Researchers find limited evidence for psychobiotics as youth anxiety treatment

Evidence appeared limited for the use of psychobiotics in treating youth anxiety, according to results of a systematic review and meta-analysis published in Translational Psychiatry.

“Altering the gut microbiota with nutritional therapeutics such as psychobiotics (ie, active compounds such as probiotics and prebiotics) shows promise in treating mental health problems such as depression and anxiety,” Kathrin Cohen Kadosh, PhD, of the School of Psychology at the University of Surrey in the U.K., and colleagues wrote. “Recent research on psychobiotics as active ingredients in host physiology shows influence on the nervous system, consequentially shaping psychological processes, behavior and ultimately exerting health benefits in psychiatric conditions in preclinical animal research and in humans. Animal research has also shown that variations in gut bacteria composition may lead to the psychological abnormalities that characterize anxiety.”

According to the investigators, this prior research suggests that manipulating the gut microbiome using psychobiotics may hold promise for treating and preventing anxiety among young people.

In the current study, Kadosh and colleagues conducted a systematic review and meta-analysis of microbiota-targeted, or psychobiotics, interventions for youth anxiety. They also conducted an online survey regarding the acceptability of psychobiotic interventions for mental health management among 46 youth with lived experience. The investigators searched six databases for controlled trials among individuals aged 10 to 24 years who sought to reduce anxiety. They extracted post-intervention outcomes as SMDs and pooled based on a random-effects model. They included 14 studies in the systematic review and 10 in the meta-analysis, with a total of 324 experimental and 293 control participants.

Results of the meta-analysis showed heterogeneity I² of 12% and a pooled SMD of 0.03 (95% CI, 0.21, 0.14), which indicated an absence of effect. Kadosh and colleagues noted low bias risk in one study, high bias risk in five and uncertain bias risk in four. Sensitivity analyses that accounted for risk showed a SMD of 0.16 (95% CI, 0.38, 0.07), which indicated minimal efficacy of psychobiotics for anxiety treatment among humans.

“As a still relatively unexplored area, any real progress will require a systematic multidisciplinary research approach, which gives priority to specifying mechanisms in the human and animal models, providing causal understanding and addressing realistic outcomes,” Kadosh and colleagues wrote. “This is particularly critical in light of strong public and commercial interests that are presently outpacing research efforts. Encouragingly, this approach has also been met with much enthusiasm from young people with lived experience of mental health problems, which suggests that these research approach and interventions may be ripe for a behavioral ‘nudge’ and potentially present few cultural barriers to use.”