How the gut speaks to the brain.

Neural (vagus nerve) 80% of fibres travel gut-to-brain. Microbiota directly influences vagal tone and HRV.

Immune (cytokines) Dysbiosis → permeability → LPS in bloodstream → chronic low-grade inflammation → mood and regulation impact.

Endocrine (HPA axis)Microbiota modulates cortisol. Mg, D, B deficiencies alter HPA signalling directly.

Metabolic (SCFAs & BDNF Gut bacteria produce butyrate/propionate (neuroprotective). BDNF increases with omega-3, fibre, micronutrients.

Key trials

The evidence that sustains this practice.

SMILES · Jacka et al. · 2017

First RCT of dietary improvement in depression. Remission 32.3% vs 8.0%. d=−1.16. NNT=4.1.

HELFIMED · Parletta et al. · 2019

Mediterranean diet + fish oil vs. social groups. Greater depression reduction at 3 and 6 months.

AMMEND · Bayes et al. · 2022

Young males with depression. Mediterranean diet, 12 weeks. First evidence in young male population.

Liao et al. · 2019

Omega-3 meta-analysis. 26 RCTs. SMD=−0.28. Greater with EPA≥60% as adjunct.

Moabedi et al. · 2023

Magnesium in MDD. 7 RCTs. SMD=−0.92.

Liu et al. · 2019

Probiotics. 34 RCTs. Small but significant effect. Depression d=−0.24, anxiety d=−0.10.

Dietary patterns

↑

Mediterranean dietThree RCTs. OR 0.67 in cohorts. Most studied pattern.

↑

Anti-inflammatory (low DII)23% lower depression risk. 2023 meta-analysis.

↑

Fermented foods & fibreProbiotics, prebiotics. Butyrate, microbiota diversity.

↓

Ultra-processedOR=1.53 for common mental disorder. +10% UPF → +11% depression risk (Lane 2022, n=385,541).

↓

Excess sugarGlycaemic spikes and crashes. Microbiota disruption. Low energy.

↓

Chronic alcoholDepletes B1, B6, Mg, Zn. Alters permeability. Independent depression risk factor.

Applied complementarily, coordinated with each person's psychological/medical process. Nutrition does not replace psychotherapy or medical treatment.

A NutriPsyc Lab session explores your specific context.

30 minutes. Free. No commitment.

Next step

30 free minutes to get to know each other and see how I can support you. No commitment.