Infants drive many lactation processes and contribute to the changing composition of human milk through multiple mechanisms. This review addresses the major topics of milk removal; chemosensory ...ecology for the parent–infant dyad; the infant’s inputs into the composition of the human milk microbiome; and the impact of disruptions in gestation on the ecology of fetal and infant phenotypes, milk composition, and lactation. Milk removal, which is essential for adequate infant intake and continued milk synthesis through multiple hormonal and autocrine/paracrine mechanisms, should be effective, efficient, and comfortable for both the lactating parent and the infant. All 3 components should be included in the evaluation of milk removal. Breastmilk “bridges” flavor experiences in utero with postweaning foods, and the flavors become familiar and preferred. Infants can detect flavor changes in human milk resulting from parental lifestyle choices, including recreational drug use, and early experiences with the sensory properties of these recreational drugs impact subsequent behavioral responses. Interactions between the infant’s own developing microbiome, that of the milk, and the multiple environmental factors that are drivers—both modifiable and nonmodifiable—in the microbial ecology of human milk are explored. Disruptions in gestation, especially preterm birth and fetal growth restriction or excess, impact the milk composition and lactation processes such as the timing of secretory activation, adequacy of milk volume and milk removal, and duration of lactation. Research gaps are identified in each of these areas. To assure a sustained and robust breastfeeding ecology, these myriad infant inputs must be systematically considered.
Bovine milk is an important nutrient source for humans. Forage plays a vital role in dairy husbandry via affecting milk quality and quantity. However, the differences in mammary metabolism of dairy ...cows fed different forages remain elucidated. In this study, we utilized transcriptomic RNA-seq and iTRAQ proteomic techniques to investigate and integrate the differences of molecular pathways and biological processes in the mammary tissues collected from 12 lactating cows fed corn stover (CS, low-quality, n = 6) and alfalfa hay (AH, high-quality, n = 6).
A total of 1631 differentially expressed genes (DEGs; 1046 up-regulated and 585 down-regulated) and 346 differentially expressed proteins (DEPs; 138 increased and 208 decreased) were detected in the mammary glands between the CS- and AH-fed animals. Expression patterns of 33 DEPs (18 increased and 15 decreased) were consistent with the expression of their mRNAs. Compared with the mammary gland of AH-fed cows, the marked expression changes found in the mammary gland of CS group were for genes involved in reduced mammary growth/development (COL4A2, MAPK3, IKBKB, LGALS3), less oxidative phosphorylation (ATPsynGL, ATP6VOA1, ATP5H, ATP6VOD1, NDUFC1), enhanced lipid uptake/metabolism (SLC27A6, FABP4, SOD2, ACADM, ACAT1, IDH1, SCP2, ECHDC1), more active fatty acid beta-oxidation (HMGCS1), less amino acid/protein transport (SLC38A2, SLC7A8, RAB5a, VPS18), reduced protein translation (RPS6, RPS12, RPS16, RPS19, RPS20, RPS27), more proteasome- (PSMC2, PSMC6, PSMD14, PSMA2, PSMA3) and ubiquitin-mediated protein degradation (UBE2B, UBE2H, KLHL9, HSPH1, DNAJA1 and CACYBP), and more protein disassembly-related enzymes (SEC63, DNAJC3, DNAJB1, DNAJB11 and DNAJC12).
Our results indicate that the lower milk production in the CS-fed dairy cows compared with the AH-fed cows was associated with a network of mammary gene expression changes, importantly, the prime factors include decreased energy metabolism, attenuated protein synthesis, enhanced protein degradation, and the lower mammary cell growth. The present study provides insights into the effects of the varying quality of forages on mammary metabolisms, which can help the improvement of strategies in feeding dairy cows with CS-based diet.
The influence of gastric proteolysis on the physicochemical characteristics of milk fat globules and the proteins of the milk fat globule membrane (MFGM) in raw milk and cream was examined in vitro ...in simulated gastric fluid (SGF) containing various pepsin concentrations at pH 1.6 for up to 2h. Apparent flocculation of the milk fat globules occurred in raw milk samples incubated in SGF containing pepsin, but no coalescence was observed in either raw milk samples or cream samples. The changes in the particle size of the fat globules as a result of the flocculation were dependent on the pepsin concentration. Correspondingly, the physical characteristics of the fat globules and the composition of the MFGM proteins in raw milk changed during incubation in SGF containing pepsin. The major MFGM proteins were hydrolyzed at different rates by the pepsin in the SGF; butyrophilin was more resistant than xanthine oxidase, PAS 6, or PAS 7. Peptides with various molecular weights, which altered with the time of incubation and the pepsin concentration, were present at the surfaces of the fat globules.
Exclusive breast feeding is recommended in all guidelines as the first choice feeding. Cow milk allergy (CMA) can be diagnosed by a diagnostic elimination diet for 2 to 4 weeks with a hypo-allergenic ...formula, followed by a challenge test with intact cow milk protein. The most often used hypo-allergenic formula for the diagnostic elimination diet and the therapeutic diet is a CM based extensive hydrolysate. CM-based partial hydrolysates cannot be recommended in the management of CMA because of insufficient efficacy and possible reactions, but about half of the infants with CMA may tolerate a partial hydrolysate. The pros and cons of other dietary options are discussed in this paper. The use of an amino acid-based formula and/or rice based hydrolysate formula during the diagnostic elimination and therapeutic diet is debated. When available, there is sufficient evidence to consider rice hydrolysates as an adequate alternative to CM-based hydrolysates, since some infants will still react to the CM hydrolysate. The pros and cons of dietary options such as soy formula, buckwheat, almond, pea or other plant based dietary products are discussed. Although the majority of the plant-based beverages are nutritionally inadequate, some are nutritionally adapted for toddlers. However, accessibility and content vary by country and, thus far there is insufficient evidence on the efficacy and tolerance of these plant-based drinks (except for soy formula and rice hydrolysates) to provide an opinion on them.
A diagnostic elimination diet, followed by a challenge remains the diagnostic standard. The use of an awareness tool may result in a decrease of delayed diagnosis. Breastmilk remains the ideal source of nutrition and when not available a CM extensively hydrolyzed formula, rice hydrolysate or amino acid formula should be recommended. More evidence is needed regarding plant-based drinks.
•A sensitive microplate fluorescent assay was developed for milk peroxidase activity.•Adding excess exogenous thiocyanate enabled milk normalisation and enzyme activation.•High assay sensitivity and ...reproducibility was demonstrated.•Lactoperoxidase activities in milk from four species were comprehensively analysed.•A hydrogen/oxygen transfer-based mechanism for LPO in the assay system was proposed.
Lactoperoxidase (LPO) is one of the major antibacterial ingredients in milk and an extensively employed indicator for milk heat treatment. The traditional method for LPO activity measurement using ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonate) cannot achieve high sensitivity and is affected by indigenous milk thiocyanate. A more sensitive microplate fluorescent assay was developed by monitoring generation of red-fluorescent resorufin from LPO catalysed oxidation of Amplex® Red (1-(3,7-dihydroxyphenoxazin-10-yl)ethanone) in this study. The assay is particularly suitable for milk LPO activity measurement as it eliminates the influences of indigenous milk hydrogen peroxide and thiocyanate. The method limit of detection was 7.1x10−6 U/mL of LPO in milk and good intra-run and inter-run precision was obtained. The LPO activities ranked as bovine > goat > camel > human in the four types of milk analysed. The high sensitivity and low cost of this assay makes it suitable for LPO activity analyses in both laboratory and commercial scales.
It is known that nutritional composition of breast milk is, to a certain extent, related to maternal diet. The question of nutritional adequacy of mothers' milk is often raised whenever a vegetarian ...or vegan diet during the lactation process is concerned. For this reason, in some countries, the recruitment of vegan lactating women as milk donors is excluded by milk banks. The purpose of this systematic review is to summarize existing knowledge on variability of specific nutrients in breastmilk of mothers adhering to a plant-based diet. The databases, including MEDLINE (Pubmed) and Scopus, were used to identify relevant publications. Data extraction and analysis were conducted following a PRISMA protocol. Thirteen publications concerning the impact of dietary pattern and levels of animal-origin food intake on breast milk composition were included. The systematic review has shown that all non-vegetarian, vegetarian and vegan mothers produce breast milk of comparable nutritional value. Several differences are primarily attributed to fatty acids and some micro-components, primarily vitamin B12. Regardless of dietary choices, nourishment and adequate nutrition have a significant impact on human milk composition - on the basis of the current evidence, vegetarian and vegan mothers are capable of producing nutritionally valuable milk for their infants, as far as the appropriate supplementation compensating for breastfeeding mother's nutritional requirements is provided. Dietary choices should not be a permanent exclusion criterion for donor candidates in human milk banks.
Human milk contains proteins and/or protein fragments that originate from nonhuman organisms. These proteinaceous molecules, of which the secretion might be related to the mother's allergy status, ...could be involved in the development of the immune system of the infant. This may lead, for example, to sensitization or the induction of allergen-specific tolerance. The aim of this study was to investigate the relation between maternal allergy and the levels of nonhuman proteinaceous molecules in their milk. In this study, we analysed trypsin-digested human milk serum proteins of 10 allergic mothers and 10 nonallergic mothers. A search was carried out to identify peptide sequences originating from bovine or other allergenic proteins. Several methods were applied to confirm the identification of these sequences, and the differences between both groups were investigated. Out of the 78 identified nonhuman peptide sequences, 62 sequences matched
proteins. Eight peptide sequences of bovine β -lactoglobulin had significantly higher levels in milk from allergic mothers than in milk from nonallergic mothers. Dietary bovine β -lactoglobulin may be absorbed through the intestinal barrier and secreted into human milk. This seems to be significantly higher in allergic mothers and might have consequences for the development of the immune system of their breastfed infant.
A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally fermented milk products of Sikkim in India viz.
dahi
, soft-variety
chhurpi
, hard-variety
chhurpi
,
...mohi
and
philu
, out of which, 68 LAB isolates were randomly grouped on the basis of phenotypic characteristics, and were identified by 16S rRNA gene sequence analysis.
Leuconostoc mesenteroides
was the most dominant genus, followed by
Leuc. mesenteroides
subsp.
jonggajibkimchii
,
Lactococcus lactis
subsp.
cremoris
,
Lc. lactis, Lc. lactis
subsp.
hordniae
,
Lc. lactis
subsp.
tructae
,
Enterococcus faecalis
,
E. italicus
and
E. pseudoavium
. LAB strains were tested for probiotics attributes by in vitro and genetic screening, based on marker genes. LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity.
Enterococcus faecalis
YS4-11 and YS4-14 and
Lactococcus lactis
subsp.
cremoris
SC3 showed more than 85% of hydrophobicity. Genes
clp L
and
tdc
encoding for low pH tolerance,
agu A and
Ir1516 encoding for bile tolerance, LBA1446 gene encoding for BSH activity,
map A
,
apf
,
mub 1
and
msa
encoding for mucosal binding property were detected. Gene
mesY
for bacteriocin production was detected only in
Leuconostoc
spp. Based on the in vitro and genetic screening of probiotic attributes,
Leuc. mesenteroides
;
Leuc. mesenteroides
subsp.
jonggajibkimchii
and
Lc. lactis
subsp.
cremoris
were tentatively selected for possible probiotic candidates.
The efficacy of conjugated linoleic acid (CLA) supplements containing trans-10, cis-12 for reducing milk fat synthesis has been well documented in dairy cows, but studies with other ruminant species ...are less convincing, and there have been no investigations of this in sheep. Therefore, the current study was designed to determine whether trans-10, cis-12 CLA would inhibit milk fat synthesis in sheep. Twenty multiparous ewes in early lactation were paired and randomly allocated to 2 treatments: grass hay plus concentrate either unsupplemented (control) or supplemented with lipid-encapsulated CLA to provide 2.4 g/d of trans-10, cis-12 CLA. The CLA dose was based on published responses of dairy cows extrapolated to ewes on a metabolic body weight basis. The experimental design was a 2-period crossover with 10-d treatment periods separated by a 10-d interval. Compared with the control, CLA supplementation reduced milk fat content from 6.4 to 4.9% and reduced fat yield from 95 to 80 g/d. The CLA treatment also increased milk yield from 1,471 to 1,611 g/d and increased protein yield from 68 to 73 g/d. Milk protein content and DMI were unaffected by treatment. The reduction in milk fat yield was due to decreases in both de novo fatty acid synthesis and uptake of preformed fatty acids. Milk fat content of trans-10, cis-12 CLA was < 0.01 and 0.12 g/100 g of fatty acids for the control and CLA treatments, respectively. The transfer efficiency of trans-10, cis-12 CLA from the dietary supplement into milk fat was 3.8%. Results of the present study demonstrate that a CLA supplement containing trans-10, cis-12 CLA reduces milk fat synthesis in lactating sheep in a manner similar to dairy cows when fed at an equivalent dose (metabolic body weight basis). Furthermore, the nutrients spared by the reduction in milk fat coincided with an increase in milk and milk protein yield.
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