The bacterial density of AKM and LGG in the fecal samples was estimated using quantitative real-time polymerase-chain reaction (qPCR) with species specific primers (AKM_Fwd: 5’-CCT TGC GGT TGG CTT CAG AT-3’ and AKM_Rev: 5’-CAG CAC GTG AAG GTG GGG AC-3’85 (link) and LGG_Fwd: 5’-GCC GAT CGT TGA CGT TAG TTG G-3’ and LGG_Rev: 5’-CAG CGG TTA TGC GAT GCG AAT-3’86 (link)) purchased from Integrated DNA Technologies. Standard curves (Table S2) were based on a dilution series of total DNA extracted from monocultures of AKM and LGG. The qPCR results were obtained using the CFX96 Touch Real-Time PCR Detections System (Bio-Rad Laboratories) and the reagent SsoFast EvaGreen Supermix with Low ROX (Bio-Rad Laboratories, cat. No. 1725211), and run as previously described87 (link).