Fig. 1

At the diagnostic stage, ALS is associated with changes in the enteral microbiome. (A) Sparse partial least squares-discriminant analyses showing differences in genus abundance between patients with ALS and healthy individuals. (B) Alpha diversity indices of the participants’ microbiome considering species abundance. (C) The abundance of the selected species is significantly affected by ALS status. (D) Phylum abundance in the studied groups showed a significantly increased Firmicutes and decreased abundance of Bacteroidetes in patients with ALS, without changes between spinal ALS and bulbar ALS subtypes. Chord diagram showing relationships (ribbons expressing significant correlations) between phylum abundances, affected by both ALS status (E) and ALS subtypes (F). In (B), Shannon Index increases as both the richness and the evenness of the community increase, providing a comprehensive measure of diversity. Also in (B) Simpson also increases with diversity, ranging from 0 to 1, where a higher value indicates greater diversity. In (C), all indicated species showed a significant difference (FDR corrected p < 0.05 after EdgeR test) between control (Ctl) and ALS patients. In (D), asterisks indicate p < 0.05 after Student’s t-test. For E and F, Spearman correlations between shown variables were calculated, and those showing significance (p < 0.05) were plotted as ribbon-connecting segments.