Insights into the early-life chemical exposome of Nigerian infants and potential correlations with the developing gut microbiome.

Early-life exposure to natural and synthetic chemicals can impact acute and chronic health conditions. Here, a suspect screening workflow anchored on high-resolution mass spectrometry was applied to elucidate xenobiotics in breast milk and matching stool samples collected from Nigerian mother-infant pairs (n = 11) at three time points. Potential correlations between xenobiotic exposure and the developing gut microbiome, as determined by 16S rRNA gene amplicon sequencing, were subsequently explored. Overall, 12,192 and 16,461 features were acquired in the breast milk and stool samples, respectively. Following quality control and suspect screening, 562 and 864 features remained, respectively, with 149 of these features present in both matrices. Taking advantage of 242 authentic reference standards measured for confirmatory purposes of food bio-actives and toxicants, 34 features in breast milk and 68 features in stool were identified and semi-quantified. Moreover, 51 and 78 features were annotated with spectral library matching, as well as 416 and 652 by in silico fragmentation tools in breast milk and stool, respectively. The analytical workflow proved its versatility to simultaneously determine a diverse panel of chemical classes including mycotoxins, endocrine-disrupting chemicals (EDCs), antibiotics, plasticizers, perfluorinated alkylated substances (PFAS), and pesticides, although it was originally optimized for polyphenols. Spearman rank correlation of the identified features revealed significant correlations between chemicals of the same classification such as polyphenols. One-way ANOVA and differential abundance analysis of the data obtained from stool samples revealed that molecules of plant-based origin elevated as complementary foods were introduced to the infants' diets. Annotated compounds in the stool, such as tricetin, positively correlated with the genus Blautia. Moreover, vulgaxanthin negatively correlated with Escherichia-Shigella. Despite the limited sample size, this exploratory study provides high-quality exposure data of matched biospecimens obtained from mother-infant pairs in sub-Saharan Africa and shows potential correlations between the chemical exposome and the gut microbiome.

Polyphenol exposure of mothers and infants assessed by LC-MS/MS based biomonitoring in breast milk.

Exposure to polyphenols is relevant throughout critical windows of infant development, including the breastfeeding phase. However, the quantitative assessment of polyphenols in human breast milk has received limited attention so far, though polyphenols may positively influence infant health. Therefore, a targeted LC-MS/MS assay was developed to investigate 86 analytes representing different polyphenol classes in human breast milk. The sample preparation consisted of liquid extraction, salting out, freeze-out, and a dilution step. Overall, nearly 70% of the chemically diverse polyphenols fulfilled all strict validation criteria for full quantitative assessment. The remaining analytes did not fulfill all criteria at every concentration level, but can still provide useful semi-quantitative insights into nutritional and biomedical research questions. The limits of detection for all analyzed polyphenols were in the range of 0.0041-87 ng*mL-1, with a median of 0.17 ng*mL-1. Moreover, the mean recovery was determined to be 82% and the mean signal suppression and enhancement effect was 117%. The developed assay was applied in a proof-of-principle study to investigate polyphenols in breast milk samples provided by twelve Nigerian mothers at three distinct time points post-delivery. In total, 50 polyphenol analytes were detected with almost half being phenolic acids. Phase II metabolites, including genistein-7-ß-D-glucuronide, genistein-7-sulfate, and daidzein-7-ß-D-glucuronide, were also detected in several samples. In conclusion, the developed method was demonstrated to be fit-for-purpose to simultaneously (semi-) quantify a wide variety of polyphenols in breast milk. It also demonstrated that various polyphenols including their biotransformation products were present in breast milk and therefore likely transferred to infants where they might impact microbiome development and infant health.

Biomonitoring of Dietary Mycotoxin Exposure and Associated Impact on the Gut Microbiome in Nigerian Infants.

Mycotoxins are toxic chemicals that adversely affect human health. Here, we assessed the influence of mycotoxin exposure on the longitudinal development of early life intestinal microbiota of Nigerian neonates and infants (NIs). Human biomonitoring assays based on liquid chromatography tandem mass spectrometry were applied to quantify mycotoxins in breast milk (n = 68) consumed by the NIs, their stool (n = 82), and urine samples (n = 15), which were collected longitudinally from month 1-18 postdelivery. Microbial community composition was characterized by 16S rRNA gene amplicon sequencing of stool samples and was correlated to mycotoxin exposure patterns. Fumonisin B1 (FB1), FB2, and alternariol monomethyl ether (AME) were frequently quantified in stool samples between months 6 and 18. Aflatoxin M1 (AFM1), AME, and citrinin were quantified in breast milk samples at low concentrations. AFM1, FB1, and ochratoxin A were quantified in urine samples at relatively high concentrations. Klebsiella and Escherichia/Shigella were dominant in very early life stool samples (month 1), whereas Bifidobacterium was dominant between months 3 and 6. The total mycotoxin levels in stool were significantly associated with NIs' gut microbiome composition (PERMANOVA, p < 0.05). However, no significant correlation was observed between specific microbiota and the detection of certain mycotoxins. Albeit a small cohort, this study demonstrates that mycotoxins may influence early life gut microbiome composition.

Enhancing microbiome research in sub-Saharan Africa.

While there are lighthouse examples of microbiome research in sub-Saharan Africa (SSA), a significant proportion of local researchers face several challenges. Here, we highlight prevailing issues limiting microbiome research in SSA and suggest potential technological, societal, and research-based solutions. We emphasize the need for considerable investment in infrastructures, training, and appropriate funding to democratize modern technologies with a view to providing useful data to improve human health.

The Austrian children's biomonitoring survey 2020 Part B: Mycotoxins, phytotoxins, phytoestrogens and food processing contaminants.

This study assessed the levels of environment and food-related exposures in urine of Austrian school children aged six to ten (n = 85) focusing on mycotoxins, phytoestrogens, and food processing by-products using two multi-analyte LC-MS/MS methods. Out of the 55 biomarkers of exposure reported in this study, 22 were quantified in the first void urine samples. Mycotoxins frequently quantified included zearalenone (detection rate 100%; median 0.11 ng/mL), deoxynivalenol (99%; 15 ng/mL), alternariol monomethyl ether (75%; 0.04 ng/mL), and ochratoxin A (19%; 0.03 ng/mL). Several phytoestrogens, including genistein, daidzein, and its metabolite equol, were detected in all samples at median concentrations of 22 ng/mL, 43 ng/mL, and 14 ng/mL, respectively. The food processing by-product 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was detected in 4% of the samples (median 0.016 ng/mL). None of the investigated samples contained the tested phytotoxins that were rarely considered for human biomonitoring previously (pyrrolizidine alkaloids, tropane alkaloids, aristolochic acids). When relating estimated exposure to current health-based guidance values, 22% of the children exceeded the tolerable daily intake for deoxynivalenol, and the estimated MOE for OTA indicates possible health risks for some children. The results clearly demonstrate frequent low-level (co-)exposure and warrant further exposome-scale exposure assessments, especially in susceptible sub-populations and longitudinal settings.

Early-life chemical exposome and gut microbiome development: African research perspectives within a global environmental health context.

The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs globally, but especially in Africa, to copious amounts and types of xenobiotics - such as mycotoxins, pesticide residues, and heavy metals - little is known about their influence on the early-life microbiome or their effects on acute or long-term health. Within the African context, the influence of fermented foods, herbal mixtures, and the delivery environment on the early-life microbiome are often neglected, despite being potentially important factors that influence the microbiome. Consequently, data on in-depth understanding of the microbiome-exposome interactions is lacking in African cohorts. Collecting and evaluating such data is important because exposome-induced gut dysbiosis could potentially favor disease progression.

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.

Trace analysis of emerging and regulated mycotoxins in infant stool by LC-MS/MS.

Infants are sensitive to negative effects caused by food contaminants such as mycotoxins. To date, analytical methods assessing mycotoxin mixture exposure in infant stool are absent. Herein, we present a novel multi-mycotoxin LC-MS/MS assay capable of detecting 30+ analytes including the regulated mycotoxin classes (aflatoxins, trichothecenes, ochratoxins, zearalenone, citrinin), emerging Alternaria and Fusarium toxins, and several key metabolites. Sample preparation consisted of a 'dilute, filter, and shoot' approach. The method was in-house validated and demonstrated that 25 analytes fulfilled all required criteria despite the high diversity of chemical structures included. Extraction recoveries for most of the analytes were in the range of 65-114% with standard deviations below 30% and limits of detection between 0.03 and 11.3 ng/g dry weight. To prove the methods' applicability, 22 human stool samples from premature Austrian infants (n = 12) and 12-month-old Nigerian infants (n = 10) were analyzed. The majority of the Nigerian samples were contaminated with alternariol monomethyl ether (8/10) and fumonisin B1 (8/10), while fumonisin B2 and citrinin were quantified in some samples. No mycotoxins were detected in any of the Austrian samples. The method can be used for sensitive human biomonitoring (HBM) purposes and to support exposure and, potentially, risk assessment of mycotoxins. Moreover, it allows for investigating potential associations between toxicant exposure and the infants' developing gut microbiome.

Dietary Risk Assessment and Consumer Awareness of Mycotoxins among Household Consumers of Cereals, Nuts and Legumes in North-Central Nigeria.

This study characterized the health risks due to the consumption of mycotoxin-contaminated foods and assessed the consumer awareness level of mycotoxins in households in two north-central Nigerian states during the harvest and storage seasons of 2018. Twenty-six mycotoxins and 121 other microbial and plant metabolites were quantified by LC-MS/MS in 250 samples of cereals, nuts and legumes. Aflatoxins were detected in all food types (cowpea, maize, peanut and sorghum) except in millet. Aflatoxin B1 was the most prevalent mycotoxin in peanut (64%) and rice (57%), while fumonisin B1 occurred most in maize (93%) and beauvericin in sorghum (71%). The total aflatoxin concentration was highest in peanut (max: 8422 µg/kg; mean: 1281 µg/kg) and rice (max: 955 µg/kg; mean: 94 µg/kg), whereas the totals of the B-type fumonisins and citrinin were highest in maize (max: 68,204 µg/kg; mean: 2988 µg/kg) and sorghum (max: 1335 µg/kg; mean: 186 µg/kg), respectively. Citrinin levels also reached 51,195 µg/kg (mean: 2343 µg/kg) in maize. Aflatoxin and citrinin concentrations in maize were significantly (p < 0.05) higher during storage than at harvest. The estimated chronic exposures to aflatoxins, citrinin and fumonisins were high, resulting in as much as 247 new liver cancer cases/year/100,000 population and risks of nephrotoxicity and esophageal cancer, respectively. Children who consumed the foods were the most vulnerable. Mycotoxin co-occurrence was evident, which could increase the health risk of the outcomes. Awareness of mycotoxin issues was generally low among the households.

Fungal Diversity and Aflatoxins in Maize and Rice Grains and Cassava-Based Flour (Pupuru) from Ondo State, Nigeria.

Grains and cassava-based foods serve as major dietary sources for many households in Nigeria. However, these foods are highly prone to contamination by moulds and aflatoxins owing to poor storage and vending practices. Therefore, we studied the fungal diversity in maize, cassava-based flour (pupuru), and rice vended in markets from Ondo state, Nigeria, and assessed their aflatoxin levels using an enzyme-linked immunosorbent assay. Molecular analysis of 65 representative fungal isolates recovered from the ground grains and pupuru samples revealed 26 species belonging to five genera: Aspergillus (80.9%), Penicillium (15.4%), and Talaromyces (1.9%) in the Ascomycota; Syncephalastrum (1.2%) and Lichtheimia (0.6%) in Mucoromycota. Aspergillus flavus was the predominant species in the ground grains and pupuru samples. Aflatoxins were found in 73.8% of the 42 representative food samples and 41.9% exceeded the 10 µg/kg threshold adopted in Nigeria for total aflatoxins.

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa.

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.

Microbiological safety of ready-to-eat foods in low- and middle-income countries: A comprehensive 10-year (2009 to 2018) review.

Ready-to-eat foods (RTEs) are foods consumed without any further processing. They are widely consumed as choice meals especially by school-aged children and the fast-paced working class in most low- and middle-income countries (LMICs), where they contribute substantially to the dietary intake. Depending on the type of processing and packaging material, RTEs could be industrially or traditionally processed. Typically, RTE vendors are of low literacy level, as such, they lack knowledge about good hygiene and food handling practices. In addition, RTEs are often vended in outdoor environments such that they are exposed to several contaminants of microbial origin. Depending on the quantity and type of food contaminant, consumption of contaminated RTEs may result in foodborne diseases and several other adverse health effects in humans. This could constitute major hurdles to growth and development in LMICs. Therefore, this review focuses on providing comprehensive and recent occurrence and impact data on the frequently encountered contaminants of microbial origin published in LMICs within the last decade (2009 to 2018). We have also suggested viable food safety solutions for preventing and controlling the food contamination and promoting consumer health.

Diversity and toxigenicity of fungi and description of Fusarium madaense sp. nov. from cereals, legumes and soils in north-central Nigeria.

Mycological investigation of various foods (mainly cowpea, groundnut, maize, rice, sorghum) and agricultural soils from two states in north-central Nigeria (Nasarawa and Niger), was conducted in order to understand the role of filamentous fungi in food contamination and public health. A total of 839 fungal isolates were recovered from 84% of the 250 food and all 30 soil samples. Preliminary identifications were made, based on macro- and micromorphological characters. Representative strains (n = 121) were studied in detail using morphology and DNA sequencing, involving genera/species-specific markers, while extrolite profiles using LC-MS/MS were obtained for a selection of strains. The representative strains grouped in seven genera (Aspergillus, Fusarium, Macrophomina, Meyerozyma, Neocosmospora, Neotestudina and Phoma). Amongst the 21 species that were isolated during this study was one novel species belonging to the Fusarium fujikuroi species complex, F. madaense sp. nov., obtained from groundnut and sorghum in Nasarawa state. The examined strains produced diverse extrolites, including several uncommon compounds: averantinmethylether in A. aflatoxiformans; aspergillimide in A. flavus; heptelidic acid in A. austwickii; desoxypaxillin, kotanin A and paspalitrems (A and B) in A. aflatoxiformans, A. austwickii and A. cerealis; aurasperon C, dimethylsulochrin, fellutanine A, methylorsellinic acid, nigragillin and pyrophen in A. brunneoviolaceus; cyclosporins (A, B, C and H) in A. niger; methylorsellinic acid, pyrophen and secalonic acid in A. piperis; aspulvinone E, fonsecin, kojic acid, kotanin A, malformin C, pyranonigrin and pyrophen in A. vadensis; and all compounds in F. madaense sp. nov., Meyerozyma, Neocosmospora and Neotestudina. This study provides snapshot data for prediction of food contamination and fungal biodiversity exploitation.

Fungal Diversity and Mycotoxins in Low Moisture Content Ready-To-Eat Foods in Nigeria.

Low moisture content ready-to-eat foods vended in Nigerian markets could be pre-packaged or packaged at point of sale. These foods are widely and frequently consumed across Nigeria as quick foods. Despite their importance in the daily diets of Nigerians, a comprehensive study on the diversity of fungi, fungal metabolite production potential, and mycotoxin contamination in the foods has not yet been reported. Therefore, this study assessed the diversity of fungi in 70 samples of low moisture content ready-to-eat foods [cheese balls, garri (cassava-based), granola (a mix of cereals and nuts) and popcorn] in Nigeria by applying a polyphasic approach including morphological examination, genera/species-specific gene marker sequencing and secondary metabolite profiling of fungal cultures. Additionally, mycotoxin levels in the foods were determined by LC-MS/MS. Fungal strains (n = 148) were recovered only from garri. Molecular analysis of 107 representative isolates revealed 27 species belonging to 12 genera: Acremonium, Allophoma, Aspergillus, Cladosporium, Fusarium, Microdochium, Penicillium, Sarocladium, Talaromyces, and Tolypocladium in the Ascomycota, and Fomitopsis and Trametes in the Basidiomycota. To the best of our knowledge Allophoma, Fomitopsis, Microdochium, Tolypocladium, and Trametes are reported in African food for the first time. A total of 21 uncommon metabolites were found in cultures of the following species: andrastin A and sporogen AO1 in Aspergillus flavus; paspalin in A. brunneoviolaceus; lecanoic acid and rugulusovin in A. sydowii; sclerotin A in P. citrinum and Talaromyces siamensis; barceloneic acid, festuclavine, fumigaclavine, isochromophilons (IV, VI, and IX), ochrephilone, sclerotioramin, and sclerotiorin in P. sclerotium; epoxyagroclavine, infectopyron, methylorsellinic acid and trichodermamide C in P. steckii; moniliformin and sporogen AO1 in P. copticola; and aminodimethyloctadecanol in Tolypocladium. Twenty-four mycotoxins in addition to other 73 fungal and plant toxins were quantified in the foods. In garri, cheeseballs, popcorn and granola were 1, 6, 12, and 23 mycotoxins detected, respectively. Deoxynivalenol, fumonisins, moniliformin, aflatoxins and citrinin contaminated 37, 31, 31, 20, and 14% of all food samples, respectively. Overall, citrinin had the highest mean concentration of 1481 µg/kg in the foods, suggesting high citrinin exposures in the Nigerian populace. Fungal and mycotoxin contamination of the foods depend on pre-food and post-food processing practices.

Fungal and plant metabolites in industrially-processed fruit juices in Nigeria.

There is scarce data on the mycotoxin profile in retailed fruit juices in Nigeria. Thirty-five industrially-processed fruit juice samples randomly purchased from retailers in Ogun state, Nigeria, were analysed for the presence of > 650 toxic fungal and plant metabolites using a liquid chromatography tandem mass spectrometric method. Only 18 metabolites, including 3-nitropropionic acid, alternariol methylether and emodin, but excluding citrinin, fumonisin B2, ochratoxin A and patulin, were detected in trace levels in at least one juice sample. Amygdalin, a plant cyanogen, was quantified (2.05-359 µg/L) in 40% of the samples. Although the levels of mycotoxins and toxic plant metabolites found in the juice may be relatively low, daily consumption of juices containing such low levels may contribute to dietary exposures to these natural chemical contaminants in consumers. Fruit juice processors should be encouraged to adhere strictly to good manufacturing practices in order to keep mycotoxins away from the final products.

Assessing the mycotoxicological risk from consumption of complementary foods by infants and young children in Nigeria.

This study assessed, for the first time, the mycotoxicological risks from consumption of complementary foods by infants and young children in Nigeria. Molds belonging to Aspergillus aculeatinus, A. flavus, A. luchuensis, A. tubingensis, A. welwitschiae and Geotrichum candidum were recovered from the complementary foods. Twenty-eight major mycotoxins and derivatives, and another 109 microbial metabolites including chloramphenicol (a bacterial metabolite), were quantified in 137 food samples by LC-MS/MS. Aflatoxins and fumonisins co-contaminated 42% of the cereal- and nut-based food samples, at mean concentrations exceeding the EU limits of 0.1 and 200 µg/kg set for processed baby foods by 300 and six times, respectively. Milk contained mainly beauvericin, chloramphenicol and zearalenone. The trichothecenes, T-2 and HT-2 toxins, were quantified only in infant formula and at levels three times above the EU indicative level of 15 µg/kg for baby food. Chronic exposure estimate to carcinogenic aflatoxin was high causing low margin of exposure (MOE). Exposures to other mycotoxins either exceeded the established reference values by several fold or revealed low MOEs, pointing to important health risks in this highly vulnerable population. The observed mycotoxin mixtures may further increase risks of adverse health outcomes of exposure; this warrants urgent advocacy and regulatory interventions.

Urinary aflatoxin exposure monitoring in rural and semi-urban populations in Ogun state, Nigeria.

Aflatoxins are a major class of fungal toxins that have food safety importance due to their economic and health impacts. This pilot aflatoxin exposure biomonitoring study on 84 individuals was conducted in a rural (Ilumafon) and a semi-urban community (Ilishan Remo) of Ogun state, Nigeria, to compare aflatoxin exposures among the two population cohorts. First morning urine samples were obtained from the participants, and the urinary aflatoxin M1 (AFM1) levels were measured by a quantitative Helica Biosystems Inc. ELISA kit assay. About 99% (83 out of 84) of the urine samples had detectable AFM1 levels in the range of 0.06 to 0.51 ng mL-1 (median: 0.27 ng mL-1). The mean urinary AFM1 levels were significantly (p = 0.001) higher in the semi-urban population (0.31 ± 0.09 ng mL-1) compared to the rural population (0.24 ± 0.07 ng mL-1). There were, however, no significant differences in mean urinary AFM1 levels of males and females, and among children, adolescents and adults. This study indicates high aflatoxin exposure to the extent of public health concerns in the studied populations. Thus, more efforts are required for aflatoxin exposure monitoring and control in high-risk regions.

Survey of roasted street-vended nuts in Sierra Leone for toxic metabolites of fungal origin.

Consumption of mycotoxin contaminated foodstuffs is common in regions where foods are not adequately controlled and routinely monitored, and this could have adverse effects on the health of consumers. In this study, 100 samples of roasted nuts (50 cashew nuts and 50 peanuts) vended within two cities of Sierra Leone were analysed for mycotoxins and other microbial metabolites by a LC-MS/MS method. The peanut samples contained detectable levels of 17 microbial metabolites, including aflatoxins B1, B2, G1 and G2 and alternariol, while none of these metabolites were found in the cashew samples. Aflatoxins (max: 5,729 µg/kg; mean: 487.8 µg/kg) and alternariol (3 µg/kg) were found in 24% and 2% of the peanut samples, respectively. One-third of the aflatoxin-contaminated peanut samples contained aflatoxins at levels exceeding the total aflatoxin limit of 4 µg/kg set by the European Union. Aflatoxin contamination of Sierra Leonean peanuts is high and requires urgent intervention to reduce consequent exposure.

Traditionally Processed Beverages in Africa: A Review of the Mycotoxin Occurrence Patterns and Exposure Assessment.

African traditional beverages are widely consumed food-grade liquids processed from single or mixed grains (mostly cereals) by simple food processing techniques, of which fermentation tops the list. These beverages are very diverse in composition and nutritional value and are specific to different cultures and countries. The grains from which home-processed traditional beverages are made across Africa are often heavily contaminated with multiple mycotoxins due to poor agricultural, handling, and storage practices that characterize the region. In the literature, there are many reports on the spectrum and quantities of mycotoxins in crops utilized in traditional beverage processing, however, few studies have analyzed mycotoxins in the beverages themselves. The available reports on mycotoxins in African traditional beverages are mainly centered on the finished products with little information on the process chain (raw material to final product), fate of the different mycotoxins during processing, and exposure estimates for consumers. Regulations targeting these local beverages are not in place despite the heavy occurrence of mycotoxins in their raw materials and the high consumption levels of the products in many homes. This paper therefore comprehensively discusses for the 1st time the available data on the wide variety of African traditional beverages, the mycotoxins that contaminate the beverages and their raw materials, exposure estimates, and possible consequent effects. Mycotoxin control options and future directions for mycotoxin research in beverage production are also highlighted.

High-Throughput Sequence Analyses of Bacterial Communities and Multi-Mycotoxin Profiling During Processing of Different Formulations of Kunu, a Traditional Fermented Beverage.

Kunu is a traditional fermented single or mixed cereals-based beverage popularly consumed in many parts of West Africa. Presently, the bacterial community and mycotoxin contamination profiles during processing of various kunu formulations have never been comprehensively studied. This study, therefore, investigated the bacterial community and multi-mycotoxin dynamics during the processing of three kunu formulations using high-throughput sequence analysis of partial 16S rRNA gene (hypervariable V3-V4 region) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. A total of 2,303 operational taxonomic units (OTUs) were obtained across six processing stages in all three kunu formulations. Principal coordinate analysis biplots of the Bray-Curtis dissimilarity between bacterial communities revealed the combined influences of formulations and processing steps. Taxonomically, OTUs spanned 13 phyla and 486 genera. Firmicutes (phylum) dominated (relative abundance) most of the processing stages, while Proteobacteria dominated the rest of the stages. Lactobacillus (genus taxa level) dominated most processing stages and the final product (kunu) of two formulations, whereas Clostridium sensu stricto (cluster 1) dominated kunu of one formulation, constituting a novel observation. We further identified Acetobacter, Propionibacterium, Gluconacetobacter, and Gluconobacter previously not associated with kunu processing. Shared phylotypes between all communities were dominated by lactic acid bacteria including species of Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Weissella. Other shared phylotypes included notable acetic acid bacteria and potential human enteric pathogens. Ten mycotoxins [3-Nitropropionic acid, aflatoxicol, aflatoxin B1 (AFB1), AFB2, AFM1, alternariol (AOH), alternariolmethylether (AME), beauvericin (BEAU), citrinin, and moniliformin] were quantified at varying concentrations in ingredients for kunu processing. Except for AOH, AME, and BEAU that were retained at minimal levels of < 2 µg/kg in the final product, most mycotoxins in the ingredients were not detectable after processing. In particular, mycotoxin levels were substantially reduced by fermentation, although simple dilution and sieving also contributed to mycotoxin reduction. This study reinforces the perception of kunu as a rich source of bacteria with beneficial attributes to consumer health, and provides in-depth understanding of the microbiology of kunu processing, as well as information on mycotoxin contamination and reduction during this process. These findings may aid the development of starter culture technology for safe and quality kunu production.