Not All Saliva Samples Are Equal: The Role Of Cellular Heterogeneity In DNA Methylation And Epigenetic Age Analyses With Biological And Psychosocial Factors
Have you ever wondered if the tiny differences in your body’s samples could tell a bigger story about your health? New research highlights that not all saliva samples are the same, especially when it comes to understanding our “epigenetic age” and how our environment affects our genes.
Our saliva, often collected for health studies because it’s easy and non-invasive, is actually a mix of different cell types, mainly immune cells and cells from the lining of our mouth. These different cells have unique “DNA methylation” patterns, which are like tiny chemical tags on our DNA that can turn genes on or off. These patterns are crucial for determining our biological age, known as “epigenetic age,” which can sometimes differ from our actual chronological age.
This study found that the specific mix of cells in a saliva sample can significantly influence the results of these genetic analyses. For instance, when studying children, using a reference guide based on children’s cell types was more accurate than using one based on adults. They also discovered that if a saliva sample had a lot of immune cells, it showed a stronger link between tobacco smoke exposure and changes in DNA methylation and epigenetic age.
This means that to get the most accurate picture of our health and how our environment shapes our genes, scientists need to carefully consider the cellular makeup of saliva samples. This understanding is vital for future research, helping us better interpret findings and replicate studies, especially in children.
Source: link to paper