Insights into the trafficking of human leukocytes to colostrum evidences a modulation of the B lymphocyte compartment in obesity

Breastmilk is a dynamic fluid which initial goal is to provide the most adapted nutrition to the neonate. Additional functions have been recently attributed to breastmilk, with the evidence of a specific microbiota and the presence of a variety of components of the immune system, such as cytokines and leukocytes. The composition of breastmilk varies through time, according to the health status of mother and child, and altogether contributes to future health of the infant. Obesity is a rising condition worldwide, that creates a state of systemic, chronic inflammation including leukocytosis. Here, we asked whether colostrum, the milk produced within the first 48 h post-partum, would contain a distinct leukocyte composition depending on the body mass index (BMI) of the mother. We applied a panel of 6 antibodies plus viability marker to the peripheral blood and colostrum obtained from obese (BMI > 30) and lean (BMI < 25) mothers to characterize 10 major leukocyte subpopulations using flow cytometry. While lymphoid cells were otherwise unaffected by their tissue of origin, the phenotypes of granulocyte and monocyte populations significantly contrasted between blood and colostrum, including variations in morphology and surface expression of CD45 and CD16. These differences recapitulated across groups, which suggests a generalized cell-specific phenotype alteration caused by trafficking to colostrum. The B lymphocyte compartment was significantly reduced in obese colostrum and these cells did not exhibit enhanced CD16 shedding in this tissue, unlike B lymphocytes from lean mothers colostrum. This is the first exhaustive characterization of major leukocyte subsets in obese mothers colostrum, and the first report of leukocyte subpopulations from Latin-American womens colostrum. This pioneering study is a steppingstone to further investigate active immunity in human breastmilk.

Participant Experiences of an Infant Obesity Prevention Program Delivered via Telephone Calls or Text Messages

A 3-arm randomised controlled trial implemented in 2017, recruited participants from four Local Health Districts (LHDs) in New South Wales (NSW) to test an early obesity prevention program delivered via telephone calls (telephone) or text messages (SMS). This sub-study explored participants’ experience and satisfaction with the program. A multimethod design was used. Quantitative satisfaction questions were completed by participants when their child was six-months old. A purposive sample of participants with varying satisfaction levels was invited for in-depth qualitative interviews. Data were analysed using Excel (quantitative) and inductive thematic analysis (qualitative). Of the 1155 participants recruited: 947 (293 telephone; 338 SMS; 316 control) completed the six-month survey; 34 (14 telephone; 13 SMS; 7 control) were interviewed. Participants’ overall program satisfaction was 100% (telephone) and 85% (SMS). Participants’ qualitative responses demonstrated appreciation of: personalised stage-based information; opportunity to communicate with health professionals (telephone); linked Healthy Beginnings booklets and SMS mostly as nudges (SMS). There is a clear need for stage-based information, and supplemented modes of delivery i.e., text messages along with telephone calls; with text messages solely seen as nudges or reminders. However, individual preferences vary according to information needs at any given time, time constraints on new mothers and hence, multiple modes of information provision are recommended in order to reach a wider population and for better engagement. Choice and flexibility in mode of delivery has the potential to provide equitable access to information, empowering women with infants to practice recommended health behaviours for infant obesity prevention.