Prebiotics shown to armor rats against stress by altering brain structure

This content item was originally published on, a William Reed online publication.

By Hank Schultz

- Last updated on GMT

Research presented at the recent Probiota Americas meeting showed that adding prebiotics to the diet to promote the growth of beneficial gut bacteria actually altered the structure of rats' brains in a model testing stress response.

Monika Fleshner, PhD, presented results from recent research her group has done at the University of Colorado Boulder at the meeting which took place earlier this month in Miami.

As a sign of the ever-broadening scope of research into the gut microbiota, Fleshner does not specialize in gut health research per se. She is rather a professor in the Department of Integrative Physiology at the university.  

Promise of microbiome alteration in stress resistance

Fleshner’s specialty is studying the effects that chronic stress has on the body and what can be done about it. She is agnostic, then, when it comes to what modalities to pursue when it comes to finding ways to harden the body and mind against stress. She has studied the effects of exercise on the body’s stress resilience, for example. But Fleshner said that the data coming from studies into the gut-brain connection is becoming ever more persuasive.

“My laboratory is very interested in promoting changes in the body that can reduce or resist the negative effects that stressors can have on mind and body,” ​Fleshner told NutraIngredients-USA.

“When you experience a stressor that’s beyond your ability to cope you start to see a lot of emotional problems like depression or anxiety. And you have problems with your ability to focus and problems with sleep,”​ she said.

Fleshner’s team examined the effects of administering an HMO (human milk oligosaccharide) and the protein lactoferrin to lab rats to measure the effect of the diets on the rats’ behavior.

This was measured via open field tests (a standard test that measures how much time rats are willing to spend in an open area, which assesses their anxiety level) as well as other tests. Electronic hookups directly to the rats’ brains collected data on the animals’ sleep patterns. The supplemented animals were less anxious and slept better than the controls. 

Supplementation changed brain structure

Another key area of the research was measuring regions of the rats’ brains after the test was completed.

Fleshner’s team showed that the diet increased the size of brain regions associated with brain plasticity. While this particular trial was aimed at brain development in young animals, as it had been funded by a company marketing infant formula, Fleshner said the results are indicative of important effects prebiotic ingredients can have in armoring subjects of any age against stress.

“In exploring this novel potential mechanism of optimizing the gut microbial community structure and the products they release, the metabolites, we have an avenue where we can relatively simply promote our ability to resist the negative effects of stress,”​ she said.

“Who would have thought that something these laboratory rats eat could actually change the structure of their brains?”​ Fleshner added.

Source: Neuroscience Letters
2018 Jun 11;677:103-109. doi: 10.1016/j.neulet.2018.01.052
“Feeding the developing brain: Juvenile rats fed diet rich in prebiotics and bioactive milk fractions exhibit reduced anxiety-related behavior and modified gene expression in emotion circuits.”
Authors: Mika A, Gaffney M, Roller R, et al.

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