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

Assessment of Mycotoxin Exposure and Associated Risk in Pregnant Dutch Women: The Human Biomonitoring Approach

Mycotoxins are toxic secondary metabolites produced by various fungi that can contaminate food crops, which, in turn, may lead to human exposure. Chronic exposure to mycotoxins can cause adverse health effects including reproductive and developmental toxicity. Pregnant women and their foetuses present a vulnerable group for exposure to mycotoxins that can cross the placenta. Human biomonitoring of mycotoxins provides a real-life approach to estimate internal exposure. In this pilot study, 24-h urine samples from 36 pregnant Dutch women were analysed for aflatoxin M1 (AFM1), total deoxynivalenol (DON), de-epoxy-deoxynivalenol (DOM-1), total zearalenone (ZEN), total α-zearalenol (α-ZEL), total β-zearalenol (β-ZEL) and total zearalanone (ZAN), where 'total' refers to mycotoxins and their conjugated forms. Serum samples from these women were analysed for fumonisin B1 (FB1) and ochratoxin A (OTA). All samples were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The most prevalent mycotoxins were total DON, total ZEN and OTA, with a detection frequency of 100%. DOM-1, total α-ZEL and total β-ZEL were detected but to a lesser extent, while AFM1, total ZAN and FB1 were undetected. Median concentrations were 4.75 μg total DON/L, 0.0350 μg DOM-1/L, 0.0413 μg total ZEN/L, 0.0379 μg total α-ZEL/L, 0.0189 μg total β-ZEL/L, and 0.121 μg OTA/L. The calculated median concentration for total ZEN and its metabolites was 0.105 μg/L. Based on two separate risk assessment approaches, total DON exposure in this group was considered to be of low concern. Similarly, exposure to total ZEN and its metabolites in this group was of low concern. For OTA, the risk of non-neoplastic effects was of low concern based on exposure in this group, and the risk of neoplastic effects was of low concern in the majority of participants in this group. The findings of this pilot study confirm the presence of mycotoxins in the urine and serum of pregnant Dutch women, with total DON, total ZEN, and OTA most frequently detected. Exposure to all measured mycotoxins was considered to be of low concern in this group, except for exposure to OTA, which was of low concern for the majority of participants. The study's findings offer valuable insights but should be confirmed using a larger and more diverse sample of the Dutch general population.

Frequent Dietary Multi-Mycotoxin Exposure in UK Children and Its Association with Dietary Intake

Mycotoxins are potent fungal toxins that frequently contaminate agricultural crops and foods. Mycotoxin exposure is frequently reported in humans, and children are known to be particularly at risk of exceeding safe levels of exposure. Urinary biomonitoring is used to assess overall dietary exposure to multiple mycotoxins. This study aims to quantify multi-mycotoxin exposure in UK children and to identify major food groups contributing to exposure. Four repeat urine samples were collected from 29 children (13 boys and 16 girls, aged 2.4-6.8 years), and food diaries were recorded to assess their exposure to eleven mycotoxins. Urine samples (n = 114) were hydrolysed with β-glucuronidase, enriched through immunoaffinity columns and analysed by LC-MS/MS for deoxynivalenol (DON), nivalenol (NIV), T-2/HT-2 toxins, zearalenone (ZEN), ochratoxin A (OTA) and aflatoxins. Food diaries were analysed using WinDiet software, and the daily intake of high-risk foods for mycotoxin contamination summarised. The most prevalent mycotoxins found in urine samples were DON (95.6% of all samples), OTA (88.6%), HT-2 toxin (53.5%), ZEN (48.2%) and NIV (26.3%). Intake of total cereal-based foods was strongly positively associated with urinary levels of DON and T-2/HT-2 and oat intake with urinary T-2/HT-2. Average daily mycotoxin excretion ranged from 12.10 µg/d (DON) to 0.03 µg/d (OTA), and co-exposure to three or more mycotoxins was found in 66% of samples. Comparing mycotoxin intake estimates to tolerable daily intakes (TDI) demonstrates frequent TDI exceedances (DON 34.2% of all samples, T-2/HT-2 14.9%, NIV 4.4% and ZEN 5.2%). OTA was frequently detected at low levels. When mean daily OTA intake was compared to the reference value for non-neoplastic lesions, the resulting Margin of Exposure (MoE) of 65 was narrow, indicating a health concern. In conclusion, this study demonstrates frequent exposure of UK children to multiple mycotoxins at levels high enough to pose a health concern if exposure is continuous.

Evaluation of Aflatoxins Occurrence and Exposure in Cereal-Based Baby Foods: An Update Review

PURPOSE OF REVIEW

The first stages of human life, which include the fetal period, infancy, and early childhood, are the most critical for human growth and development. This is the most vulnerable phase to health challenges due to the immature immune system and rapid development. Mycotoxins such as aflatoxins, ochratoxin A, patulin, fumonisins, zearalenone, and deoxynivalenol are secondary metabolites secreted by various fungal species, primarily Aspergillus, Fusarium, Penicillium, and Alternaria. Aflatoxins are one of the major mycotoxins produced in cereals and cereal-based foods by several species of Aspergillus, mainly Aspergillus flavus. In this context, this review provides a brief overview of the occurrence, exposure, legal regulations, and health effects of aflatoxins (B1, B2, G1, G2, and M1) in cereal-based baby foods and breast milk.

RECENT FINDINGS

Human aflatoxin exposure in utero and through breast milk, infant formulas, cereals, and cereal-based foods has been linked to various health consequences, including adverse birth outcomes, impaired growth and development, immune system suppression, and hepatic dysfunction. Recent evidence suggests that especially infants and children are more susceptible to aflatoxins due to their lower body weight, lowered capacity to detoxify harmful substances, more restrictive diet, immature metabolism and elimination, and faster rates of growth and development. It is essential for both food safety and infant and child health that aflatoxins in cereal and cereal-based products are precisely detected, detoxified, and managed.

Exposure assessment of children to dietary mycotoxins: A pilot study conducted in Ribeirão Preto, São Paulo, Brazil

Exposure to mycotoxins through food is a major health concern, especially for youngsters. This study performed a preliminary investigation on children's exposure to dietary mycotoxins in Ribeirão Preto, Brazil. Sampling procedures were conducted between August and December 2022, to collect foods (N = 213) available for consumption in the households of children (N = 67), including preschoolers (aged 3-6 years, n = 21), schoolers (aged 7-10 years, n = 15), and adolescents (aged 11-17 years, n = 31) cared in the Vila Lobato Community Social Medical Center of Ribeirão Preto. Ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was used to determine concentrations of the mycotoxins in foods. Mycotoxins measured in all foods comprised aflatoxins (AFs), fumonisins (FBs), zearalenone (ZEN), T-2 toxin, deoxynivalenol (DON) and ochratoxin A (OTA). Higher incidence and levels were found for FBs, ZEN, and DON in several commonly consumed foods. Furthermore, 32.86 % foods had two to four quantifiable mycotoxins in various combinations. The mean estimated daily intake (EDI) values were lower than the tolerable daily intake (TDI) for AFs, FBs, and ZEN, but higher than the TDI (1.0 µg/kg bw/day) for DON, hence indicating a health risk for all children age groups. Preschoolers and adolescents were exposed to DON through wheat products (EDIs: 2.696 ± 7.372 and 1.484 ± 2.395 µg/kg body weight (bw)/day, respectively), while schoolers were exposed through wheat products (EDI: 1.595 ± 1.748 µg/kg bw/day) and rice (EDI: 1.391 ± 1.876 µg/kg bw/day). The results indicate that wheat-based foods and rice may be risky to children, implying the need for stringent measures to avoid DON contamination in these products.

Bioaccessibility data of potentially toxic elements in complementary foods for infants: A review

The introduction of complementary foods (CFs) is a critical step in an infant's transition to solid foods, providing essential nutrients beyond breast milk. However, CFs may contain potentially toxic elements (PTEs), such as arsenic and cadmium that pose health risks to infants. In this context, understanding the bioaccessibility of PTEs is vital as it determines the fraction of a contaminant released from the food matrix and available for absorption in the gastrointestinal tract. Efforts have been made to standardize the assessment methodology for bioaccessibility, ensuring consistent and reliable data. Moreover, regulatory agencies have established guidelines for PTEs levels in food. However, important gaps still exist, which motivates many research opportunities on this topic.

Mycotoxins in Cereal-Based Products and Their Impacts on the Health of Humans, Livestock Animals and Pets

Cereal grains are the most important food staples for human beings and livestock animals. They can be processed into various types of food and feed products such as bread, pasta, breakfast cereals, cake, snacks, beer, complete feed, and pet foods. However, cereal grains are vulnerable to the contamination of soil microorganisms, particularly molds. The toxigenic fungi/molds not only cause quality deterioration and grain loss, but also produce toxic secondary metabolites, mycotoxins, which can cause acute toxicity, death, and chronic diseases such as cancer, immunity suppression, growth impairment, and neural tube defects in humans, livestock animals and pets. To protect human beings and animals from these health risks, many countries have established/adopted regulations to limit exposure to mycotoxins. The purpose of this review is to update the evidence regarding the occurrence and co-occurrence of mycotoxins in cereal grains and cereal-derived food and feed products and their health impacts on human beings, livestock animals and pets. The effort for safe food and feed supplies including prevention technologies, detoxification technologies/methods and up-to-date regulation limits of frequently detected mycotoxins in cereal grains for food and feed in major cereal-producing countries are also provided. Some important areas worthy of further investigation are proposed.

Comparison between pollutants found in breast milk and infant formula in the last decade: A review

Since ancient times, breastfeeding has been the fundamental way of nurturing the newborn. The benefits of breast milk are widely known, as it is a source of essential nutrients and provides immunological protection, as well as developmental benefits, among others. However, when breastfeeding is not possible, infant formula is the most appropriate alternative. Its composition meets the nutritional requirements of the infant, and its quality is subject to strict control by the authorities. Nonetheless, the presence of different pollutants has been detected in both matrices. Thus, the aim of the present review is to make a comparison between the findings in both breast milk and infant formula in terms of contaminants in the last decade, in order to choose the most convenient option depending on the environmental conditions. For that, the emerging pollutants including metals, chemical compounds derived from heat treatment, pharmaceutical drugs, mycotoxins, pesticides, packaging materials, and other contaminants were described. While in breast milk the most concerning contaminants found were metals and pesticides, in infant formula pollutants such as metals, mycotoxins, and packaging materials were the most outstanding. In conclusion, the convenience of using a feeding diet based on breast milk or either infant formula depends on the maternal environmental circumstances. However, it is important to take into account the immunological benefits of the breast milk compared to the infant formula, and the possibility of using breast milk in combination with infant formula when the nutritional requirements are not fulfilled only with the intake of breast milk. Therefore, more attention should be paid in terms of analyzing these conditions in each case to be able to make a proper decision, as it will vary depending on the maternal and newborn environment.

Prenatal Fumonisin Exposure Impairs Bone Development via Disturbances in the OC/Leptin and RANKL/RANK/OPG Systems in Weaned Rat Offspring

The goal of the current study was to examine the effects of prenatal exposure to fumonisins (FBs) on bone properties and metabolism in weaned rat offspring divided into groups intoxicated with FBs at either 0 (the 0 FB group), 60 (the 60 FB group), or 90 mg/kg b.w. 0 (the 90 FB group). Female and male offspring exposed to FBs at a dose of 60 mg/kg b.w. had heavier femora. Mechanical bone parameters changed in a sex and FBs dose-dependent manner. Growth hormone and osteoprotegerin decreased in both sexes, regardless of FBs dose. In males osteocalcin decreased, while receptor activator for nuclear factor kappa-Β ligand increased regardless of FBs dose; while in females changes were dose dependent. Leptin decreased in both male FBs-intoxicated groups, bone alkaline phosphatase decreased only in the 60 FB group. Matrix metalloproteinase-8 protein expression increased in both female FBs-intoxicated groups and decreased in male 90 FB group. Osteoprotegerin and tissue inhibitor of metalloproteinases 2 protein expression decreased in males, regardless of FBs dose, while nuclear factor kappa-Β ligand expression increased only in the 90 FB group. The disturbances in bone metabolic processes seemed to result from imbalances in the RANKL/RANK/OPG and the OC/leptin systems.

A Novel Multicellular Placental Barrier Model to Investigate the Effect of Maternal Aflatoxin B1 Exposure on Fetal-Side Neural Stem Cells

Ingestion of food toxins such as aflatoxin B₁ (AFB₁) during pregnancy may impair fetal neurodevelopment. However, animal model results may not be accurate due to the species' differences, and testing on humans is ethically impermissible. Here, we developed an in vitro human maternal-fetal multicellular model composed of a human hepatic compartment, a bilayer placental barrier, and a human fetal central nervous system compartment using neural stem cells (NSCs) to investigate the effect of AFB₁ on fetal-side NSCs. AFB₁ passed through the HepG2 hepatocellular carcinoma cells to mimic the maternal metabolic effects. Importantly, even at the limited concentration (0.0641 ± 0.0046 μM) of AFB_1, close to the national safety level standard of China (GB-2761-2011), the mixture of AFB₁ crossing the placental barrier induced NSC apoptosis. The level of reactive oxygen species in NSCs was significantly elevated and the cell membrane was damaged, causing the release of intracellular lactate dehydrogenase (p < 0.05). The comet experiment and γ-H2AX immunofluorescence assay showed that AFB₁ caused significant DNA damage to NSCs (p < 0.05). This study provided a new model for the toxicological evaluation of the effect of food mycotoxin exposure during pregnancy on fetal neurodevelopment.

Mycotoxins Exposure of Lactating Women and Its Relationship with Dietary and Pre/Post-Harvest Practices in Rural Ethiopia

Mycotoxins can be transferred to breast milk during lactation. Hence, the presence of multiple mycotoxins (aflatoxins B1, B2, G1, G2, and M1, alpha and beta zearalanol, deoxynivalenol, fumonisins B1, B2, B3, and hydrolyzed B1, nivalenol, ochratoxin A, ochratoxin alpha, and zearalenone) in breast milk samples was assessed in our study. Furthermore, the relationship between total fumonisins and pre/post-harvest and the women's dietary practices was examined. Liquid chromatography coupled with tandem mass spectrometry was used to analyze the 16 mycotoxins. An adjusted censored regression model was fitted to identify predictors of mycotoxins, i.e., total fumonisins. We detected only fumonisin B2 (15% of the samples) and fumonisin B3 (9% of the samples) while fumonisin B1 and nivalenol were detected only in a single breast milk sample. No association between total fumonisins and pre/post-harvest and dietary practices was found (p < 0.05). The overall exposure to mycotoxins was low in the studied women, although fumonisins contamination was not negligible. Moreover, the recorded total fumonisins was not associated with any of the pre/post-harvest and dietary practices. Therefore, to better identify predictors of fumonisin contamination in breast milk, longitudinal studies with food samples in addition to breast milk samples and with larger sample sizes are needed for the future.

Mycotoxins: Emerging toxic mechanisms, and unanswered research questions

Recently, a series of toxic mechanisms have been explored in mycotoxins. Emerging evidence show that mycotoxins may induce human neurodegenerative diseases (ND); however, this idea is still unproven. Besides to identify this hypothesis, some questions, for example, how the mycotoxins induce this disease and what the molecular mechanism is, as well as whether the brain-gut axis is involved in this context, should be answered. Very recent studies further reported an "immune evasion" mechanism in trichothecenes; moreover, hypoxia seems to play important function in this process; nevertheless, whether this "immune evasion" process is present in other mycotoxins, especially in aflatoxins, should be tested. In this work, we mainly discussed some key scientific questions that need to be answered in the toxic mechanisms of mycotoxins. We especially focused on the research questions in the key signaling pathways, balance mechanism of immunostimulatory and immunosuppressive effects, and the relationship between autophagy and apoptosis. Interesting topics such as mycotoxins and aging, cytoskeleton and immunotoxicity are also discussed. More importantly, we compile a special issue: "New insight into mycotoxins and bacterial toxins: toxicity assessment, molecular mechanism and food safety" for Food and Chemical Toxicology. Researchers are encouraged to submit their newest work to this special issue.

Early-life AFB1 exposure: DNA methylation and hormone alterations

Aflatoxins are secondary metabolites of mold that contaminate food and feedstuff. They are found in various food including grains, nuts, milk and eggs. Aflatoxin B1 (AFB1) is the most poisonous and commonly found of the various types of aflatoxins. Exposures to AFB1 start early in life viz. in utero, during breastfeeding, and during weaning through the waning foods which are mainly grain based. Several studies have shown that early-life exposures to various contaminants may have various biological effects. In this chapter, we reviewed the effects of early-life AFB1 exposures on changes in hormone and DNA methylation. In utero AFB1 exposure results in alterations in steroid and growth hormones. Specifically, the exposure results in a reduction in testosterone levels later in life. The exposure also affects the methylation of various genes that are significant in growth, immune, inflammation, and signaling pathways.

Maternal dietary exposure to mycotoxin aflatoxin B1 promotes intestinal immune alterations and microbiota modifications increasing infection susceptibility in mouse offspring

Mycotoxins are secondary metabolites produced by fungi occurring in food that are toxic to animals and humans. Early-life mycotoxins exposure has been linked to diverse pathologies. However, how maternal exposure to mycotoxins impacts on the intestinal barrier function of progeny has not been explored. Here, exposure of pregnant and lactating C57Bl/6J female mice to aflatoxin B₁ (AFB₁; 400 μg/kg body weight/day; 3 times a week) in gelatine pellets, from embryonic day (E)11.5 until weaning (postnatal day 21), led to gut immunological changes in progeny. The results showed an overall increase of lymphocyte number in intestine, a reduction of expression of epithelial genes related to microbial defence, as well as a decrease in cytokine production by intestinal type 2 innate lymphoid cells (ILC2). While susceptibility to chemically induced colitis was not worsened, immune alterations were associated with changes in gut microbiota and with a higher vulnerability to infection by the protozoan Eimeria vermiformis at early-life. Together these results show that maternal dietary exposure to AFB₁ can dampen intestinal barrier homeostasis in offspring decreasing their capability to tackle intestinal pathogens. These data provide insights to understand AFB₁ potential harmfulness in early-life health in the context of intestinal infections.

Assessment of Agricultural Practices for Controlling Fusarium and Mycotoxins Contamination on Maize Grains: Exploratory Study in Maize Farms

Maize is a significant crop to the global economy and a key component of food and feed, although grains and whole plants can often be contaminated with mycotoxins resulting in a general exposure of the population and animals. To investigate strategies for mycotoxins control at the grain production level, a pilot study and exploratory research were conducted in 2019 and 2020 to compare levels of mycotoxins in grains of plants treated with two fertilizers, F-BAC and Nefusoil, under real agricultural environment. The 1650 grains selected from the 33 samples were assessed for the presence of both Fusarium species and mycotoxins. Only fumonisins and deoxynivalenol were detected. Fumonisin B1 ranged from 0 to 2808.4 µg/Kg, and fumonisin B2 from 0 to 1041.9 µg/Kg, while deoxynivalenol variated from 0 to 465.8 µg/Kg. Nefusoil showed to be promising in regard to fumonisin control. Concerning the control of fungal contamination rate and the diversity of Fusarium species, no significant differences were found between the two treatments in any of the years. However, a tendency for was observed Nefusoil of lower values, probably due to the guaranteed less stressful conditions to the Fusarium spp. present in the soil, which do not stimulate their fumonisins production.

Hypoxia and Cellular Senescence, Emerging Toxic Mechanisms of Mycotoxins and Toxins: A New Understanding of the Negative Immune Regulations

Mycotoxin contamination is an important issue that has plagued the world [...]