Use of probiotics in mental health

Although still a novel topic, it can now be comfortably said that the presence of the intestinal microbiota, formerly called bacterial flora, has several implications for overall health. Hence, supplementation with probiotics, or live microorganisms that, when administered in adequate amounts, confer health benefits to the host, has become so popular in recent years.

Regarding mental health, science has discovered several mechanisms by which the modification of the intestinal microbiota would be able to improve this aspect for the better, leading to the possibility of implementing dietary changes or the use of probiotics a supportive therapy in certain psychological disorders.

So let's see more about how this relationship occurs...

The important existence of the brain-gut axis.

In terms of mental health, it has been discovered that there is bidirectional communication between the brain and the gut, known as the gut-brain axis, which includes neurological, endocrine, immunological, and metabolic pathways. Given the importance of this axis, probiotics that serve functions that benefit mental health are referred to as psychobiotics.

With this in mind, it can be noted that there is a close relationship between gut microbial composition and multiple effects throughout the body, including the brain. This has given way to a large number of studies that have linked the use of probiotics to mental conditions such as mental stress, depression, and anxiety.

Gut dysbiosis as a predominant factor in mental health.

At an intestinal level, it is believed that the presence of bacteria that favor local inflammatory processes, as well as the absence of species that produce anti-inflammatory substances, corresponds to the development of mental conditions, such as depression and anxiety.

There is evidence that has demonstrated the existence of a relationship between mental stress and the behavior of the microbiota through the hypothalamic-pituitary-adrenal axis. It is believed that the imbalance of this axis in favor of increased stress may affect the intestinal bacterial composition, generating dysbiosis.

However, there is also evidence that indicates that imbalances in the microbiota, where there is an increased production of prostaglandins and pro-inflammatory cytokines, produce the activation of this axis, generating an increased secretion of cortisol, a hormone closely related not only to stress, but also to the development of depression and anxiety.

Other mechanisms involved in the brain-gut axis.

Short-chain fatty acids (SCFA) play a major role in this area, with acetate, propionate, and butyrate being the most abundant in the intestine. Produced by bacteria from food, mainly from soluble dietary fiber, at a neurological level, these compounds can directly influence neurotransmission, which is compromised in patients with low populations of SCFA-producing bacteria.

Additionally, the production of different neurotransmitters such as serotonin, norepinephrine, acetylcholine, GABA, histamine, and dopamine is directly regulated by the intestinal microbiota. Evidence indicates that intestinal dysbiosis and the presence of local inflammatory factors are able to affect the production of these neurotransmitters by decreasing the concentration of certain precursors.

Although much more research is needed in this novel area, the evidence showing the great potential of probiotic supplementation for overall and mental health is growing. Indeed, as new studies are published, the close link between the gut microbiota and the functioning of various organs and systems becomes clearer.