milk

UBERON:0001913 ·resolve ·HOST_ASSOCIATED ·EXACT SEEDED

An emulsion of fat globules within a fluid that is secreted by the mammary gland during lactation. — UBERON

SEEDED workflow status. The source-seeding rules supplied this record; consult its curation history for later attributed changes. This status does not establish human review.

Source attestations

Each upstream vocabulary's own account of this habitat. Assertion counts are per-source units and are not comparable across sources — GOLD counts organisms, BacDive strains, PREGO taxa.

What each upstream vocabulary says about this habitat
Source	Label / path	Assertions	Unit
ENVIRONMENTS_TABLE	milk Physicochemical parameter bands from kg-microbe's environment table.	—
GOLD	Host-associated > Mammals: Human > Integumentary system > Mammary gland > Milk	93	ORGANISM
GOLD	Host-associated > Mammals > Integumentary system > Mammary gland > Milk	650	ORGANISM
MADIN	milk	70	TAXON

Broader habitats

animal substance FOODON:02010001
mammalian milk product FOODON:03315150
bodily fluid UBERON:0006314
mammary gland fluid/secretion UBERON:0006539
Mammary gland habitatmech:GOLD.1a6a558ccf
Mammary gland habitatmech:GOLD.89cf14e129

Environmental parameters

Physicochemical parameters
Parameter	Value	Source
GRADIENTS	low	kg-microbe environments.csv (milk)
NUTRIENTS	high	kg-microbe environments.csv (milk)
ORGANIC_MATTER	high	kg-microbe environments.csv (milk)
PH	medium	kg-microbe environments.csv (milk)
PRESSURE	low	kg-microbe environments.csv (milk)
SALINITY	low	kg-microbe environments.csv (milk)
SALINITY_VARIABILITY	small	kg-microbe environments.csv (milk)
STRUCTURAL_COMPLEXITY	low	kg-microbe environments.csv (milk)
TEMPERATURE	medium	kg-microbe environments.csv (milk)
TEMPERATURE_VARIABILITY	medium	kg-microbe environments.csv (milk)
WATER_AVAILABILITY	high	kg-microbe environments.csv (milk)
WATER_VARIABILITY	permanently wet	kg-microbe environments.csv (milk)

Causal graphs

Milk carbohydrate lactic-acid assembly

Mammary glands secrete milk as a nutrient-rich aqueous emulsion containing lactose, oligosaccharides, fat globules, proteins, antimicrobial bioactives, and low-abundance milk microbiota. Milk sugars select saccharolytic lactic-acid bacteria and bifidobacteria, while fermentation converts carbohydrates into lactate and acetate that can acidify the milk habitat and reshape downstream community structure.

Directed graph · arrows run from subject to object. Focus or hover over a node or arrow for details; the evidence table follows.

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milk_carbohydrate_lactic_acid_assembly edges
Edge	Subject	Predicate	Object	Evidence
`mammary_gland_secretes_milk`	mammary gland	secretes Mammary tissue secretes milk into a nutrient-rich host fluid that carries endogenous and environmental microbes.	milk	`PMID:21695057` Hunt and colleagues characterized bacterial communities in milk produced by healthy lactating women.
`milk_forms_aqueous_emulsion`	milk	forms Milk is an aqueous emulsion whose water phase carries soluble sugars and proteins while dispersing fat globules.	aqueous fat-protein emulsion	`PMID:23808865` Quigley and colleagues reviewed raw milk as a nutrient-rich matrix whose composition can support a complex microbiota.
`milk_contains_lactose`	aqueous fat-protein emulsion	contains Lactose is a major soluble carbohydrate in milk and a substrate for dairy lactic-acid bacteria.	lactose	`PMID:21175746` Schwab and Ganzle assayed lactic-acid bacterial fermentation of milk sugars, including lactose and human milk oligosaccharide components.
`milk_contains_oligosaccharides`	aqueous fat-protein emulsion	contains Human milk contains soluble oligosaccharides that can serve as selective substrates for milk- and infant-associated saccharolytic bacteria.	milk oligosaccharides	`PMID:19033196` Sela and colleagues identified a Bifidobacterium infantis genome cluster specialized for human milk oligosaccharide use. `PMID:21175746` Schwab and Ganzle tested microbial fermentation of human milk oligosaccharide components and related galactooligosaccharides.
`milk_contains_fat_globules`	aqueous fat-protein emulsion	contains Dispersed milk fat globules create lipid-rich particles within the aqueous milk matrix.	milk fat globules	`PMID:23808865` The raw-milk review summarized milk constituents and the microbial groups that can enter and grow in raw milk.
`milk_contains_proteins`	aqueous fat-protein emulsion	contains Casein and whey proteins provide organic nitrogen that proteolytic milk microbes can hydrolyze during growth and fermentation.	milk proteins	`PMID:23808865` Quigley and colleagues reviewed milk as a nutrient-rich substrate for lactic-acid and other dairy-associated microbes.
`milk_contains_antimicrobial_bioactives`	milk	contains Human milk carries lactoferrin, lysozyme, immunoglobulins, and other bioactive factors that can restrict or modulate bacteria.	antimicrobial bioactives	`PMID:33643310` Carr and colleagues reviewed antimicrobial and immunomodulatory human milk components including oligosaccharides, lactoferrin, lysozyme, and immunoglobulins.
`milk_harbors_microbiota`	milk	harbors Milk harbors low-biomass bacterial communities that include staphylococci, streptococci, lactic-acid bacteria, bifidobacteria, and other taxa.	milk microbiota	`PMID:21695057` Hunt and colleagues used 16S rRNA sequencing to characterize human milk bacterial communities over time. `PMID:23808865` Quigley and colleagues reviewed the bacteria, fungi, spoilage organisms, and fermentation organisms detected in raw milk.
`milk_microbiota_includes_lactic_acid_bacteria`	milk microbiota	includes Lactic-acid bacteria are repeatedly detected in human and raw ruminant milk communities.	lactic-acid bacteria	`PMID:14657823` Martin and colleagues isolated lactic-acid bacteria from human milk and interpreted breastfeeding as a source of these bacteria to infants. `PMID:23808865` The raw-milk review describes lactic-acid bacteria among the major milk-associated functional groups.
`milk_microbiota_includes_bifidobacteria`	milk microbiota	includes Bifidobacteria can occur in milk and carry adaptations for utilizing milk-derived oligosaccharides.	bifidobacteria	`PMID:21695057` Hunt and colleagues detected diverse bacterial taxa across human milk samples. `PMID:19033196` Sela and colleagues linked Bifidobacterium infantis genome content to use of human milk oligosaccharides.
`lactose_supports_lactic_acid_bacteria`	lactose	supports Milk lactose is a fermentable carbohydrate supporting lactic-acid bacteria in milk.	lactic-acid bacteria	`PMID:21175746` Schwab and Ganzle measured milk-sugar fermentation by Lactobacillus, Streptococcus, and Leuconostoc strains.
`oligosaccharides_support_bifidobacteria`	milk oligosaccharides	supports Milk oligosaccharides select bifidobacterial lineages whose genomes encode transport and catabolism systems for these glycans.	bifidobacteria	`PMID:19033196` The PNAS genome study identified loci predicted to import and catabolize human milk oligosaccharides.
`lactic_acid_bacteria_ferment_lactose`	lactic-acid bacteria	performs Lactic-acid bacteria ferment lactose and related milk sugars into organic acids.	lactose fermentation	`PMID:21175746` Schwab and Ganzle directly assayed lactic-acid bacterial fermentation of human milk sugar substrates.
`bifidobacteria_catabolize_oligosaccharides`	bifidobacteria	performs Infant-associated bifidobacteria catabolize milk oligosaccharides through glycosidase, transporter, and central metabolic pathways.	oligosaccharide catabolism	`PMID:19033196` Sela and colleagues identified oligosaccharide transporters and glycosidases in Bifidobacterium infantis ATCC 15697.
`sugar_catabolism_releases_organic_acids`	lactose fermentation	releases Fermentation of lactose and milk-derived sugars releases lactate, acetate, and related short-chain organic acids.	lactate and acetate	`PMID:21175746` The FEMS Microbiology Letters study measured strain-specific production of lactate and acetate from milk sugar substrates.
`oligosaccharide_catabolism_releases_organic_acids`	oligosaccharide catabolism	releases Bifidobacterial catabolism of milk oligosaccharides releases acetate and lactate as soluble fermentation products.	lactate and acetate	`PMID:19033196` The Bifidobacterium infantis genome study connected human milk oligosaccharide import and catabolism to fermentative metabolism.
`organic_acids_drive_acidification`	lactate and acetate	drives Organic-acid accumulation lowers milk pH during lactic fermentation.	acidification	`PMID:23808865` Quigley and colleagues reviewed lactic-acid bacteria in milk fermentations and their role in acidifying the substrate.
`antimicrobial_bioactives_filter_milk_microbiota`	antimicrobial bioactives	filters Antimicrobial milk bioactives constrain which bacteria can persist in the milk matrix and the infant gut after milk consumption.	milk microbiota	`PMID:33643310` Carr and colleagues reviewed how milk bioactives can regulate gut and microbiota function.

Associated taxa

Taxa reported from this habitat, which is weaker than being characteristic of it. rank is out of pool: a high rank in a pool of thousands of near-tied scores is a weak claim. Entries corroborated by a second, independent source are listed first.

Taxa reported from this habitat
Taxon	Source	Rank	Pool
Listeria monocytogenes M7 `NCBITaxon:1030009`	MADIN	—	70
Bifidobacterium breve 26M2 `NCBITaxon:1036735`	MADIN	—	70
Brucella suis VBI22 `NCBITaxon:1112912`	MADIN	—	70
Bacillus coagulans DSM 1 = ATCC 7050 `NCBITaxon:1121088`	MADIN	—	70
Lactobacillus paracasei subsp. tolerans `NCBITaxon:113557`	MADIN	—	70
Escherichia coli O157:H43 T22 `NCBITaxon:1137135`	MADIN	—	70
Lactobacillus gastricus PS3 `NCBITaxon:1144300`	MADIN	—	70
Streptococcus salivarius PS4 `NCBITaxon:1157946`	MADIN	—	70
alloscardovia_macacae `NCBITaxon:1160091`	MADIN	—	70
Escherichia coli O32:H37 P4 `NCBITaxon:1167694`	MADIN	—	70
Lactobacillus gasseri CECT 5714 `NCBITaxon:1185324`	MADIN	—	70
Lactobacillus coryniformis coryniformis CECT 5711 `NCBITaxon:1185325`	MADIN	—	70
Mycoplasma capricolum capricolum 14232 `NCBITaxon:1188238`	MADIN	—	70
Parascardovia denticolens IPLA 20019 `NCBITaxon:1193128`	MADIN	—	70
Mycobacterium vaccae NBRC 14118 `NCBITaxon:1223499`	MADIN	—	70
Paenibacillus lentimorbus NRRL B-30488 `NCBITaxon:1244087`	MADIN	—	70
Leuconostoc lactis `NCBITaxon:1246`	MADIN	—	70
Staphylococcus fleurettii CIP 106114 `NCBITaxon:1255628`	MADIN	—	70
Staphylococcus aureus PB32 `NCBITaxon:1265302`	MADIN	—	70
kocuria_varians `NCBITaxon:1272`	MADIN	—	70
Lactobacillus rhamnosus CRL1505 `NCBITaxon:1286405`	MADIN	—	70
Streptococcus salivarius subsp. thermophilus `NCBITaxon:1308`	MADIN	—	70
Streptococcus agalactiae `NCBITaxon:1311`	MADIN	—	70
Bacillus cereus `NCBITaxon:1396`	MADIN	—	70
bacillus_mycoides `NCBITaxon:1405`	MADIN	—	70

Also called

mammary gland milk — UBERON

Curation

What a curator decided about this record, and why. A record built from several source concepts can carry one decision per concept.

ADD_CAUSAL_GRAPH 2026-09-04 · codex
Added a milk carbohydrate lactic-acid assembly graph backed by PMID:21695057, PMID:23808865, PMID:21175746, PMID:19033196, PMID:33643310, and PMID:14657823.

Provenance

Generated by scripts/seed_from_sources.py from the committed inventories in data/raw/. View the record.