Kiecolt-Glaser JK, Wilson SJ, Bailey ML, Andridge R, Peng J, Jaremka LM, Fagundes CP, Malarkey WB, Laskowski B, Belury MA (2018) Psychoneuroendocrinology. 2018 Aug 4;98:5 2-60. doi: 10.1016/j.psyneuen.2018.08.007. [Epub ahead of print]
Marital distress and depression work in tandem to escalate risks for inflammation-related disorders. Translocation of bacterial endotoxin (lipopolysaccharide, LPS) from the gut microbiota to blood circulation stimulates systemic inflammatory responses.
To investigate increased gut permeability (a "leaky gut") as one potential mechanistic pathway from marital distress and depression to heightened inflammation, this secondary analysis of a double-blind, randomized crossover study examined serial assessments of two endotoxin biomarkers, LPS-binding protein (LBP) and soluble CD14 (sCD14), as well as C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) during two separate 9.5 h visits. The 43 (N = 86) healthy married couples, ages 24-61 (mean = 38.22), discussed a marital disagreement during both visits; behavioral coding of these interactions provided data on hostile marital behaviors, a hallmark of marital distress. The Structured Diagnostic Interview for DSM-IV assessed participants' mood disorder history.
Participants with more hostile marital interactions had higher LBP than those who were less hostile. Additionally, the combination of more hostile marital interactions with a mood disorder history was associated with higher LBP/sCD14 ratios. Higher LBP and LBP/sCD14 were associated with greater CRP production; for example, only 21% of low LBP participants (lowest quartile) had average CRP across the day > 3, compared to 79% of those in the highest quartile. Higher sCD14 was associated with higher IL-6.
These bacterial LPS translocation data illustrate how a distressed marriage and a mood disorder history can promote a proinflammatory milieu through increased gut permeability, thus fueling inflammation-related disorders.