Stress‐related salivary proteins affect the production of volatile sulfur compounds by oral bacteria

Objective To determine whether stress‐related substances and sex hormones influence the growth and in vitro production of volatile sulfur compounds ( VSC s) by Solobacterium moorei and Fusobacterium nucleatum . Materials and Methods Bacteria growth and VSC s production were evaluated in the presence of alpha‐amylase, beta‐defensin‐2, mucin, estradiol, and progesterone. Growth was evaluated by colony counting, and the production of the VSC s hydrogen sulfide (H 2 S) and methyl mercaptan ( CH 3 SH ) was measured using the Oral Chroma™ instrument. Results Mucin induced the production of H 2 S by both bacteria, but had a slight inhibitory effect on CH 3 SH production by F. nucleatum . It also increased the viability of F. nucleatum . Alpha‐amylase increased H 2 S production by S. moorei and CH 3 SH production by F. nucleatum , but had no effect on H 2 S production by F. nucleatum . No substance altered the viability of S. moorei . No effects of beta‐defensin‐2, estradiol, or progesterone were observed. Conclusion The salivary stress‐related proteins mucin and alpha‐amylase altered VSC s production by F. nucleatum and S. moorei, favoring H 2 S production. These findings are a step toward understanding the relation between stress and increased amounts of H 2 S.