Mediterranean diet and subsequently improved gut microbiome tied to lower PTSD symptom burden in women
By Sravya Valiveti. This article was initially published in the 2/1/24 edition of our Concussion Update newsletter; please consider subscribing.
Findings from a recent study exploring the gut-brain-microbiota axis by researchers Shanlin Ke et al. revealed that post-traumatic stress disorder (PTSD) symptoms were found to be associated with lower adherence to the Mediterranean dietary pattern and impaired function of the gut microbiome in a cohort of women. Those who adhered to a Mediterranean diet experienced reduced PTSD symptoms, according to this study published in Nature Mental Health.
Through this research, the study team wanted to further explore the relationship between PTSD (a mental health condition that is linked to fear and can often result from witnessing traumatic events) and the gut microbiome, which is a vital indicator of physical health. They also note that prior research has established that dietary patterns and gut microbiome health tend to play a role in emotional responses or regulation and can influence mental health.
Chronic PTSD symptoms can be a significant risk factor that can be burdensome for patients and families, often contributing to other adverse health risks over time. Those with PTSD are more likely to develop chronic conditions––such as coronary artery disease, diabetes, and stroke––that may lead to untimely death, according to a press release by the Harvard T.H. Chan School of Public Health.
The research team collected data on trauma exposure, microbiome, and dietary information from a cohort of 191 women enrolled in the sub-studies of the Nurses’ Health Study-II. For one part of the study, the team tested whether Eubacterium eligens (E. eligens) was consistently the top PTSD-protective species and determined that an “inverse association of E. eligens abundance with PTSD symptoms was highly consistent.” In other words, the more abundant E. eligens in the gut microbiome, the fewer PTSD symptoms participants experienced. The teams’ findings highlighted an association between higher levels of PTSD symptoms, less adherence to the Mediterranean diet, and a lowered amount of E.eligens in the gut microbiome. Adherence to a Mediterranean diet that included vegetables, fruits, fish, and reduced red and processed meat was linked to fewer PTSD symptoms and an increased E.eligens abundance in participants. Notably, they found that eating plant-based food was associated with a reduction in PTSD symptoms. On the other hand, consuming red and processed meats was associated with experiencing worse PTSD symptoms and reduced E. eligens in the gut microbiome.
The 191 subjects were categorized based on level of trauma exposure and assigned into probable PTSD, exposed to trauma but no PTSD, and no trauma exposure groups. They also collected data on factors associated with overall well-being and gut health, such as PTSD symptoms, depression, medications, age, BMI, and other dietary information––and how these additional factors could influence the microbiome structure. They evaluated this data to assess how stable the patients’ microbiome was over a span of 6 months. This longer data collection window helped them identify patterns associated with microbial pathways as well as gut microbiome species that were putative PTSD protective and involved in PTSD symptoms.
Results from this study can help inform future dietary recommendations and interventions that factor in the Mediterranean diet and are aimed at minimizing symptoms or distress associated with PTSD to improve the overall quality of health for patients. However, the study team notes that additional insights into the gut microbiome and diet might be needed to address the prevention of PTSD symptoms and to examine the role of diet in other mental health disorders. The study authors note that one study limitation was their use of a short PTSD screening scale instead of a formal PTSD clinical diagnosis.