In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.

[EX Q]:  The goal of this study was to determine whether immunosuppression plays a role in the level and duration of fecal shedding of Escherichia coli O157 .
[EX A]: fecal

[EX Q]:  Lastly , already in 1992 Martin and co - workers showed the occurrence of a significant correlation between the content of serotonin in the aqueous humor and IOP in the human eye [ 85 ] .
[EX A]: humor

[EX Q]:  Neural network analysis of spectroscopic data of lycopene and beta - carotene content in food samples compared to HPLC - UV - vis .
[EX A]:
samples