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Breastfeeding and microbial colonization during infancy occur within a critical time window for development, and both are thought to influence the risk of respiratory illness. However, the mechanisms underlying the protective effects of breastfeeding and the regulation of microbial colonization are poorly understood. Here, we profiled the nasal and gut microbiomes, breastfeeding characteristics, and maternal milk composition of 2,227 children from the CHILD Cohort Study. We identified robust colonization patterns that, together with milk components, predict preschool asthma and mediate the protective effects of breastfeeding. We found that early cessation of breastfeeding (before 3 months) leads to the premature acquisition of microbial species and functions, including Ruminococcus gnavus and tryptophan biosynthesis, which were previously linked to immune modulation and asthma. Conversely, longer exclusive breastfeeding supports a paced microbial development, protecting against asthma. These findings underscore the importance of extended breastfeeding for respiratory health and highlight potential microbial targets for intervention., Competing Interests: Declaration of interests M.B.A. receives research funding from the Canadian and US governments, the Bill and Melinda Gates Foundation, and the Garfield Weston Foundation. She holds a Canada Research Chair in Early Nutrition and the Developmental Origins of Health and Disease and is a fellow of the CIFAR Humans and the Microbiome program. She has consulted for DSM Nutritional Products, serves on the scientific advisory board for TinyHealth, and has received speaking honoraria from Prolacta Biosciences. She has contributed without remuneration to online courses on breast milk and the infant microbiome produced by Microbiome Courses. L.B. receives research funding from the United States National Institutes of Health and the Bill and Melinda Gates Foundation. L.B. is the UC San Diego Chair of Collaborative Human Milk Research endowed by the Family Larsson-Rosenquist Foundation in Switzerland. V.B. is currently an employee of F. Hoffman-La Roche Ltd.; however, the published work was done prior to her employment and does not involve/promote any of Roche’s materials or point of view., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Despite global public health organizations endorsing breastfeeding or human milk (HM) as the optimal source of nutrition for infants, detailed knowledge of how HM composition influences infant growth is lacking. In this commentary we summarize and interpret the key findings of a large systematic review on HM components and child growth (N = 141 articles included). We highlight the most consistent associations, discuss study quality issues, explore socio-economic and time trends in this body of research, and identify gaps and future research directions., Key Findings of Systematic Review: We grouped HM components into three categories: micronutrients (28 articles), macronutrients (57 articles), and bioactives (75 articles). Overall, we struggled to find consistent associations between HM components and infant growth. The majority of studies (85%) were of moderate or low-quality, with inconsistent HM collection and analysis strategies being identified as the most substantial quality concerns. Additional quality issues included failing to account for potential confounding by factors such as breastfeeding exclusivity and maternal body mass index., Considerations for Future Human Milk Research: Many opportunities exist for the future of HM research. Using untargeted metabolomics will expand our understanding of HM components beyond previously defined and well-understood components. Machine learning will allow researchers to investigate HM as an integrated system, rather than a collection of individual components. Future research on HM composition should incorporate evidence-based HM sampling strategies to encompass circadian variation as well as infant consumption. Additionally, researchers need to focus on developing high quality growth data using consistent growth metrics and definitions. Building multidisciplinary research teams will help to ensure that outcomes are meaningful and clinically relevant., Conclusion: Despite a large body of literature, there is limited quality evidence on the relationship between HM composition and infant growth. Future research should engage in more accurate collection of breastfeeding data, use standardized HM collection strategies and employ assays that are validated for HM. By systematically evaluating the existing literature and identifying gaps in existing research methods and practice, we hope to inspire standardized methods and reporting guidelines to support robust strategies for examining relationships between HM composition and child growth., (© 2024. The Author(s).)

Background: A lack of safety data on postpartum medication use presents a potential barrier to breastfeeding and may result in infant exposure to medications in breastmilk. The type and extent of medication use by lactating women requires investigation., Methods: Data were collected from the CHILD Cohort Study which enrolled pregnant women across Canada between 2008 and 2012. Participants completed questionnaires regarding medications and non-prescription medications used and breastfeeding status at 3, 6 and 12 months postpartum. Medications, along with self-reported reasons for medication use, were categorized by ontologies [hierarchical controlled vocabulary] as part of a large-scale curation effort to enable more robust investigations of reasons for medication use., Results: A total of 3542 mother-infant dyads were recruited to the CHILD study. Breastfeeding rates were 87.4%, 75.3%, 45.5% at 3, 6 and 12 months respectively. About 40% of women who were breastfeeding at 3 months used at least one prescription medication during the first three months postpartum; this proportion decreased over time to 29.5% % at 6 months and 32.8% at 12 months. The most commonly used prescription medication by breastfeeding women was domperidone at 3 months (9.0%, n = 229/2540) and 6 months (5.6%, n = 109/1948), and norethisterone at 12 months (4.1%, n = 48/1180). The vast majority of domperidone use by breastfeeding women (97.3%) was for lactation purposes which is off-label (signifying unapproved use of an approved medication). Non-prescription medications were more often used among breastfeeding than non-breastfeeding women (67.6% versus 48.9% at 3 months, p < 0.0001), The most commonly used non-prescription medications were multivitamins and Vitamin D at 3, 6 and 12 months postpartum., Conclusions: In Canada, medication use is common postpartum; 40% of breastfeeding women use prescription medications in the first 3 months postpartum. A diverse range of medications were used, with many women taking more than one prescription and non-prescription medicines. The most commonly used prescription medication by breastfeeding women were domperidone for off-label lactation support, signalling a need for more data on the efficacy of domperidone for this indication. This data should inform research priorities and communication strategies developed to optimize care during lactation., (© 2024. The Author(s).)

Competing Interests: Competing interests: None declared.

Objective: Breastfeeding is associated with reduced postpartum depression, stronger parent-child relationships, and fewer behavioral disorders in early childhood. We tested the mediating roles of postpartum depression and parent-child relationship in the association between breastfeeding practices and child behavior., Study Design: We used standardized questionnaire data from a subset of the CHILD Cohort Study (n = 1,573) to measure postpartum depression at 6 months, 1 year and 2 years, parent-child relationship 1 year and 2 years, and child behavior at 5 years using the Child Behavior Checklist (range 0-100). Breastfeeding practices were measured at 3 months (none, partial, some expressed, all direct at the breast), 6 months (none, partial, exclusive), 12 months, and 24 months (no, yes). Confounders included birth factors, maternal characteristics, and socioeconomic status., Results: Breast milk feeding at 3 or 6 months was associated with - 1.13 (95% CI: -2.19-0.07) to -2.14 (95% CI: -3.46, -0.81) lower (better) child behavior scores. Reduced postpartum depression at 6 months mediated between 11.5% and 16.6% of the relationship between exclusive breast milk feeding at 3 months and better child behavior scores. Together, reduced postpartum depression at 1 year and reduced parent-child dysfunction at 2 years mediated between 21.9% and 32.1% of the relationship between breastfeeding at 12 months and better child behavior scores., Conclusion: Postpartum depression and parent-child relationship quality partially mediate the relationship between breastfeeding practices and child behavior. Breastfeeding, as well as efforts to support parental mental health and parent-child relationships, may help to improve child behavior., (© 2024. The Author(s).)

Among exclusively breastfed infants, human milk (HM) provides complete nutrition in the first mo of life and remains an important energy source as long as breastfeeding continues. Consisting of digestible carbohydrates, proteins, and amino acids, as well as fats and fatty acids, macronutrients in human milk have been well studied; however, many aspects related to their relationship to growth in early life are still not well understood. We systematically searched Medline, EMBASE, the Cochrane Library, Scopus, and Web of Science to synthesize evidence published between 1980 and 2022 on HM components and anthropometry through 2 y of age among term-born healthy infants. From 9992 abstracts screened, 57 articles reporting observations from 5979 dyads were included and categorized based on their reporting of HM macronutrients and infant growth. There was substantial heterogeneity in anthropometric outcome measurement, milk collection timelines, and HM sampling strategies; thus, meta-analysis was not possible. In general, digestible carbohydrates were positively associated with infant weight outcomes. Protein was positively associated with infant length, but no associations were reported for infant weight. Finally, HM fat was not consistently associated with any infant growth metrics, though various associations were reported in single studies. Fatty acid intakes were generally positively associated with head circumference, except for docosahexaenoic acid. Our synthesis of the literature was limited by differences in milk collection strategies, heterogeneity in anthropometric outcomes and analytical methodologies, and by insufficient reporting of results. Moving forward, HM researchers should accurately record and account for breastfeeding exclusivity, use consistent sampling protocols that account for the temporal variation in HM macronutrients, and use reliable, sensitive, and accurate techniques for HM macronutrient analysis., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Human milk (HM) contains macronutrients, micronutrients, and a multitude of other bioactive factors, which can have a long-term impact on infant growth and development. We systematically searched MEDLINE, EMBASE, Cochrane Library, Scopus, and Web of Science to synthesize evidence published between 1980 and 2022 on HM components and anthropometry through 2 y of age among term-born infants. From 9992 abstracts screened, 141 articles were included and categorized based on their reporting of HM micronutrients, macronutrients, or bioactive components. Bioactives including hormones, HM oligosaccharides (HMOs), and immunomodulatory components are reported here, based on 75 articles from 69 unique studies reporting observations from 9980 dyads. Research designs, milk collection strategies, sampling times, geographic and socioeconomic settings, reporting practices, and outcomes varied considerably. Meta-analyses were not possible because data collection times and reporting were inconsistent among the studies included. Few measured infant HM intake, adjusted for confounders, precisely captured breastfeeding exclusivity, or adequately described HM collection protocols. Only 5 studies (6%) had high overall quality scores. Hormones were the most extensively examined bioactive with 46 articles (n = 6773 dyads), compared with 13 (n = 2640 dyads) for HMOs and 12 (n = 1422 dyads) for immunomodulatory components. Two studies conducted untargeted metabolomics. Leptin and adiponectin demonstrated inverse associations with infant growth, although several studies found no associations. No consistent associations were found between individual HMOs and infant growth outcomes. Among immunomodulatory components in HM, IL-6 demonstrated inverse relationships with infant growth. Current research on HM bioactives is largely inconclusive and is insufficient to address the complex composition of HM. Future research should ideally capture HM intake, use biologically relevant anthropometrics, and integrate components across categories, embracing a systems biology approach to better understand how HM components work independently and synergistically to influence infant growth., Competing Interests: Conflict of interest M(M)B, SMR, and MBA have contributed to online courses on breast milk and the infant microbiome produced by Microbiome Courses. SMR has also served as the scientific advisor for SimpliFed and as a consultant for TraverseScience®. She is a current employee of Prolacta Bioscience®; her contribution to this review occurred prior to this employment. JMM has received support from the Bill & Melinda Gates Foundation and serves on the Council on Research for the American Academy of Nutrition and Dietetics. DC is supported by a Canadian Nurses Foundation Scholarship. DTG is funded by an unrestricted research grant from Medela AG. She is also currently funded by Telethon Child Health Grants and the Australian National Health and Medical Research Council. LHA has research grants from the Bill & Melinda Gates Foundation. MBA is supported by a Canada Research Chair and is a CIFAR Fellow in the Humans and the Microbiome Program; she has consulted for DSM and is a scientific advisor to TinyHealth. LB is UC San Diego Chair of Collaborative Human Milk Research endowed by the Family Larsson-Rosenquist Foundation and also receives support from the USNational Institutes of Health and The Bill & Melinda Gates Foundation. AID, MG, RR, KKS, SM, PPP, CM, FJ, PK, DH, and KGE have no conflicts of interest., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Previous research shows that the COVID-19 pandemic resulted in both barriers and facilitators to breastfeeding. However, little research has looked specifically at first-time mothers' experiences of breastfeeding during the pandemic or compared experiences of mothers living in different countries., Aim: This research explores mothers' breastfeeding experiences to describe how the COVID-19 pandemic has affected breastfeeding journeys in Canada and the United Kingdom., Methods: Ten semi-structured online interviews were undertaken with first-time mothers who breastfed their baby at least once during the COVID-19 pandemic and are living in Canada or the United Kingdom. Interview transcripts were coded inductively using thematic analysis., Findings: One overarching theme (all on mother) and four sub-themes were identified: 1) accessing and advocating for health care, 2) social support, 3) becoming a mother in isolation, and 4) breastfeeding baby. Similar themes were constructed for both countries., Discussion: Mothers reported that diminished health care and social support created challenges in their breastfeeding journey. Many mothers reported receiving virtual breastfeeding support, which was largely experienced as unhelpful. Some mothers reported fewer distractions from visitors and more one-on-one time with their infant, which helped them to establish breastfeeding and a strong mother-infant bond., Conclusion: In both Canada and the United Kingdom, new mothers need consistent, reliable health care and social support when breastfeeding. This study supports the need to protect breastfeeding support in the midst of a global emergency and beyond to ensure positive breastfeeding experiences for both mother and baby., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Human milk is a highly complex liquid food tailor-made to match an infant's needs. Beyond documented positive effects of breastfeeding on infant and maternal health, there is increasing evidence that milk constituents also impact child neurodevelopment. Non-nutrient milk bioactives would contribute to the (long-term) development of child cognition and behavior, a process termed 'Lactocrine Programming'. In this review we discuss the current state of the field on human milk composition and its links with child cognitive and behavioral development. To promote state-of-the-art methodologies and designs that facilitate data pooling and meta-analytic endeavors, we present detailed recommendations and best practices for future studies. Finally, we determine important scientific gaps that need to be filled to advance the field, and discuss innovative directions for future research. Unveiling the mechanisms underlying the links between human milk and child cognition and behavior will deepen our understanding of the broad functions of this complex liquid food, as well as provide necessary information for designing future interventions.

New guidelines for peanut allergy prevention in high-risk infants recommend introducing peanut during infancy but do not address breastfeeding or maternal peanut consumption. We assessed the independent and combined association of these factors with peanut sensitization in the general population CHILD birth cohort (N = 2759 mother-child dyads). Mothers reported peanut consumption during pregnancy, timing of first infant peanut consumption, and length of breastfeeding duration. Child peanut sensitization was determined by skin prick testing at 1, 3, and 5 years. Overall, 69% of mothers regularly consumed peanuts and 36% of infants were fed peanut in the first year (20% while breastfeeding and 16% after breastfeeding cessation). Infants who were introduced to peanut early (before 1 year) after breastfeeding cessation had a 66% reduced risk of sensitization at 5 years compared to those who were not (1.9% vs. 5.8% sensitization; aOR 0.34, 95% CI 0.14-0.68). This risk was further reduced if mothers introduced peanut early while breastfeeding and regularly consumed peanut themselves (0.3% sensitization; aOR 0.07, 0.01-0.25). In longitudinal analyses, these associations were driven by a higher odds of outgrowing early sensitization and a lower odds of late-onset sensitization. There was no apparent benefit (or harm) from maternal peanut consumption without breastfeeding. Taken together, these results suggest the combination of maternal peanut consumption and breastfeeding at the time of peanut introduction during infancy may help to decrease the risk of peanut sensitization. Mechanistic and clinical intervention studies are needed to confirm and understand this "triple exposure" hypothesis.

Background Breastfeeding in infancy is associated with lower cardiovascular disease risk in adulthood; however, the amount of breastfeeding required to achieve this benefit is unknown. Methods and Results In the CHILD (Canadian Healthy Infant Longitudinal Development) Cohort Study, we analyzed 2382 children with complete data on early life feeding and blood pressure. Infant feeding was documented from hospital records in the first few days of life and reported by mothers throughout infancy. Blood pressure was measured at 3 years of age. Analyses controlled for birth weight, gestational age, socioeconomic status, maternal body mass index, and other potential confounders. We found that nearly all children (2333/2382; 97.9%) were ever breastfed, of whom 98 (4.2%) only briefly received breast milk during their birth hospitalization ("early limited breastfeeding"). At 3 years of age, blood pressure was higher in children who were never breastfed (mean systolic/diastolic 103/60 mm Hg) compared with those who were ever breastfed (99/58 mm Hg), including those who received only early limited breastfeeding (99/57 mm Hg). These differences in systolic blood pressure persisted in adjusted models (ever breastfed: -3.47 mm Hg, 95% CI, -6.14 to -0.80; early limited breastfeeding: -4.24 mm Hg, 95% CI, -7.45 to -1.04). Among breastfed children, there was no significant dose-response association according to the duration or exclusivity of breastfeeding. Associations were not mediated by child body mass index. Conclusions Although the benefits of sustained and exclusive breastfeeding are indisputable, this study indicates any breastfeeding, regardless of duration or exclusivity, is associated with lower blood pressure at 3 years of age. Further research examining the bioactive components of early breast milk, underlying mechanisms, and long-term associations is warranted.

Breastfeeding and human milk (HM) are critically important to maternal, infant and population health. This paper summarizes the proceedings of a workshop that convened a multidisciplinary panel of researchers to identify key priorities and anticipated breakthroughs in breastfeeding and HM research, discuss perceived barriers and challenges to achieving these breakthroughs and propose a constructive action plan to maximize the impact of future research in this field. Priority research areas identified were as follows: (1) addressing low breastfeeding rates and inequities using mixed methods, community partnerships and implementation science approaches; (2) improving awareness of evidence-based benefits, challenges and complexities of breastfeeding and HM among health practitioners and the public; (3) identifying differential impacts of alternative modes of HM feeding including expressed/pumped milk, donor milk and shared milk; and (4) developing a mechanistic understanding of the health effects of breastfeeding and the contributors to HM composition and variability. Key barriers and challenges included (1) overcoming methodological limitations of epidemiological breastfeeding research and mechanistic HM research; (2) counteracting 'breastfeeding denialism' arising from negative personal breastfeeding experiences; (3) distinguishing and aligning research and advocacy efforts; and (4) managing real and perceived conflicts of interest. To advance research on breastfeeding and HM and maximize the reach and impact of this research, larger investments are needed, interdisciplinary collaboration is essential, and the scientific community must engage families and other stakeholders in research planning and knowledge translation., (© 2020 The Authors. Maternal & Child Nutrition published by John Wiley & Sons Ltd.)

Diarrhea is a major cause of infant mortality. Being a "nonsecretor" (having an inactive fucosyltransferase-2 gene) protects against diarrhea by inhibiting enteric infections. Breastfeeding also protects against diarrhea; however, the impact of maternal secretor status is unknown. In the ALSPAC cohort (N = 4971), we found that breastfeeding by nonsecretor mothers was especially protective against diarrhea, which could inform new prevention strategies., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Human milk contains a diverse community of bacteria. The growing appreciation of commensal microbes and increasing availability of high-throughput technology has set the stage for a theory-driven approach to the study of milk microbiota, and translation of this knowledge to improve maternal and child health. We recently profiled the milk microbiota of healthy Canadian mothers and applied theory-driven causal modeling, finding that mode of breast milk feeding (nursing directly at the breast vs. pumping and feeding breast milk from a bottle) was significantly associated with milk microbiota composition. This observation could reflect an increased exposure to pumps and/or a decreased exposure to the infant mouth. Either way, it provides evidence for the retrograde mechanism of milk inoculation. Here, we discuss the implications of this research and related controversies, and raise new questions about the origins and function of milk bacteria.

Gut microbiota play a critical role in infant health. It is now accepted that breastmilk contains live bacteria from endogenous and exogenous sources, but it remains unclear whether these bacteria transfer to the infant gut and whether this process is influenced by breastmilk feeding practices. Here, we show that certain bacteria, including Streptococcus spp. and Veillonella dispar, co-occur in mothers' milk and their infants' stool, and co-occurrence is reduced when infants receive pumped breastmilk. The relative abundances of commonly shared species are positively correlated between breastmilk and stool. Overall, gut microbiota composition is strongly associated with breastfeeding exclusivity and duration but not breastmilk feeding mode (nursing versus pumping). Moreover, breastmilk bacteria contributed to overall gut microbiota variation to a similar extent as other modifiers of the infant microbiome, such as birth mode. These results provide evidence that breastmilk may transfer bacteria to the infant gut and influence microbiota development., Competing Interests: Declaration of Interests M.B.A. receives research funding from CIHR, Research Manitoba, the Canada Foundation for Innovation, the Bill and Melinda Gates Foundation, the Manitoba Children’s Hospital Foundation, Prolacta Biosciences, and the Garfield G. Weston Foundation. M.B.A. serves as Secretary to the International Society for Research on Human Milk and Lactation. M.B.A. regularly speaks at conferences and workshops on infant nutrition, some supported by Medela and Prolacta Biosciences; she has contributed without remuneration to online courses on breastmilk and the infant microbiome. L.B. receives research funding from the United States National Institutes of Health and the Bill and Melinda Gates Foundation. L.B. is the UC San Diego Chair of Collaborative Human Milk Research, endowed by the Family Larsson-Rosenquist Foundation. L.B. is a (co-)inventor on patent applications regarding the use of HMOs in the prevention of necrotizing enterocolitis in preterm infants and other chronic inflammatory diseases throughout the entire lifespan. L.B. frequently speaks at national and international conferences and other events, some supported by Nestle Nutrition Institute, Abbott Nutrition International, Prolacta Biosciences, or Medela AG. L.B. currently serves on the Scientific Advisory Board for the Family Larsson-Rosenquist Foundation, as immediate past president of the International Society for Research in Human Milk and Lactation. C.J.F. receives research funding from the Canadian Institute for Health Sciences, the Natural Sciences and Engineering Research Council of Canada, Canada Research Chair’s Program and Dairy Farmers of Canada. She is the Past President of the American Society for Nutrition and serves on the Lipids Committee of the International Institute for Life Sciences North America and the Expert Science Advisory Committee for Dairy Farmers of Canada. She is Associate Editor for Advances in Nutrition. These entities had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. The remaining authors declare no potential conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Colonization with Clostridioides difficile occurs in up to half of infants under the age of 3 months, is strongly influenced by feeding modality and is largely asymptomatic. In spite of this, C. difficile 's presence has been associated with susceptibility to chronic disease later in childhood, perhaps by promoting or benefiting from changes in infant gut microbiome development, including colonization with pathogenic bacteria and disrupted production of microbial bioactive metabolites and proteins. In this study, the microbiomes of 1554 infants from the CHILD Cohort Study were described according to C. difficile colonization status and feeding mode at 3-4 months of age. C. difficile colonization was associated with a different gut microbiome profile in exclusively breastfed (EBF) vs. exclusively formula fed (EFF) infants. EBF infants colonized with C. difficile had an increased relative abundance of Firmicutes and Proteobacteria, decreased relative abundance of Bifidobacteriaceae, greater microbiota alpha-diversity, greater detectable fecal short chain fatty acids (SCFA), and lower detectable fecal secretory Immunoglobulin A (sIgA) than those not colonized. Similar but less pronounced differences were seen among partially breastfed infants (PBF) but EFF infants did not possess these differences in the gut microbiome according to colonization status. Thus, breastfed infants colonized with C. difficile appear to possess a gut microbiome that differs from non-colonized infants and resembles that of EFF infants, but the driving force and direction of this association remains unknown. Understanding these compositional differences as drivers of C. difficile colonization may be important to ensure future childhood health., (Copyright © 2019 Drall, Tun, Morales-Lizcano, Konya, Guttman, Field, Mandal, Wishart, Becker, Azad, Lefebvre, Mandhane, Moraes, Sears, Turvey, Subbarao, Scott and Kozyrskyj.)

Breastmilk contains a complex community of bacteria that may help seed the infant gut microbiota. The composition and determinants of milk microbiota are poorly understood. Among 393 mother-infant dyads from the CHILD cohort, we found that milk microbiota at 3-4 months postpartum was dominated by inversely correlated Proteobacteria and Firmicutes, and exhibited discrete compositional patterns. Milk microbiota composition and diversity were associated with maternal factors (BMI, parity, and mode of delivery), breastfeeding practices, and other milk components in a sex-specific manner. Causal modeling identified mode of breastfeeding as a key determinant of milk microbiota composition. Specifically, providing pumped breastmilk was consistently associated with multiple microbiota parameters including enrichment of potential pathogens and depletion of bifidobacteria. Further, these data support the retrograde inoculation hypothesis, whereby the infant oral cavity impacts the milk microbiota. Collectively, these results identify features and determinants of human milk microbiota composition, with potential implications for infant health and development., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Breastfeeding has many established benefits for mothers, children, and society at large; however, the vast majority of infants globally do not meet international breastfeeding recommendations. There are many complex reasons for suboptimal breastfeeding rates, including social and societal factors. Alongside increasing social media use worldwide, there is an expanding research focus on how social media use affects health behaviours, decisions and perceptions. The objective of this study was to systematically determine if and how breastfeeding is promoted and supported on the popular social media platform Instagram, which currently has over 700 million active users worldwide. To assess how Instagram is used to depict and portray breastfeeding, and how users share perspectives and information about this topic, we analysed 4,089 images and 8,331 corresponding comments posted with popular breastfeeding-related hashtags (#breastfeeding, #breastmilk, #breastisbest, and #normalizebreastfeeding). We found that Instagram is being mobilized by users to publicly display and share diverse breastfeeding-related content and to create supportive networks that allow new mothers to share experiences, build confidence, and address challenges related to breastfeeding. Discussions were overwhelmingly positive and often highly personal, with virtually no antagonistic content. Very little educational content was found, contrasted by frequent depiction and discussion of commercial products. Thus, Instagram is currently used by breastfeeding mothers to create supportive networks and could potentially offer new avenues and opportunities to "normalize," protect, promote, and support breastfeeding more broadly across its large and diverse global online community., (© 2018 John Wiley & Sons Ltd.)

Background: Breastfeeding has many established health benefits for women and children. We examined the association between maternal education, newborn feeding in hospital, and long-term breastfeeding duration., Methods: We studied 3195 Canadian mother-infant dyads in the CHILD pregnancy cohort. Newborn feeding was documented from hospital records. Caregivers reported sociodemographic factors and infant feeding at 3, 6, 12, 18, and 24 months., Results: Overall, 97% of newborns initiated breastfeeding and 74% were exclusively breastfed in hospital. Exclusively breastfed newborns were ultimately breastfed longer compared with those who received formula supplementation during their hospital stay (median 11.0 vs 7.0 months, P < .001). After controlling for maternal age, ethnicity, birth mode, and gestational age, exclusively breastfed newborns had a 21% reduced risk of breastfeeding cessation (HR = 0.79, 0.71-0.87). This effect was strongest among women without a postsecondary education (HR = 0.65, 0.53-0.79)., Discussion: Exclusive breastfeeding in hospital is associated with longer breastfeeding duration, particularly among women of lower socioeconomic status. Initiatives that support exclusive breastfeeding of newborns in hospital could improve long-term breastfeeding rates and help reduce health inequities arising in early life., (© 2018 Wiley Periodicals, Inc.)

Previous studies on the differences in gut microbiota between exclusively breastfed (EBF) and non-EBF infants have provided highly variable results. Here we perform a meta-analysis of seven microbiome studies (1825 stool samples from 684 infants) to compare the gut microbiota of non-EBF and EBF infants across populations. In the first 6 months of life, gut bacterial diversity, microbiota age, relative abundances of Bacteroidetes and Firmicutes, and predicted microbial pathways related to carbohydrate metabolism are consistently higher in non-EBF than in EBF infants, whereas relative abundances of pathways related to lipid metabolism, vitamin metabolism, and detoxification are lower. Variation in predicted microbial pathways associated with non-EBF infants is larger among infants born by Caesarian section than among those vaginally delivered. Longer duration of exclusive breastfeeding is associated with reduced diarrhea-related gut microbiota dysbiosis. Furthermore, differences in gut microbiota between EBF and non-EBF infants persist after 6 months of age. Our findings elucidate some mechanisms of short and long-term benefits of exclusive breastfeeding across different populations.

Objectives: Studies addressing breastfeeding and obesity rarely document the method of breast milk feeding, type of supplementation, or feeding in hospital. We investigated these practices in the CHILD birth cohort., Methods: Feeding was reported by mothers and documented from hospital records. Weight and BMI z scores (BMIzs) were measured at 12 months. Analyses controlled for maternal BMI and other confounders., Results: Among 2553 mother-infant dyads, 97% initiated breastfeeding, and the median breastfeeding duration was 11.0 months. Most infants (74%) received solids before 6 months. Among "exclusively breastfed" infants, 55% received some expressed breast milk, and 27% briefly received formula in hospital. Compared with exclusive direct breastfeeding at 3 months, all other feeding styles were associated with higher BMIzs: adjusted β: +.12 (95% confidence interval [CI]: .01 to .23) for some expressed milk, +.28 (95% CI: .16 to .39) for partial breastfeeding, and +.45 (95% CI: .30 to .59) for exclusive formula feeding. Brief formula supplementation in hospital did not alter these associations so long as exclusive breastfeeding was established and sustained for at least 3 months. Formula supplementation by 6 months was associated with higher BMIzs (adjusted β: +.25; 95% CI: .13 to .38), whereas supplementation with solid foods was not. Results were similar for weight gain velocity., Conclusions: Breastfeeding is inversely associated with weight gain velocity and BMI. These associations are dose dependent, partially diminished when breast milk is fed from a bottle, and substantially weakened by formula supplementation after the neonatal period., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2018 by the American Academy of Pediatrics.)

Breastfeeding has many established health benefits, but its impact on asthma development is uncertain. Breastfeeding appears to have a positive and dose-dependent impact on respiratory health, particularly during early childhood and in high-risk populations; however, the strength and causality of these associations are unclear. It is challenging to compare results across studies due to methodological differences and biological variation. Resolving these inconsistencies will require well-designed, prospective studies that accurately capture asthma diagnoses and infant feeding exposures (including breastfeeding duration, exclusivity, and method of feeding), account for key confounders, evaluate dose effects, and consider effect modification and reverse causality. Mechanistic studies examining human milk bioactives and their impact on lung health and asthma development are beginning to emerge, and these will be important in establishing the causality and mechanistic basis of the observed associations between breastfeeding and asthma. In this review, we summarize current evidence on this topic, identify possible reasons for disagreement across studies, discuss potential mechanisms for a causal association, and provide recommendations for future research.

Non-nutritive sweeteners (NNS) are increasingly consumed by children and pregnant women around the world, yet their long-term health impact is unclear. Here, we review an emerging body of evidence suggesting that early-life exposure to NNS may adversely affect body composition and cardio-metabolic health. Some observational studies suggest that children consuming NNS are at increased risk for obesity-related outcomes; however, others find no association or provide evidence of confounding. Fewer studies have examined prenatal NNS exposure, with mixed results from different analytical approaches. There is a paucity of RCTs evaluating NNS in children, yielding inconsistent results that can be difficult to interpret due to study design limitations (e.g., choice of comparator, multifaceted interventions). The majority of this research has been conducted in high-income countries. Some rodent studies demonstrate adverse metabolic effects from NNS, but most have used extreme doses that are not relevant to humans, and few have distinguished prenatal from postnatal exposure. Most studies focus on synthetic NNS in beverages, with few examining plant-derived NNS or NNS in foods. Overall, there is limited and inconsistent evidence regarding the impact of early-life NNS exposure on the developmental programming of obesity and cardio-metabolic health. Further research and mechanistic studies are needed to elucidate these effects and inform dietary recommendations for expectant mothers and children worldwide., Competing Interests: The authors declare no conflict of interest.

Background: Recent trials have shown that avoiding peanuts during infancy increases the risk of peanut allergy; however, these studies did not address maternal peanut consumption., Objective: We sought to investigate the relationship between maternal peanut consumption while breast-feeding, timing of direct peanut introduction, and peanut sensitization at age 7 years., Methods: Secondary analysis of a nested cohort within the 1995 Canadian Asthma Primary Prevention Study intervention study was performed. Breast-feeding and maternal and infant peanut consumption were captured by repeated questionnaires during infancy. Skin prick testing for peanut sensitization was performed at age 7 years., Results: Overall, 58.2% of mothers consumed peanuts while breast-feeding and 22.5% directly introduced peanuts to their infant by 12 months. At 7 years, 9.4% of children were sensitized to peanuts. The lowest incidence (1.7%) was observed among children whose mothers consumed peanuts while breast-feeding and directly introduced peanuts before 12 months. Incidence was significantly higher (P < .05) if mothers consumed peanuts while breast-feeding but delayed introducing peanuts to their infant beyond 12 months (15.1%), or if mothers avoided peanuts themselves but directly introduced peanuts by 12 months (17.6%). Interaction analyses controlling for study group and maternal atopy confirmed that maternal peanut consumption while breast-feeding and infant peanut consumption by 12 months were protective in combination, whereas either exposure in isolation was associated with an increased risk of sensitization (P interaction = .003)., Conclusions: In this secondary analysis, maternal peanut consumption while breast-feeding paired with direct introduction of peanuts in the first year of life was associated with the lowest risk of peanut sensitization, compared with all other combinations of maternal and infant peanut consumption., (Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Objective: To determine whether different modes of infant feeding are associated with childhood asthma, including differentiating between direct breastfeeding and expressed breast milk., Study Design: We studied 3296 children in the Canadian Healthy Infant Longitudinal Development birth cohort. The primary exposure was infant feeding mode at 3 months, reported by mothers and categorized as direct breastfeeding only, breastfeeding with some expressed breast milk, breast milk and formula, or formula only. The primary outcome was asthma at 3 years of age, diagnosed by trained healthcare professionals., Results: At 3 months of age, the distribution of feeding modes was 27% direct breastfeeding, 32% breastfeeding with some expressed breast milk, 26% breast milk and formula, and 15% formula only. At 3 years of age, 12% of children were diagnosed with possible or probable asthma. Compared with direct breastfeeding, any other mode of infant feeding was associated with an increased risk of asthma. These associations persisted after adjusting for maternal asthma, ethnicity, method of birth, infant sex, gestational age, and daycare attendance (some expressed breast milk: aOR, 1.64, 95% CI, 1.12-2.39; breast milk and formula, aOR, 1.73, 95% CI, 1.17-2.57; formula only: aOR, 2.14, 95% CI, 1.37-3.35). Results were similar after further adjustment for total breastfeeding duration and respiratory infections., Conclusions: Modes of infant feeding are associated with asthma development. Direct breastfeeding is most protective compared with formula feeding; indirect breast milk confers intermediate protection. Policies that facilitate and promote direct breastfeeding could have impact on the primary prevention of asthma., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The impact of breastfeeding on respiratory health is uncertain, particularly when the mother has asthma. We examined the association of breastfeeding and wheezing in the first year of life.We studied 2773 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort. Caregivers reported on infant feeding and wheezing episodes at 3, 6 and 12 months. Breastfeeding was classified as exclusive, partial (supplemented with formula or complementary foods) or none.Overall, 21% of mothers had asthma, 46% breastfed for at least 12 months and 21% of infants experienced wheezing. Among mothers with asthma, breastfeeding was inversely associated with infant wheezing, independent of maternal smoking, education and other risk factors (adjusted rate ratio (aRR) 0.52; 95% CI 0.35-0.77 for ≥12 versus <6 months breastfeeding). Compared with no breastfeeding at 6 months, wheezing was reduced by 62% with exclusive breastfeeding (aRR 0.38; 95% CI 0.20-0.71) and by 37% with partial breastfeeding supplemented with complementary foods (aRR 0.63; 95% CI 0.43-0.93); however, breastfeeding was not significantly protective when supplemented with formula (aRR 0.89; 95% CI 0.61-1.30). Associations were not significant in the absence of maternal asthma (p-value for interaction <0.01).Breastfeeding appears to confer protection against wheezing in a dose-dependent manner among infants born to mothers with asthma., Competing Interests: Conflict of interest: None declared., (Copyright ©ERS 2017.)

Human milk contains all of the essential nutrients required by the infant within a complex matrix that enhances the bioavailability of many of those nutrients. In addition, human milk is a source of bioactive components, living cells and microbes that facilitate the transition to life outside the womb. Our ability to fully appreciate the importance of this matrix relies on the recognition of short- and long-term health benefits and, as highlighted in previous sections of this supplement, its ecology (i.e., interactions among the lactating parent and breastfed infant as well as within the context of the human milk matrix itself). Designing and interpreting studies to address this complexity depends on the availability of new tools and technologies that account for such complexity. Past efforts have often compared human milk to infant formula, which has provided some insight into the bioactivity of human milk, as a whole, or of individual milk components supplemented with formula. However, this experimental approach cannot capture the contributions of the individual components to the human milk ecology, the interaction between these components within the human milk matrix, or the significance of the matrix itself to enhance human milk bioactivity on outcomes of interest. This paper presents approaches to explore human milk as a biological system and the functional implications of that system and its components. Specifically, we discuss study design and data collection considerations and how emerging analytical technologies, bioinformatics, and systems biology approaches could be applied to advance our understanding of this critical aspect of human biology.