Association between Urinary Aflatoxin (AFM₁) and Dietary Intake among Adults in Hulu Langat District, Selangor, Malaysia

AFB1 Toxicity in Human Food and Animal Feed Consumption: A Review of Experimental Treatments and Preventive Measures

AIMS

The current review aims to outline and summarize the latest research on aflatoxin, with research studies describing natural, herbal and chemical compound applications in animal (pig) models and in vitro cellular studies. Aflatoxin, a carcinogenic toxin metabolite, is produced by Aspergillus flavus in humid environments, posing a threat to human health and crop production. The current treatment involves the prevention of exposure to aflatoxin and counteracting its harmful toxic effects, enabling survival and research studies on an antidote for aflatoxin.

OBJECTIVES

To summarize current research prospects and to outline the influence of aflatoxin on animal forage in farm production, food and crop processing. The research application of remedies to treat aflatoxin is undergoing development to pinpoint biochemical pathways responsible for aflatoxin effects transmission and actions of treatment.

SIGNIFICANCE

To underline the environmental stress of aflatoxin on meat and dairy products; to describe clinical syndromes associated with aflatoxicosis on human health that are counteracted with proposed treatment and preventive interventions. To understand how to improve the health of farm animals with feed conditions.

Assessment of aflatoxin M1 exposure and associated determinants in children from Lahore, Pakistan

Aflatoxins are potent carcinogenic and immunomodulatory mycotoxins, and exposure may lead to deleterious effects on human health. This study aimed to detect aflatoxin M₁ (AFM₁) as biomarker of exposure and determine associated risk factors in children attending a specialized-childcare hospital in Lahore. Urine samples collected from 238 children (1-11 years) during winter (January-mid-March 2020) and hot-humid summer (August-September 2020) were tested for AFM₁ presence using ELISA. Data on potential risk factors were also collected. Of 238 samples, 156 (65.5%) were positive for urinary AFM₁. Season was significantly associated (OR = 2.64; 95% CI = 1.49-4.79; p = 0.001) with AFM₁ positivity; prevalence was higher in hot-humid months (74.6%) than winter (57.3%). The place of living was also significantly associated (OR = 2.21; 95% CI = 1.25-3.97; p = 0.007), and urinary AFM₁ positivity was higher in urban children (71.1%) compared to rural (58.3%). Median value for creatinine-adjusted AFM₁ was 1.9 ng/mg creatinine (Q1-Q3 = 0.82-6.0 ng/mg creatinine), while non-creatinine-adjusted AFM₁ was 0.57 ng/mL (Q1-Q3 = 0.23-1.4 ng/mL). Significantly higher urinary AFM₁ levels were detected in children; age ≤2 years (p = 0.037), who consumed more milk (p = 0.048), and who presented to the nutrition clinic (p = 0.003). These findings highlight the need for an effective control program to reduce the AFM₁ burden in children.

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.

A preliminary study on aflatoxin exposure by urine biomonitoring in Chile

We assessed the occurrence of aflatoxin M₁ (AFM₁) in urine in a sample of the MAUCO population-based cohort (n = 120) using an enzyme-linked immune sorbent assay (ELISA) kit specially designed for the analysis of AFM₁ in urine. We found AFM₁ in the urine of 59% of the participants (> limit of detection), with 12% of the samples being over the limit of quantification. The mean of the quantifiable samples was 0.66 (± 0.35) ng/mg adjusted creatinine, ranging from 0.31 to 1.39 ng/mg creatinine. The mean probable daily intake (PDI) of AFB₁ was 0.23 (± 0.37) ng/kg bw according to the upper bound (UB), being significantly higher in women and 0.14 (± 0.23) ng/kg bw in the modified lower bound (mLB) approach, ranging from 0.01 to 1.98 ng/kg bw. The risk of AFB₁ was assessed with the margin of exposure (MOE) approach estimated at 2800 in the mean mLB and 1733 in the mean UB. According to the MOE values obtained in this study, aflatoxin B₁ exposure must be considered a public health concern and must be taken as a priority for food risk management.

Biomonitoring aflatoxin B1 exposure of residents from the Amazon region: a pilot study

The present study was a pilot study that aimed to evaluate the occurrence of aflatoxins (AF) in the human diets and its presence in human urine as a metabolite (aflatoxin M1; AFM1). Volunteers from the Amazon region were evaluated before and after the consumption of 2 Brazil nuts/day for thirty days. At the end of 30 days (t=30) without the consumption of Brazil nuts, 9 samples (30%) were positive for AFM1. After 30 days (t=30) consuming 2 Brazil nuts per day, there was a reduction to 2 positive samples (7%). Questionnaires were also applied to volunteers, and the foods most often cited as consumed in their normal diet were cereals and bovine milk. However, there was no statistical relationship between these foods and the levels of AFM1 in the urine or in relation to those who already consumed Brazil nuts in culinary preparations or derived products. Despite the reduction of positive samples for AFM1 after 30 days of Brazil nut consumption, we suggest further studies regarding the clinical condition and genetics of individuals from the Amazon region, as well as the nutrient levels of the diet, e.g. for selenium, and which may protect the human body against aflatoxins.

Exposure Assessment of Multiple Mycotoxins and Cumulative Health Risk Assessment: A Biomonitoring-Based Study in the Yangtze River Delta, China

The extensive exposure to multiple mycotoxins has been demonstrated in many countries; however, realistic assessments of the risks related to cumulative exposure are limited. This biomonitoring study was conducted to investigate exposure to 23 mycotoxins/metabolites and their determinants in 227 adults (aged 20-88 years) in the Yangtze River Delta, China. Eight mycotoxins were detected in 110 urine samples, and multiple mycotoxins co-occurred in 51/227 (22.47%) of urine samples, with deoxynivalenol (DON), fumonisin B1 (FB1), and zearalenone (ZEN) being the most frequently occurring. For single mycotoxin risk assessment, FB1, ZEN, aflatoxin B1 (AFB1), and ochratoxin A (OTA) all showed potential adverse effects. However, for the 12 samples containing DON and ZEN, in which none had a hazard risk, the combination of both mycotoxins in two samples was considered to pose potential endocrine disrupting risks to humans by hazard index (HI) method. The combined margin of exposure (MOET) for AFB1 and FB1 could constitute a potential health concern, and AFB1 was the main contributor. Our approach provides a blueprint for evaluating the cumulative risks related to different types of mycotoxins and opens a new horizon for the accurate interpretation of epidemiological health outcomes related to multi-mycotoxin exposure.

Aflatoxin exposure among lactating women in southern Ethiopia

In Ethiopia and many other low-income countries, little is known about the exposure of lactating women to aflatoxin, which is a major health concern to the mother and her nursing infant. We determined the aflatoxin B1 contamination of family foods (AFB1) and urinary aflatoxin M1 (AFM1) of lactating women in Sidama, southern Ethiopia, and compared the levels across agroecological settings (lowland, midland, highland) and two seasons. We conducted two surveys (n = 360) that represented the dry and wet seasons of the locality. AFM1 and AFB1 were determined using enzyme-linked immunosorbent assay (ELISA). Statistical analysis was made using Mann-Whitney U test and Kruskal-Wallis test. The median (interquartile range) AFB1 was 0.94 (0.63-1.58) ppb. AFB1 was detected in 95.6% of the food samples, and 13.6% exceeded the 2.0 ppb threshold. We observed an increasing trend for aflatoxin exposure from highland to lowland (p < .001), but there was no difference between seasons (p = .743). The median (interquartile range) urinary AFM1 was 214 (undetectable to 2,582) ppt, and AFM1 was detectable in 53.3% of the samples. Urinary AFM1 showed significant difference among agroecological zones (p < .001) but not between seasons (p = .275). A significant but weak correlation was observed between AFB1 and urinary AFM1 (rs  = 0.177, p = .001). We concluded that lactating women in Sidama, especially those in the lowland area, have unsafe exposure to aflatoxin.

Screening of the aflatoxin M1 metabolite in urine samples of residents in Terengganu, Malaysia

A study was conducted to screen the occurrence and level of aflatoxin M₁ (AFM₁) in urine samples of 206 urban and rural residents in Terengganu, Malaysia. The level of AFM₁ was quantified by competitive enzyme-linked immune-absorbent assay (ELISA). Of the 206 samples, 84 were positive for AFM₁ (40.8%) in a range of 0.07-5.53 ng/ml (mean = 0.589 ng/ml). Residents of Terengganu are moderately exposed to AFM₁. Age, ethnicity, marital status and employment status were associated with urinary level of AFM₁. Subjects aged 30 years and above, non-Malays, married, and those unemployed had significantly higher levels of urinary AFM₁ (p < 0.05)_. Since aflatoxin is recognised as a potent-carcinogen for liver cancer and a continuous exposure to this toxin can be fatal, the present findings could provide a baseline for future studies where larger samples and more advanced techniques might be used to find the possible effects of the exposure of this toxin on the community's health.

Aflatoxins: Occurrence, Exposure, and Binding to Lactobacillus Species from the Gut Microbiota of Rural Ugandan Children

Chronic exposure of children in sub-Saharan Africa to aflatoxins has been associated with low birth weight, stunted growth, immune suppression, and liver function damage. Lactobacillus species have been shown to reduce aflatoxin contamination during the process of food fermentation. Twenty-three Lactobacillus strains were isolated from fecal samples obtained from a cohort of rural Ugandan children at the age of 54 to 60 months, typed by 16S rRNA gene sequencing, and characterized in terms of their ability to bind aflatoxin B₁ in vitro. Evidence for chronic exposure of these children to aflatoxin B₁ in the study area was obtained by analysis of local foods (maize flour and peanuts), followed by the identification of the breakdown product aflatoxin M₁ in their urine samples. Surprisingly, Lactobacillus in the gut microbiota of 140 children from the same cohort at 24 and 36 months showed the highest positive correlation coefficient with stunting among all bacterial genera identified in the stool samples. This correlation was interpreted to be associated with dietary changes from breastfeeding to plant-based solid foods that pose an additional risk for aflatoxin contamination, on one hand, and lead to increased intake of Lactobacillus species on the other.