STG and CIT combination, enabling a 50-fold reduction in CIT dosage for an equivalent toxic effect. These findings highlight the biological relevance of robust synergistic interactions, emphasizing the need to assess human exposure hazards accurately, particularly considering frequent mycotoxin co-occurrence in environmental and food settings.

Occurrence of ochratoxin A in breast milk and urine samples of nursing mothers in Bangladesh

The mycotoxin ochratoxin A (OTA) is a potent nephrotoxin with carcinogenic properties and, thus, of concern as a food contaminant. Since food contaminant data are scarce in Bangladesh, we applied human biomonitoring to gain more insights into OTA exposure in the country's population. OTA concentrations in human milk and urine samples of nursing mothers were determined with the aim to assess also exposure to this mycotoxin in breastfed infants. Breastfeeding mothers (n = 74) from three districts of Bangladesh (Sylhet, Cumilla, and Mymensingh region) participated in this study. They provided demographic data, along with breast milk and urine samples. OTA levels were measured by a competitive enzyme-linked immunosorbent assay (ELISA) with a detection limit of 60 ng/L for milk and 30 ng/L for urine.OTA was detected in 62.2% of all breast milk samples (mean 74.8 ± 49.0 ng/L, range < LOD-243.3 ng/L) and in 51.4% of all urine samples (mean 44.3 ± 63.5 ng/L, range < LOD-519.3 ng/L). The differences observed between regions for mean breast milk or for urinary OTA levels were relatively small. No significant correlation was observed between OTA levels in breast milk and food consumption patterns among nursing mothers. Regarding infant exposure, the estimated average daily intake of OTA for all was 15.0 ng/kg bw/day (range 4.5-45 ng/kg bw/day). In 34.5% of these infants, their estimated daily OTA intake exceeded a preliminary TDI value set by EFSA (17 ng/kg bw/day). The mean OTA intake was slightly higher (16.2 ± 7.8 ng/kg bw/day) in 1-2 months babies than in older infants (< 2 to 12 months), although the difference was not significant. Presence of OTA in most milk and urine samples of nursing mothers documents their widespread dietary mycotoxin exposure. Although based on a relatively small number of participants, the present analysis indicates non-negligible exposure of some nursed infants in Bangladesh. Therefore, further biomonitoring studies and investigations on major sources of OTA in food commodities are encouraged.

Aflatoxin M1 Analysis in Urine of Mill Workers in Bangladesh: A Pilot Study

Presence of aflatoxin B1 (AFB1) in food and feed is a serious problem, especially in developing countries. Human exposure to this carcinogenic mycotoxin can occur through dietary intake, but also through inhalation or dermal contact when handling and processing AFB1-contaminated crops. A suitable biomarker of AFB1 exposure by all routes is the occurrence of its hydroxylated metabolite aflatoxin M1 (AFM1) in urine. To assess mycotoxin exposure in mill workers in Bangladesh, we analyzed AFM1 levels in urine samples of this population group who may encounter both dietary and occupational AFB1 exposure. In this pilot study, a total of 76 participants (51 mill workers and 25 controls) were enrolled from the Sylhet region of Bangladesh. Urine samples were collected from people who worked in rice, wheat, maize and spice mills and from controls with no occupational contact to these materials. A questionnaire was used to collect information on basic characteristics and normal food habits of all participants. Levels of AFM1 in the urine samples were determined by a competitive enzyme linked immunosorbent assay. AFM1 was detected in 96.1% of mill workers' urine samples with a range of LOD (40) of 217.7 pg/mL and also in 92% of control subject's urine samples with a range of LOD of 307.0 pg/mL). The mean level of AFM1 in mill workers' urine (106.5 ± 35.0 pg/mL) was slightly lower than that of the control group (123.3 ± 52.4 pg/mL), whilst the mean AFM1 urinary level adjusted for creatinine was higher in mill workers (142.1 ± 126.1 pg/mg crea) than in the control group (98.5 ± 71.2 pg/mg crea). Yet, these differences in biomarker levels were not statistically significant. Slightly different mean urinary AFM1 levels were observed between maize mill, spice mill, rice mill, and wheat mill workers, yet biomarker values are based on a small number of individuals in these subgroups. No significant correlations were found between the study subjects' urine AFM1 levels and their consumption of some staple food items, except for a significant correlation observed between urinary biomarker levels and consumption of groundnuts. In conclusion, this pilot study revealed the frequent presence of AFM1 in the urine of mill workers in Bangladesh and those of concurrent controls with dietary AFB1 exposure only. The absence of a statistical difference in mean biomarker levels for workers and controls suggests that in the specific setting, no extra occupational exposure occurred. Yet, the high prevalence of non-negligible AFM1 levels in the collected urines encourage further studies in Bangladesh regarding aflatoxin exposure.

Trace analysis of food by surface-enhanced Raman spectroscopy combined with molecular imprinting technology: Principle, application, challenges, and prospects

Surface-enhanced Raman spectroscopy (SERS) is a rapid detection method with high sensitivity and simple pretreatment, but can be affected by interference from matrix components. By incorporating molecularly imprinted polymers (MIPs) that recognize specific targets, MIP-SERS sensors effectively overcome the interference of complex matrices and offer improved stability and sensitivity. This review provides a comprehensive understanding of the applications of MIP-SERS sensors for the detection of trace toxic substances in food. The underlying mechanism and development of SERS technology and the principle and classification of MIPs technology are discussed. Furthermore, the types of MIP-SERS sensors are introduced, with their advantages and disadvantages systematically illustrated. Recent advances in MIP-SERS technology for the detection of mycotoxins, additives, prohibited dyes, pesticides, veterinary drug residues, and other hazardous substances in food are highlighted. Finally, this review discusses the challenges associated with MIP-SERS technology and proposes future development prospects.

Maternal exposure to multiple mycotoxins and adverse pregnancy outcomes: a prospective cohort study in rural Bangladesh

There is limited and inconsistent evidence, primarily from cross-sectional studies, linking mycotoxins to adverse birth outcomes. This study investigates the potential role of maternal dietary exposure to multiple mycotoxins in the development of several adverse pregnancy and birth outcomes. We analyzed data from 436 singleton pregnancies enrolled in a prospective cohort study in the rural Habiganj district, Bangladesh, between July 2018 and November 2019. Thirty-five urinary mycotoxin biomarkers were quantified using liquid chromatography coupled with tandem mass spectrometry and used to estimate dietary mycotoxin exposure. Multivariable regression models, adjusted for potential confounding and clustering, were fitted to assess the associations between maternal exposure to frequently occurring mycotoxins (ochratoxin A-OTA, citrinin- CIT, and Deoxynivalenol- DON) and pregnancy loss, preterm birth (PTB), low birth weight (LBW), born small-for-gestational-age (SGA) and small-vulnerable newborn. The results indicate that only in 16 of 436 pregnancies (4%) were urine samples free from all investigated mycotoxins. Biomarkers for six major mycotoxins were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with at least two mycotoxins co-occurring in the majority of women (63%). There was evidence that maternal dietary intake of OTA was associated with higher odds of having an LBW baby, with the odds increasing in a dose-dependent manner. We found no evidence of associations between pregnancy loss, PTB, SGA, small-vulnerable newborns, and maternal dietary exposure to OTA, CIT, and DON, albeit with large confidence intervals, so findings are consistent with protective as well as large harmful effects. Exposure to multiple mycotoxins during pregnancy is widespread in this rural community and represents a health risk for mothers and babies. Tailored public health policies and interventions must be implemented to reduce mycotoxin exposure to the lowest possible level.

A prospective study of total urinary deoxynivalenol in adolescents in Shanghai, China

There is growing interest in deoxynivalenol (DON) exposure during puberty because experimental evidence shows that DON-exposed to adolescents are more sensitive to DON and have limited detoxification ability. Nevertheless, there have been few surveys of DON exposure for adolescents in China. Furthermore, little is known about the effects of collection times on risk exposure. In the study, we estimated the risk of DON exposure for adolescents in Shanghai and explore the effects of collection time, areas, sex and BMI on intake estimates. A total of 315 adolescents aged 14-16 years, including 161 boys and 154 girls, were recruited. Urine samples were collected for three consecutive days and digested with β-glucuronidase and then purified using a DON-immunoaffinity column (IAC). Total deoxynivalenol levels were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in combination with a stable isotope dilution assay (SIDA). DON was detected in 945 morning urine samples taken from 315 individuals for three consecutive days. The mean estimated dietary intake of DON did not exceed the tolerable daily intake (TDI) of l μg/kg·bw/day, showing that exposure of adolescents in Shanghai is not of concern. However, 10-20% of probable daily intake (PDI) values exceed the TDI, indicating potential adverse effects. In addition, the DON concentration at the population level did not differ for urine samples collected at different times except for those of overweight adolescents. Therefore, assessment of exposure to DON by monitoring the morning urine of a healthy adolescent, except for overweight people, provides an appropriate estimate of exposure and related risk at the population level, but intake estimates for individuals are uncertain; these could be used to assess exposure of adolescents to DON rapidly and effectively for epidemiological investigations.

Analytical Validation of a Direct Competitive ELISA for Multiple Mycotoxin Detection in Human Serum

Mycotoxin exposure in humans is primarily assessed through its occurrence in external sources, such as food commodities. Herein, we have developed a direct competitive ELISA to facilitate the detection of aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin (FUM B1/B2), ochratoxin A (OTA), and zearalenone (ZEA) in human serum. The analytical validation of the assay followed practices endorsed by the international research community and the EU directive 96/23/EC in order to examine detection capability, recovery, and cross-reactivity. The assay demonstrated a lower limit of quantitation (LLOQ) for AFB1 [0.61 ng/mL (hereon ng/mL = ppb)], DON (19.53 ppb), FUM (4.88 ppb), OTA (19.53 ppb), and ZEA (0.15 ppb). Recovery from human serum for all mycotoxins spanned from 73% to 106%. Likewise, the specificity for monoclonal antibodies against cross-reactant mycotoxins ranged from 2% to 11%. This study compares the LLOQ and recovery values with commercial and emerging immuno-based methods for detecting mycotoxins in foodstuffs. The LLOQ values from the present study were among the lowest in commercial or emerging methods. Despite the differences in the extraction protocols and matrices, the recovery range in this study, commercial tests, and other procedures were similar for all mycotoxins. Overall, the assay detected AFB1, DON, FUM, OTA, and ZEA in human serum with excellent accuracy, precision, and specificity.

Assessment of multiple mycotoxin exposure and its association with food consumption: a human biomonitoring study in a pregnant cohort in rural Bangladesh

Aflatoxins (AFs), ochratoxin A (OTA), citrinin (CIT), fumonisin B1 (FB1), zearalenone (ZEN), and deoxynivalenol (DON) are mycotoxins that may contaminate diets, especially in low-income settings, with potentially severe health consequences. This study investigates the exposure of 439 pregnant women in rural Bangladesh to 35 mycotoxins and their corresponding health risks and links their exposure to certain foods and local stimulants. Overall, 447 first-morning urine samples were collected from pregnant women between July 2018 and November 2019. Mycotoxin biomarkers were quantified by DaS-HPLC-MS/MS. Urinary concentration of frequently occurring mycotoxins was used to estimate dietary mycotoxin exposure. Median regression analyses were performed to investigate the association between the consumption of certain foods and local stimulants, and urinary concentration of frequently occurring mycotoxins. Only in 17 of 447 urine samples (4%) were none of the investigated mycotoxins detected. Biomarkers for six major mycotoxins (AFs, CIT, DON, FB1, OTA, and ZEN) were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with multiple mycotoxins co-occurring in 281/447 (63%) of urine samples. Under the lowest exposure scenario, dietary exposure to OTA, CIT, and DON was of public health concern in 95%, 16%, and 1% of the pregnant women, respectively. Consumption of specific foods and local stimulants-betel nut, betel leaf, and chewing tobacco-were associated with OTA, CIT, and DON urine levels. In conclusion, exposure to multiple mycotoxins during early pregnancy is widespread in this rural community and represents a potential health risk for mothers and their offspring.

Hyperspectral imaging and machine learning in food microbiology: Developments and challenges in detection of bacterial, fungal, and viral contaminants

Hyperspectral imaging (HSI) is a robust and nondestructive method that can detect foreign particles such as microbial, chemical, and physical contamination in food. This review summarizes the work done in the last two decades in this field with a highlight on challenges, risks, and research gaps. Considering the challenges of using HSI on complex matrices like food (e.g., the confounding and masking effects of background signals), application of machine learning and modeling approaches that have been successful in achieving better accuracy as well as increasing the detection limit have also been discussed here. Foodborne microbial contaminants such as bacteria, fungi, viruses, yeast, and protozoa are of interest and concern to food manufacturers due to the potential risk of either food poisoning or food spoilage. Detection of these contaminants using fast and efficient methods would not only prevent outbreaks and recalls but will also increase consumer acceptance and demand for shelf-stable food products. The conventional culture-based methods for microbial detection are time and labor-intensive, whereas hyperspectral imaging (HSI) is robust, nondestructive with minimum sample preparation, and has gained significant attention due to its rapid approach to detection of microbial contaminants. This review is a comprehensive summary of the detection of bacterial, viral, and fungal contaminants in food with detailed emphasis on the specific modeling and datamining approaches used to overcome the specific challenges associated with background and data complexity.

Citrinin-Induced Hepatotoxicity in Mice Is Regulated by the Ca2+/Endoplasmic Reticulum Stress Signaling Pathway

Citrinin (CTN) is a mycotoxin found in crops and agricultural products and poses a serious threat to human and animal health. The aim of this study is to investigate the hepatotoxicity of CTN in mice and analyze its mechanisms from Ca2+-dependent endoplasmic reticulum (ER) stress perspective. We showed that CTN induced histopathological damage, caused ultrastructural changes in liver cells, and induced abnormal values of biochemical laboratory tests of some liver functions in mice. Treatment with CTN could induce nitric oxide (NO), malondialdehyde (MDA), and reactive oxygen species (ROS) accumulation in mice, accompanied with losses of activities of superoxide dismutase (SOD) and catalase (CAT), levels of glutathione (GSH), and capacities of total antioxidant (T-AOC), resulting in oxidative stress in mice. Furthermore, CTN treatment significantly increased Ca2+ accumulation, upregulated protein expressions of ER stress-mediated apoptosis signal protein (glucose regulated protein 78 (GRP78/BIP), C/EBP-homologous protein (CHOP), Caspase-12, and Caspase-3), and induced hepatocyte apoptosis. These adverse effects were counteracted by 4-phenylbutyric acid (4-PBA), an ER stress inhibitor. In summary, our results showed a possible underlying molecular mechanism for CTN that induced hepatocyte apoptosis in mice by the regulation of the Ca2+/ER stress signaling pathway.

Mycotoxin Exposure during the First 1000 Days of Life and Its Impact on Children’s Health: A Clinical Overview

The first 1000 days of life are very sensitive to any event that alters health programming, and they represent a window for intervention to improve population health. Pregnant women, fetuses, and infants are particularly vulnerable to exposure to food contaminated with mycotoxins. This review aimed to gather data from the literature on mycotoxins exposure during intrauterine life and early childhood, and associated health risks, as assessed through human biomonitoring and mycotoxins occurrence in foods, in different continents. Maternal internal exposure to aflatoxins is associated with fetal growth restriction, while exposure to fumonisins increases the risk of offspring’s neural tube defects. Mycotoxin contamination of breast milk is reported worldwide, but data on adverse effects of the lactational transfer of mycotoxins on infant health are lacking. Young children are exposed to mycotoxins through contaminated infant formulas and baby foods. Both external and internal exposure to aflatoxins and fumonisins in children are reported to be associated with growth impairment. In low-income settings, where other co-factors can affect growth, this association should be interpreted with caution. Further studies on human biomonitoring of mother–infant pairs and young children are needed to guide management strategies aiming to minimize mycotoxin exposure at critical developmental stages.

Mycotoxin exposure biomonitoring in breastfed and non-exclusively breastfed Nigerian children

A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1-18 months, in Ogun state, Nigeria. Aflatoxin M₁ was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; including dihydrocitrinone (6/22 (27%); range: 14.0-59.7 ng/L) and sterigmatocystin (1/22 (5%); 1.2 ng/L) detected for the first time. Seven distinct classes of mycotoxins including aflatoxins (9/42 (21%); range: 1.0-16.2 µg/kg) and fumonisins (12/42 (29%); range: 7.9-194 µg/kg) contaminated complementary food. Mycotoxins covering seven distinct classes with diverse structures and modes of action were detected in 64/65 (99%) of the urine samples, demonstrating ubiquitous exposure. Two aflatoxin metabolites (AFM₁ and AFQ₁) and FB₁ were detected in 6/65 (9%), 44/65 (68%) and 17/65 (26%) of urine samples, respectively. Mixtures of mycotoxin classes were common, including 22/22 (100%), 14/42 (33%) and 56/65 (86%) samples having 2-6, 2-4, or 2-6 mycotoxins present, for breast milk, complementary food and urine, respectively. Aflatoxin and/or fumonisin was detected in 4/22 (18%), 12/42 (29%) and 46/65 (71%) for breast milk, complimentary foods and urine, respectively. Furthermore, the detection frequency, median concentrations and occurrence of mixtures were typically greater in urine of non-exclusively breastfed compared to exclusively breastfed infants. The study provides novel insights into mycotoxin co-exposures in early-life. Albeit a small sample set, it highlights transition to higher levels of infant mycotoxin exposure as complementary foods are introduced, providing impetus to mitigate during this critical early-life period and encourage breastfeeding.

Assessment of Human Mycotoxin Exposure in Hungary by Urinary Biomarker Determination and the Uncertainties of the Exposure Calculation: A Case Study

Urinary biomarkers of mycotoxin exposure were evaluated in the case of healthy people (n = 41) and coeliac patients (n = 19) by using a multi-biomarker LC-MS/MS immunoaffinity based method capable to analyse biomarkers of nine mycotoxins, i.e., fumonisin B1 (FB1), fumonisin B2 (FB2), deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA), Aflatoxin B1 (AFB1), T-2 toxin, HT-2 toxin and Nivalenol (NIV). Urinary biomarker concentrations were used to calculate the probable daily intake (PDI) of fumonisin B1, deoxynivalenol, zearalenone and ochratoxin A and compared with their tolerable daily intake (TDI). The human urinary excretion rate values reported in the literature and the 24 h excretion rate measured in piglets were used to estimate and compare the PDI values of the four mycotoxins. The highest mean biomarker concentrations were found for DON (2.30 ng/mL for healthy people and 2.68 ng/mL for coeliac patients). Mean OTA concentration was significantly higher (p < 0.001) in healthy people compared to coeliac patients. PDI calculated with piglets excretion data exceeded the TDI values by a much smaller percentage than when they were calculated from human data, especially for FB₁. The uncertainties arising from the different calculations can be well perceived on the basis of these data.

Associations between Serum Aflatoxin-B1 and Anemia in Pregnant Women: Evidence from Guangxi Zhuang Birth Cohort in China

Aflatoxin B1 (AFB1) is a common toxic mycotoxin and is detectable in pregnant women. Animal studies have revealed that AFB1 caused the lysis of erythrocytes and a decrease in hemoglobin. We conducted a prospective cohort study in Guangxi, China, in order to evaluate the association between AFB1 exposure and anemia in pregnant women during the entire pregnancy. A total of 616 pregnant women from the Guangxi Zhuang Birth Cohort were included in the study. Serum AFB1-albumin (AFB1-ALB) adduct levels were measured. The effect of AFB1-ALB adducts on hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were analyzed by using multivariable linear regression. The risks of anemia from AFB1-ALB adduct exposure were assessed by multivariable logistic regression. We found that the AFB1-ALB adduct was significantly associated with a decrease in Hb (β = -4.99, 95% CI: -8.42, -1.30), MCV (β = -4.58, 95% CI: -7.23, -1.94), MCH (β = -1.86, 95% CI: -2.87, -0.85), and MCHC (β = -5.23, 95% CI: -8.28, -2.17) in the first trimester with the third tertile of AFB1-ALB adducts when compared with the first tertile. Furthermore, the third tertile of the AFB1-ALB adduct significantly increased the risk of anemia by 2.90 times than compared to the first tertile in the first trimester (OR = 3.90, 95% CI: 1.67, 9.14). A significant positive does-response relationship existed between AFB1-ALB adduct levels and anemia risk (Ptrend = 0.001). When dividing anemia types, we only found that the third tertile of AFB1-ALB adduct increased the risk of microcytic hypochromic anemia (MHA) in the first trimester (OR = 14.37, 95% CI: 3.08, 67.02) and second trimester (OR = 4.75, 95% CI: 1.96, 11.51). These findings demonstrate the correlation between maternal AFB1 exposure during early pregnancy and risk of anemia, especially MHA, and during different trimesters in Southern China. More efforts should be made to diminish AFB1 exposure for pregnant women.

Awareness, Experience, and Knowledge of Farming Households in Rural Bangladesh Regarding Mold Contamination of Food Crops: A Cross-Sectional Study

Aside from specific environmental conditions, poor agricultural practices contribute to mold and thus the mycotoxin contamination of crops. This study investigated Bangladeshi farming households' (i) awareness of and experience with mold contamination of food crops; (ii) knowledge and awareness of the timing, causes, and consequences of mold and mycotoxin contamination; and (iii) knowledge of the recommended agricultural practices for controlling and preventing mold contamination of food crops. A survey was conducted with 1280 households in rural areas of Habiganj district, Bangladesh. Basic descriptive statistics were calculated, and mixed-effects linear regression analyses were performed to examine associations between household characteristics and overall knowledge scores. The awareness of mold contamination of food crops was very high (99%; 95% CI: 98-100%) and a shared experience among households (85%; 95% CI: 80-88%). Yet, the majority (80%; 95% CI: 76-84%) demonstrated a low level of knowledge of the timing, causes, and preventive practices regarding mold contamination of crops. Knowledge scores were similar over demographic groups and better for households with more arable land. The findings suggest a generally insufficient knowledge of the conditions that favor mold contamination and the measures for preventing mold contamination of food crops. These findings underline the need for tailored interventions to promote good agricultural practices and reduce mold contamination of food crops.

Emerging mycotoxins in infant and children foods: A review

A proper nutrition is crucial for children's healthy development. Regardless of the usual recommendations to follow a varied diet, some foods can be a source of toxic natural contaminants such as mycotoxins, potent secondary metabolites produced by filamentous fungi. In addition to the most well-known mycotoxins, many of which are subject to tight regulation regarding the maximum levels allowed in different types of food, there is a large group of mycotoxins, the so-called emerging mycotoxins, about which less knowledge has already been acquired, which have gradually been the target of interest from the scientific community due to their prevalence in most foodstuffs, particularly in cereals and cereal-based products. Alternariol and his metabolite alternariol mono-methyl ether, beauvericin, citrinin, culmorin, enniatins, ergot alkaloids, fusaproliferin, kojic acid, moniliformin, sterigmatocystin, tentoxin and tenuazonic acid are the most representative of them. The current review gathered the information of the last ten years that have been published on the levels of emerging mycotoxins in food products dedicated for infants and children. European Union countries are responsible for most of the reported studies, which showed levels that can reach hundreds of mg/kg.

Detection of Ustiloxin A in urine by ultra-high-performance liquid chromatography-tandem mass spectrometry coupled with two-step solid-phase extraction

Due to global outbreak of rice false smut disease, ustiloxin A (UA) was detected in rice. However, accurate methods for monitoring UA in human body fluids were lacking. In this context, a UPLC-MS/MS method based on two-step SPE was constructed for measuring UA in urine. The limits of UA quantification in human and mice urine were 58.3 and 108.7 ng/L, respectively. The proposed method was applied to detect UA in urine samples collected from human and mice. After dietary exposure, the contents of UA in mice urine were from 6.03 to 16.76 μg/g of creatine, accounting for approximate 14% of daily intake dose. Furthermore, due to the trace residues in rice (78-109 ng/kg), no detectable UA was observed in the urine of 20 volunteers. To the best of our knowledge, it is the first time to report the occurrence of UA in mammal urine.

Assessment of Human Exposure to Deoxynivalenol, Ochratoxin A, Zearalenone and Their Metabolites Biomarker in Urine Samples Using LC-ESI-qTOF

Human are exposed to a wide range of mycotoxins through dietary food intake, including processed food. Even most of the mycotoxin exposure assessment studies are based on analysis of foodstuffs, and evaluation of dietary intake through food consumption patterns and human biomonitoring methods are rising as a reliable alternative to approach the individual exposures, overcoming the limitations of the indirect dietary assessment. In this study, human urine samples were analyzed, seeking the presence of deoxynivalenol (DON), ochratoxin A (OTA), zearalenone (ZEA), and their metabolites. For this purpose, 40 urine samples from female and male adult residents in the city of Valencia (Spain) were evaluated by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-ESI-qTOF) after salting-out liquid–liquid extraction. Analytical data showed that 72.5% of analyzed samples were contaminated by at least one mycotoxin at variable levels. The most prevalent mycotoxins were de-epoxy DON (DOM-1) (53%), ZEA (40%), and α-zearalenol (αZOL) (43%), while OTA was only detected in one sample. The mean concentrations in positive samples were DON (9.07 ng/mL), DOM-1 (20.28 ng/mL), ZEA (6.70 ng/mL), ZEA-14 glucoside (ZEA-14-Glc) (12.43 ng/mL), αZOL (27.44 ng/mL), αZOL-14 glucoside (αZOL-14-Glc) (12.84 ng/mL), and OTA (11.73 ng/mL). Finally, probable daily intakes (PDIs) were calculated and compared with the established tolerable daily intakes (TDIs) to estimate the potential risk of exposure to the studied mycotoxins. The calculated PDI was below the TDI value established for DON in both female and male adults, reaching a percentage up to 30%; however, this percentage increased up to 92% considering total DON (DON + DOM-1). On the other hand, the PDI obtained for ZEA and its metabolites were higher than the TDI value fixed, but the low urine excretion rate (10%) considered should be highlighted. Finally, the PDI calculated in the detected positive sample for OTA exceeded the TDI value. The findings of the present study confirm the presence of the studied mycotoxins and their metabolites as some of the most prevalent in urine.

Occurrence of aflatoxin M1 in human breast milk in Bangladesh

Breast milk is the best, most complete form of nutrition for newborns and infants. However, human milk can contain aflatoxin M₁ (AFM₁) upon ingestion of dietary mycotoxin contaminants, namely, aflatoxin B₁ (AFB₁), by lactating mothers. AFB₁ and its hydroxylated metabolite AFM₁ are potent carcinogens and thus an important issue in food safety and public health. This study is the first to explore the presence of AFM₁ in breast milk samples from Bangladesh and assess infant exposure to this toxin, as a consequence of maternal mycotoxin intake. A total of 62 breast milk samples were collected from nursing mothers in Sylhet region of Bangladesh. The milk samples were collected between October 2019 and March 2020 and analyzed by a sensitive enzyme-linked immunosorbent assay. AFM₁ was detected in 51.6% of the breast milk samples (colostrum, transitional and mature milk), with a mean concentration of 4.42 ± 0.56 pg/mL, and in the range between LOD (4.0 pg/mL) and 6.66 pg/mL. The frequent detection of AFM₁ in breast milk indicates widespread dietary exposure to mycotoxins in our cohort. The estimated average daily intake of AFM₁ for all nursed infants was 0.49 ng/kg b.w./day. No significant correlations were observed between AFM₁ levels in human milk and food items regularly consumed by nursing women. Overall, AFM₁ levels in breast milk samples from the Sylhet region of Bangladesh are moderate, and lower than the permissible levels established for AFM₁ in dairy milk or infant formulae (50 and 25 ng/kg, respectively). Yet, this first data for AFM₁ breast milk contaminant levels just reflect the recent situation in one cohort, and monitoring should be continued.

Determination of Urinary Mycotoxin Biomarkers Using a Sensitive Online Solid Phase Extraction-UHPLC-MS/MS Method

In the course of assessing the human exposure to mycotoxins, biomarker-based approaches have proven to be important tools. Low concentration levels, complex matrix compositions, structurally diverse analytes, and the large size of sample cohorts are the main challenges of analytical procedures. For that reason, an online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry (online SPE-UHPLC-MS/MS) method was developed, allowing for the sensitive, robust, and rapid analysis of 11 relevant mycotoxins and mycotoxin metabolites in human urine. The included spectrum of analytes comprises aflatoxin M₁ (AFM₁), altenuene (ALT), alternariol monomethyl ether (AME), alternariol (AOH), citrinin (CIT) and its metabolite dihydrocitrinone (DH-CIT), fumonisin B₁ (FB₁), ochratoxin A (OTA), and zearalenone (ZEN) as well as α- and β-zearalenol (α- and β-ZEL). Reliable quantitation was achieved by means of stable isotope dilution, except for ALT, AME and AOH using matrix calibrations. The evaluation of method performance displayed low limits of detection in the range of pg/mL urine, satisfactory apparent recovery rates as well as high accuracy and precision during intra- and interday repeatability. Within the analysis of Zimbabwean urine samples (n = 50), the applicability of the newly developed method was shown. In addition to FB₁ being quantifiable in all analyzed samples, six other mycotoxin biomarkers were detected. Compared to the occurrence rates obtained after analyzing the same sample set using an established dilute and shoot (DaS) approach, a considerably higher number of positive samples was observed when applying the online SPE method. Owing to the increased sensitivity, less need of sample handling, and low time effort, the herein presented online SPE approach provides a valuable contribution to human biomonitoring of mycotoxin exposure.

Development and Limitations of Exposure Biomarkers to Dietary Contaminants Mycotoxins

Mycotoxins are toxic secondary fungal metabolites that frequently contaminate cereal crops globally, presenting exposure hazards to humans and livestock in many settings. The heterogeneous distribution of mycotoxins in food restricts the usefulness of food sampling and intake estimates for epidemiological studies, making validated exposure biomarkers better tools for informing epidemiological investigations. While biomarkers of exposure have served important roles for understanding the public health impact of mycotoxins such as aflatoxins (AF), the science of biomarkers must continue advancing to allow for better understanding of mycotoxins' roles in the etiology of disease and the effectiveness of mitigation strategies. This review will discuss mycotoxin biomarker development approaches over several decades for four toxins of significant public health concerns, AFs, fumonisins (FB), deoxynivalenol (DON), and ochratoxin A (OTA). This review will also highlight some knowledge gaps, key needs and potential pitfalls in mycotoxin biomarker interpretation.

Case-Control Study of Nodding Syndrome in Acholiland: Urinary Multi-Mycotoxin Screening

This case-control study adds to the growing body of knowledge on the medical, nutritional, and environmental factors associated with Nodding Syndrome (NS), a seizure disorder of children and adolescents in northern Uganda. Past research described a significant association between NS and prior history of measles infection, dependence on emergency food and, at head nodding onset, subsistence on moldy maize, which has the potential to harbor mycotoxins. We used LC-MS/MS to screen for current mycotoxin loads by evaluating nine analytes in urine samples from age-and-gender matched NS cases (n = 50) and Community Controls (CC, n = 50). The presence of the three mycotoxins identified in the screening was not significantly different between the two groups, so samples were combined to generate an overall view of exposure in this community during the study. Compared against subsequently run standards, α-zearalenol (43 ± 103 µg/L in 15 samples > limit of quantitation (LOQ); 0 (0/359) µg/L), T-2 toxin (39 ± 81 µg/L in 72 samples > LOQ; 0 (0/425) µg/L) and aflatoxin M1 (4 ± 10 µg/L in 15 samples > LOQ; 0 (0/45) µg/L) were detected and calculated as the average concentration ± SD; median (min/max). Ninety-five percent of the samples had at least one urinary mycotoxin; 87% were positive for two of the three compounds detected. While mycotoxin loads at NS onset years ago are and will remain unknown, this study showed that children with and without NS currently harbor foodborne mycotoxins, including those associated with maize.

Biomonitoring of Multiple Mycotoxins in Urine by GC-MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran

A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON; 3-acetyldeoxynivalenol, 3-ADON; 15-acetyldeoxynivalenol, 15-ADON; fusarenon-X, FUS-X; diacetoxyscirpenol, DAS; nivalenol, NIV; neosolaniol, NEO; zearalenone, ZON; zearalanone, ZAN; T-2 toxin, T-2; and HT-2 toxin, HT-2) in esophageal cancer patients was performed with the urinary biomarkers approach in Golestan, Iran. Urine multimycotoxin analysis was performed by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry (GC–MS/MS) analysis, and values were normalized with urinary creatinine (μg/g). Four mycotoxins, namely NEO (40%), HT-2 (17.6%), DON (10%), and HT-2 (5.8%), were detected in the analyzed urine samples. DON was only detected in the control group (5.09 μg/g creatinine), while T-2 (44.70 μg/g creatinine) was only present in the esophageal cancer group. NEO and HT-2 were quantified in both control and case groups, showing average of positive samples of 9.09 and 10.45 μg/g creatinine for NEO and 16.81 and 29.09 μg/g creatinine for HT-2, respectively. Mycotoxin co-occurrence was observed in three samples as binary (NEO/HT-2 and T-2/HT-2) and ternary (DON/NEO/HT-2) combinations, reaching total concentrations of 44.58, 79.13, and 30.04 µg/g creatinine, respectively. Further investigations are needed to explore a causal association between mycotoxin contamination and esophageal cancer. For this pilot study in Golestan, the low sample size was a very limiting factor.

Mycotoxins-Biomonitoring and Human Exposure

Mycotoxins are secondary metabolites produced by fungal species that commonly have a toxic effect on human and animal health. Different foodstuff can be contaminated and are considered the major source of human exposure to mycotoxins, but occupational and environmental exposure can also significantly contribute to this problem. This review aims to provide a short overview of the occurrence of toxigenic fungi and regulated mycotoxins in foods and workplaces, following the current literature and data presented in scientific papers. Biomonitoring of mycotoxins in plasma, serum, urine, and blood samples has become a common method for determining the exposure to different mycotoxins. Novel techniques are more and more precise and accurate and are aiming toward the simultaneous determination of multiple mycotoxins in one analysis. Application of liquid chromatography (LC) methodologies, coupled with tandem mass spectrometry (MS/MS) or high-resolution mass spectrometry (HRMS) has become a common and most reliable method for determining the exposure to mycotoxins. Numerous references confirm the importance of mycotoxin biomonitoring to assess the exposure for humans and animals. The objectives of this paper were to review the general approaches to biomonitoring of different mycotoxins and the occurrence of toxigenic fungi and their mycotoxins, using recent literature sources.

Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh

The mycotoxins aflatoxin B1 (AFB1) and deoxynivalenol (DON) are found worldwide in crops and dietary staples. The prevalence and levels of these contaminants can vary greatly, and data in Bangladeshi food commodities are scarce. To characterize human exposure, we have conducted biomonitoring, analyzing AFM1 (a metabolite of AFB1) and DON levels in urines of adult cohorts in Bangladesh. Yet, AFM1 and DON occurrence has not been studied in the very young population of this country. Thus, the same methods, HPLC-FD for AFM1 and LC-MS/MS for DON analysis, were now applied to determine these biomarkers in urines of infants (n = 49) and young children (n = 105) in Rajshahi and Dhaka district. Overall, AFM1 and DON detection frequency was 43.5% and 33.4%, with 34.7% and 11.5% in infant and 47.6% and 39.4% in children urines, respectively. The mean AFM1 levels in all infants (9.1 ± 14.3, max 55.6 pg/mL) and children (8.8 ± 12.9, max 75.3 pg/mL) were not significantly different. The AFM1 mean level was slightly higher in Dhaka (9.4 ± 12.4) compared to Rajshahi (8.5 ± 13.9 pg/mL) district. The average DON level was about 2-fold higher in infant (3.8 ± 2.9, max 6.8 ng/mL) than children urines (1.6 ± 1.8, max 8.6 ng/mL), and higher in Rajshahi (2.1 ± 2.3 ng/mL) than Dhaka (1.4 ± 1.6 ng/mL) district. The biomarker-based estimated average daily DON intake (29.6 ± 108.3 ng/kg bw in infants and 36.4 ± 81.8 ng/kg bw in children) or the maximum exposure (560 ng/kg bw) do not exceed the current maximum provisional tolerable daily intake value of 1 µg/kg bw for DON, although DON exposure in infants and children is higher than that of Bangladeshi adults. The AFM1 urine levels in young children are somewhat lower than those found previously in adult cohorts in Bangladesh, but the frequent detection of this biomarker for AFB1 exposure raises further concerns, also for this vulnerable part of the population. Therefore, continuous surveillance for aflatoxins in Bangladeshi food commodities is clearly required, first to identify major sources of intake and then to reduce exposure.

Human dietary and internal exposure to zearalenone based on a 24-hour duplicate diet and following morning urine study

Zearalenone is a widespread mycotoxin with high estrogenic activity. This study aimed to characterize the exposure of ZEN in a Chinese population during harvest season in 2016. Exposure to ZEN was measured using both duplicate diet method and human biomonitoring approaches. Duplicate diet samples from 199 individuals (4-80 years old) and their following morning urine samples were collected and analyzed using LC-MS/MS methods sensitive for ZEN, ZAN, α/β-ZEL and α/β-ZAL. ZEN was detected in 59.8% of the food samples at a mean level of 1.21 ± 2.15 μg/kg. The estimated daily intake (EDI) of ZEN was calculated from food contamination and consumption data at a mean level of 25.6 ± 38.6 ng/kg bw/day, representing 10.2% of the tolerable daily intake (TDI) set by EFSA and 5.1% of the provisional maximum tolerable daily intake (PMTDI) set by JECFA, respectively. Wheat appears to be the main diet source of ZEN exposure, contributing over 80% of the mean EDI. Children had the highest EDI at 37.5 ± 56.3 ng/kg bw/day (p < 0.05). Urine samples were analyzed both before and after enzymatic hydrolysis to determine the free and total amounts of ZEN biomarkers. The majority of ZEN was excreted as conjugates with the mean fZEN/tBM ratio of 25.4%. Adolescents had the highest excretion of ZEN biomarkers among all age groups (p < 0.05). Probable daily intake (PDI) was calculated from ZEN biomarkers and an excretion rate of 36.8%, giving a mean value of 41.6 ± 65.5 ng/kg bw/day. Significant correlation between internal and external exposure measurement was evidenced in this study (r = 0.344, p < 0.01). Although the mean PDI was approximately 1.6 times the mean EDI, these two approaches resulted in similar calculated degrees of ZEN exposure, both markedly below the health-based guidance value. This study is the first to compare ZEN exposure in a same population based on both diet study and human biomonitoring approaches. Significant differences of PDI/EDI ratios were found in different age groups (p < 0.05), possibly indicative of diversified excretion capabilities and metabolism patterns within the population.

Mycotoxin exposure and human cancer risk: A systematic review of epidemiological studies

In recent years, there has been an increasing interest in investigating the carcinogenicity of mycotoxins in humans. This systematic review aims to provide an overview of data linking exposure to different mycotoxins with human cancer risk. Publications (2019 and earlier) of case-control or longitudinal cohort studies were identified in PubMed and EMBASE. These articles were then screened by independent reviewers and their quality was assessed according to the Newcastle-Ottawa scale. Animal, cross-sectional, and molecular studies satisfied criteria for exclusion. In total, 14 articles were included: 13 case-control studies and 1 longitudinal cohort study. Included articles focused on associations of mycotoxin exposure with primary liver, breast, and cervical cancer. Overall, a positive association between the consumption of aflatoxin-contaminated foods and primary liver cancer risk was verified. Two case-control studies in Africa investigated the relationship between zearalenone and its metabolites and breast cancer risk, though conflicting results were reported. Two case-control studies investigated the association between hepatocellular carcinoma and fumonisin B1 exposure, but no significant associations were observed. This systematic review incorporates several clear observations of dose-dependent associations between aflatoxins and liver cancer risk, in keeping with IARC Monograph conclusions. Only few human epidemiological studies investigated the associations between mycotoxin exposures and cancer risk. To close this gap, more in-depth research is needed to unravel evidence for other common mycotoxins, such as deoxynivalenol and ochratoxin A. The link between mycotoxin exposures and cancer risk has mainly been established in experimental studies, and needs to be confirmed in human epidemiological studies to support the evidence-based public health strategies.

The toxicity of graphene oxide affected by algal physiological characteristics: A comparative study in cyanobacterial, green algae, diatom

Though the main toxic mechanisms of graphene oxide (GO) to algae have been accepted as the shading effect, oxidative stress and mechanical damage, the effect of algal characteristics on these three mechanisms of GO toxicity have seldom been taken into consideration. In this study, we investigated GO toxicity to green algae (Chlorella vulgaris, Scenedesmus obliquus, Chlamydomonas reinhardtii), cyanobacteria (Microcystis aeruginosa) and diatoms (Cyclotella sp.). The aim was to assess how the physiological characteristics of algae affect the toxicity of GO. Results showed that 10 mg/L of GO significantly inhibited the growth of all tested algal types, while S. obliquus and C. reinhardtii were found to be the most susceptible and tolerant species, respectively. Then, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the physiological characteristics of the assessed algae. The presence of locomotive organelles, along with smaller and more spherical cells, was more likely to alleviate the shading effect. Variations in cell wall composition led to different extents of mechanical damage as shown by Cyclotella sp. silica frustules and S. obliquus autosporine division being prone to damage. Meanwhile, growth inhibition and cell division were significantly correlated with the oxidative stress and membrane permeability, suggesting the latter two indicators can effectively signal GO toxicity to algae. The findings of this study provide novel insights into the toxicity of graphene materials in aquatic environments.

Deoxynivalenol: toxicological profiles and perspective views for future research

Deoxynivalenol (DON) is a secondary metabolite mainly produced by the fungi Fusarium in agricultural crops, widely existing in feeds and cereal-based foodstuffs. Because of the high occurrence and potentials to induce a variety of toxic effects on animals and humans, DON has been a very harmful exogenous dietary toxicant threating public health. The focus of this review is to summarise the DON-induced broad spectrum of adverse health effects, to probe the current state of knowledge of combined toxicity of DON with other mycotoxins and its derivatives, and to put forward prospective ideas that multi-generational toxicity of DON and its overall impacts on intestinal-immuno-neuroendocrine system could receive more attention in future investigations. The general aim is to provide a scientific basis for the necessity to re-consider risk-assessment and regulations.

Human Biomonitoring of Mycotoxins in Blood, Plasma and Serum in Recent Years: A Review

This manuscript reviews the state-of-the-art regarding human biological monitoring (HBM) of mycotoxins in plasma serum and blood samples. After a comprehensive and systematic literature review, with a focus on the last five years, several aspects were analyzed and summarized: a) the biomarkers analyzed and their encountered levels, b) the analytical methodologies developed and c) the relationship between biomarker levels and some illnesses. In the literature reviewed, aflatoxin B1-lysine (AFB1-lys) and ochratoxin A (OTA) in plasma and serum were the most widely studied mycotoxin biomarkers for HBM. Regarding analytical methodologies, a clear increase in the development of methods for the simultaneous determination of multiple mycotoxins has been observed. For this purpose, the use of liquid chromatography (LC) methodologies, especially when coupled with tandem mass spectrometry (MS/MS) or high resolution mass spectrometry (HRMS), has grown. A high percentage of the samples analyzed for OTA or aflatoxin B1 (mostly as AFB1-lys) in the reviewed papers were positive, demonstrating human exposure to mycotoxins. This review confirms the importance of mycotoxin human biomonitoring and highlights the important challenges that should be faced, such as the inclusion of other mycotoxins in HBM programs, the need to increase knowledge of mycotoxin metabolism and toxicokinetics, and the need for reference materials and new methodologies for treating samples. In addition, guidelines are required for analytical method validation, as well as equations to establish the relationship between human fluid levels and mycotoxin intake.

Optimization and validation of a LC-HRMS method for aflatoxins determination in urine samples

Mycotoxins' exposure by inhalation and/or dermal contact can occur in different branches of industry especially where heavily dusty settings are present and the handling of dusty commodities is performed. This study aims to explore the possible contribution of the occupational exposure to aflatoxins by analysing urine samples for the presence of aflatoxins B₁ and M₁ and aflatoxin B₁-N⁷-guanine adduct. The study was conducted in 2017 on two groups of volunteers, the workers group, composed by personnel employed in an Italian feed plant (n = 32), and a control group (n = 29), composed by the administrative employees of the same feed plant; a total of 120 urine samples were collected and analysed. A screening method and a quantitative method with high-resolution mass spectrometry determination were developed and fully validated. Limits of detections were 0.8 and 1.5 pg/mL_urine for aflatoxin B₁ and M₁, respectively. No quantitative determination was possible for the adduct aflatoxin B₁-N⁷-guanine. Aflatoxin B₁ and its adduct were not detected in the analysed samples, and aflatoxin M₁, instead, was found in 14 samples (12%) within the range 1.9-10.5 pg/mL_urine. Only one sample showed a value above the limit of quantification (10.5 pg/mL_urine). The absence of a statistical difference between the mean values for workers and the control group which were compared suggests that in this specific setting, no professional exposure occurs. Furthermore, considering the very low level of aflatoxin M₁ in the collected urine samples, the contribution from the diet to the overall exposure is to be considered negligible.

Maternal mycotoxin exposure and adverse pregnancy outcomes: a systematic review

Mycotoxin exposure from food occurs globally but is more common in hot humid environments, especially in low-income settings, and might affect pregnancy outcomes. This study aimed to synthesize the evidence from epidemiological studies on the relationship between maternal or fetal exposure to different mycotoxins and the occurrence of adverse pregnancy outcomes. Multiple databases were systematically searched up to December 2018 to identify studies that assessed the association between mycotoxin exposure in pregnant women or fetuses and at least one pregnancy outcome. Studies were appraised and results were synthesized using standard methods for conducting systematic reviews. This review identified and included 17 relevant studies. There is some evidence to suggest that exposure to various Aspergillus mycotoxins (e.g., aflatoxin) during pregnancy may impair intrauterine fetal growth and promote neonatal jaundice. Findings were inconclusive concerning the influence of aflatoxin exposure on perinatal death and preterm birth. Only two studies assessed effects of maternal exposure to Fusarium mycotoxins (e.g., fumonisin) on adverse pregnancy outcomes. These studies found that maternal fumonisin exposure may be associated with hypertensive emergencies in pregnancy and with neural tube defects. Studies using grain farming and weather conditions as a proxy measure for mycotoxin exposure found that such exposure was associated with an increased risk of preterm birth and late-term miscarriage. In conclusion, there is already some evidence to suggest that exposure to mycotoxins during pregnancy may have detrimental effects on pregnancy outcomes. However, given the limited number of studies, especially on effects of Fusarium mycotoxins, more studies are needed for a more comprehensive understanding of the effects of different mycotoxins on maternal and fetal health and to guide public health policies and interventions.

Multimycotoxin Exposure Assessment in UK Children Using Urinary Biomarkers-A Pilot Survey

Cereal foods are commonly contaminated with multiple mycotoxins resulting in frequent human mycotoxin exposure. Children are at risk of high-level exposure because of their high cereal intake relative to body weight. Hence, this study aims to assess multimycotoxin exposure in UK children using urinary biomarkers. Spot urines (n = 21) were analyzed for multimycotoxins (deoxynivalenol, DON; nivalenol, NIV; ochratoxin A, OTA; zearalenone, ZEN; α-zearalenol, α-ZEL; β-zearalenol, β-ZEL; T-2 toxin, T-2; HT-2 toxin, HT-2; and aflatoxin B₁ and M_1, AFB₁, AFM₁) using liquid chromatography-coupled tandem mass spectrometry. Urine samples frequently contained DON (13.10 ± 12.69 ng/mL), NIV (0.36 ± 0.16 ng/mL), OTA (0.05 ± 0.02 ng/mL), and ZEN (0.09 ± 0.07 ng/mL). Some samples (1-3) contained T-2, HT-2, α-ZEL, and β-ZEL but not aflatoxins. Dietary mycotoxin estimation showed that children were frequently exposed to levels exceeding the tolerable daily intake (52 and 95% of cases for DON and OTA). This demonstrates that UK children are exposed to multiple mycotoxins through their habitual diet.

Dietary determinants of aflatoxin B1-lysine adduct in pregnant women consuming a rice-dominated diet in Nepal

Background

Aflatoxins are found in diverse foods widely consumed worldwide. This study investigated the association between aflatoxin exposure and (a) consumption of specific foods, (b) dietary diversity (DD), and (c) seasonality.

Methods

Women enrolled in the AflaCohort Study in Banke, Nepal (n = 1648) were asked how often they ate certain food items in the past 7 days and 24 h. Serum aflatoxin B₁-lysine (AFB₁-lys) adduct levels, measured during pregnancy, were determined using high-performance liquid chromatography. Multivariable ordinary least squares and quantile regression models were used to examine incremental increases in AFB₁-lys adduct levels per frequency of food consumption and the relationship between DD, seasonality, and increases in AFB₁-lys adduct.

Results

Roughly 94% of women were exposed to aflatoxin (geometric mean 1.37 pg/mg). Women in the 30th, 50th, and 70th quantiles of aflatoxin exposure who reported one more occasion of maize consumption in the past week showed increases in AFB₁-lys adduct levels: 0.094, 0.112, and 0.109 pg/mg (p < 0.05, all). Women in the 30th, 50th, 70th, and 90th quantiles of exposure who reported one more occasion of groundnut consumption in the past week also showed increases in AFB₁-lys adduct levels: 0.058 (p < 0.001), 0.085 (p < 0.01), 0.133 (p < 0.001), and 0.133 (p < 0.001) pg/mg. Winter month recruitment was positively associated with AFB₁-lys adduct levels at all quantiles of aflatoxin exposure (range: 0.313–1.101 pg/mg, p < 0.001). DD was not predictive of aflatoxin exposure.

Conclusions

Our findings justify integrated approaches to aflatoxin reduction, including regulatory, agricultural, and food safety interventions across the value chain and at the household level.

Preliminary study on the relationship between aflatoxin-bovine serum albumin adducts in blood and aflatoxin M1 levels in milk of dairy cows

The aflatoxin (AF) albumin adduct is often used as a biomarker for aflatoxin exposure in humans. An ELISA method previously used for aflatoxin serum albumin in human blood was used to analyse bovine serum samples (n = 22) collected from dairy cattle during an aflatoxin mitigation study in Kenya. Albumin adduct data were compared with aflatoxin M₁ (AFM₁) levels in corresponding milk samples from these cows. The concentration ranged from < LOD to 487.9 pg/mL for AFM₁ and < LOD and 96.3 pg/mg for aflatoxin-albumin. This study indicates that aflatoxin-albumin adducts could be used as a measure of chronic aflatoxin exposure in dairy cattle.

Aflatoxins in rice: Worldwide occurrence and public health perspectives

Aflatoxins are fungal secondary metabolites that contaminate dietary staples worldwide, including maize, rice and groundnuts. Dietary exposure to aflatoxins is a public health concern due to their carcinogenic, acute and chronic effects. Rice is an important staple food consumed widely and consists of a major part of the diets for half of the world population. Human exposure to these mycotoxins is a serious problem especially in developing countries where hot and humid climates favor the fungal growth and where food storage conditions are poor and lack of regulatory limits enforcement. The recent developments of biomarkers have provided opportunities in assessing aflatoxins exposure and related health effects in the high-risk population groups. This review describes the worldwide occurrence of aflatoxins in rice during the period from 1990 to 2015 and biomarkers-based evidence for human exposure to aflatoxins and their adverse health effects. Aflatoxin is a potent hepatocarcinogen and humans may expose to it at any stage of life. Epidemiological studies reported an association between aflatoxin intake and the incidence of hepatocellular carcinoma in some sub-Saharan and Asian countries. Even daily high intake of rice with a low level of contamination is of health concern. Thus, it is necessary to implement effective strategies to prevent contamination and fungal growth in rice. A good agricultural and manufacturing practice should be applied during handling, storage and distribution of rice to ensure that aflatoxins contamination level is lower in the final product. Moreover, a regular survey for aflatoxins occurrence in rice and biomarkers-based studies is recommended to prevent and reduce the adverse health effects in the world population.

Analyses of biomarkers of exposure to nephrotoxic mycotoxins in a cohort of patients with renal tumours

The Czech Republic occupies the first place in the world in the frequency of renal and other urinary tract tumours, but their aetiology is unknown. To explore whether carcinogenic and nephrotoxic mycotoxins may contribute to kidney diseases in the Czech population, biomarkers of ochratoxin A (OTA) and citrinin (CIT) exposure were determined in biological specimens from a cohort of 50 patients with malignant renal tumours. Biomarker analyses in blood and urine samples used validated targeted methods for measuring OTA and CIT plus dihydrocitrinone (DH-CIT) after enrichment of analytes by specific immunoaffinity clean-up. OTA and CIT plus its metabolite DH-CIT were frequently detected in patient urine samples (OTA 62%; CIT 91%; DH-CIT 100%). The concentration ranges in urine were 1-27.8 ng/L for OTA, 2-87 ng/L for CIT and 2-160 ng/L for DH-CIT. The analyses of blood samples revealed also a frequent co-occurrence of OTA and CIT, in the ranges of 40-870 ng/L serum for OTA and 21-182 ng/L plasma for CIT. This first analysis of biomarkers in blood and urine samples of Czech patients revealed no major differences in comparison with published data for the general healthy Czech and European populations. Nonetheless, a frequent co-occurrence of CIT and OTA biomarkers in patient samples may be of interest with regard to potential interactions with other risk factors for renal disease.

Citrinin biomarkers: a review of recent data and application to human exposure assessment

The mycotoxin citrinin (CIT) deserves attention due to its known toxic effects in mammalian species and a widespread occurrence in food commodities, often along with ochratoxin A, another nephrotoxic mycotoxin. Human exposure, a key element in assessing risks related to these food contaminants, depends upon mycotoxin levels in food and on food consumption. Yet, data available for CIT levels in food are insufficient for reliable intake estimates. Now biomonitoring, i.e., analysis of parent compound and/or metabolites in human specimen (blood, urine, breast milk), is increasingly used to investigate mycotoxin exposure. Biomonitoring requires sensitive methods for determining biomarkers of exposure, combined with kinetic data to conclude on the absorbed internal dose in an individual. Recent advances in LC-MS/MS-based analytical techniques have facilitated biomonitoring studies on the occurrence of CIT biomarkers in body fluids, mainly in urine samples. This review compiles evidence on human exposure to CIT in different countries, on CIT kinetics in humans, and on biomarker-based CIT intake estimates. Human CIT exposures are discussed in light of an intake value defined as 'level of no concern for nephrotoxicity' by the European Food Safety Agency, and some uncertainties in the toxicological data base. Further studies on CIT, including biomarker-based studies are warranted along with regular food surveys for this mycotoxin to protect consumers against undesirable health effects.

High-performance liquid chromatography and Enzyme-Linked Immunosorbent Assay techniques for detection and quantification of aflatoxin B1 in feed samples: a comparative study

OBJECTIVE

Comparison was done between high-performance liquid chromatography (HPLC) and a competitive enzyme-linked immunosorbent assay (ELISA) for detection and quantification of aflatoxin B₁ (AFB₁) in feed samples. The two procedures were standardized and validated before the actual experiment. Five concentrations (0, 5, 10, 20 and 30 ppb) of feed samples were used for both methods. For the HPLC technique, the samples were extracted in acetonitrile/water (90/10) solution, cleaned-up using solid phase extraction (SPE) column, and derivatized by water/trifluoroacetic acid/glacial acetic acid (35/10/5) solution before instrument analysis. The samples were extracted in 70% methanol for the ELISA technique.

RESULTS

The two tests showed very strong linearity with correlation coefficient value of > 0.99 using standard solutions. The mean recovery rate was 92.42% (with relative standard deviation (RSD) of 5.97) and 75.64% (RSD = 34.88) for HPLC and ELISA, respectively. There was no statistically significant difference in recovery rate between the two methods. There was a positive correlation (r = 0.84) between them which indicated that the two techniques can be used to detect and quantify aflatoxin B₁ in feed samples. However, there were variations among replicates for the ELISA method, which shows that this method is more applicable for screening purposes.