Fig. 2: Mother–offspring sharing of the gut microbiome.
From: The person-to-person transmission landscape of the gut and oral microbiomes
a, Mother–offspring strain-sharing rates (left axis; box plots and non-grey dots) decrease, whereas species richness (right axis; grey dots) in offspring increases, as a function of offspring age (17 datasets in 14 countries). The median number of SGBs profiled by StrainPhlAn in the offspring is used as a proxy for richness (right axis). Kruskal–Wallis test, n = 448, χ2 = 156, P < 2.2 × 10−16, post hoc Dunn tests; NS, not significant (Padj ≥ 0.05); all other comparisons are significant (Supplementary Table 10). In box plots, box edges delineate lower and upper quartiles, the centre line represents the median and whiskers extend to 1.5 times the IQR. Novel datasets from the present study are highlighted with asterisks. b, The distribution of mother–infant SGB transmissibility in the first year of life. c, A panel of 33 SGBs that are highly maternally transmitted during their first year of life (SGB transmissibility >0.5 and significantly higher mother–infant transmissibility than unrelated mother–infant transmissibility; Methods) showing their transmissibility (transm.) in specific datasets (separated by westernized-lifestyle status) and in other age categories. NS, non-significant SGB transmissibility in the category (χ2 test on the number of transmitted and non-transmitted SGBs between mother–offspring pairs and between unrelated mother and offspring pairs, Supplementary Table 16). Only comparisons with at least three possible transmissions (species shared by at least three mother–offspring pairs) are shown; comparisons with less than three possible transmissions are marked with a dot. Prevalence is defined as the percentage of mother–offspring samples in which the SGB was detected. Novel datasets from the present study are highlighted with asterisks. SGB names in grey use a strain identity threshold of 5% inter-individual nGD (Supplementary Table 4). B. cellulosilyticus-timonensis, Bacteroides cellulosilyticus and Bacteroides timonensis; Bacteroides uniformis-rodentium, Bacteroides uniformis and Bacteroides rodentium; B. pseudocatenulatum, Bifidobacterium pseudocatenulatum; B. ovatus-xylanisolvens-caecim., Bacteroides caecimuris.
