Gut-brain connection: 5 evidence-based ingredients that help stress, calm, and sleep
The gut and brain communicate continuously via neural, immune, and metabolic pathways (the “gut-brain axis”). Modulating your gut microbiome can change neuroactive metabolites, inflammation, and even sleep and mood. Clinical trials and systematic reviews show that targeted probiotics can improve aspects of mood and stress in certain groups.
L-theanine — an amino acid in tea — has randomized trial evidence for reducing acute stress and improving sleep quality and attention in controlled studies, making it a common ingredient for calming supplements.
Ashwagandha (Withania somnifera) is an adaptogen with randomized controlled trials showing reductions in perceived stress and cortisol in adults at typical doses (often 300–600 mg/day of standardized extract). NIH/ODS guidance and systematic reviews summarize these effects and note safety precautions and drug interaction potentials.
Tryptophan, a precursor to serotonin and melatonin, and specific probiotic strains can influence neurotransmitter precursors and sleep; combining these ingredients with targeted prebiotics (like HMOs) may help the microbes and pathways that support calm. Manufactured HMOs have been shown to be tolerable in adult supplementation trials and can modulate microbiome composition.
Sources:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8387231
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8475422
- https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10458772