It’s probably not the first time that you’ve heard about gut microbes and MS. Particularly, the role that they may play in the development and regulation of MS.
Almost every study published in the literature has demonstrated differences in the gut microbiome in MS patients vs. healthy controls with the possibility that interventions on diet and the use of probiotics may have a favorable outcome.
This latest article on the topic published in Science Advances focuses on the finding that isoflavone-metabolizing bacteria are depleted in the gut of MS patients. Isoflavones are almost exclusively produced by the bean family, for example soya, and may have anti-inflammatory and anti-oxidant properties that may limit disease activity. In a mouse experimental model (EAE), investigators found that mice fed with isoflavones had suppression of their disease, with a reduction in CD4+ T cell infiltration into the CNS. Also, the gut micobiota fed with isoflavones paralleled that of healthy individuals, whereas those fed with an isoflavon-free diet were similar to those found in MS patients (see figure below). In essence the diversity of bacteria in each mouse (called the alpha diversity) was reduced in those on an isoflavone-free diet compared to an isoflavone diet suggesting that an isoflavone diet increases the species richness of the microbiome. Together these may help lower inflammatory triggers.
Sci Adv. 2021 Jul 9;7(28):eabd4595. doi: 10.1126/sciadv.abd4595. Print 2021 Jul.
Isoflavone diet ameliorates experimental autoimmune encephalomyelitis through modulation of gut bacteria depleted in patients with multiple sclerosis
The gut microbiota is a potential environmental factor that influences the development of multiple sclerosis (MS). We and others have demonstrated that patients with MS and healthy individuals have distinct gut microbiomes. However, the pathogenic relevance of these differences remains unclear. Previously, we showed that bacteria that metabolize isoflavones are less abundant in patients with MS, suggesting that isoflavone-metabolizing bacteria might provide protection against MS. Here, using a mouse model of MS, we report that an isoflavone diet provides protection against disease, which is dependent on the presence of isoflavone-metabolizing bacteria and their metabolite equol. Notably, the composition of the gut microbiome in mice fed an isoflavone diet exhibited parallels to healthy human donors, whereas the composition in those fed an isoflavone-free diet exhibited parallels to patients with MS. Collectively, our study provides evidence that dietary-induced gut microbial changes alleviate disease severity and may contribute to MS pathogenesis.