The microbes in our bodies can have a significant influence on our health and well-being. While many studies investigating the microbial communities that live in and on us have focused on the gut microbiome, bacteria live in many others parts of our bodies too, including on our skin and in our mouths. The oral microbiome can affect our health in a variety of ways. New research has shown that college students who had recently experienced suicidal thoughts carried different bacteria in their saliva compared to college students who had not had such thoughts.
This study, which was published in Scientific Reports, assessed saliva samples from about 500 undergraduate student volunteers. At the time the volunteers submitted a sample, they were asked questions about their mental health within the previous two weeks. Patient Health Questionnaire-9 was used; it screens for feelings of depression and suicide ideation, in which people have thoughts of ending their own life. If you are struggling with thoughts of suicide, you can seek help by dialing the National Suicide Prevention Lifeline at 988.
The researchers controlled for other factors that may have been contributing to suicide ideation, such as sleep levels and dietary habits. The work indicated that students who experienced recent suicide ideation had higher levels of bacteria that have been linked to inflammatory and periodontal disease. Those students also had lower levels of a bacterium called Alloprevotella rava, a microbe that is known to generate a compound that improves brain health. These individuals also carried a genetic variant that might be affecting Alloprevotella rava levels.
While these results have identified bacteria that researchers should focus on and the data is "exciting," more work will be needed to find out exactly how these bacteria are affecting mental health, noted first study author Angelica Ahrens, PhD, of 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," Ahrens added.
In 2020, the Centers for Disease Control and Prevention determined that about one quarter of college-aged adults thought about suicide seriously within the previous month. It may one day be possible to screen for suicidal thoughts by analyzing saliva samples.
In this study, any student who reported suicide ideation was referred to mental health services on campus.
"Mental health and suicide are serious issues on college campuses, and our students were very interested in being a part of research that can help address this problem. We are continuing to collect data for follow-up studies and hope more students and universities will become involved," noted senior study author Eric Triplett, chair of the microbiology and cell science department at UF.