Short-chain fatty acids during pregnancy in multiple sclerosis: A prospective cohort study.

Background and Purpose: Short-chain fatty acids (SCFAs) can have pro- or anti-inflammatory properties, but their relationship with multiple sclerosis (MS) relapses during pregnancy remains unknown. This study aimed to explore SCFA profiles in MS patients during pregnancy and to assess their association with the appearance of relapses during pregnancy and postpartum.
Methods: We prospectively included 53 pregnant MS patients and 21 healthy control women. Patients were evaluated during pregnancy and puerperium. SCFAs were measured by liquid chromatography-mass spectrometry.
Results: Sixteen patients (32%) had relapses during pregnancy or puerperium, and 37 (68%) did not. All MS patients showed significant increases in acetate levels during pregnancy and the postpartum period compared to non-MS women. However, propionate and butyrate values were associated with disease activity. Their values were higher in nonrelapsing patients and remained similar to the control group in relapsing patients. The variable that best identified active patients was the propionate/acetate ratio. Ratios of <0.36 during the first trimester were associated with higher inflammatory activity (odds ratio = 165, 95% confidence interval = 10.2-239.4, p < 0.01). Most nonrelapsing patients showed values of >0.36, which were similar to those in healthy pregnant women.
Conclusions: Low propionate/acetate ratio values during the first trimester of gestation identified MS patients at risk of relapses during pregnancy and the postpartum period.
(© 2021 European Academy of Neurology.)