# Gut microbiota, probiotics, and migraine: a clinical review and meta-analysis

## TL;DR

This paper reviews the link between gut microbiota and migraines, finding that probiotics may help reduce migraine frequency.

## Contribution

It provides a meta-analysis showing probiotics' potential to reduce migraine frequency, despite limited study consistency.

## Key findings

- Probiotics may reduce migraine frequency, with a statistically significant result.
- Migraine patients show microbiome alterations linked to clinical symptoms.
- Probiotics do not significantly affect migraine severity or duration.

## Abstract

Migraine is a primary headache disorder affecting about 14% of the global
population. The knowledge about migraine pathophysiology is increasing
constantly; however, there are still many unknowns and uncertainties. Intestinal
microbiota builds the gut environment together with metabolites and the immune
system. Its connections with disorders outside the digestive system have been
described, mainly neuropsychiatric diseases, due to the existence of the
microbiota-gut-brain axis. Therefore, it is suggested that migraine is also
correlated with changes in the microbiome. The review aimed to summarize the
available literature related to the topic. We performed an electronic article
search through the Embase Database and PubMed Database, and included 14 articles
after analysis under the Preferred Reporting Items for Systematic Reviews and
Meta-analyses (PRISMA) 2020 guidelines. Subsequently, a meta-analysis of
randomized controlled clinical trials summarizing probiotics’ effect on migraine
prevention was conducted based on the same guidelines and resulted in including 2
adequate trials. Microbiome alterations have been observed in migraine patients
with an influence on clinical presentation. Preclinical studies suggested a
direct connection between migraine and microbiome changes. The meta-analysis has
shown the influence of probiotics on migraine frequency (p = 0.003;
Hedges’ g = 1.22; standard error (SE) = 0.41), and no impact on migraine
severity (p = 0.069; Hedges’ g = 1.10; SE = 0.61) and attacks’
duration (p = 0.149; Hedges’ g = 0.18; SE = 0.15). However, the
former was close to the statistical significance. The following work demonstrates
a correlation between migraine and microbiome, which has a putative positive
impact on migraine management. Moreover, probiotic supplementation can alleviate
migraine symptoms. However, the main limitation is the limited number of studies,
together with high heterogeneity and limited methodological consistency in the
meta-analysis.