Evidence for fumonisin inhibition of ceramide synthase in humans consuming maize‐based foods and living in high exposure communities in Guatemala

Scope Fumonisin (FB) occurs in maize and is an inhibitor of ceramide synthase (CerS). We determined the urinary FB 1 (UFB 1 ) and sphingoid base 1‐phosphate levels in blood from women consuming maize in high and low FB exposure communities in Guatemala. Methods and results FB 1 intake was estimated using the UFB 1 . Sphinganine 1‐phosphate (Sa 1‐P), sphingosine 1‐phosphate (So 1‐P), and the Sa 1‐P/So 1‐P ratio were determined in blood spots collected on absorbent paper at the same time as urine collection. In the first study, blood spots and urine were collected every 3 months (March 2011 to February 2012) from women living in low (Chimaltenango and Escuintla) and high (Jutiapa) FB exposure communities (1240 total recruits). The UFB 1 , Sa 1‐P/So 1‐P ratio, and Sa 1‐P/mL in blood spots were significantly higher in the high FB 1 intake community compared to the low FB 1 intake communities. The results were confirmed in a follow‐up study (February 2013) involving 299 women living in low (Sacatepéquez) and high (Santa Rosa and Chiquimula) FB exposure communities. Conclusions High levels of FB 1 intake are correlated with changes in Sa 1‐P and the Sa 1‐P/So 1‐P ratio in human blood in a manner consistent with FB 1 inhibition of CerS.