Current status of human biomonitoring of beauvericin and enniatins

Beauvericin (BEA) and enniatins (ENNs) are Fusarium mycotoxins found in cereals and cereal-based foods as reported in several studies. But information on human internal exposure remains scattered. Human biomonitoring (HBM) enables the investigation of exposure to these nonregulated contaminants. This review summarizes data from studies published since 2014 on occurrence of BEA and ENNs in human urine, blood, breast milk, tissues and hair. Most studies from Europe, Africa, Asia and North America applied state-of-art methodologies for biomarker analysis. ENN B was the most frequently detected compound and was found in a high proportion of blood samples across different populations. Although BEA was reported less frequently, measurable levels were found in plasma, breast milk, tissues and, more recently, in urine. Both BEA and ENNs were found in human milk, indicating transfer from mother to infant, but generally at low concentrations. Data for human tissues suggest differences in distribution, with BEA occurring mainly in adipose tissue and ENN B reaching the highest concentrations in liver. Some studies reported phase-I metabolites of ENNs in urine, demonstrating that biotransformation contributes to their elimination in humans. Available HBM data indicate widespread dietary exposure to BEA and ENNs in several human populations. Concentrations measured in blood and tissues are much lower than those associated with their cytotoxic effects in vitro. Uncertainties remain regarding human toxicokinetics and the toxicological relevance of their metabolites. Further studies addressing these gaps will improve interpretation of biomonitoring data and support the human health risk assessment of these emerging mycotoxins.