Fig. 2

Nod2 influences responses to antibiotic treatment during the neonatal period. a Experimental outline. WT and Nod2^−/− littermates were divided into two treatment groups: water-treated (litters received only non-acidified control water from day 0 (following birth) throughout the study); or antibiotic-treated (litters received treatment with non-acidified water supplemented with amoxicillin (Abx) at 200 mg/L following birth until weaning (day 21). Weaned pups received control water until endpoint.). Arrows indicate stool collection time points. b Species richness as measured by the Chao1 index on day 21 and 35. c Principal coordinates plot of Bray–Curtis dissimilarity on day 21 and 35. Each dot represents the stool microbiome of one mouse. (ANOSIM, Day 21: WT vs. Nod2^−/−: R = 0.1796, p = 0.019, WT vs. WT+Abx: R = 0.5229, p = 0.001; Nod2^−/− vs. Nod2^−/−+Abx: R = 0.4929, p = 0.001; WT+Abx vs. Nod2^−/−+Abx: R = 0.0906, p = 0.084; Day 35: WT vs. Nod2^−/−: R = 0.0199, p = 0.250; WT vs. WT+Abx: R = 0.1322, p = 0.091; Nod2^−/− vs. Nod2^−/−+Abx: R = 0.3726, p = 0.001; WT+Abx vs. Nod2^−/−+Abx: R = 0.2377, p = 0.046). d Bacterial composition at the Family level at day 21 and 35. Taxa that differed significantly between untreated and antibiotic-treated WT (asterisk), or Nod2^−/− (hash) mice are indicated (false-discovery rate corrected p-value < 0.05). Data are presented as mean ± SD (b) or mean (d). *p < 0.05, **p < 0.01, ***p < 0.001; by paired Student’s t-test (b) or Kruskal–Wallis (d). (n = 9–14 mice per genotype per treatment. Data are from four untreated litters and five antibiotic-treated litters)