Milk Flashcards
Complex glycans
Human milk oligosaccharides (HMOs)
Who breaks down HMOs?
Bifidobacterium (In MOM)
HMOs allow
Mitigation of harmful bacteria with growth of beneficial
Abundance of HMOs
Third most abundant component in human milk and more than protein
HMOs
Indigestible that serve as metabolic substrate for beneficial bacteria and commensals
Variations in HMOs
Concentration: Lactation stage (colostrum vs mature milk) and Type: Genetics of mother
Colostrum vs Mature milk HMO numbers
20-25g/L vs 5-15g/L
Number of HMOs identified in human milk
> 200
HMOs are ___ because ___
Prebiotics because they are indigestible and make their way to the gut without modification
Benefits of HMOs
1) Grow beneficial bacteria
2) Modulate intestinal epithelial cell responses
3) Prevent pathogens in epithelium (antimicrobial and antibiofilm activity)
Genetics of HMOs
Goes along with mom’s blood group + depends on type of glucosyltransferase expressed
HMOs can have _____ units
15 disaccharide units with different isomeric forms
Number of HMOs that are neutral
75%
Culturing of human milk have found
Staph (aureus and epidermidis), Strep salvarius, Lactobacillus, and Bifidobacterium
9 Core Genera of Milk
Staphylococcus, Strep, Sphingomonas, Serratia, Pseudomonas, Propionibacterium, Ralstornia, Corynebacterium, Bradyrhizobiaceae
Core Genera in milk %
95%
Number of bacteria BF babies consume a day
8x10^5
Enteromammary Pathway
Bacteria from human gut travels to the mammary gland to mold epi cells, immune cells, and bacteria itself
HMM unique to
Mother
HMM influenced by
Mother’s skin (Staph and Corynebacterium), Enteromammary pathway, backflow from baby
Sources of baby microbiomes
delievery –> HMM
Two core genera in HMM
Staph and Strep
NEC
Most common GI disease in pre-term infants and most common cause of death but incompletely understood
% of low birth weight babies that develop NEC
7%
Mortality of NEC
10-30%
Risk factors of NEC
Formula + acid supplement medications + Longterm antibiotics
How human milk protects from NEC
Down-regulates pro-inflammatory genes + SCFA production to lower pH and O2 to suppress pathogens and support barrier maturation and function
DHM
Mimicking MOM that is usually a complex mix of different samples of MOM
Limitations of DHM
No microbiome and inactivation of components due to pasteurisation and varies + no specific gestational age or nutritional needs of infant considered
Downfall of DHM (3)
Lack microbiota so more vulnerable to infection + reduced Ig, lactoferrin, cytokines, growth factors + harder to digest and absorb nutrients
Human milk banks all over
US and Australia with Japan and Norway having pasteurisation free options
Mimicking MOM new option
Mix donor and MOM and incubate over time (3 or 10% MOM)
MOM + DHM –>
No change in alpha diversity, but significant difference in members (50% restoration to famiies in MOM)
Frozen MOM + DHM
No difference in repopulation from immediate processing
MOM + DHM vs MOM
Metabolic analysis similar + similar IL8 in cell lines (safe)
HMO structures
Lactose elongated by 1,3 or 1,6 linked lactobiose or N-acetyl glucosamine
3 Types of HMOs
Fructose at end (35-50%), N-acetylglucosamine at end (42-55%), or Salic acid at end (12-14%)
Neutral VS Acidic HMOs
Sialic acid is acidic and fructose or N-acetylglucosamine neutral (75%)
Bioactives (5)
Ig, HMOs, WBC, AMPs, miRNAs
MOM benefits
Complete and personal nutrition, Enhances immune development, gut colonisation, pathogen protection, less GI disease
