Ecoevolutionary processes structure milk microbiomes across the mammalian tree of life

Milk production is an ancient adaptation that unites all mammals. Milk contains a microbiome that can contribute to offspring health and microbial-immunological development. We generated a comprehensive milk microbiome dataset (16S rRNA gene) for the class Mammalia, representing 47 species from all placental superorders, to determine processes structuring milk microbiomes. We show that across Mammalia, milk exposes offspring to maternal bacterial and archaeal symbionts throughout lactation. Deterministic processes of environmental selection accounted for 20% of milk microbiome assembly processes; milk microbiomes were similar from mammals with the same host superorder (Afrotheria, Laurasiathera, Euarchontoglires, and Xenarthra: 6%), environment (marine captive, marine wild, terrestrial captive, and terrestrial wild: 6%), diet (carnivore, omnivore, herbivore, and insectivore: 5%), and milk nutrient content (sugar, fat, and protein: 3%). We found that diet directly and indirectly impacted milk microbiomes, with indirect effects being mediated by milk sugar content. Stochastic processes, such as ecological drift, accounted for 80% of milk microbiome assembly processes, which was high compared to mammalian gut and mammalian skin microbiomes (69% and 45%, respectively). Even amid high stochasticity and indirect effects, our results of direct dietary effects on milk microbiomes provide support for enteromammary trafficking, representing a mechanism by which bacteria are transferred from the mother's gut to mammary gland and then to offspring postnatally. The microbial species present in milk reflect both selective pressures and stochastic processes at the host level, exemplifying various ecological and evolutionary factors acting on milk microbiomes, which, in turn, set the stage for offspring health and development.

Pregnant Women's Concerns Regarding COVID-19 and Their Willingness to Be Vaccinated

Objectives: We investigated coronavirus disease 2019 (COVID-19) opinions, experiences, and willingness to accept COVID-19 vaccination during pregnancy at two prenatal clinics in early 2021 and early 2022. Materials and Methods: Paper questionnaires were distributed to pregnant women at prenatal care facilities in Virginia and Florida between January and April 2021 and January and April 2022. Questions regarding acceptance and opinions of the influenza vaccine served as a baseline to assess COVID-19 vaccine opinions. Associations between demographic parameters and vaccine opinions and acceptance were examined using Chi-square. A COVID-19 concern score was constructed by principal component analysis with differences between groups assessed by analysis of variance (ANOVA) and analysis of covariance (ANCOVA). Results: Many participants (40.6%) reported that the COVID pandemic had affected their pregnancy. Main themes were problems with social networks, increased stress/anxiety, and being more cautious. In 2021, 19.5% reported they would accept a COVID-19 vaccination during their pregnancy, which increased to 45.8% in 2022. Vaccine hesitancy did not vary by race or between sites, but educational attainment was significant (p < 0.001). Women with a higher concern score were more likely to report they would accept a COVID-19 vaccine. Women who would accept COVID vaccination had a positive opinion regarding the influenza vaccine. Main themes for refusing COVID-19 vaccination were concerns about side effects, lack of research/data, and mistrust of vaccines. Conclusions: The proportion of women willing to accept COVID-19 vaccination increased but remained below 50%. Willingness to accept vaccination during pregnancy was associated with higher education, higher concern about COVID-19, and a positive opinion of the influenza vaccine.