Oct 312017
 

Dr Stefanie Malan-Muller

The bacteria in your gut could hold clues to whether or not you will develop posttraumatic stress disorder (PTSD) after experiencing a traumatic event.

PTSD is a serious psychiatric disorder that can develop after a person experiences a life-threatening trauma. However, not everyone exposed to a traumatic event will develop PTSD, and several factors influence an individual’s susceptibility, including living conditions, childhood experiences and genetic makeup. Stellenbosch University researchers are now also adding gut bacteria to this list.

In recent years, scientists have become aware of the important role of microbes existing inside the human gastrointestinal tract, called the gut microbiome. These microbes perform important functions, such as metabolising food and medicine, and fighting infections. It is now believed that the gut microbiome also influences the brain and brain function by producing neurotransmitters/hormones, immune-regulating molecules and bacterial toxins.

In turn, stress and emotions can change the composition of the gut microbiome. Stress hormones can affect bacterial growth and compromise the integrity of the intestinal lining, which can result in bacteria and toxins entering the bloodstream. This can cause inflammation, which has been shown to play a role in several psychiatric disorders.

“Our study compared the gut microbiomes of individuals with PTSD to that of people who also experienced significant trauma, but did not develop PTSD (trauma-exposed controls). We identified a combination of three bacteria (Actinobacteria, Lentisphaerae and Verrucomicrobia) that were different in people with PTSD,” explains the lead researcher, Dr Stefanie Malan-Muller. She is a postdoctoral fellow in the Department of Psychiatry at the Faculty of Medicine and Health Sciences.

Individuals with PTSD had significantly lower levels of this trio of bacteria compared to trauma-exposed control groups. Individuals who experienced trauma during their childhood also had lower levels of two of these bacteria (Actinobacteria and Verrucomicrobia). “What makes this finding interesting, is that individuals who experience childhood trauma are at higher risk of developing PTSD later in life, and these changes in the gut microbiome possibly occurred early in life in response to childhood trauma,” says Malan-Muller. She collaborated with researchers from the University of Colorado Boulder on the study.

One of the known functions of these bacteria is immune system regulation, and researchers have noted increased levels of inflammation and altered immune regulation in individuals with PTSD. “Changes in immune regulation and increased inflammation also impact the brain, brain functioning and behaviour. Levels of inflammatory markers measured in individuals shortly after a traumatic event, was shown to predict later development of PTSD.

“We therefore hypothesise that the low levels of those three bacteria may have resulted in immune dysregulation and heightened levels of inflammation in individuals with PTSD, which may have contributed to their disease symptoms,” explains Malan-Muller.

However, researchers are unable to determine whether this bacterial deficit contributed to PTSD susceptibility, or whether it occurred as a consequence of PTSD.

“It does, however, bring us one step closer to understanding the factors that might play a role in PTSD. Factors influencing susceptibility and resilience to developing PTSD are not yet fully understood, and identifying and understanding all these contributing factors could in future contribute to better treatments, especially since the microbiome can easily be altered with the use of prebiotics (non-digestible food substances), probiotics (live, beneficial microorganisms), and synbiotics (a combination of probiotics and prebiotics), or dietary interventions.”

The research group is launching a large-scale, population based initiative to unravel the intricate connections between the gut microbiome and the brain, in collaboration with the South African Microbiome Initiative in Neuroscience (www.saneurogut.org). The study will focus on people that have been diagnosed with any kind of psychiatric disorder in comparison to healthy control groups. This study will identify more links between the gut microbiome and disorders that affect the brain.

Learn more: The role of the gut microbiome in posttraumatic stress disorder

 

The Latest on: Gut microbiome
  • It might be possible to remodel a baby's microbiome
    on December 16, 2017 at 1:54 am

    That presents the last big challenge: What exactly is “normal” microbiome? Gut microbes are highly dependent on diet, and that depends on a multitude of factors (culture, location, and personal preference, to name just a few). Even diets high in fruits ... […]

  • What makes your gut microbiome the way it is
    on December 14, 2017 at 8:10 am

    Each person's gut bacteria is so unique to them that it's almost like a fingerprint. So how does it get that way? A study of thousands of European children has teased out a link between a healthy diet and higher self-esteem, fewer emotional problems, and ... […]

  • DanoneWave opens applications for $50K grant in yogurt, probiotics, and gut microbiome research
    on December 12, 2017 at 4:00 pm

    Food and beverage giant Dannon, as a part of DanoneWave Public Benefit Corporation, announced it 6th Annual Yogurt, Probiotics, and the Gut Microbiome Fellowship Grant, which awards two $25,000 research grants for use in 2018. "Fostering scientific ... […]

  • Gut Microbiome Health Linked to Social Circles
    on December 10, 2017 at 7:00 am

    We influence one another more than we’ll ever know. Ideas, mores, customs, and religions spread through communities like contagions. So does bacteria, as we know from a history of infections as well as new research on the social circles of lemurs. […]

  • Gut Microbiome Remodeling in Infants With B. Infantis
    on December 8, 2017 at 5:52 am

    Providing dietary B. infantis EVC001 resulted in rapid, substantial, and persistent remodeling of the gut microbiome in breastfed infants. This stable colonization of B. infantis EVC001 led to significant reduction in the abundance of potentially ... […]

  • Touch and other signs of affection found to nourish the gut microbiome: Animal study
    on December 8, 2017 at 2:34 am

    Gut bacteria appears to thrive with regular physical contact and ‘huddling’ actions with Oxford University scientists crediting this behaviour to microbe spread leading to a synchronised microbiome. The findings have implications for human health as ... […]

  • Evolve BioSystems' Activated B. infantis EVC001 Demonstrates Substantial and Persistent Remodeling of the Infant Gut Microbiome
    on December 6, 2017 at 10:32 am

    A dysbiotic gut microbiome during infancy has been associated with the growing pandemic of chronic health issues including allergies, asthma, obesity, and type 1 diabetes. To date, no other clinical study has demonstrated a substantial change in the gut ... […]

  • Gut Microbiome Influenced Heavily by Social Circles in Lemurs, UT Study Says
    on December 6, 2017 at 12:00 am

    AUSTIN, Texas — Social group membership is the most important factor in structuring gut microbiome composition, even when considering shared diet, environment and kinship, according to research on lemurs at The University of Texas at Austin. The gut ... […]

  • Lemur Study Highlights Role of Diet in Shaping Gut Microbiome
    on December 5, 2017 at 8:23 am

    A study of the bacteria in the guts of three lemur species offers new insights into the role of diet in shaping these microbial ecosystems – and how these microbes may relate to primate health. “We wanted to know which microbes were present and what ... […]

  • Exercise can beneficially alter the composition of your gut microbiome
    on December 5, 2017 at 12:00 am

    Two new studies led by researchers at the University of Illinois have delivered the first clear evidence that the composition of gut bacteria can be changed by exercise alone. Designed to isolate the effects of exercise from other factors that could ... […]

via Google News and Bing News

Leave a Reply

%d bloggers like this: