Lactobacillus reuteri is one of the most extensively studied probiotic species, notable for its production of neuroactive metabolites (GABA, histamine) and its effects on the hypothalamic-pituitary-gonadal axis (testosterone, oxytocin).
Key Functions
- GABA production: Possesses glutamate decarboxylase (GAD), producing GABA from dietary glutamate — relevant to the gut brain axis in anxiety and depression.
- Histamine production: Produces histamine via histidine decarboxylase; at physiological levels, histamine acts as an immunomodulator suppressing TNF-alpha via H2 receptors.
- Testosterone/oxytocin: L. reuteri supplementation increases testosterone and oxytocin levels in animal models, with implications for male fertility and social behavior jin 2023 3hpaa spermatogenesis ferroptosis.
- Spermatogenesis protection: Protects against ferroptosis-mediated testicular damage jin 2023 3hpaa spermatogenesis ferroptosis.
- Thyroid: Part of the probiotic species affecting thyroid hormone metabolism docimo 2020 human microbiota endocrinology thyroid.
Clinical Evidence
- Schizophrenia RCT: L. reuteri-containing probiotic + vitamin D improved metabolic parameters in schizophrenia patients ghaderi 2019 vitamin d probiotic schizophrenia metabolic rct.
- ASD: Reviewed as potential gut-brain axis intervention feng 2023 probiotics asd gut brain axis review.
- Reproductive health: Discussed in FMT for female reproductive tract diseases quaranta 2019 fmt female reproductive tract diseases.
Cross-References
- lactobacillus — genus page
- gaba — GABA-producing species
- gut brain axis — neuroactive metabolite producer
- serotonin — complementary gut-brain mediator
- ferroptosis — protection against testicular ferroptosis