Sexual problems can occur for men and women at any age. It is estimated that 43% of women and 31% of men report some sort of sexual disorder. The symptoms range from an-orgasm to sexual discomfort for women to premature ejaculation and erectile dysfunction for men as well as low sexual desire for both sexes (Rosen, R.C.). Sexual dysfunctions have been found to have a significant impact on overall quality of life and functioning in both men and women. Sexual function is a complex phenomenon affected by sex hormones, psychological and neurological factors, hemodynamics, hormonal disorders, obesity, stress, anxiety, hypertension, diabetes and so on (Geng, Q).
What is human sexual behavior regulated by?
Sexual desire, arousal, and orgasm are mediated by a complex interplay of the somatic and autonomic nervous systems. Sexual behavior in humans is regulated by key areas in the brain through the actions of various neurotransmitters: norepinephrine, dopamine, melanocortin, oxytocin, and vasopressin arbitrate sexual excitement, while serotonin, opioids, prolactin, and the endogenous cannabinoid system arbitrate sexual inhibition (Li, G. et al). Therefore, neurotransmitter optimization is a promising target for improving human sexual desire and outcome. Neurotransmitters are made in our guts!
Conventional treatments aim to target neurotransmitter levels utilizing pharmaceutical agents to address low sexual desire, low libido, erectile dysfunction, low sex-drive, orgasmic disorders, and other symptoms. For example, the medication flibanserin works to lower serotonin and increase dopamine and norepinephrine levels in the brain, and viagra works on the vascular system by causing a release of nitrous oxide resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum.
Conditions that commonly occur with sexual dysfunction...
testosterone deficiency (Geng, Q)
These conditions are known to affect the gut microbiome, where neurotransmitters are made by our gut bacteria. Gut microbiota can either produce neurotransmitter precursors, catalyze the synthesis of neurotransmitters through dietary metabolism, or a combination of both (Chen, Y). The aforementioned conditions promote dysbiosis (an imbalance in microbial diversity), fungal overgrowth and are a symptom of increased toxic load and impaired detoxification.
How is the gut connected to sex?
The gut-sex connection looks at the relationship between microbes inside our guts, their neurotransmitters they synthesize, and how these messages are conveyed to the brain. As mentioned earlier there are certain neurotransmitters that arbitrate sexual excitement such as dopamine, while neurotransmitters like serotonin arbitrate sexual inhibition (Li, G. et al). So, to increase sexual desire, performance, and satisfaction the body needs to be producing neurotransmitters that are excitatory and in balance with neurotransmitters that are inhibitory. Again, neurotransmitters are synthesized by our gut bacteria through dietary consumption.
In a study done by Chen, Y., it was found that increases in bacteria such as Prevotellaceae, Erysipelotrichaceae, and Erysipelotrichales, and decreases of Bifidobacterium, Lachnospiraceae, Clostridiales, and Proteobacteria groups were associated with decreased levels of dopamine (sexual excitatory neurotransmitter) in patients with parkinson's disease, which is a low dopamine state. They also found that serotonin levels (sexual inhibitory neurotransmitter) are increased with staphylococci and clostridia species.
Low serotonin is also associated with depression and commonly treated with SSRI (selective serotonin reuptake inhibitor) medications. SSRI medications commonly cause low libido due to increasing serotonin levels. Interestingly enough, increases in staphylococci species has a strong connection in food allergies as well and leaky gut and low serotonin levels.
It is also important to note that certain bacteria in the gut will prevent the elimination of toxins and estrogens and promote their recirculation leading to hormone imbalance, inflammation, and altered hormone production. This is common in conditions like leaky gut and dysbiosis.
Symptoms of leaky gut:
The balance of microbes in the gut is necessary to maintaining sexual function. Even overgrowth of "good" bacteria can be problematic. The metabolites, molecules, and endotoxins released by intestinal bacteria potentially affect the expression levels of neurotransmitters as well as their precursors and receptors in the central nervous system via the blood stream or vagus nerve pathways, thereby affecting brain function (Chen, Y).
While a diverse microbiome is an important factor to preventing and treating sexual dissatisfaction disorders, other factors such as environment, emotional well-being, sex and non-sex hormone