Psychobiotic interventions for anxiety in young people: a systematic review and meta-analysis, with youth consultation

Abstract

The human gut microbiome influence on brain function and mental health is an emerging area of intensive research. Animal and human research indicates adolescence as a sensitive period when the gut-brain axis is fine-tuned, where dietary interventions to change the microbiome may have long-lasting consequences for mental health. This study reports a systematic review and meta-analysis of microbiota-targeted (psychobiotics) interventions on anxiety in youth, with discussion of a consultation on the acceptability of psychobiotic interventions for mental health management amongst youth with lived experience. Six databases were searched for controlled trials in human samples (age range: 10–24 years) seeking to reduce anxiety. Post intervention outcomes were extracted as standard mean differences (SMDs) and pooled based on a random-effects model. 5416 studies were identified: 14 eligible for systematic review and 10 eligible for meta-analysis (total of 324 experimental and 293 control subjects). The meta-analysis found heterogeneity I2 was 12% and the pooled SMD was −0.03 (95% CI: −0.21, 0.14), indicating an absence of effect. One study presented with low bias risk, 5 with high, and 4 with uncertain risk. Accounting for risk, sensitivities analysis revealed a SMD of −0.16 (95% CI: −0.38, 0.07), indicative of minimal efficacy of psychobiotics for anxiety treatment in humans. There is currently limited evidence for use of psychobiotics to treat anxiety in youth. However, future progress will require a multidisciplinary research approach, which gives priority to specifying mechanisms in the human models, providing causal understanding, and addressing the wider context, and would be welcomed by anxious youths.

Association Between Consumption of Fermented Food and Food-Derived Prebiotics With Cognitive Performance, Depressive, and Anxiety Symptoms in Psychiatrically Healthy Medical Students Under Psychological Stress: A Prospective Cohort Study

“…The link is likely independent of overall diet quality and other potentially confounding factors. This result is in contrast with the majority of probiotic intervention studies ( 58 – 63 ) and correlational research assessing the frequency of fermented food intake ( 64 , 65 ). Although such result is intriguing, it is not completely isolated.…”

The microbiota–gut–brain axis: pathways to better brain health. Perspectives on what we know, what we need to investigate and how to put knowledge into practice

“…Overall, clinical studies are held back by a lack of disease- and microbiota-specific biomarkers, absence of clinically relevant behavioural phenotypes and poor tools for cohort stratification. Still, over the last year a number of meta-analyses have appeared which show a moderately positive evaluation on the use of psychobiotic [ 104 ] interventions for anxiety [ 105 ], schizophrenia [ 106 ] or cognitive functions [ 107 , 108 ], pointing to the diversity and complexity of—and the numerous confounding factors that may affect—the gut microbiota [ 21 , 109 ].…”

Nutrient Intake and Gut Microbial Genera Changes after a 4-Week Placebo Controlled Galacto-Oligosaccharides Intervention in Young Females

“…This is promising for designing individualized nutrient interventions to improve host health. While making food choices is complex, identifying strategies that will lead to better well-being would assist in making healthier decisionsadvice that is desirable particularly for young people, who are still undergoing significant developmental changes [25].…”

“…Therefore, if gut microbiota influence food choice, food choice may also influence the gut microbiome, complicating causal attribution. In addition, although pre-and probiotics have been investigated in the treatment of psychiatric disorders (e.g., anxiety, depression, neurodevelopmental disorders [24], to date there is mixed evidence for efficacy [25][26][27]. We postulate that to ascertain true prebiotic effects, data on nutritional intake must be acquired in consideration of humans as holobionts [28].…”