Samantha Murray

A new University of Florida study has found that bacteria in the saliva of college students who reported recent thoughts of suicide differed in significant ways from those found in students who had not experienced recent suicidal thinking.

While there is a growing body of research on mental health and the human microbiome, this is the first study to look at bacterial differences in the saliva of those with and without recent suicidal thoughts, also called suicidal ideation. Recent suicidal ideation was defined as thoughts of suicide within the two weeks before the saliva sample was taken.

Controlling for the influence of other factors known to impact mental health, such as diet and sleep, the researchers found that students with recent suicidal thoughts had higher levels of bacteria associated with periodontal disease and other inflammatory health conditions.

They also found that these students had lower levels of Alloprevotella rava, a bacterium known to produce a compound that promotes brain health. These students also shared a genetic variation that the researchers found may influence the presence of Alloprevotella rava in the mouth.

“These results are exciting because they tell us which bacteria we need to look at more closely. Our question now is, what are these bacteria doing biologically that affects mental health?” said Angelica Ahrens, first author of the study and a postdoctoral researcher in the UF/IFAS microbiology and cell science department. Ahrens led the study as part of her doctoral program in the UF/IFAS College of Agricultural and Life Sciences.

“Eventually, we hope this line of research could help predict suicidal ideation based on a person’s microbiome and could inform pro- or prebiotic treatments for those at risk,” said Ahrens.

The study analyzed saliva collected from nearly 500…read more