The membrane lining the inside of our intestines forms a barrier that simultaneously prevents bacteria and toxins from reaching the inside our intestines and from getting out and into the bloodstream.
When it doesn't function properly, however, this lining may have cracks or holes in it, allowing pathogens and food waste to get into the bloodstream and new pathogens to get into the gut.
Now, a first-of-its-kind study examines the impact of marital hostility on the risk of developing leaky gut syndrome. The new research was led by psychiatry professor Janice Kiecolt-Glaser, director of the Institute for Behavioral Medicine Research at the Ohio State University Wexner Medical Center in Columbus.
Prof. Kiecolt-Glaser and team published their findings in the journal Psychoneuroendocrinology.
Studying marital hostility and gut health
The researchers examined 43 married couples aged 24–61. The study participants were all healthy overall and had been married for at least 3 years.
The scientists asked the couples about the topics that were most likely to cause a disagreement in the relationship.
Once they established that money and in-laws were the most sensitive topics, the researchers left the spouses to have 20-minute discussions on these topics. They videotaped the interactions and then assessed the arguing style.
The couples' fighting style was characterized as hostile if it included gestures such as eye rolling and verbal criticism of one's spouse.
Participants also gave the researchers blood samples both before and after the interactions, and the scientists tested the samples for a marker of leaky gut syndrome called LPS-binding protein (LBP).
Marital hostility and depression harm the gut
The study revealed that people who engaged in more hostile marital interactions had higher LBP levels in their blood.
The team also looked at the associations between LBP and another marker for inflammation: C-reactive protein.
People with the highest levels of LBP also had almost 80 percent higher levels of C-reactive protein, compared with those who had the lowest levels of LBP.
These participants had also been part of another study conducted by Ohio State researchers, which looked at how the convergence of marital hostility and depression can cause obesity.
So, in this study, the scientists were also able to look at the participants' history of depression. They found that those who had experienced a depressive episode or another mood disorder were most vulnerable to the gut-harming effects of marital hostility.
Prof. Kiecolt-Glaser comments on their findings, saying, "We think that this everyday marital distress — at least for some people — is causing changes in the gut that lead to inflammation and, potentially, illness."
"Hostility is a hallmark of bad marriages — the kind that lead to adverse physiological changes," she adds.
"Marital stress is a particularly potent stress, because your partner is typically your primary support and in a troubled marriage your partner becomes your major source of stress," Prof. Kiecolt-Glaser explains.
"Depression and a poor marriage — that really made things worse [...] This may reflect persistent psychological and physiological vulnerabilities among people who have suffered from depression and other mood disorders."
Prof. Janice Kiecolt-Glaser