Exposure of pregnant and non-pregnant African women to highly toxic environmental compounds
Gregor Reid1,2*, Stephanie L Collins2, Justin B Renaud3, Amy M McMillan1,2, Jacob Walsh3, Nicholas Nduti4, Remco Kort5, Wilbert Sybesma5, Ivan Mukisa6, and Mark W Sumarah3
1Departments of Microbiology & Immunology, and Surgery, Western University, 2Lawson Health Research Institute, 3Agriculture and Agri-Foods Canada, London, Canada, 4Technical University of Kenya, 5Yoba-for-life Uganda, and 6Makerere University, Uganda
The reproductive health of women and their babies can be severely affected by exposure to environmental toxins. A report showing 15% of Canadian women with mercury levels sufficiently high to cause neurological damage to the fetus illustrated the extent of the problem. We previously showed that pregnant women in Tanzania are exposed to high levels of mercury and arsenic, likely from consumption of fish from Lake Victoria, and Kenyan children are exposed to mycotoxins, carcinogenic and teratogenic compounds that enter the food chain. In this study, we explored exposure in 149 pregnant and non-pregnant Rwandan women to aflatoxins (AF), deoxynivalenol (DON), fumonisins (F), ochratoxin A (OTA) and zearalenone (ZEA). Using a state-of-the-art LC-MS/MS approach with isotope-labelled standards, we found that plasma AFB1-lysine, a sensitive biomarker for AFB1 exposure, was widely prevalent in 85% of women at a mean concentration of 2.195 ± 1.750 pg/mg albumin. Urinary AFM1, AFB1, and AFG1 were also found in 47%, 8% and 26% of women at concentrations of 97.9 ± 145.1, 9.08 ± 5.70, and 38.4 ± 79.7 pg/mg creatinine. DON, FB1, FB2, OTA and ZEA were detected in the urine of 60%, 30%, 15%, 71% and 42% of individuals in this population, at a mean quantity of 117.5 ± 342.6 ng/mg creatinine, 9.00 ± 18.16, 51.7 ± 39.8, 24.1 ± 31.2 and 42.9 ± 72.6 pg/mg creatinine, respectively. Although the source of contamination remains unknown, AFM1 levels were elevated in women with daily vegetable intake. In addition, pregnant women had greater exposure to AFB1 consistently across each trimester, compared to their non-pregnant counterparts. There was no correlation with vaginal microbiome abundance profiles or Nugent scores, emphasizing that urinary metabolites provide additional information on the health of the mother and fetus. Laboratory studies showed that Lactobacillus rhamnosus Yoba 2012, a probiotic that along with L. rhamnosus GR-1 is now distributed to over 350,000 people in fermented milk and cereal across east Africa further to program we initiated, can degrade aflatoxins. Daily intake of this food offers the potential to reduce adsorption of these carcinogens.