Fig. 2. Bacterial flagellins bound by antibodies disproportionally in patients with severe ME/CFS stem from the family of Lachnospiraceae and share an N-terminal motif.

(A) Bacterial flagellins that exhibited antibody responses in ≥30% of CFS patients. Additional peptides per protein are shown if they appeared in >4 individuals. Peptide number: #, Uniref-derived annotation (see Methods). Ratio: Ratio of prevalence in CFS/healthy (Ctrl., control). See table S1 for a full list of all flagellin peptides. (B and C) Alignments of bound flagellin peptides suggest shared motifs bound by cross-reactive Ig responses. In (B), alignments of peptides appearing in ≥50% of CFS patients are shown. In (C), peptides appearing in ≥25% are shown. The peptides from (B) were also used in (C) but are not shown due to space constraints. See fig. S1 for full alignments. Alignments were generated with MegaX [MUSCLE algorithm in standard settings (81)].