The Gut-Brain Axis: A Complex Network of Influences
The gut-brain axis represents a complex network of two-way communication between the gastrointestinal system and the central nervous system, through an exchange of neurochemical and hormonal signals that not only influences digestion, but also plays a crucial
role in mental health.
The gut microbiome, which consists of a diverse community of micro-organisms inhabiting the
digestive tract, plays a crucial role in this axis. The composition and activity of these microorganisms can affect the production of neurotransmitters and hormones that influence mood and cognition. This emerging understanding of the gut-brain axis has led to the exploration of how certain approaches, such as the use of probiotics, can positively influence mental health.
Probiotics and Mental Health
Probiotics, beneficial microorganisms that promote a healthy gut environment, have emerged as promising agents in the quest to improve mental health.
Numerous studies have examined how these microorganisms may contribute to maintaining mental health. Certain strains, such as Lactobacillus and Bifidobacterium, have been found to
have the potential to modulate the stress response and reduce symptoms of anxiety and depression. This effect may be related to the ability of probiotics to regulate inflammation and
produce neuroactive compounds, such as gamma-aminobutyric acid (GABA), which has relaxing properties.
In addition, probiotics may enhance the absorption of essential nutrients, such as B vitamins and tryptophan, which are precursors of key neurotransmitters, such as serotonin. A proper serotonin balance is linked to positive mood and stress management, further highlighting the importance of probiotics in mental health.
Alongside probiotics,saffron emerges as a mental health ally. Comparative studies with fluoxetine in mild to moderate depression show that saffron, at specific doses, significantly improves cognitive performance and reduces the concentration of kynurenine, a marker associated with depression. Numerous studies suggest that saffron is useful in the management of mild to moderate
depression, and its combination with probiotics may be particularly beneficial.
Bibliografia:
Majeed, M., Nagabhushanam, K., Arumugam, S., Majeed, S., & Ali, F. (2018). Bacillus
coagulans MTCC 5856 for the management of major depression with irritable bowel syndrome: a randomised, double-blind, placebo controlled, multi-centre, pilot clinical study. Food & nutrition research, 62, 10.29219/fnr.v62.1218.
https://doi.org/10.29219/fnr.v62.1218
Double-blind clinical study, 40 patients with Major Depression and Irritable Bowel Syndrome (IBS). They randomly received placebo or a daily dose of Bacillus coagulans (2 × 10 9 CFU) for 3 months.
Results: Statistical and clinical improvement in depressive symptoms, relief in IBS and reduction of the pro-inflammatory marker myeloperoxidase.
Allen, A. P., Hutch, W., Borre, Y. E., Kennedy, P. J., Temko, A., Boylan, G., Murphy, E., Cryan, J. F., Dinan, T. G., & Clarke, G. (2016). Bifidobacterium longum 1714 as a translational psychobiotic: modulation of stress, electrophysiology and neurocognition in healthy volunteers. Translational psychiatry, 6(11), e939. https://doi.org/10.1038/tp.2016.191
Clinical study with 22 participants: Bifidobacterium longum 1714 versus placebo, exploring acute stress response.
Results highlighted a significant reduction in stress and improvement in memory when B.
longum 1714 was ingested. Evaluation included analysis of decreased salivary cortisol, improved EEG and a detailed questionnaire.
Kazemi, A., Noorbala, A. A., & Djafarian, K. (2020). Effect of probiotic and prebiotic
versus placebo on appetite in patients with major depressive disorder: post hoc analysis of a randomised clinical trial. Journal of human nutrition and dietetics : the official journal of the British Dietetic Association, 33(1), 56–65. https://doi.org/10.1111/jhn.12675
Clinical study with 81 people diagnosed with Major Depression, experiencing inappetence.
Probiotics (Lactobacillus helveticus and Bifidobacterium longum), prebiotics (galactooligosaccharide) or placebo were randomly administered orally for 8 weeks.
Result: Food craving increased significantly in the probiotic group. No significant differences in BMI or weight were observed between the three groups. Energy intake and leptin were significantly increased in the probiotic group compared to the prebiotic.
Saccarello, A., Montarsolo, P., Massardo, I., Picciotto, R., Pedemonte, A., Castagnaro, R., Brasesco, P. C., Guida, V., Picco, P., Fioravanti, P., Montisci, R.,
Schiavetti, I., & Vanelli, A. (2020). Oral Administration of S-Adenosylmethionine (SAMe) and Lactobacillus Plantarum HEAL9 Improves the Mild-To-Moderate Symptoms of Depression: A Randomized, Double-Blind, Placebo-Controlled Study.
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Six week, randomised, double-blind, placebo-controlled study of 90 patients with mild to moderate depression according to ICD-10 criteria.
In the second week of treatment, symptoms of depression, anxiety, cognitive and somatic components significantly improved.
Rudzki, L., Ostrowska, L., Pawlak, D., Małus, A., Pawlak, K., Waszkiewicz, N., & Szulc, A. (2019). Probiotic Lactobacillus Plantarum 299v decreases kynurenine concentration and improves cognitive functions in patients with major depression: A double-blind, randomized, placebo controlled study. Psychoneuroendocrinology, 100, 213–222. https://doi.org/10.1016/j.psyneuen.2018.10.010
Randomised, double-blind, placebo-controlled clinical study involving sixty patients with Major Depressive Disorder (MDD), with a duration of 8 weeks. Patients received Lactobacillus plantarum together with selective serotonin reuptake inhibitors (SSRIs), while the other group received SSRIs alone. The addition of probiotic bacteria Lactobacillus plantarum 299v to SSRI treatment improved cognitive performance and reduced the concentration of kynurenine in patients with MDD. The decrease in kynurenine could contribute to improvements in cognitive function in the LP299v group compared to the placebo group.
Ho, Y. T., Tsai, Y. C., Kuo, T. B. J., & Yang, C. C. H. (2021). Effects of Lactobacillus plantarum PS128 on Depressive Symptoms and Sleep Quality in Self-Reported Insomniacs: A Randomized, Double-Blind, Placebo-Controlled Pilot Trial. Nutrients, 13(8), 2820. https://doi.org/10.3390/nu13082820
Clinical study with forty participants aged 20-40 years with insomnia, randomly assigned to two groups: Lactobacillus plantarum and placebo, in a 30-day double-blind trial. Measures included depressive symptoms, anxiety and sleep questionnaires, and mini-polysomnography. At 30 days,
the L. plantarum group showed significant decreases in Beck Depression Inventory-II scores, fatigue levels, brain wave activity and awakenings during the deep sleep phase.
Akhondzadeh S, Tahmacebi-Pour N, Noorbala A, Amini H, Fallah-Pour H, Jamshidi AH, Khani M. Crocus sativus L. in the treatment of mild to moderate depression: a double-blind, randomized and placebo-controlled trial. Phytother Res. 2005;19(2):148–151 Forty adult outpatients who met the Diagnostic and Statistical Manual of Mental Disorders criteria for depression participated in the trial.
Patients had a baseline Hamilton depression scale score of at least 18. In this double-blind, placebo-controlled, single-centre, randomised trial, patients were randomly assigned to receive either a 30 mg saffron capsule or a placebo capsule during a 6-week study. At 6 weeks, Crocus
sativus produced a significantly better score on the Hamilton depression rating scale than placebo.
Noorbala, A. A., Akhondzadeh, S., Tahmacebi-Pour, N., & Jamshidi, A. H. (2005).
Hydro-alcoholic extract of Crocus sativus L. versus fluoxetine in the treatment of mild to moderate depression: a double-blind, randomized pilot trial. Journal of ethnopharmacology, 97(2), 281–284. https://doi.org/10.1016/j.jep.2004.11.004
A 6-week comparative study evaluating the efficacy of Crocus sativus extract versus fluoxetine in the treatment of mild to moderate depression. Forty adult outpatients meeting Diagnostic and Statistical Manual of Mental Disorders criteria participated. In this randomised, double-blind trial, patients received saffron capsules (30 mg/day) or fluoxetine (20 mg/day) for 6 weeks.
Saffron extract showed similar efficacy to fluoxetine in the treatment of mild to moderate depression.