# Gut Brain Evidence > The gut-brain axis, the microbiome and dietary fibre — separated from the probiotic marketing. Gut Brain Evidence covers what randomised trials actually show about the microbiome, psychobiotics and fibre, and is candid that most of the mechanism is established in mice and most of the marketing is ahead of the humans. ## About this source - **Publisher:** Stéphane Sprauer - **Editorial stance:** Independent. We describe what the evidence shows, including when it is weak or contested. - **Evidence base:** 81 peer-reviewed citations, each linked to its PubMed record or DOI. - **Languages:** 42 European languages. Add a language prefix to any URL, e.g. `https://gutbrainevidence.org/de/`. - **Licence:** Content may be quoted with attribution to Gut Brain Evidence (https://gutbrainevidence.org). - **Not medical advice:** Educational content only. ## How to cite this site > Gut Brain Evidence. "". https://gutbrainevidence.org. Accessed . ## Home - [Gut Brain Evidence](https://gutbrainevidence.org/): What randomised trials show about the microbiome, probiotics and dietary fibre — and how much of the mechanism is still only established in mice. ## Fibre - [Dietary fibre: the finding that actually holds up](https://gutbrainevidence.org/fibre/): Meta-analyses of dietary fibre intake and mortality, cardiovascular disease and colorectal cancer — dose-dependent and consistent. ## Probiotics - [Do probiotics do anything for mood?](https://gutbrainevidence.org/probiotics/): Meta-analyses of probiotics, prebiotics and synbiotics for depression and anxiety — small effects, and real trial-quality problems. ## Gut-brain axis - [What the gut-brain axis actually is](https://gutbrainevidence.org/gut-brain-axis/): The mechanisms connecting gut and brain — vagal signalling, microbial metabolites and immune pathways — and how much is established in humans. ## Strains - [Probiotic strains](https://gutbrainevidence.org/strain/): What 7 probiotic strains have actually been studied for, and how strong the evidence is. - [Lacticaseibacillus rhamnosus GG: what this strain is actually good for](https://gutbrainevidence.org/strain/lactobacillus-rhamnosus-gg/): Studied for antibiotic-associated diarrhoea, paediatric acute gastroenteritis. Evidence: established. - [Saccharomyces boulardii CNCM I-745: what this strain is actually good for](https://gutbrainevidence.org/strain/saccharomyces-boulardii/): Studied for antibiotic-associated diarrhoea, traveller's diarrhoea. Evidence: established. - [Bifidobacterium longum 1714: what this strain is actually good for](https://gutbrainevidence.org/strain/bifidobacterium-longum-1714/): Studied for stress response, subjective anxiety. Evidence: promising. - [Lactiplantibacillus plantarum 299v: what this strain is actually good for](https://gutbrainevidence.org/strain/lactobacillus-plantarum-299v/): Studied for ibs symptoms, iron absorption. Evidence: promising. - [Bifidobacterium infantis 35624: what this strain is actually good for](https://gutbrainevidence.org/strain/bifidobacterium-infantis-35624/): Studied for ibs. Evidence: promising. - [Limosilactobacillus reuteri DSM 17938: what this strain is actually good for](https://gutbrainevidence.org/strain/lactobacillus-reuteri-dsm-17938/): Studied for infant colic. Evidence: promising. - [The De Simone eight-strain formulation: what this strain is actually good for](https://gutbrainevidence.org/strain/vsl-de-simone-formulation/): Studied for pouchitis, ulcerative colitis. Evidence: promising. ## About - [About Gut Brain Evidence](https://gutbrainevidence.org/about/): Who publishes Gut Brain Evidence, how pages are researched, and how the site makes money. - [Editorial policy](https://gutbrainevidence.org/editorial-policy/): How Gut Brain Evidence selects evidence, scores products and handles conflicts of interest. - [Affiliate and partnership disclosure](https://gutbrainevidence.org/disclosure/): Every commercial relationship that could affect what you read on Gut Brain Evidence. - [Privacy](https://gutbrainevidence.org/privacy/): What Gut Brain Evidence collects — which is close to nothing. ## Research - [New research](https://gutbrainevidence.org/research/): Newly indexed peer-reviewed research relevant to Gut Brain Evidence, updated weekly from PubMed and Crossref. - [Research digest, 8 August 2026](https://gutbrainevidence.org/research/2026-08-08/): No newly indexed research matched this site's topics in the week of 8 August 2026. ## Related sites in this network - 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[Food Label Evidence](https://foodlabelevidence.org): Nutri-Score, front-of-pack labelling and whether any of it changes what people buy. - [Travel Health Evidence](https://travelhealthevidence.org): Jet lag, travellers' diarrhoea, food safety and eating with an allergy abroad. - [Meditation Evidence](https://meditationevidence.org): Mindfulness, breathwork and meditation apps — effect sizes, and the adverse effects nobody mentions. - [Supplement Evidence](https://supplementevidence.org): Vitamin D, melatonin, magnesium and omega-3 — what the large trials found, and what is in the bottle. - [Screen Time Evidence](https://screentimeevidence.org): Screen time and wellbeing, digital detox trials, notifications and sleep. - [Carbon Evidence](https://carbonevidence.org): Personal carbon footprints, life-cycle assessment, and which changes actually move the number. - [Habit Evidence](https://habitevidence.org): Behaviour change, craving and relapse prevention — what actually has trial support. - [The EV Route](https://theevroute.com): Planning an electric road trip around real range, real charge curves and where the chargers actually are. - [Charging Compared](https://chargingcompared.com): European charging networks compared on price, reliability and whether your card will work. - [Motorway Food](https://motorwayfood.com): Where to actually eat on a long drive — including with coeliac disease, an allergy or a restricted diet. - [Family Road Travel](https://familyroadtravel.com): Long drives with children — stop cadence, facilities, accessibility and what the evidence says about breaks. - [EV Across Europe](https://evacrosseurope.com): Country-by-country electric vehicle ownership: charging costs, incentives, infrastructure and cross-border roaming. - [Evidence Network](https://evidencenetwork.eu): A network of cited, multilingual reference sites on health, technology and sound.