Premasticated food transfer by wild chimpanzee mothers with their infants: Effects of maternal parity, infant age and sex, and food properties.

Premasticated food transfer, when an individual partially breaks down food through chewing and feeds it to another individual, usually mouth-to-mouth, is described widely across human cultures. This behavior plays an important role in modern humans' strategy of complementary feeding, which involves supplementing maternal milk in infant diets with processed, easily digestible versions of adult foods. The extent to which other primates engage in premasticated food transfer with infants is unclear, as premasticated food transfers have been only occasionally reported in other ape species. We investigated premasticated food transfers in 62 mother-infant pairs of wild chimpanzees at Ngogo, Uganda, as well as unresisted food taking, when mothers passively allow infants to seize food. We evaluated the presence or absence and rates of premasticated food transfer and unresisted food taking relative to maternal parity and infant age and sex and assessed the food species and part used. We found that chimpanzee mothers regularly shared premasticated food with their infants aged between 6 months and 4 years, but they were more likely to share, and more frequently shared, with younger infants. The frequency with which females shared premasticated food may relate to maternal experience, as multiparous females shared premasticated food more often than did first-time mothers, which we did not find with unresisted food taking. Both easy-to-chew, commonly eaten foods and tougher, rarely eaten foods were shared. Premasticated food transfer and unresisted food taking may be infant-rearing strategies to facilitate the transition from a diet of exclusive maternal milk to solid food during early infancy. Premasticated food transfer in particular may provide energetic, immune, or growth benefits to infants through reduced chewing effort and maternal saliva. Given our findings in chimpanzees and earlier reports in other ape species, we suggest that the foundation of complementary feeding, a uniquely hominin strategy, might have been present in a common ancestor shared with the other great apes in the form of premasticated, mouth-to-mouth food transfer by mothers with their offspring.

Premastication and length for age among children under 24 months in Laos.

Premastication of infant food by caregivers is common in Laos. Premastication is hypothesized to have both positive and negative implications for children, but the net effect of premastication on child health and nutrition is largely unknown because of a lack of research. This study quantitatively describes premastication in 5 provinces of Laos and examines the associations between premastication and the length of young children. We analyzed cross-sectional data from the Laos 2015 Food and Nutrition Security Survey to characterize premastication among children under 2 years of age (n = 1,661) and to test associations between premastication and child length-for-age z-score. We explored associations using multilevel mixed effects linear regression. Among children 0-23 months, 27.2% of mothers reported giving premasticated food in the past week. Receipt of premasticated food was inversely associated with length-for-age z-score after controlling for potential confounders (child's age, ethno-linguistic group, wealth, and parity) among children 6-13 months (ß -0.36, CI [-0.68, -0.04]) and among children 14-23 months (ß -0.43, CI [-0.81, -0.05]). For breastfed children 0-5 months who received complementary food, the coefficient was similar, but the association was not statistically significant (ß -0.42, CI [-1.2, 0.37]). Premastication is a common feeding practice for children 0-23 months of age, and many infants consume premasticated food on a daily basis. There was a negative relationship between premastication and child length. However, given the cross-sectional nature of this study and potential unmeasured confounding factors, reverse causality or confounding cannot be ruled out. Longitudinal studies are needed to develop recommendations on premastication.

Association of Household Food- and Drink-Sharing Practices With Human Herpesvirus 8 Seroconversion in a Cohort of Zambian Children.

Background: Human herpesvirus 8 (HHV-8) infection occurs in early childhood and is associated with human immunodeficiency virus type 1 (HIV-1) infection and risk for Kaposi sarcoma, but behaviors associated with HHV-8 transmission are not well described. Methods: We enrolled and followed a prospective cohort of 270 children and their household members to investigate risk factors for HHV-8 transmission in Lusaka, Zambia. Results: We report an incidence of 30.07 seroconversions per 100 child-years. Independent risk factors for HHV-8 incident infection included having a child who shared utensils with a primary caregiver (hazards ratio [HR], 2.33; 95% confidence interval [CI], 1.49-7.14), having an increasing number of HHV-8-infected household members (HR, 1.27; 95% CI, 1.09-2.79), and having ≥5 siblings/children in the household (HR, 2.24; 95% CI, 1.03-4.88). Playing with >5 children a day was protective against infection (HR, 0.54; 95% CI, .33-0.89), as was increasing child age (HR, 0.96; 95% CI, .93-.99). Conclusions: This is the first study to find a temporal association between limited child feeding behaviors and risk for HHV-8 infection. Child food- and drink-sharing behaviors should be included in efforts to minimize HHV-8 transmission, and households with a large number of siblings should receive additional counseling as childhood infections occur in the home context.

Short report: premastication in rural Gabon--a cross-sectional survey.

Premastication-defined as pre-chewing of food for infants by their caregiver-is a common feeding practice in various societies. To date the impact of premastication on children's health including the potential for transmission of infectious diseases is not well understood. Since there are no epidemiologic data on premastication from resource poor regions in Central Africa, we investigated the epidemiology and demographic variables associated with premastication in Central Africa. Between 2011 and 2012, mothers were interviewed about child feeding behaviors in three rural communities in Gabon. A quarter (n = 20, 24%) of 82 participants stated to perform premastication regularly. Despite the small sample size, our study provides first baseline data for the epidemiology of premastication in Central Africa, indicating that this feeding practice is common in rural communities.

Higher likelihood of 6-months exclusive breastfeeding among HIV infected than uninfected mothers: a household survey in Kenya.

BACKGROUND: Exclusive breastfeeding (EBF) (breast milk feeding without additional food or drink, except medicine) is associated with deceased risk of postnatal transmission of HIV from mother to child. METHODS: This analysis used data from a household survey in Western Kenya in 2011. Participants were mothers with HIV and uninfected mothers, aged ≥14 years who gave birth in the prior year (ever breastfed) within the Kenya Medical Research Institute/US Centers for Disease Control and Prevention (KEMRI/CDC) Health and Demographic Surveillance System. Data on breastfeeding counseling and knowledge and practices regarding breastfeeding were collected. Rates and correlates of EBF were determined using multivariable logistic regression. RESULTS: Of 652 mothers enrolled in the study, 435 were included in this analysis. Median age was 28 years among 154 mothers with HIV and 25 years among 281 uninfected mothers. Mothers with HIV were more likely than uninfected mothers to report breastfeeding counseling at a health facility (88.9% vs. 51.6%, respectively, p <  0.001) and EBF for 6-months (64.9% versus 34.5%, p <  0.001). Premastication (pre-chewing of food by adults prior to feeding to children) was less prevalent among mothers with HIV (3.9% vs. 13.2% p = 0.001) who were also more knowledgeable about potential risk of HIV transmission through premastication (83.1% vs 71.2% p = 0.005). Mothers with HIV who EBF for six months were 3.68-fold more likely to report counseling on EBF (aOR 3.68; 95% CI: 1.00,13.70). Uninfected mothers with polygamous marriage, any antenatal care visit, unskilled delivery and delayed breastfeeding initiation (> 1 h) were less likely to practice EBF for six months 62% (aOR 0.38; 95%CI: 0.20,0.94), 72% (aOR 0.28; 95%CI: 0.10,1.00), 54% (aOR 0.46; 95% CI: 0.22,1.00) and 46% (aOR 0.54; 95%CI: 0.30,1.00) respectively. CONCLUSIONS: Mothers with HIV were more likely to report breastfeeding counseling at a health facility, EBF for six months and less likely to practice premastication than uninfected mothers. Lessons learned from breastfeeding counseling in mothers with HIV could be used to improve awareness and change breastfeeding practices for all mothers.

Salivary microbiomes of indigenous Tsimane mothers and infants are distinct despite frequent premastication.

BACKGROUND: Premastication, the transfer of pre-chewed food, is a common infant and young child feeding practice among the Tsimane, forager-horticulturalists living in the Bolivian Amazon. Research conducted primarily with Western populations has shown that infants harbor distinct oral microbiota from their mothers. Premastication, which is less common in these populations, may influence the colonization and maturation of infant oral microbiota, including via transmission of oral pathogens. We collected premasticated food and saliva samples from Tsimane mothers and infants (9-24 months of age) to test for evidence of bacterial transmission in premasticated foods and overlap in maternal and infant salivary microbiota. We extracted bacterial DNA from two premasticated food samples and 12 matched salivary samples from maternal-infant pairs. DNA sequencing was performed with MiSeq (Illumina). We evaluated maternal and infant microbial composition in terms of relative abundance of specific taxa, alpha and beta diversity, and dissimilarity distances. RESULTS: The bacteria in saliva and premasticated food were mapped to 19 phyla and 400 genera and were dominated by Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The oral microbial communities of Tsimane mothers and infants who frequently share premasticated food were well-separated in a non-metric multi-dimensional scaling ordination (NMDS) plot. Infant microbiotas clustered together, with weighted Unifrac distances significantly differing between mothers and infants. Infant saliva contained more Firmicutes (p < 0.01) and fewer Proteobacteria (p < 0.05) than did maternal saliva. Many genera previously associated with dental and periodontal infections, e.g. Neisseria, Gemella, Rothia, Actinomyces, Fusobacterium, and Leptotrichia, were more abundant in mothers than in infants. CONCLUSIONS: Salivary microbiota of Tsimane infants and young children up to two years of age do not appear closely related to those of their mothers, despite frequent premastication and preliminary evidence that maternal bacteria is transmitted to premasticated foods. Infant physiology and diet may constrain colonization by maternal bacteria, including several oral pathogens.

Conflict or congruence? Maternal and infant-centric factors associated with shorter exclusive breastfeeding durations among the Tsimane.

Six months of exclusive breastfeeding (EBF) is considered optimal for infant health, though globally most infants begin complementary feeding (CF) earlier-including among populations that practice prolonged breastfeeding. Two frameworks for understanding patterns of early CF emerge in the literature. In the first, maternal and infant needs trade-off, as "maternal-centric" factors-related to time and energy demands, reproductive investment, cultural influences, and structural barriers- favor supplanting breastfeeding with earlier and increased CF. A second framework considers that "infant-centric" factors-related to infant energetic needs-favor CF before six months to supplement breastfeeding. We apply these two frameworks in examining early CF among the Tsimane-a high-fertility, high-mortality, forager-horticulturalist population residing in the Bolivian Amazon. Data were collected from a mixed-longitudinal sample of 161 Tsimane mother-infant pairs from August 2012-April 2013. Tsimane mothers generally reported introducing CF because of perceived infant needs. However, CF is introduced with continued intensive breastfeeding, and generally coupled with premastication. Risks of earlier CF relative to the minimum hazard (estimated at 5 births) were elevated for lower and higher parity mothers, but were significantly greater only after 9 births. Seventeen percent of mothers reported introducing CF because of low milk supply. Introducing CF because of low milk was most common from 0 to 3 months of age and among higher parity mothers, which may reflect physiological constraints. Maternal reproductive trade-offs and perceived infant needs may help explain the low prevalence of EBF to six months among other populations in which breastfeeding is not structurally or culturally constrained.