The gut microbiome plays role in migraine
Migraine is a debilitating, highly prevalent condition that affects approximately 15% of the population. It is well-known that many migraineurs experience nausea or vomiting, but other GI complaints occur often too. For example, migraineurs have IBS 2-4 times more often than healthy peers (1,2). This is a strong indication that gut health is linked to migraine.
In recent years, several mechanisms have been identified that can play a role in the microbiome-migraine connection. For example, impaired anatomical barriers such as the gut-blood and blood-brain barrier are observed in migraineurs and can lead to systemic and neuroinflammatory responses (3,4). Insulin signaling is also impaired in migraine patients and it is known that the microbiome can directly modulate this (4,5).
In addition, it is well-known that disturbed serotonin signaling plays an important role in the pathogenesis of migraine (6). Importantly, metabolism of its precursor tryptophan via the serotonin, indole, or kynurenine pathways is influenced by the gut microbiome (7). It is known, for example, that metabolites from the kynurenine pathway affect the NMDA receptor, which plays a role in the cortical spreading depression phase of migraine. Interestingly, various tryptophan metabolites are disturbed in IBS patients too.
Another potential mechanism that has been identified is pathogen overgrowth. For example, Heliobacter pylori infection is associated with migraine (7). Moreover, overgrowth of other pathogenic bacteria and yeasts has been found in migraineurs as well (8). Since many pathogenic bacterial species are known to be able to synthesize histamine, it is interesting that histamine oversensitivity is implicated in migraine too (9).
Together, the identification of these mechanisms suggests that if a migraine patient also has GI complaints, a function-focused fecal analysis can help to identify which pathways may be involved in that individual. Based on this and on other complaints and medical problems, a targeted intervention can be compiled.
References:
- https://doi.org/10.1002/brb3.2291
- https://doi.org/10.1155/2022/8690562
- https://doi.org/10.1177/1535370217743766
- https://doi.org/10.1111/ped.14946
- https://doi.org/10.1016/j.molcel.2020.03.005
- https://doi.org/10.1152/physrev.00034.2015
- https://doi.org/10.3390/ijms221810134
- https://doi.org/10.2147/NDT.S144955
- https://doi.org/10.1186/s10194-019-0984-1