What is GABA?
Gamma-amino butyric acid (GABA) is the main inhibitory neurotransmitter of the central nervous system, which plays a role in calming neural excitability, reducing anxiety and supporting stress resilience. Dysregulation of the GABA system is linked to insomnia and anxiety. Interestingly, GABA has a close relationship with our reproductive hormones.
A woman’s life is marked by dramatic hormonal fluctuations: puberty, when the ovaries begin producing oestrogen and progesterone; pregnancy, with sustained high levels of both; and menopause, which will be the focus of this blog, when these hormones sharply decline. Each of these transitions is accompanied by changes in the GABA system.
Why GABA Fluctuates with Hormonal Shifts:
GABA naturally fluctuates with hormonal shifts to help maintain the delicate balance between excitation and inhibition in the brain, when this balance is lost, it increases the risk of anxiety.
The Hormone GABA Connection:
Progesterone produces a metabolite called allopregnanolone, or ALLO for short. ALLO can activate GABA A receptors, producing significant anti-depressant, anti-stress, and anxiolytic effects.
Hormonal Decline and Its Impact on GABA
As progesterone levels drop during perimenopause, so do ALLO levels and, in turn, GABA receptor activation. The consequences of these changes have been linked to altered cognitive functioning, mood alterations, insomnia, and susceptibility to psychiatric disorders (anxiety and depression).
Studies have found that there are significantly lower levels of GABA in certain areas of the brain of menopausal women. The areas of the brain involved in decision making, self-reflection, memory, emotion processing, and decision making. These findings suggest that dysfunction in the GABA system may contribute to brain health issues during menopause.
Can the Gut Microbiome help?
Beyond digesting food, the gut plays an important role in regulating our oestrogen and progesterone levels, which in turn affects our GABA levels. Certain gut bacteria such as Lactobacillus, Bifidobacterium and Lactiplantibacillus plantarum support GABA production. This raises the question: could the gut microbiome be a natural way to replenish GABA and ease some of the most common and distressing symptoms of menopause?
Take-Home Message
The connection between hormones, GABA, and the gut microbiome opens up an exciting area of exploration. As progesterone, it’s metabolites, and GABA decline during perimenopause, symptoms like anxiety, low mood, and poor sleep increase. The gut’s ability to synthesise GABA offers a hopeful perspective for women.