Gut-brain connection: Prebiotics show ability to reduce anxiety

Studies interlinking the microbiome of the gut and the brain show evidence of changes in emotional health. Recent research in the UK is exploring how the gut-brain axis affects anxiety. The findings indicate that introducing a prebiotic called galacto-oligosaccharides (GOS) into the gut microbiome has a positive effect on gut health and greater emotional wellbeing.        

The Study Aspects

Researchers from the University of Surrey examined the food diaries and stool samples of 64 female volunteers between the ages of 18 and 25 over 28 days. The volunteers were given either 7.5g of the GOS Biotis prebiotic or a placebo made of maltodextrin and dried glucose syrup. 

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Both supplements were given to test subjects as a powder and in blind packaging. The placebo supplement absorbs in the upper portion of the gastrointestinal tract, never affecting the colon. The GOS supplement reaches the entire gastrointestinal tract still somewhat unchanged because it is a non-digestible carbohydrate. 

Study volunteers also received a sampling kit for stool collection and food journals for nutritional information documentation, including portion size and ingredients, for baseline and follow-up testing.

A total of 86 taxonomies were collected and tested for differential abundance. Additionally, abundance testing of bacterial content was shown as a percentage of the total composition of the gut microbiome to determine bacterial predictors and nutrient output. Bacteroides, Barnesiella, Gardnerella, Bifidobacterium, Aestuariispira, Desulfovibrio, Peptoniphilus, and Sporobacter were the predictive bacteria of choice for this particular scientific study. 

The Results and Conclusions of the Study

Researchers observed growth in healthy gut flora in subjects who had received GOS. Specifically, as a craving for certain carbohydrates in the diet decreased, the good bacteria in the gut, Bifidobacterium, increased. The GOS study group showed 11.5% more Bifidobacterium in their gut composition than those in the placebo group. 

Thus stimulation and greater production of the Bifidobacterium in the gut shifted subjects’ nutrient intake from digestible fibers with 4.3% less energy use from carbohydrate absorption. The healthy gut bacteria also changed nutrient intake showing 4.2% more energy burn from fat consumption and 4.1% less energy burn from sugar uptake. This shift in internal metabolic performance indicates GOS likely increases the Bifidobacterium composition in the gut and lessens the need to consume certain carbohydrates.

In addition to internal metabolic changes and dietary shifts, the ingestion of GOS over four weeks also showed anxiety reduction in subjects. There was a lessening of anxiety-ridden behaviors during cognitive testing in GOS subjects who previously displayed high anxiety levels. Studies of participants’ gut microbiome composition showed the stimulation and generation of healthy gut flora, including increases in Bifidobacteria.

This research also indicates that the growth of good gut bacteria shows a reduction in bouts of emotional eating and food cravings. Since prebiotics influence appetite and shift internal metabolic performance, this could lead to healthier nutrient consumption, thus leading to a healthier gut microbiome and overall confidence and emotional health. 

The strong connection between gut and brain may play an essential role in benefiting those living with extreme anxiety and other emotional challenges. By introducing beneficial prebiotics to nutrient intake, medical professionals can help to influence a healthier gut microbial ecosystem and emotional wellbeing for patients in the future.

This study is published in Nutrients.

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