As scientists try to learn more about the impact of the gut microbiome on physical and mental health, a new study finds the Mediterranean diet may prevent PTSD symptoms.

“There is a very intriguing relationship between the human gut microbiome and the brain,” said co-corresponding study author Yang-Yu Liu, of the Channing Division of Network Medicine at Brigham and Women’s Hospital, in Boston.

“Through our study, we examined how factors, like diet, are associated with PTSD symptoms. While further research is needed, we are closer to being able to provide dietary recommendations for PTSD prevention or amelioration,” Liu said in a hospital news release.

PTSD, or post-traumatic stress disorder, is a trauma-based mental health disorder. Some people develop it after experiencing a disturbing and horrifying situation involving severe injury, violence, threatened death or actual death.

It affects not only the individual, but can extend to their family, the health care industry and society.

People living with PTSD have an increased risk of developing chronic diseases such as heart disease, stroke, diabetes, autoimmune diseases and premature death.

“Examining the gut-brain axis can provide insights on the interdependence of mental and physical health,” said co-corresponding study author Karestan Koenen, of the department of epidemiology at Harvard T.H. Chan School of Public Health.

“Our findings suggest the PTSD and human gut microbiome relationship is a promising area of research that may lead to recommendations for alleviating the downstream negative health consequences of PTSD,” Koenen added.

To study this, the researchers collected data from 191 participants in sub-studies of the Nurses’ Health Study II.

The investigators assigned participants to three groups: probable PTSD; exposed to trauma but no PTSD; and no trauma exposure.

All of the participants provided two sets of four stool samples, once at the beginning of the study and again six months later. The reason for the samples was to have microbial DNA information and to confirm that the participant’s gut microbiome was stable over six months.

The researchers then looked at associations between overall microbiome makeup and other individual factors, such as a person’s symptoms, body mass index (BMI), age and diet.

The team found certain factors (BMI, depression and antidepressant use) were associated with the microbiome structure.

The scientists then assessed the relationship between diet and PTSD symptoms, finding that participants who followed a Mediterranean diet had fewer PTSD symptoms.

Eating red and processed meats was associated with having PTSD symptoms. Eating plant-based foods was not associated with having PTSD symptoms. However, the associations seen in the study do not prove a cause-and-effect relationship.

The team then examined the link between symptoms and gut microbiome makeup.

They found that a microbe called the Eubacterium eligens was protective at four different time points.

E. eligens was positively associated with components of the Mediterranean diet, such as vegetables, fruits and fish. It was negatively associated with red or processed meat, which people following a Mediterranean diet typically limit or avoid.

Study limitations include using a short screening scale for PTSD rather than a formal clinical diagnosis.

“It’s exciting that our results imply that the Mediterranean diet may provide potential relief to individuals experiencing PTSD symptoms,” Liu said. “We are eager to learn more about the relationship between PTSD, diet and the gut microbiome. In a future study, we will attempt to validate the efficacy of probiotics as a method to prevent PTSD.”

The findings were published Oct. 19 in the journal Nature Mental Health. Support for the study came from the U.S. National Institutes of Health.

More information

The National Library of Medicine has more on the Mediterranean diet.

SOURCE: Brigham and Women’s Hospital, news release, Oct. 19, 2023

Source: HealthDay