Figure 3.

Dispersal patterns of gut bacteria and their link to bacterial evolution

(A) Dispersal patterns of bacteria were reflected in their associations: strong geographic and host association (spatiopersistent); strong family and host association (heredipersistent); no associations (non-persistent); all associations (tenacious); and average geographic or family and host associations (average persistent). The analysis was restricted to 50 high abundant genera.

(B) Tenacious taxa could be genetically well-adapted (high purifying selection [d_N/d_S], fewer selective sweeps [Tajima’s D_s], high population sizes [π_S]), while non-persistent taxa show opposing population genetics. p values are calculated with a non-parametric Kruskal-Wallis test, comparing all six groups.

(C) Tenacious bacteria are significantly more often transmitted vertically than horizontally in families, having a higher likelihood to be inherited between generations. Antibiotic usage usually reduces strain persistence, especially in adult hosts and tenacious bacteria. The color reflects the log₁₀ OR (odds ratio), the value in the squares is the rounded, multiple testing corrected q value of Fisher’s exact test conducted separately for each square, q ≥ 0.1 are shown as white squares. Children are hosts < 3 years old. d_N/d_S, non-synonymous to synonymous nucleotide substitutions.; π_S, synonymous nucleotide diversity; OR, odds ratio in Fisher’s exact test. Boxplot centers represent the median; the edges represent first and third quartiles.