Recurrent blocked duct(s) in a mother with immunoglobulin A deficiency

Residents or Tourists: Is the Lactating Mammary Gland Colonized by Residential Microbiota?

The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that the lactating mammary gland houses a warm and nutrient-rich environment and is in contact with the external environment, it may be expected that the lactating mammary gland would contain a high biomass microbiome. This discrepancy raises the question of whether the bacteria in milk come from true microbial colonization in the mammary gland ("residents") or are merely the result of constant influx from other bacterial sources ("tourists"). By drawing together data from animal, in vitro, and human studies, this review will examine the question of whether the lactating mammary gland is colonized by a residential microbiome.

25 Years of Research in Human Lactation: From Discovery to Translation

Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation.

Immunopathology of mastitis: insights into disease recognition and resolution

Mastitis is an inflammation of the mammary gland commonly caused by bacterial infection. The inflammatory process is a normal and necessary immunological response to invading pathogens. The purpose of host inflammatory responses is to eliminate the source of tissue injury, restore immune homeostasis, and return tissues to normal function. The inflammatory cascade results not only in the escalation of local antimicrobial factors, but also in the increased movement of leukocytes and plasma components from the blood that may cause damage to host tissues. A precarious balance between pro-inflammatory and pro-resolving mechanisms is needed to ensure optimal bacterial clearance and the prompt return to immune homeostasis. Therefore, inflammatory responses must be tightly regulated to avoid bystander damage to the milk synthesizing tissues of the mammary gland. The defense mechanisms of the mammary gland function optimally when invading bacteria are recognized promptly, the initial inflammatory response is adequate to rapidly eliminate the infection, and the mammary gland is returned to normal function quickly without any noticeable clinical symptoms. Suboptimal or dysfunctional mammary gland defenses, however, may contribute to the development of severe acute inflammation or chronic mastitis that adversely affects the quantity and quality of milk. This review will summarize critical mammary gland defense mechanisms that are necessary for immune surveillance and the rapid elimination of mastitis-causing organisms. Situations in which diminished efficiency of innate or adaptive mammary gland immune responses may contribute to disease pathogenesis will also be discussed. A better understanding of the complex interactions between mammary gland defenses and mastitis-causing pathogens should prove useful for the future control of intramammary infections.

Predictors of inflammatory breast diseases during lactation--results of a cohort study

PROBLEM

Inflammatory breast diseases during lactation are major reasons for early weaning.

METHOD OF STUDY

A prospective cohort study was performed to examine the association between stress and inflammatory breast diseases. Psychometric data, cytokine levels in breast milk and blood samples were analysed postpartum (T1). Psychometric data and course of breast feeding were evaluated twelve weeks later (T2). Patients were divided into case- and control-groups (according to the presence of breast diseases).

RESULTS

Mothers of the case group (n = 23) were significantly older and showed significantly increased stress levels between T1 and T2 compared with the control group (n = 43). Leucocytes in the postpartum blood count were significantly decreased in the case group. There were no significant differences between groups in the concentrations of Th-1- and Th-2-cytokines in breast milk postpartum.

CONCLUSION

Higher maternal age, postpartum increase in stress perception and low number of leucocytes are associated with a higher incidence of inflammatory breast diseases. Further studies must examine the causality of this effect.

Ultrasound imaging of the lactating breast: methodology and application

Ultrasound imaging has been used extensively to detect abnormalities of the non-lactating breast. In contrast, the use of ultrasound for the investigation of pathology of the lactating breast is limited. Recent studies have re-examined the anatomy of the lactating breast highlighting features unique to this phase of breast development. These features should be taken into consideration along with knowledge of common lactation pathologies in order to make an accurate diagnosis when examining the lactating breast. Scanning techniques and ultrasound appearances of the normal lactating breast will be contrasted to those of the non-lactating breast. In addition ultrasound characteristics of common pathologies encountered during lactation will be described.