Microbiome study on PTSD sufferers adds to baseline data for gut-brain connection

Research in the connection between the microbiome and cognitive issues continues to expand, with research done in South Africa on subjects suffering post traumatic stress disorder.

The recent pilot study done by a team led by Stephanie Malan-Müller, PhD of Stellenbosch University in Cape Town, South Africa adds to a growing body of literature on the gut-brain connection and its implications for health. Much of this research has been presented at NutraIngredients-USA’s Probiota Americas events over the past several years.  

Gathering baseline data on gut-brain connection

The term ‘psychobiotics’ has been bandied about in recent years, as research opens up the possibility of finding ways to affect cognitive function through microbiome alterations. Could anxiety disorders, cognitive decline, even ADHD or autism be positively affected by altering the makeup of a subject’s gut microbiome?

Researchers from both UCLA and McMaster University in Canada have presented their findings on the interactions at past Probiota Americas events. The most recent one took place in early June in Miami, where Malan-Müller spoke.

One question that has hovered around this research from the beginning is the chicken-and-egg question. This is true, too, of other areas of microbiome research, such as how the guts of obese people differ from those of habitually slim individuals.

Do these different microbiome profiles determine or raise the risk of the condition in question? Or are they symptomatic of it? Researchers working in this field say across the board that more data is needed to start to get at the root of these questions. A significant amount of rat and mice data is available, but human data is scant, they say.

How are the guts of PTSD sufferers different?

Malan-Müller’s recent study is along this line, and sought to gather some baseline data in the area of post traumatic stress disorder.  A basic question in this research is that (in theory) you could expose 100 subjects to the same stressful stimulus, and a percentage of them will go on to develop the disorder, whereas the majority will not. What’s the difference between the groups?

Her team sequenced the microbiomes of a number of subjects who where diagnosed with the condition, which arose from a variety of events, such as gunshot wounds, sexual abuse and so forth. They compared those findings to controls who had been exposed to similar traumatic events but had not developed PTSD. Their working hypothesis was that a poorly performing immune system and a heightened state of inflammation—conditions that could be associated with intestinal dysbiosis—might predispose those individuals to developing PTSD.  

Malan-Müller said three bacterial phyla—Actinobacteria, Lentisphaerae, and Verrucomicrobia—were found at decreased levels in the PTSD individuals. She emphasized that the findings were preliminary, but opened a door for further research.

Source: Psychosomatic Medicine

“The Microbiome in Posttraumatic Stress Disorder and Trauma-Exposed Controls: An Exploratory Study.”

2017 Oct;79(8):936-946. doi: 10.1097/PSY.0000000000000512

Authors: Hemmings MJ, Malan-Müller S, van der Heuvel LL, et al.