Widespread Bifidobacterium deficit in United States infants drives prevalent gut dysbiosis https://www.nature.com/articles/s42003-025-08274-7 Missing beneficial bacteria in infant guts linked to rising asthma and allergy cases https://medicalxpress.com/news/2025-07-beneficial-bacteria-infant-guts-linked.html The study obtained fecal samples from participants in 48 of 50 US States