Fig. 3: Intrasample strain diversity.

a Pairwise average nucleotide identity (ANI) between strains of the same species in a single sample of maternal stool, infant stool, and maternal breast milk. b Pairwise SNP distance between strains of the same species in an individual sample of maternal stool (n = 122), infant stool (n = 108), or maternal breast milk (n = 14) with an ANI ≥ 99.9%. Boxplots visualise the middle 50% of data with the median relative abundance shown in the central line. The whiskers extend to show the range of values excluding the outliers. c B. bifidum from individuals with multiple strains. Strains from PB066 34-week stool sample are highlighted. d Midpoint rooted phylogenetic tree of B. breve strains from this study. e Comparison of 8 complete B. breve genomes from group II.