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Prebiotic and probiotic supplementation and the tryptophan-kynurenine pathway: a systematic review and meta analysis

Purton, Terry ORCID: 0000-0002-1588-9530, Staskova, L, Lane, MM, Dawson, SL, West, M, Firth, J, Clarke, G, Cryan, JF, Berk, M, ONeil, A, Dean, O, Hadi, A, Honan, C ORCID: 0000-0001-5735-4270 and Marx, W 2021 , 'Prebiotic and probiotic supplementation and the tryptophan-kynurenine pathway: a systematic review and meta analysis' , Neuroscience and Biobehavioral Reviews, vol. 123 , pp. 1-13 , doi: 10.1016/j.neubiorev.2020.12.026.

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This systematic review aimed to synthesise the results from studies investigating the effects of prebiotics andprobiotics on kynurenine pathway metabolism. Thirteen studies were identified for inclusion, comprising 12probiotic and two prebiotic arms. Participants included healthy individuals and individuals with various clinicalconditions. Twelve metabolites were examined across the studies, using a range of biological samples. Across allinterventions, 11 reported an effect on ≤ metabolite. Although limited by clinical and methodological heterogeneity,pooled analysis (n = 253) found probiotics to significantly affect serum kynurenine (g = 0.315,CI = 0.070 to 0.560, p = 0.012, 4 studies, I2 = 0%) and the kynurenine:tryptophan ratio (g = 0.442, CI = 0.074 to0.810, p = 0.018, 4 studies, I2 = 42 %). Risk of bias across the studies was generally low. The results providepreliminary evidence that probiotics can modulate kynurenine pathway metabolism, with less evidence availableregarding prebiotics. Future studies which further consider methodological confounds and sample characteristicsare required, to establish intervention efficacy. PROSPERO registration #CRD42019154677.

Item Type: Article
Authors/Creators:Purton, Terry and Staskova, L and Lane, MM and Dawson, SL and West, M and Firth, J and Clarke, G and Cryan, JF and Berk, M and ONeil, A and Dean, O and Hadi, A and Honan, C and Marx, W
Keywords: kynurenine, tryptophan, gut-brain axis, prebiotic, probiotic, nutraceutical, systematic review, mental health, psychiatry, neuroscience
Journal or Publication Title: Neuroscience and Biobehavioral Reviews
Publisher: Pergamon-Elsevier Science Ltd
ISSN: 0149-7634
DOI / ID Number: 10.1016/j.neubiorev.2020.12.026
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© 2021 Elsevier Ltd. All rights reserved

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