I stumbled upon a study I thought was interesting, in light of recent reports that PwPD harbor elevated levels of desulfovibrio in their microbiome. Desulfovibrio is a sulfur reducing bacteria (SRB). Sulfur reducing bacteria produce hydrogen sulfide, which in small amounts can be beneficial, but in larger amounts is thought to promote anxiety. In this experiment, researchers treated mice with desulfovibrio to elicit hydrogen sulfide production and anxiety behavior, then treated the mice with magnesium oxide which ameliorated both, apparently by suppressing the growth of SRB.
Magnesium is often used to address anxiety/sleep issues, but I've never come across a proposal that it works via the gut microbiome. On the contrary, it's usually advised not to use the magnesium oxide form because it isn't well absorbed but tends to stay in the gut and cause loose stools!
Seems like those with anxiety/constipation issues might benefit from trying magnesium oxide, but I'm not sure about the applicability otherwise. Still, it got me wondering if other measures to suppress desulfovibrio would have an impact on anxiety. For instance, did anyone who incorporated agave inulin into their stack find it lessened their anxiety?
Research on the microbiome in PD just can't come fast enough! I suspect one day there will be pre/probiotics tailored to individual symptoms like this.