Gingival Transcriptome Patterns During Induction and Resolution of Experimental Gingivitis in Humans:
A relatively small subset (11.9%) of the immune response genes analyzed by array was transiently activated in response to biofilm overgrowth, suggesting a degree of specificity in the transcriptome-expression response. The fact that this same subset demonstrates a reversal in expression patterns during clinical resolution implicates these genes as being critical for maintaining tissue homeostasis at the biofilm–gingival interface. In addition to the immune response pathway as the dominant response theme, new candidate genes and pathways were identified as being selectively modulated in experimental gingivitis, including neural processes, epithelial defenses, angiogenesis, and wound healing.
ScienceDaily has a more awesome title, Nearly One Third of Human Genome Is Involved in Gingivitis, Study Shows:
Research conducted jointly by the University of North Carolina at Chapel Hill and Procter & Gamble (P&G) Oral Care has found that more than 9,000 genes — nearly 30 percent of the genes found in the human body — are expressed differently during the onset and healing process associated with gingivitis. Biological pathways associated with activation of the immune system were found to be the major pathways being activated and critical to controlling the body’s reaction to plaque build-up on the teeth. Additionally, other gene expression pathways activated during plaque overgrowth include those involved in wound healing, neural processes and skin turnover.
Perhaps then bad breath and poor oral hygiene are simply a fitness indicator, and kissing evolved as a method for humans to evaluate each other’s health as an “honest” signal?