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. 2015 May;232(10):1793-801.
doi: 10.1007/s00213-014-3810-0. Epub 2014 Dec 3.

Prebiotic Intake Reduces the Waking Cortisol Response and Alters Emotional Bias in Healthy Volunteers

Free PMC article

Prebiotic Intake Reduces the Waking Cortisol Response and Alters Emotional Bias in Healthy Volunteers

Kristin Schmidt et al. Psychopharmacology (Berl). .
Free PMC article


Rationale: There is now compelling evidence for a link between enteric microbiota and brain function. The ingestion of probiotics modulates the processing of information that is strongly linked to anxiety and depression, and influences the neuroendocrine stress response. We have recently demonstrated that prebiotics (soluble fibres that augment the growth of indigenous microbiota) have significant neurobiological effects in rats, but their action in humans has not been reported.

Objectives: The present study explored the effects of two prebiotics on the secretion of the stress hormone, cortisol and emotional processing in healthy volunteers.

Methods: Forty-five healthy volunteers received one of two prebiotics (fructooligosaccharides, FOS, or Bimuno®-galactooligosaccharides, B-GOS) or a placebo (maltodextrin) daily for 3 weeks. The salivary cortisol awakening response was sampled before and after prebiotic/placebo administration. On the final day of treatment, participants completed a computerised task battery assessing the processing of emotionally salient information.

Results: The salivary cortisol awakening response was significantly lower after B-GOS intake compared with placebo. Participants also showed decreased attentional vigilance to negative versus positive information in a dot-probe task after B-GOS compared to placebo intake. No effects were found after the administration of FOS.

Conclusion: The suppression of the neuroendocrine stress response and the increase in the processing of positive versus negative attentional vigilance in subjects supplemented with B-GOS are consistent with previous findings of endocrine and anxiolytic effects of microbiota proliferation. Further studies are therefore needed to test the utility of B-GOS supplementation in the treatment of stress-related disorders.


Fig. 1
Fig. 1
Cortisol awakening response before and after administration of placebo, B-GOS or FOS. There were no differences in the salivary CAR pre-administration. Salivary cortisol awakening response was significantly lower after 3 weeks of B-GOS intake, but not FOS intake, compared with placebo
Fig. 2
Fig. 2
Area under the curve (with respect to ground) of salivary cortisol awakening response pre- and post-prebiotic supplement/placebo intake. *p < 0.05
Fig. 3
Fig. 3
Vigilance reaction times in the attentional dot-probe task. a Attentional vigilance did not differ between groups during masked trials of the attentional dot-probe task. b Participants showed decreased attentional vigilance to negative versus positive words in the unmasked condition of the dot-probe task after B-GOS but not FOS intake compared to placebo

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    1. Abou Hachem M, Andersen JM, Barrangou R, et al. Recent insight into oligosaccharide uptake and metabolism in probiotic bacteria. Biocatal Biotransform. 2013;31:226–235. doi: 10.3109/10242422.2013.828048. - DOI
    1. Ait-Belgnaoui A, Durand H, Cartier C, et al. Prevention of gut leakiness by a probiotic treatment leads to attenuated HPA response to an acute psychological stress in rats. Psychoneuroendocrinology. 2012;37:1885–1895. doi: 10.1016/j.psyneuen.2012.03.024. - DOI - PubMed
    1. Anderson N. Likableness ratings of 555 personality trait words. J Pers Soc Psychol. 1968;9:272–279. doi: 10.1037/h0025907. - DOI - PubMed
    1. Beck AT. The evolution of the cognitive model of depression and its neurobiological correlates. Am J Psychiatr. 2008;165:969–977. doi: 10.1176/appi.ajp.2008.08050721. - DOI - PubMed
    1. Beck AT, Clark DA. An information processing model of anxiety: automatic and strategic processes. Behav Res Ther. 1997;35:49–58. doi: 10.1016/S0005-7967(96)00069-1. - DOI - PubMed

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