title: Comparison of colostrum TGF-β2 levels between lactating women in Japan and Nepal.
abstract: BACKGROUND
  Maternal milk-borne transforming growth factor (TGF-β plays a potential role in the development of the mucosal immune system in infants. However, it remains unclear what factors determine TGF-β levels in breast milk. We hypothesized that microbial pressures during pregnancy might affect the expression levels of TGF-β in colostrum.
  
  
  OBJECTIVE
  This study compared TGF-β2 levels in colostrum of lactating women living in Japan and Nepal with contrasting hygiene statuses. Additionally, we identified environmental and intrinsic factors influencing TGF-β levels in colostrum.
  
  
  METHODS
  Breast milk samples and structured questionnaires were collected from 80 women living in Japan and 208 women living in Nepal. A robust regression model was used to identify factors associated with colostral TGF-β levels.
  
  
  RESULTS
  Analysis using the Mann-Whitney U test showed that TGF-β levels were significantly higher in Japanese women than in Nepalese women. Japanese women who consumed animal milk daily during pregnancy and had atopic dermatitis expressed lower levels of TGF-β in colostrum, as compared to Japanese women who did not. Among Nepalese women, large family size and higher birth order were associated with lower TGF-β levels and women who gave birth to infants with low birth weight had higher expression of TGF-β levels in milk than women who gave birth to infants with normal birth weight.
  
  
  CONCLUSIONS
  The results suggest that induction of TGF-β levels in colostrum depends on differences in the ethnicity of lactating women. Consumption of animal protein and parturition characteristics may affect TGF-β levels in breast milk, and may explain differences in these levels in breast milk between countries.
authors.affiliation: Department of Health Sciences, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Aihara
authors.forename: Kyoko
authors.initials: K
authors.lastname: Oh-oka
authors.forename: Naoki
authors.initials: N
authors.lastname: Kondo
authors.forename: Jyoti
authors.initials: J
authors.lastname: Sharma
authors.forename: Kayoko
authors.initials: K
authors.lastname: Ishimaru
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Hara
authors.forename: Zentaro
authors.initials: Z
authors.lastname: Yamagata
authors.forename: Atsuhito
authors.initials: A
authors.lastname: Nakao
mesh_terms: D000328:Adult; D000818:Animals; D002417:Cattle; D003126:Colostrum / Q000378:metabolism*; D003876:Dermatitis, Atopic / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007564:Japan; D007774:Lactation; D008892:Milk; D009390:Nepal; D011247:Pregnancy; D011248:Pregnancy Complications / Q000378:metabolism*; D011795:Surveys and Questionnaires; D053781:Transforming Growth Factor beta2 / Q000378:metabolism*
chemical_list: D004044:Dietary Proteins; C509041:TGFB2 protein, human; D053781:Transforming Growth Factor beta2