Occurrence of ochratoxin A in breast milk and urine samples of nursing mothers in Bangladesh.

The mycotoxin ochratoxin A (OTA) is a potent nephrotoxin with carcinogenic properties and, thus, of concern as a food contaminant. Since food contaminant data are scarce in Bangladesh, we applied human biomonitoring to gain more insights into OTA exposure in the country's population. OTA concentrations in human milk and urine samples of nursing mothers were determined with the aim to assess also exposure to this mycotoxin in breastfed infants. Breastfeeding mothers (n = 74) from three districts of Bangladesh (Sylhet, Cumilla, and Mymensingh region) participated in this study. They provided demographic data, along with breast milk and urine samples. OTA levels were measured by a competitive enzyme-linked immunosorbent assay (ELISA) with a detection limit of 60 ng/L for milk and 30 ng/L for urine.OTA was detected in 62.2% of all breast milk samples (mean 74.8 ± 49.0 ng/L, range < LOD-243.3 ng/L) and in 51.4% of all urine samples (mean 44.3 ± 63.5 ng/L, range < LOD-519.3 ng/L). The differences observed between regions for mean breast milk or for urinary OTA levels were relatively small. No significant correlation was observed between OTA levels in breast milk and food consumption patterns among nursing mothers. Regarding infant exposure, the estimated average daily intake of OTA for all was 15.0 ng/kg bw/day (range 4.5-45 ng/kg bw/day). In 34.5% of these infants, their estimated daily OTA intake exceeded a preliminary TDI value set by EFSA (17 ng/kg bw/day). The mean OTA intake was slightly higher (16.2 ± 7.8 ng/kg bw/day) in 1-2 months babies than in older infants (< 2 to 12 months), although the difference was not significant. Presence of OTA in most milk and urine samples of nursing mothers documents their widespread dietary mycotoxin exposure. Although based on a relatively small number of participants, the present analysis indicates non-negligible exposure of some nursed infants in Bangladesh. Therefore, further biomonitoring studies and investigations on major sources of OTA in food commodities are encouraged.

Occurrence of aflatoxin M1 in human breast milk in Bangladesh.

Breast milk is the best, most complete form of nutrition for newborns and infants. However, human milk can contain aflatoxin M1 (AFM1) upon ingestion of dietary mycotoxin contaminants, namely, aflatoxin B1 (AFB1), by lactating mothers. AFB1 and its hydroxylated metabolite AFM1 are potent carcinogens and thus an important issue in food safety and public health. This study is the first to explore the presence of AFM1 in breast milk samples from Bangladesh and assess infant exposure to this toxin, as a consequence of maternal mycotoxin intake. A total of 62 breast milk samples were collected from nursing mothers in Sylhet region of Bangladesh. The milk samples were collected between October 2019 and March 2020 and analyzed by a sensitive enzyme-linked immunosorbent assay. AFM1 was detected in 51.6% of the breast milk samples (colostrum, transitional and mature milk), with a mean concentration of 4.42 ± 0.56 pg/mL, and in the range between LOD (4.0 pg/mL) and 6.66 pg/mL. The frequent detection of AFM1 in breast milk indicates widespread dietary exposure to mycotoxins in our cohort. The estimated average daily intake of AFM1 for all nursed infants was 0.49 ng/kg b.w./day. No significant correlations were observed between AFM1 levels in human milk and food items regularly consumed by nursing women. Overall, AFM1 levels in breast milk samples from the Sylhet region of Bangladesh are moderate, and lower than the permissible levels established for AFM1 in dairy milk or infant formulae (50 and 25 ng/kg, respectively). Yet, this first data for AFM1 breast milk contaminant levels just reflect the recent situation in one cohort, and monitoring should be continued.