Fig. 1. Identifying factors that affect the efficiency of colonization of gnotobiotic dam–pup dyads with P. copri in the presence of other cultured age-discriminatory and WLZ-associated bacterial strains and the effects of colonization on pup weight gain.

a, Energy contribution from different modules of the ‘weaning diet supplemented with MDCF-2’. b,c, Study design (n = 2 dams and 8, 5 and 7 offspring for arms 1, 2 and 3, respectively). b, The timing of bacterial colonization of dams and diet switches. c, The gavages administered to members of each treatment arm. d, Body weights of the offspring of dams, normalized to P23. e, Absolute abundance of B. infantis Bg2D9 (arm 1) and B. infantis Bg463 (arm 2) in faecal samples obtained from pups. f, Absolute abundance of P. copri in faecal samples collected from pups in the indicated treatment arms at the indicated postnatal time points. Inset: the absolute abundance of P. copri in faecal samples collected from pups at P21. g, Principal components analysis of absolute abundances of other community members in faecal samples obtained from pups at P21 and P53. Mean values ± s.d. are shown in d–f. Each dot in d–f represents an individual animal. P values were calculated using a linear mixed-effects model (d, Methods), a two-sided Mann–Whitney U test (f, inset) or PERMANOVA (g). Centroids are denoted by a coloured ‘X’. Shaded ellipses represent the 95% confidence interval of the sample distribution. Each dot represents an individual animal. Data generated from all of the offspring were used in the analyses shown in d–g.