*2.5. Statistical Analyses*

Data extracted from the FFQ were analyzed by Pearson's chi-square. Comparisons between relative expression units and cytokines' concentrations in MS patients and controls were performed by a nonparametric Mann–Whitney U test. Zonulin concentrations were analyzed by unpaired *t* test with Welch's correction, since the data presented < Gaussian distribution. Correlations among the read percentages of the gu<sup>t</sup> microbiota, cytokines, and zonulin concentrations were performed by Spearman's correlation.

We performed analyses of variance and obtained rarefaction curves and diversity indexes by using annotated operational taxonomic units (OTUs). Alpha diversity summarizes the microbial diversity within each sample, and beta diversity measures differences between samples. Sequencing analysis of bacterial 16S was conducted as described in a previous study [46]. *p* values less than 0.05 were considered statistically significant.
