Aflatoxin contamination of human breast milk and complementary foods in southern Ethiopia

Prevalence and concentration of aflatoxin M1 in breast milk in Africa: a meta-analysis and implication for the interface of agriculture and health

Breast milk is one of the many distinct forms of food that can be contaminated with aflatoxin M1 (AFM1). They may be consumed by eating contaminated foods, such as contaminated meat and crops, which would then be present in breast milk and cause health problems, including nervous system disorders and cancers of the lungs, liver, kidneys, and urinary tract. However, the prevalently inconsistent explanation of prevalence and concentration remains a big challenge. Thus, this meta-analysis was conducted to determine the prevalence and concentration of harmful chemicals in breast milk in an African context. The databases MEDLINE, PubMed, Embase, SCOPUS, Web of Science, and Google Scholar were searched for both published and unpublished research. To conduct the analysis, the collected data were exported to Stata version 18. The results were shown using a forest plot and a prevalence with a 95% confidence interval (CI) using the random-effects model. The Cochrane chi-square (I2) statistics were used to measure the studies' heterogeneity, and Egger's intercept was used to measure publication bias. This review included twenty-eight studies with 4016 breast milk samples and newborns. The analysis showed the overall prevalence and concentration of aflatoxin M1 in breast milk were 53% (95% CI 40, 65; i2 = 98.26%; P = 0.001). The pooled mean aflatoxin M1 concentration in breast milk was 93.02 ng/l. According to this study, the eastern region of Africa was 62% (95% CI 39-82) profoundly affected as compared to other regions of the continent. In subgroup analysis by publication year, the highest level of exposure to aflatoxins (68%; 95% CI 47-85) was observed among studies published from 2010 to 2019. This finding confirmed that more than half of lactating women's breast milk was contaminated with aflatoxin M1 in Africa. The pooled mean aflatoxin M1 concentration in breast milk was 93.02 ng/l. According to this study, the eastern region of Africa was profoundly affected compared with other regions. Thus, the government and all stakeholders must instigate policies that mitigate the toxicity of aflatoxins in lactating women, fetuses, and newborns.

Feed handling practices, aflatoxin awareness and children's milk consumption in the Sidama region of southern Ethiopia

Consumption of milk is linked to improved nutrient intake and reduced risk of child malnutrition in low and middle-income countries. However, these benefits are contingent on the safety and quality of the milk. Milk consumption may alleviate the widespread risk of malnutrition in rural Ethiopia, but milk-borne contaminants may also compromise child health. We aimed to: i) identify the types of dairy feeds used, their storage conditions, and potential risk of aflatoxin contamination; ii) assess stakeholders' knowledge about aflatoxin contamination along the value chain; and iii) assess parental practices on feeding milk to infants and young children. This qualitative study was conducted in the Sidama region, southern Ethiopia. In-depth interviews (n = 12) and key-informant interviews (n = 18) were conducted with actors along the dairy value chain. Focus-group discussions were conducted with farmers (9FGD/n = 129) and child caregivers (9FGD/n = 122). Study participants were selected to represent a rural-urban gradient, as well as low- and high- dairy cow holdings. We found that while animal-feed processors and their distribution agents had relatively good knowledge about aflatoxin, farmers and retailers did not. Feed storage conditions were poor. Many respondents linked moldy feeds to animal health but not to human health. Farmers' feed choice was influenced by cost, seasonality, and herd size. Small-holding farmers had limited access to commercial feed. Children's consumption of milk was limited to skim milk, as butter was extracted and sold for income. The high cost of dairy products also led some parents to dilute skim milk with water before feeding children, compromising the nutritional value and safety of the milk. Our findings underscore the need to address the gaps in aflatoxin and food safety knowledge, improve storage conditions, and ensure the availability of quality feed to increase the sector's productivity, but most importantly to protect consumers' health and well-being, especially infants and young children.

Dietary aflatoxins exposure, environmental enteropathy, and their relation with childhood stunting

Childhood stunting is a global phenomenon affecting more than 149 million children under the age of 5 worldwide. Exposure to aflatoxins (AFs) in utero, during breastfeeding, and consumption of contaminated food affect the gut microbiome, resulting in intestinal dysfunction and potentially contributing to stunting. This review explores the potential relationship between AF exposure, environmental enteropathy and childhood stunting. AFs bind to DNA, disrupt protein synthesis and elicit environmental enteropathy (EE). An EE alters the structure of intestinal epithelial cells, impairs nutrient uptake and leads to malabsorption. This article proposes possible intervention strategies for researchers and policymakers to reduce AF exposure, EE and childhood stunting, such as exposure reduction, the implementation of good agricultural practices, dietary diversification and improving environmental water sanitation and hygiene.

Determination of aflatoxin M1 and ochratoxin A in breast milk in rural centers of Yazd, Iran: Exposure assessment and risk characterization

Breast milk (BM) is considered as the best source of nutrition which could have prevention effects on various diseases in the first years of a child. Along with nutritive compounds, presence of contaminants such as mycotoxins in BM could be transmitted into neonate. The aim of this study was to determine the occurrence, levels, and factors associated with the presence of aflatoxin M1 (AFM1) and ocratoxin a (OTA) in BM samples of nursing mothers in rural centers of Yazd, Iran. The presence and average AFM1 and OTA concentration in 72 BM samples was measured by competitive ELISA. The demographic and diet parameters of nursing mothers were collected by a questionnaire and were analyzed using SPSS 18 software. AFM1 and OTA were detected in 63 (87.5%) and 47 (65.2%) samples with the mean concentration levels of 19.46 ± 13.26 ng/L (ranges from 5.1 to 53.9) and 200 ± 160 ng/L (ranges from 100 to 2460), respectively. Of these, 32 samples (50.7%) for AFM1 and 23 samples (48.9%) for OTA had values exceeding the limit set by the European Union regulation for infant foods (25 ng/L for AFM1 and 500 ng/L for OTA). It was also found that the risk of AFM1 and OTA occurrence in BM increased significantly with the consumption of beans, bread, cereals, fruit juice and crackers, and cream, respectively. This study showed that the estimated daily intake for AFM1 and OTA by 1 month of age infants was 2.7 and 28.5 ng/kg bw/day, respectively, while, as the age of the infant increased, the values were lower and close to 0.9 and 9.9 ng/kg bw/day for AFM1 and OTA in 12 months of age infants, respectively. The high occurrence and noticeable levels of AFM1 and OTA detected in this study indicated that some infants receive undesirable exposures to AFM1 and OTA with breast milk. Therefore, it is recommended that mothers are advised to avoid certain foods during pregnancy and breastfeeding that are likely sources of mycotoxins.

Prevalence of aflatoxin along processing points of locally made complementary food formulae in northern Uganda: Safety and children's exposure across seasons

Aflatoxin contamination along the processing points of locally made complementary food composite needs to be ascertained and minimized to reduce exposure to weaning children. The study established the concentrations of total aflatoxin (TAF) and aflatoxin B1 (AFB1) along the processing points of locally made malted millet sesame soybean composite (MMSSC) across season one (wet) and season two (dry) and determined children's exposure to them. A total of 363 samples were collected in 2019. TAF and AFB1 concentrations were determined quantitatively using an enzyme-linked immunosorbent assay (ELISA). Consequently, exposure of individual children was assessed as Estimated Daily Intake (EDI), (ng kg-1 bw day-1). All the samples along the processing points had detectable concentrations of TAF and AFB1 ranging from 0.578 μg kg-1 to 1.187 μg kg-1 and 0.221 μg kg-1 to 0.649 μg kg-1 respectively. Contamination was highest in raw materials; soybean (Glycine max) > sesame (Sesamum indicum), followed by stored composite, freshly prepared composite, and least in millet (Eleusine coracana). Contamination varied significantly across seasons with the wet season having higher contamination than the dry season at P = 0.05. All samples (100%) were within the European Commission (EC) acceptable maximum tolerable level for TAF and AFB1 (4 μg kg-1 and 2 μg kg-1) respectively for processed foods for general consumption. But were below the EU acceptable maximum tolerable level for TAF and AFB1 (0.4 μg kg-1 and 0.1 μg kg-1) respectively for processed baby foods cereals. However, all were within the United States- Food and Drug Authority (US-FDA) and East African Community (EAC) set maximum acceptable limit of 20 μg kg-1 for TAFs, 10 μg kg-1 and 5 μg kg-1 for TAF and AFB1 respectively. Conversely, exposure to these toxins was much higher than the Provisional Maximum Tolerable Dietary Intake (PMTDI) of 0.4 ng kg-1 bw day-1 to 1.0 ng kg-1 bw day-1. A significant difference in exposure to both toxins was observed with the weight. The age of 5 months was the most exposed. A concerted effort is needed to reduce children's exposure to MMSSC to TAF and AFB1, taking sesame and soybean as priority ingredients and proper storage based on season to control contamination.

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.

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.

Effects of aflatoxin B1 on human breast cancer (MCF-7) cells: cytotoxicity, oxidative damage, metabolic, and immune-modulatory transcriptomic changes

Aflatoxin B1 (AFB1) is a potent mycotoxin that is commonly produced by molds such as Aspergillus (A.) flavus and A. parasiticus. AFB1 is associated with several health adverse effects in humans including mutagenesis and carcinogenesis. Aflatoxin is commonly secreted in the milk leading to deleterious effects on breast tissue and potential nursing infants. However, the effects of aflatoxins, particularly AFB1, on the breast cells are less investigated. In this study, AFB1-associated effects on human breast cancer cell lines (MCF-7) were investigated. AFB1 caused significant cytotoxicity on MCF-7 cells. Such cytotoxicity had a positive correlation with the induction of oxidative stress. In addition, AFB1 caused significant transcriptomic alterations in xenobiotics and drug-metabolizing enzymes, transporters, and antioxidant enzymes. Besides, AFB1 upregulated pro-inflammatory markers such as tumor necrosis factor-α and cyclooxygenase-2 with a significant reduction of mRNA expressions of the immunity-related genes including interleukins 8 and 10.

Human Breast Milk Contamination with Aflatoxins, Impact on Children's Health, and Possible Control Means: A Review

Aflatoxins are natural toxicants produced mainly by species of the Aspergillus genus, which contaminate virtually all feeds and foods. Apart from their deleterious health effects on humans and animals, they can be secreted unmodified or carried over into the milk of lactating females, thereby posing health risks to suckling babies. Aflatoxin M1 (AFM1) is the major and most toxic aflatoxin type after aflatoxin B1 (AFB1). It contaminates human breast milk upon direct ingestion from dairy products or by carry-over from the parent molecule (AFB1), which is hydroxylated in the liver and possibly in the mammary glands by cytochrome oxidase enzymes and then excreted into breast milk as AFM1 during lactation via the mammary alveolar epithelial cells. This puts suckling infants and children fed on this milk at a high risk, especially that their detoxifying activities are still weak at this age essentially due to immature liver as the main organ responsible for the detoxification of xenobiotics. The occurrence of AFM1 at toxic levels in human breast milk and associated health conditions in nursing children is well documented, with developing countries being the most affected. Different studies have demonstrated that contamination of human breast milk with AFM1 represents a real public health issue, which should be promptly and properly addressed to reduce its incidence. To this end, different actions have been suggested, including a wider and proper implementation of regulatory measures, not only for breast milk but also for foods and feeds as the upstream sources for breast milk contamination with AFM1. The promotion of awareness of lactating mothers through the organization of training sessions and mass media disclosures before and after parturition is of a paramount importance for the success of any action. This is especially relevant that there are no possible control measures to ensure compliance of lactating mothers to specific regulatory measures, which can yet be appropriate for the expansion of breast milk banks in industrialized countries and emergence of breast milk sellers. This review attempted to revisit the public health issues raised by mother milk contamination with AFM1, which remains undermined despite the numerous relevant publications highlighting the needs to tackle its incidence as a protective measure for the children physical and mental health.

Urinary Aflatoxin M1 Concentration and Its Determinants in School-Age Children in Southern Ethiopia

Aflatoxins are mycotoxins that can contaminate grains, legumes, and oil seeds. These toxic compounds are an especially serious problem in tropical and sub-tropical climates. The objective of this study was to raise awareness of aflatoxin exposure among primary school children in Shebedino woreda, southern Ethiopia, by measuring urinary aflatoxin M1 (AFM1). The study employed a cross-sectional design and systematic random sampling of children from eight schools in the district. The mean ± SD age of the children was 9.0 ± 1.8 years. Most (84.6%) households were food insecure with 17.9% severely food insecure. Urinary AFM1 was detected in more than 93% of the children. The median [IQR] concentration of AFM1/Creat was 480 [203, 1085] pg/mg. Based on a multiple regression analysis: DDS, consumption of haricot bean or milk, source of drinking water, maternal education, and household food insecurity access scale scores were significantly associated with urinary AFM1/Creat. In conclusion, a high prevalence of urinary AFM1 was observed in this study. However, the relation between AFM1 and dietary intake was analyzed based on self-reported dietary data; hence, all of the staple foods as well as animal feeds in the study area should be assessed for aflatoxin contamination.

Validation of a HACCP community-based infants' complementary food safety assurance method in cash crop producing communities in Gedeo zone, Southern Ethiopia

A method based on a hazard analysis critical control point (HACCP)-based standard operating procedure (SOP) has been developed and implemented in community-based (CB) production of complementary foods (CFs) in agrarian regions in rural Ethiopia. The objective of this study was to validate the method in another setup, more specifically in cash crop (coffee and khat) producing communities in Southern Ethiopia. A quasi-experimental study was employed for the method validation. Two villages in the Gedeo zone, Southern Ethiopia were selected and a total of 40 mother-child pairs, 20 in each village, were involved in the study. Sociodemographic data, knowledge, and complementary feeding practices were collected using pretested questionnaires. The training was given to each mother for 1 h about community-based CFs production and implementation of the method. Then, 30 CF samples were collected and the level of aflatoxins (AFB1, AFB2, AFG1, and AFG2) was determined using a validated method. The majority (77.5%) of the mothers understand the importance of complementary feeding and give it to their infants beyond 6 months. Nearly two-thirds (62.5%) of the mothers had knowledge about the health impacts of aflatoxins, but the remaining 37.5% lacked awareness about the health risks of aflatoxins. Mothers were very well-motivated for the training and they promised to implement the knowledge and skill gained from the training for improving the nutritional status of their children. Overall, 23.3% of the CFs were contaminated by aflatoxins. AFB1 and AFG1 were detected in 6.7 and 16.7% of the CF samples, respectively. In cash crop-producing communities around the country, the HACCP-based SOP is easily validated in CB CFs production. Therefore, a scaleup of the method at the national level and beyond is recommended.

Ex Vivo and In Vitro Studies Revealed Underlying Mechanisms of Immature Intestinal Inflammatory Responses Caused by Aflatoxin M1 Together with Ochratoxin A

Aflatoxin M1 (AFM1) and ochratoxin A (OTA), which are occasionally detected in milk and commercial baby foods, could easily enter and reach the gastrointestinal tract, posing impairment to the first line of defense and causing dysfunction of the tissue. The objective of this study was to investigate the immunostimulatory roles of individual and combined AFM1 and OTA on the immature intestine. Thus, we used ELISA assays to evaluate the generation of cytokines from ex vivo CD-1 fetal mouse jejunum induced by AFM1 and OTA and explored the related regulatory pathways and pivot genes using RNA-seq analysis. It was found that OTA exhibited much stronger ability in stimulating pro-inflammatory cytokine IL-6 from jejunum tissues than AFM1 (OTA of 4 μM versus AFM1 of 50 μM), whereas the combination of the two toxins seemed to exert antagonistic actions. In addition, transcriptomics also showed that most gene members in the enriched pathway ‘cytokine–cytokine receptor interaction’ were more highly expressed in OTA than the AFM1 group. By means of PPI network analysis, NFKB1 and RelB were regarded as hub genes in response to OTA but not AFM1. In the human FHs 74 Int cell line, both AFM1 and OTA enhanced the content of reactive oxygen species, and the oxidative response was more apparent in OTA-treated cells in comparison with AFM1. Furthermore, OTA and AFM1 + OTA raised the protein abundance of p50/RelB, and triggered the translocation of the dimer from cytosol to nucleus. Therefore, the experimental data ex vivo and in vitro showed that OTA-induced inflammation was thought to be bound up with the up-regulation and translocation of NF-κB, though AFM1 seemed to have no obvious impact. Since it was the first attempt to uncover the appearances and inner mechanisms regarding inflammation provoked by AFM1 and OTA on immature intestinal models, further efforts are needed to understand the detailed metabolic steps of the toxin in cells and to clarify their causal relationship with the signals proposed from current research.

Influence of fermentation time on proximate composition and microbial loads of Enset, (Ensete ventricosum), sampled from two different agroecological districts

In southern Ethiopian households, kocho is one of the staple foods which can be kept longer and fermented naturally using locally prepared pits, but evidence about the influences of fermentation of kocho at a different time and agroecology on proximate compositions and microbial loads are limited. Fermented kocho samples at different fermentation times were collected from highland and midland districts of Sidama region of Ethiopia. The standard procedure of AOAC (2005) method was followed. Four microbiological load analyses were conducted. Factorial analysis using JMP 13 was conducted. Across the fermentation time, total carbohydrate, ash, crude protein, and crude fat ranged 36%-40%, 1.9%-3.2%, 3%-4.3%, and 0.1%-0.3%, respectively. The highest total ash content was observed in week one of fermentation both in midland and highland samples. However, in midland, the increment of fermentation time showed a reduction of total ash percentage. Crude protein and fat were observed similar both in midland and highland (p > .05). The titrable acidity of Kocho varied from 0.16% to 0.22%. It was shown that it increased in the first three months of fermentation. It was also found to be increased as the fermentation time is increasing. Aerobic mesophilic, lactic acid bacteria, yeast, and mold were highly observed in Kocho as compared to Enterobacteriaceae. The loads varied across the fermentation time. Enterobacteriaceae and yeast and mold count of Kocho decreased with increased fermentation time. In conclusion, agroecology did not affect crude protein percentage as the fermentation time is increased. However, it was shown that fermentation increases protein and fat percentages. The increment of the acidic contents may also suppress the microbial growth for better food safety of kocho products.

Aflatoxin contamination of human breast milk and complementary foods in southern Ethiopia

Exposure to unsafe level of aflatoxin in early life may lead to growth faltering. However, the extent of contamination of breast milk and complementary foods is poorly examined. We determined aflatoxin M₁ (AFM₁ ) and B₁ (AFB₁ ) contamination of human breast milk and cereal-based cooked complementary foods, respectively, among households having children 6-23 months of age in Sidama zone, southern Ethiopia. Data were collected through two cross-sectional surveys implemented in the wet (n = 180) and dry (n = 180) seasons. Eligible households (n = 360) were recruited from three agroecological zones (lowland, midland and highland, each with sample size of 120) using a multistage sampling technique. AFB₁ and AFM₁ levels were determined using enzyme-linked immunosorbent assay. Mann-Whitney U and Kruskal-Wallis tests were performed to compare aflatoxin levels between seasons and across the agroecological zones. Among 360 breast milk samples tested, 64.4% had detectable AFM₁ and 5.3% exceeded the 0.025 parts per billion (ppb) limit set by the European Union for infant milk. The median AFM₁ in the lowlands was significantly higher than in the other agroecological settings (P < 0.001). By season, AFM₁ was higher in breast milk samples collected in the dry season (P = 0.041). AFB₁ was detected in 96.4% of the food samples tested, and 95.0% had concentration exceeding the permissible European Union limit of 0.1 ppb. The median AFB₁ was significantly higher in the lowland (P = 0.002), but there was no difference between the seasons (P = 0.386). The study indicated that, in southern Ethiopia, foods intended for infants are heavily contaminated with AFB₁ . Contamination of breast milk is also a significant health concern.