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Social networks, cooperative breeding, and the human milk microbiome
Author(s) -
Meehan Courtney L.,
Lackey Kimberly A.,
Hagen Edward H.,
Williams Janet E.,
Roulette Jennifer,
Helfrecht Courtney,
McGuire Mark A.,
McGuire Michelle K.
Publication year - 2018
Publication title -
american journal of human biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.559
H-Index - 81
eISSN - 1520-6300
pISSN - 1042-0533
DOI - 10.1002/ajhb.23131
Subject(s) - diversity (politics) , dyad , subsistence agriculture , breastfeeding , social network (sociolinguistics) , typology , biology , geography , demography , developmental psychology , ecology , psychology , sociology , medicine , anthropology , pathology , political science , archaeology , social media , law , agriculture
Objectives We present the first available data on the human milk microbiome (HMM) from small‐scale societies (hunter‐gatherers and horticulturalists in the Central African Republic [CAR]) and explore relationships among subsistence type and seasonality on HMM diversity and composition. Additionally, as humans are cooperative breeders and, throughout our evolutionary history and today, we rear offspring within social networks, we examine associations between the social environment and the HMM. Childrearing and breastfeeding exist in a biosocial nexus, which we hypothesize influences the HMM. Methods Milk samples from hunter‐gatherer and horticultural mothers ( n = 41) collected over two seasons, were analyzed for their microbial composition. A subsample of these women's infants ( n = 33) also participated in detailed naturalistic behavioral observations which identified the breadth of infants' social and caregiving networks and the frequency of contact they had with caregivers. Results Analyses of milk produced by CAR women indicated that HMM diversity and community composition were related to the size of the mother‐infant dyad's social network and frequency of care that infants receive. The abundance of some microbial taxa also varied significantly across populations and seasons. Alpha diversity, however, was not related to subsistence type or seasonality. Conclusion While the origins of the HMM are not fully understood, our results provide evidence regarding possible feedback loops among the infant, the mother, and the mother's social network that might influence HMM composition.