Anxiety symptoms are popular among people with mental diseases and various physical disorders, especially stress-related disorders. Researchers revealed anxiety symptoms affected 1/3 of people in their lifetime.
Research has increasingly indicated that gut microbiota helps regulate brain functions through the gut-brain axis. Microbiota are trillions of microorganisms found in the gut. They carry out important functions in metabolism and in the immune system. They do so by providing essential nutrients, inflammatory mediators and vitamins.
Researchers suggested regulating intestinal microbiota can treat mental disorders.
A research team from the Shanghai Mental Health Center decided to investigate whether there was evidence supporting the improvement of anxiety symptoms through regulating intestinal microbiota.
The team reviewed 21 studies which had taken a look at 1,503 people combined. Out of those 21 studies, 14 had chosen probiotics as interventions to regulate intestinal microbiota (IRIFs). The remaining 7 chose non-probiotic means like adjusting the daily diet.
Probiotics, also called “good” bacteria or “friendly” bacteria, are living organisms that are found naturally in foods. They fight harmful bacteria and prevent them from setting in the gut.
The team discovered that probiotic supplements in 7 studies within their analysis had only one type of probiotic, 2 of the studies used a product containing 2 types of probiotics. The supplements in the other 5 studies had at least 3 kinds of probiotics.
11 out of the 21 studies revealed a positive effect in anxiety symptoms by regulating intestinal microbiota. More than half of the studies revealed the approach was effective.
Of the 14 studies which had used probiotics as the intervention, more than a third found them effective in reducing anxiety symptoms. 6 of the remaining 7 studies deemed them to be effective. They used non-probiotics as interventions.
Some studies used both the IRIF approach and treatment as usual. In 5 studies that used IRIF as interventions and treatment as usual, only the studies which had conducted non-probiotic ways had positive results which showed a reduction in anxiety symptoms.
Non-probiotic interventions were more effective in studies using IRIF alone. In the studies that did not use IRIF, 80% were effective when they used non-probiotic interventions. Only 45% were effective when they used probiotic ways.
Most studies never reported serious undesirable events. Only 4 studies reported small adverse effects like diarrhea and dry mouth.
The researchers found more than half of the studies involved showed it was positive to treat anxiety symptoms by regulation of intestinal microbiota. They said, it should be noted that non-probiotic interventions were more effective as compared to probiotic interventions. Researchers cannot run meta-analysis right now. They need to research more. Regulating intestinal flora should be considered to alleviate anxiety symptoms.
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- BMJ. (2019, May 20). Anxiety might be alleviated by regulating gut bacteria: Review of studies suggests a potentially useful link between gut bacteria and mental disorders. ScienceDaily. Retrieved May 22, 2019 from www.sciencedaily.com/releases/2019/05/190520190110.htm