Fig. 8
From: Polyamine metabolism links gut microbiota and testicular dysfunction
TP influenced gut microbiota and the function of testis. TP decreased the levels of ODC and SLC22A16 in testis, which impaired the biosynthesis of spermine and its uptake. ODC is responsible for the generation of putrescine from ornithine, which is further transformed into spermidine and spermine. Parabacteroides distasonis that produces spermine was decreased following TP exposure. The decrease of spermine concentration in testis resulted in the downregulation of HSP70s and testicular injury