Does Breast Milk Nurture T Lymphocytes in Their Cradle?

Update on Early-Life T Cells: Impact on Oral Rotavirus Vaccines

Rotavirus infection continues to be a significant public health problem in developing countries, despite the availability of several vaccines. The efficacy of oral rotavirus vaccines in young children may be affected by significant immunological differences between individuals in early life and adults. Therefore, understanding the dynamics of early-life systemic and mucosal immune responses and the factors that affect them is essential to improve the current rotavirus vaccines and develop the next generation of mucosal vaccines. This review focuses on the advances in T-cell development during early life in mice and humans, discussing how immune homeostasis and response to pathogens is established in this period compared to adults. Finally, the review explores how this knowledge of early-life T-cell immunity could be utilized to enhance current and novel rotavirus vaccines.

Preterm birth and Kawasaki disease: a nationwide Japanese population-based study

BACKGROUND

Previous studies showed that preterm birth increased the risk for hospital admissions in infancy and childhood due to some acute diseases. However, the risk of preterm children developing Kawasaki disease remains unknown. In the present study, we investigate whether preterm birth increased the morbidity of Kawasaki disease.

METHODS

We included 36,885 (34,880 term and 2005 preterm) children born in 2010 in Japan. We examined the association between preterm birth and hospitalization due to Kawasaki disease using a large nationwide survey in Japan.

RESULTS

In log-linear regression models that were adjusted for children's characteristics (sex, singleton birth, and parity), parental characteristics (maternal age, maternal smoking, paternal smoking, maternal education, and paternal income), and residential area, preterm infants were more likely to be hospitalized due to Kawasaki disease (adjusted risk ratio: 1·55, 95% confidence interval: 1.01-2.39). We then examined whether breastfeeding status modified the potential adverse effects of preterm birth on health outcome. Preterm infants with partial breastfeeding or formula feeding had a significantly higher risk of hospitalization due to Kawasaki disease compared with term infants with exclusive breastfeeding.

CONCLUSIONS

Preterm infants were at a high risk for Kawasaki disease, and exclusive breastfeeding might prevent this disease among preterm infants.

IMPACT

Previous studies showed that preterm birth increased the risk for hospital admissions in infancy and childhood due to some acute diseases, however, the risk of preterm children developing Kawasaki disease remains unknown. This Japanese large population-based study showed that preterm infants were at a high risk for Kawasaki disease for the first time. Furthermore, this study suggested that exclusively breastfeeding might prevent Kawasaki disease among preterm infants.

Chrononutrition and Human Milk

Background

Breastfed infants have a reduced risk of infections and allergies. The study of chrononutrition in human milk seeks to understand the circadian variation of various human milk immune factors.

Methods

Empirical studies on human milk, chrononutrition, and immune factors were searched through PUBMED, Google Scholar, and SCOPUS. Keywords included “chrononutrition,” “breastmilk composition,” “human milk,” “day-night cycles,” “sleep-wake cycles” and the names of various immune factors. After excluding duplicate articles, animal studies, studies looking at other human milk components, studies that did not collect human milk samples over a 24 hour period, and studies that were not in English, eleven studies on the topic remained and ten studies were included in the review. The excluded study had a sample size of two.

Results

This review identified the circadian variation of certain immune factors found in human milk such as antibodies, complement proteins, cytokines, by-products of phagocyte activity, nucleotides, microRNAs, and antioxidants.

Conclusion

The circadian variation observed in some human milk components highlights the unique ability of human milk to vary in composition based on the circadian rhythms of mothers and infants. The limited number of studies makes it difficult to make conclusive recommendations and creates an opportunity for further research in this growing field.

Breast Milk: A Meal Worth Having

A mother is gifted with breast milk, the natural source of nutrition for her infant. In addition to the wealth of macro and micro-nutrients, human milk also contains many microorganisms, few of which originate from the mother, while others are acquired from the mouth of the infant and the surroundings. Among these microbes, the most commonly residing bacteria are Staphylococci, Streptococci, Lactobacilli and Bifidobacteria. These microorganisms initiate and help the development of the milk microbiota as well as the microbiota of the gastrointestinal tract in infants, and contribute to developing immune regulatory factors such as cytokines, growth factors, lactoferrin among others. These factors play an important role in reducing the risk of developing chronic diseases like type 2 diabetes, asthma and others later in life. In this review, we will summarize the known benefits of breastfeeding and highlight the role of the breast milk microbiota and its cross-talk with the immune system in breastfed babies during the early years of life.

The Role of CD4+ T Cells and Microbiota in the Pathogenesis of Asthma

Asthma, a chronic respiratory disease involving variable airflow limitations, exhibits two phenotypes: eosinophilic and neutrophilic. The asthma phenotype must be considered because the prognosis and drug responsiveness of eosinophilic and neutrophilic asthma differ. CD4+ T cells are the main determinant of asthma phenotype. Th2, Th9 and Tfh cells mediate the development of eosinophilic asthma, whereas Th1 and Th17 cells mediate the development of neutrophilic asthma. Elucidating the biological roles of CD4+ T cells is thus essential for developing effective asthma treatments and predicting a patient's prognosis. Commensal bacteria also play a key role in the pathogenesis of asthma. Beneficial bacteria within the host act to suppress asthma, whereas harmful bacteria exacerbate asthma. Recent literature indicates that imbalances between beneficial and harmful bacteria affect the differentiation of CD4+ T cells, leading to the development of asthma. Correcting bacterial imbalances using probiotics reportedly improves asthma symptoms. In this review, we investigate the effects of crosstalk between the microbiota and CD4+ T cells on the development of asthma.

Traditional plant use during lactation and postpartum recovery: Infant development and maternal health roles

ETHNOPHARMACOLOGICAL RELEVANCE

Evidence of phytochemical roles in infant development and maternal recovery offers insights into beneficial functions of traditional plant use during lactation and the postpartum period. Ethnopharmacological research has relevance to global priorities on maternal and child health, to understanding origins and determinants of human self-medication, and for reconciling traditional postpartum practices and mainstream healthcare.

AIM OF THE STUDY

Present emerging evidence, within evolutionary and socio-cultural contexts, on the role of maternal consumption on transfer of phytochemicals into breast milk with impacts on maternal and child health, and on infant development. Establish current state of knowledge and an ethnopharmacological research agenda that is attentive to cross-cultural and regional differences in postpartum plant use.

MATERIALS AND METHODS

An extensive literature review using Medline, Scopus, and Web of Science focused on traditional and contemporary use and socio-cultural context, as well as physiological, pharmacological, toxicological, and behavioral activities of plants used medicinally by women during postpartum recovery and lactation.

RESULTS

The most widely reported postpartum plants show antimicrobial, anti-inflammatory, immunological, and neurophysiological activities, with low toxicity. Phytochemicals transfer from maternal consumption into breast milk in physiological concentrations, while animal studies demonstrate immunomodulation and other actions of medicinal plants during lactation. Reporting on the use and diverse traditional knowledge of women about plants during the postpartum period is obscured by the marginal place of obstetric issues and by gender biases in ethnobotanical research. In many contemporary contexts use is prejudiced by precautionary risk warnings in health literature and practice that confound lactation with pregnancy.

CONCLUSIONS

Although systematic investigation of postpartum plant use is lacking, known pharmacological activities support potential benefits on infant development and maternal health with immediate and long-term consequences in relation to allergic, inflammatory, autoimmune, and other diseases. An ethnopharmacological agenda focused on the perinatal period requires directed methodologies and a regional approach in relation to culturally-specific knowledge and practices, traditional plant use, and local health needs. Testing the hypothesis that phytochemicals transferred from medicinal plants into breast milk impact the human immune system and other aspects of infant development requires extended analysis of phytochemicals in human milk and infant lumen and plasma, as well as effects on gastrointestinal and milk microbiome.

Global survey of medicinal plants during lactation and postpartum recovery: Evolutionary perspectives and contemporary health implications

ETHNOPHARMACOLOGICAL RELEVANCE

Cross-cultural comparison of plants used during lactation and the postpartum period offers insight into a largely overlooked area of ethnopharmacological research. Potential roles of phytochemicals in emerging models of interaction among immunity, inflammation, microbiome and nervous system effects on perinatal development have relevance for the life-long health of individuals and of populations in both traditional and contemporary contexts.

AIM OF THE STUDY

Delineate and interpret patterns of traditional and contemporary global use of medicinal plants ingested by mothers during the postpartum period relative to phytochemical activity on immune development and gastrointestinal microbiome of breastfed infants, and on maternal health.

MATERIALS AND METHODS

Published reviews and surveys on galactagogues and postpartum recovery practices plus ethnobotanical studies from around the world were used to identify and rank plants, and ascertain regional use patterns. Scientific literature for 20 most-cited plants based on frequency of publication was assessed for antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antidepressant, analgesic, galactagogic and safety properties.

RESULTS

From compilation of 4418 use reports related to 1948 species, 105 plant taxa were recorded ≥7 times, with the most frequently cited species, Foeniculum vulgare, Trigonella foenum-graecum, Pimpinella anisum, Euphorbia hirta and Asparagus racemosus, 81, 64, 42, 40 and 38 times, respectively. Species and use vary globally, illustrated by the pattern of aromatic plants of culinary importance versus latex-producing plants utilized in North Africa/Middle East and Sub-Saharan Africa with opposing predominance. For 18/20 of the plants a risk/benefit perspective supports assessment that positive immunomodulation and related potential exceed any safety concerns. Published evidence does not support a lactation-enhancing effect for nearly all the most-cited plants while antidepressant data for the majority of plants are predominately limited to animal studies.

CONCLUSIONS

Within a biocultural context traditional postpartum plant use serves adaptive functions for the mother-infant dyad and contributes phytochemicals absent in most contemporary diets and patterns of ingestion, with potential impacts on allergic, inflammatory and other conditions. Polyphenolics and other phytochemicals are widely immunologically active, present in breast milk and predominately non-toxic. Systematic analysis of phytochemicals in human milk, infant lumen and plasma, and immunomodulatory studies that differentiate maternal ingestion during lactation from pregnancy, are needed. Potential herb-drug interaction and other adverse effects should remain central to obstetric advising, but unless a plant is specifically shown as harmful, considering potential contributions to health of individuals and populations, blanket advisories against postpartum herbal use during lactation appear empirically unwarranted.

Maternal Leukocytes and Infant Immune Programming during Breastfeeding

The fetal immune system develops in a rather sterile environment relative to the outside world and, therefore, lacks antigenic education. Soon after birth, the newborn is exposed to the hostile environment of pathogens. Recently, animal- and limited human-based studies have indicated that help from the mother, upon transfer of leukocytes and their products via breast milk feeding, greatly assists the newborn's immune system. Here, I discuss the newest advances on how milk leukocytes impact early life immunity, with an emphasis on the development of the infant T cell repertoire and early immune responses in the periphery and gut-associated lymphoid tissue. A deeper understanding of these novel mechanistic insights may inform potential translational approaches to improving immunity in infants.

Association Between Exclusive Breastfeeding and Infant Health Outcomes in Pakistan

PURPOSE

The infant mortality rate in Pakistan is one of the highest in the world with most cases attributed to diarrheal or respiratory diseases. Exclusive breastfeeding for the first 6 months of life is recommended by the World Health Organization to achieve optimal growth and health, however, in Pakistan the rate of exclusive breastfeeding by mothers is <40%. The aim of this study was to investigate the relationship of exclusive breastfeeding, diarrhea, acute respiratory infections and fever among infants under the age of 6 months.

DESIGN AND METHODS

The cross-sectional study analyzed secondary data from the 2017-18 Pakistan Demographic and Health-Survey. The sampling frame for the current study consisted of last-born children who were under the age of 6 months. The study sample consisted of 1033 infants under the age of 6 months.

RESULTS

The prevalence of exclusive breastfeeding was 53.6%. Compared to infants who were not breastfed exclusively, infants who were had lower odds of diarrhea, acute respiratory infection, and fever. The observed association was independent of potential confounders.

CONCLUSIONS

Exclusive breastfeeding reduces the odds of childhood illnesses. Plausible explanations for the observed association may be related to human milk's contents including necessary nutrients to fulfill an infant's needs within first months of life. Additionally, continued exposure to breastfeeding also reduces exposure to other contaminated foods to ensure adequate nutrition for the infant.

PRACTICE IMPLICATIONS

The findings have important implications for educating families and healthcare providers about the benefits of exclusive breastfeeding for optimal child health outcomes.

Exclusive breastfeeding among Saudi mothers: Exposing the substantial gap between knowledge and practice

Background:

Rates of exclusive breastfeeding are exceedingly low in the Arabic world. This study aims to estimate the local prevalence of, and knowledge about, exclusive breastfeeding in Saudi Arabia.

Method:

This is a cross-sectional survey of mothers of infants aged 6–12 months who attended Taif-based “well-baby clinic.” A structured questionnaire was developed to explore predictors of, and participants’ knowledge about, exclusive breastfeeding.

Results:

Participants in the study were 202 mothers. The rate for initiation of breastfeeding in the first hour after childbirth was 13.9%. The prevalence of exclusive breastfeeding was 16.3%. Knowledge level was great among participating mothers as 65.3% of mothers scored over 75% of the total knowledge score and 95% got more than half of the questions right. Only having 3–6 children (P = 0.023) and 1-year interpregnancy interval (P = 0.005) were associated with the positive likelihood of exclusive breastfeeding. Baby age (P = 0.0218), birth in a private facility (P = 0.00843), and university education (P = 0.0131) were associated with better knowledge.

Discussion and Conclusion:

Rates of exclusive breastfeeding practice are low in Saudi Arabia despite adequate knowledge about its benefits and necessity.

Impact of breast milk on respiratory outcomes in infants with bronchopulmonary dysplasia

BACKGROUND

The objective of our study was to examine whether outpatient respiratory morbidities in infants with bronchopulmonary dysplasia (BPD) are influenced by the human milk consumption.

METHODS

Caregivers of subjects recruited from a BPD clinic completed questionnaires regarding breast milk intake and respiratory outcomes.

RESULTS

One-hundred eighty-eight caregivers completed the questionnaire. Of these, 173 (92.0%) reported that the child received some breast milk. Infants who received breast milk for fewer months were more likely to be non-white, and have a lower household income, public insurance, and secondhand smoke exposure. A longer receipt of breast milk was associated with reduced likelihoods of emergency department visits, systemic steroid courses, and cough or chest congestion, and a trend towards a lower risk of re-hospitalizations.

CONCLUSIONS

Longer duration of breast milk intake was associated with markers of higher socio-economic status, and reduced likelihood of acute and chronic respiratory morbidities among preterm infants with bronchopulmonary dysplasia.