Table 3.

Summary of GEE models comparing presence or absence of Bifidobacterium species in individual infants by cohort history of breastfeeding. Reference group was the high-breastfeeding group. To account for multiple comparisons, a p-value less than 0.0062 is considered significant. The model for B. animalis failed to run, because after excluding infants who were not breastfed at time of sample collection, there were no infants from a low historical breastfeeding pattern cohort colonized by B. animalis. Taxa that differed significantly in prevalence from the high historical breastfeeding pattern cohorts are in bold.

Cohort Breast-Feeding Pattern	B. adolescentis Odds Ratio (95% CI, p-Value)	B. animalis Odds Ratio (95% CI, p-Value)	B. bifidum Odds Ratio (95% CI, p-Value)	B. breve Odds Ratio (95% CI, p-Value)	B. longum Subspecies infantis Odds Ratio (95% CI, p-Value)	B. longum Subspecies longum Odds Ratio (95% CI, p-Value)	B. longum Unknown Subspecies Odds Ratio (95% CI, p-Value)	B. pseudocatenulatum Odds Ratio (95% CI, p-Value)
Medium	4.1 (1.6–11, p = 0.0041)	NA	0.22 (0.16–0.31, p < 0.0001)	2.0 (1.3–3.1, p = 0.0019)	0.010 (0.0037–0.029, p < 0.0001)	2.2 (0.98–5.0, p = 0.055)	2.8 (0.92–8.2, p = 0.069)	12 (10–13, p < 0.0001)
Low	2.4 (1.0–5.6, p = 0.041)	NA	0.40 (0.28–0.58, p < 0.0001)	1.4 (0.70–2.9, p = 0.32)	0.0084 (0.0024–0.029, p < 0.0001)	1.8 (0.57–5.7, p = 0.31)	0.63 (0.16–2.4, p = 0.51)	2.1 (1.8–2.5, p < 0.0001)