Caffeine is one of the most widely used xenobiotic compounds in the world and has earlier been linked to an increased risk of first trimester spontaneous abortion among heavy coffee drinkers .

咖啡因是世界上应用最广泛的外源性化合物之一，并且早年被认为与大量咖啡饮用者中增加的妊娠早期自然流产风险有关。

The reversible genes were particularly involved in xenobiotic functions ( managing chemicals not produced in the body ) , nucleotide metabolism and mucus secretion .

可逆基因一般和异生物质功能（管理不由身体产生的化学物质）、核苷代谢、黏液分泌有关。