“Namely, these gut species, Eggerthella and Eubacterium ventriosum, have been shown to produce butyrate — an important precursor molecule to GABA, a brain chemical that functions in regulatory control of glutamate,” he explained.
Some research shows that certain Lactobacillus species improve stress resilience and anxiety. Some studies even show that taking probiotics can help alleviate symptoms of depression.
A 2018 study found that the probiotic Lactobacillus plantarum P8 may be helpful for depression. It was shown to relieve stress and anxiety and improve memory and learning. Bifidobacterium is another probiotic shown to improve mental health.
And a small study in the journal Nutrition found that 3 probiotic strains — Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium bifidum — helped reduce symptoms of depression. Other research has linked several strains, including lactobacillus and bifidobacterium, to improvements in mental health.
The intestinal bacterial strains Eggerthella, Subdoligranulum, Coprococcus and Ruminococcaceae have been reported to be associated with major depression in earlier studies.
Serotonin is an important neurotransmitter for gut and mental health. Tryptophan-containing foods like poultry, canned tuna, chocolate, dried prunes, and peanuts provide the building blocks of serotonin, but direct sources of serotonin like wild rice, spinach, potato, and bananas may also boost serotonin levels.
More than 90% of the body's serotonin is synthesized in the gut18,19. Various bacteria such as Streptococcus spp., Enterococcus spp., Escherichia spp., Lactobacillus plantarum, Klebsiella pneumonia, and Morganella morganii have the ability to produce serotonin20,21,22,23.
People diagnosed with depression, or who are susceptible to depressive symptoms, may benefit from eating more fibre, fish and grains as a measure to alter the gut-brain axis, a new report by some of Europe's leading experts suggests.
Research shows gut microbiota may play a role in depressive disorders and that depressive symptom levels vary across ethnic groups. Now, researchers from the United Kingdom and the Netherlands have demonstrated that 13 types of bacteria found in the gut are associated with depression symptoms.
Many additional psychobiotics have been shown to treat depression and anxiety in animal studies. Lactobacillus plantarum strain PS128, for example, is known to increase dopamine and serotonin and decrease depression-like behaviors in mice.
After 8 weeks, those who took the probiotic capsules each day reported fewer depressive symptoms at the end of the 8-week trial. An even larger study that included 71 people also measured positive results after 8 weeks. There were improvements across the board, even for those taking a placebo.
“Although generally safe and palatable, in clinical settings it cannot be recommended that probiotics replace antidepressant medications as the primary treatment for depressed patients.
Techniques include progressive muscle relaxation, visualization and restful music. Research suggests that these therapies are most effective when combined with cognitive behavioral therapy (CBT). Cognitive behavioral therapy (CBT).
(6) Lactobacillus plantarum PS128 administration improves dopamine metabolism and increases norepinephrine levels [92].
Certain drugs and substances such as caffeine, alcohol, nicotine, NutraSweet, antidepressants, and some cholesterol-lowering medications deplete serotonin and other neurotransmitter levels. Hormone changes cause low levels of serotonin and neurotransmitter imbalances.