# Colostrum

Colostrum (from Latin, of unknown origin) is the first form of milk produced by the mammary glands of humans and other mammals immediately following delivery of the newborn. Animal colostrum may be called beestings, the traditional word from Old English dialects. Most species will begin to generate colostrum just prior to giving birth. Colostrum contains antibodies to protect the newborn against disease and infection, and immune and growth factors and other bioactives that help to activate a newborn's immune system, jumpstart gut function, and seed a healthy gut microbiome in the first few days of life. The bioactives found in colostrum are beneficial for a newborn's health, growth and vitality. Colostrum strengthens a baby's immune system and is filled with white blood cells to protect it from infection.
At birth, the environment of the newborn mammal shifts from the sterile conditions of the mother's uterus, with a constant nutrient supply via the placenta, to the microbe-rich environment outside, with irregular oral intake of complex milk nutrients through the gastrointestinal tract. This transition puts high demands on the gastrointestinal tract of the neonate, as the gut plays an important part in both the digestive system and the immune system. Colostrum has evolved to care for highly sensitive mammalian neonates and contributes significantly to initial immunological defense as well as to the growth, development, and maturation of the neonate's gastrointestinal tract by providing key nutrients and bioactive factors. Bovine colostrum powder is rich in protein and low in sugar and fat. Bovine colostrum can also be used for nonorganic failure to thrive in children and acute non-steroidal anti-inflammatory drug-induced increase in intestinal permeability in males and can boost a neonate's immunity.
Colostrum also has a mild laxative effect, encouraging the passing of a baby's first stool, which is called meconium. This clears excess bilirubin, a waste-product of dead red blood cells which is produced in large quantities at birth due to blood volume reduction from the infant's body, and which is often responsible for jaundice.
Research on possible health benefits and medical applications of bovine colostrum is ongoing. As of January 2025, there is no accepted medical use of bovine colostrum to treat any condition.

## Composition

Colostrum, like other forms of milk, is mostly water, and also contains lactose, fat, minerals and protein. It also contains bioactive components including antibodies to protect the newborn against disease and infection, and immune and growth factors. Colostrum contains white blood cells.
Newborns have very immature and small digestive systems, and colostrum delivers its bioactives in a concentrated low-volume form. Colostrum is known to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG, and IgM. These are some of the components of the adaptive immune system. Other immune components of colostrum include the major components of the innate immune system, such as lactoferrin, lysozyme, lactoperoxidase, complement, and proline-rich polypeptides (PRP). A number of cytokines (small messenger peptides that control the functioning of the immune system) are found in colostrum as well, tumor necrosis factor, and others.
Colostrum also contains a number of growth factors, such as insulin-like growth factor I (IGF-1), and II, transforming growth factor alpha, beta 1 and beta 2, fibroblast growth factors, epidermal growth factor, granulocyte-macrophage-stimulating growth factor, platelet-derived growth factor, vascular endothelial growth factor, and colony-stimulating factor 1.

### Proline-rich polypeptides

Proline-rich polypeptides (PRPs) are small immune signaling peptides that were independently discovered in colostrum and other sources, such as blood plasma, in the United States, Czechoslovakia and Poland. Hence they appear under various names in the literature, including Colostrinin, CLN, transfer factor and PRP. They function as signal transducing molecules that have the unique effect of modulating the immune system, turning it up when the body comes under attack from pathogens or other disease agents, and damping it when the danger is eliminated or neutralized. At first thought to actually transfer immunity from one immune system to another, it now appears that PRPs simply stimulate cell-mediated immunity.

## Human colostrum

In humans, colostrum is produced for the first two to four days after childbirth. It enhances immunity in infants and is hypothesized to have anti-inflammatory properties. It is suggested infants fed with human colostrum have lower incidence of gastrointestinal infections. Colostrum has a laxative effect, encouraging the baby's body to excrete stool, which helps eliminate excess bilirubin, although jaundice lasts longer in breastfed infants than in those who are formula-fed.

## Bovine Colostrum

After dairy cattle are exposed to pathogens, they produce antibodies against them. These antibodies are present in the cow's bloodstream and colostrum. Some of these antibodies are specific to human pathogens, including Escherichia coli, Cryptosporidium parvum, Shigella flexneri, Salmonella species, Staphylococcus species, and rotavirus (which causes diarrhea in infants). Albert Sabin, who developed the first oral vaccine against polio, used colostrum in an experiment to evaluate the protective effect of breastfeeding against the poliomyelitis virus. Sabin obtained blood serum and milk samples from 30 human nursing mothers at different times after delivery. He then mixed the serum and blood from each individual mother together, in systematically differing proportions, and added "a constant amount" of the Lansing strain of the poliomyelitis virus. The mixtures were then injected into the brains of mice. The results showed that 100% of the human colostrum samples had antipoliomyelitic activity whereas only "80 per cent of the milk specimens obtained between 101 and 340 days after delivery" had such activity. He also tested cow's milk (not specified as colostrum) and found that milk samples from 2 of 9 cows contained antipoliomyelitic activity. When antibiotics began to appear, interest in colostrum waned, but after antibiotic-resistant strains of pathogens developed, interest turned to colostrum as a natural alternative to antibiotics.

### Health effects of consumption by humans

Bovine colostrum and human colostrum contain many of the same antibodies, immune and growth factors, and nutrients.
There is also research suggesting that a large proportion of colostrum is not fit for human consumption "due to tremendous bacterial loads". Salmonella was detected in 15% of unpasteurised samples. Pasteurisation reduces the bioactive proteins many of the benefits rely upon, however.

#### Respiratory system

Colostrum may support respiratory health in adults and children. One study of human subjects suggested that oral colostrum was effective in preventing influenza. Bovine colostrum was shown to reduce symptoms of allergic rhinitis in children.

#### Digestive system

Colostrum may help to maintain and support intestinal integrity and improve nutrient absorption, while its naturally occurring prebiotics feed beneficial gut bacteria in adults and children.

#### Older children

Colostrum may have continued benefits in children over the age of one: to support children's immune systems, soothe digestive upsets, and otherwise support digestive health.

#### Sports nutrition

Bovine colostrum may help maintain a healthy immune system during athletic training, while supporting cellular proliferation as well as protein synthesis and soft tissue repair. One study showed that one brand of concentrated bovine colostrum powder improved running performance in one test, on average, in thirty males but did not improve performance in another test.

#### Skin

Bovine colostrum (BC) affects skin. A study conducted in 2021 by Jogi Reena et al. found that Bovine Colostrum may help delay skin aging by reducing telomere shortening, which is a marker of cellular aging. The researchers attributed these benefits to the antioxidant properties of BC, which help maintain telomere length and boost fibroblast proliferation—a key element in collagen production and the maintenance of skin structure.
Enhanced Healing and Regeneration: BC has been shown to stimulate fibroblast activity, aiding in the repair of damaged skin and the creation of new tissue, making it effective for wound healing and scar reduction.
Anti-Aging Properties: BC is rich in antioxidants that combat free radicals, which are significant contributors to skin aging. These antioxidants, combined with growth factors, improve skin elasticity and firmness, helping to diminish the appearance of wrinkles and fine lines. A clinical study published in the Journal of Cosmetic Dermatology found that topical application of antioxidants significantly improved skin texture and reduced signs of aging in participants over a 12-week period.
Wound Healing: The immunoglobulins and lactoferrin in topically applied BC work together to improve the Bates-Jensen Wound Assessment score of chronic non-healing ulcers on day 21 of treatment.

### Use in animal husbandry

Colostrum is beneficial for newborn farm animals. They receive no passive transfer of immunity via the placenta before birth, so any antibodies that they need have to be either ingested or supplied by injection or other artificial means. The ingested antibodies are absorbed from the intestine of the neonate. Maximum absorption of colostral antibodies by the newborn animal occurs within 4 hours or thirty minutes of birth.
The role of colostrum for newborn animals is to provide nutrition, and protect against infection while the immune and digestive systems are developing and maturing. Bovine colostrum provides macro- and micro-nutrients, as well as growth factors, cytokines, nucleosides, oligosaccharides, natural antimicrobials, antioxidants; and a range of immunoglobulins such as IgG, IgA, IgD, IgM and IgE. Minimal levels of IgG are essential to prevent failure of passive transfer. The iron-binding glycoproteins lactoferrin and transferrin in bovine colostrum assist in attacking pathogens by impacting their cell membrane and making them more susceptible to the immune systems attack by neutrophils. Cytokines in bovine colostrum enhance B and T cell maturation and increase endogenous antibody production. They also help regulate epithelial cell growth and development, proliferation, and restitution. Transfer factors enhance the activity of T cells. Other growth and immune factors such as IGF-1, IGF-2, FGF, EGF, TGF, PDGF, etc.
Bovine Colostrum contains bioactive components that support immunity and gut health in animals, and fight bacteria, viruses, and other pathogens. Early, high-quality colostrum is beneficial for survival and healthy development. It repairs intestinal damage and improves nutrient absorption. In calves, colostrum helps develop their gut and prevents death. It reduces infections, antibiotic use, and diarrhea, leading to faster growth and higher profits for farmers.

### Use in companion animals

Much like in humans and production animals, companion animal survival in the newborn stage of life is largely dependent upon colostrum. Companion animal immune systems require several weeks to several months in order to fully develop. Maternal antibodies provide benefit for a relatively short period of time so a gap exists with immune sufficiency where an animal is at risk of infection. Like humans, companion animal immune response changes with age where early life and later in life have similarities. That is, an immune bias whereby the animal has less of an ability to fend off infections and greater prevalence of allergy at both ends of the age spectrum. Stress also affects a companion animal's immune system including changes in environment, diet, etc. Maintaining gut microbial balance is key to maintaining a healthy immune system as well as mucosal integrity, similar to humans, demonstrated to benefit companion animal immunity and digestive health.
In humans, bovine colostrum plays a role in increasing Ig levels, increasing lymphocyte proliferation stimulating activity and increasing phagocytosis activity. These are supported by other components of colostrum which further enhance the activity of the immune response. The iron binding glycoproteins lactoferrin and transferrin in bovine colostrum assist in attacking pathogens by impacting their cell membrane and making them more susceptible to the immune systems attack by neutrophils. Cytokines present in bovine colostrum enhance B and T cell maturation and increase endogenous antibody production. They also play a major role in regulation of epithelial cell growth and development, proliferation, restitution. Transfer factors enhance the activity of T cells. Other growth and immune factors such as IGF-1, IGF-2, FGF, EGF, TGF, PDGF, etc. Colostrum contains glycomacropeptides which help to regulate appetite. Studies suggest that bovine colostrum may enhance animal immunity, improve gut health, and lower the risk of illness.

### Hyperimmune

Hyperimmune colostrum is natural bovine colostrum collected from a population of cows immunized repeatedly with a specific pathogen. The colostrum is collected within 24 hours of the cow giving birth. Antibodies towards the specific pathogens or antigens that were used in the immunization are present in higher levels than in the population before treatment. Although some papers have been published stating that specific human pathogens were just as high as in hyperimmune colostrum, and natural colostrum nearly always had higher antibody titers than did the hyperimmune version. A clinical trial showed that if the immunization is by surface antigens of a strain of E. coli bacteria, the Bovine Colostrum Powder can be used to make tablets capable of binding to the bacteria so that they are excreted in stools, thus preventing diarrhea that is caused by this strain of E. coli. This prevents the successful colonization of the gut, which would otherwise lead to bacteria releasing enterotoxigenic materials which cause diarrhea.

### Potential applications

Although bovine colostrum has been consumed by humans for centuries, only in recent decades have we seen randomized clinical trials to test for health benefits. It is probable that little absorption of intact growth factors and antibodies into the bloodstream occurs, due to digestion in the gastrointestinal tract. However, two experiments, one using human pancreatic fluid and one using rats, suggested the presence of casein and other buffering proteins allows epidermal growth factor but not transforming growth factor α to survive degradation induced by human pancreatic fluid and allows epidermal growth factor to pass into the lumen of the small intestine in rats, where it can stimulate repair, working via local effects. This provides a probable mechanism explaining reductions in gut permeability after colostrum administration in some published studies, while another study found colostrum promising as treatment for distal colitis. The effect of colostrum on extra-gastrointestinal problems has been studied in a small number of randomised double-blind studies.
The gut can be affected by ulcers, inflammation, and infectious diarrhea. There is currently much interest in the potential value of colostrum for the prevention and treatment of these conditions., As pointed out by Kelly, inconsistency between results in some published studies may be due in part to variation in dose given and to the timing of the colostrum collection being tested (first milking versus pooled colostrum collected up to day 5 following calving).
Some athletes have used colostrum in an attempt to improve their performance, decrease recovery time, and prevent sickness during peak performance levels. Supplementation with bovine colostrum, 20 grams per day (g/d), in combination with exercise training for eight weeks may increase bone-free lean body mass in active men and women.
Low IGF-1 levels may be associated with dementia in the very elderly, although causation has not been established. Malnutrition can cause low levels of IGF-1, as can obesity. Although IGF-1 is not absorbed intact by the body, some studies suggest it stimulates the production of IGF-1 when taken as a supplement whereas others do not.
Colostrum also has antioxidant components, such as lactoferrin and hemopexin, which binds free heme in the body.
The Isle of Man had a local delicacy called "Groosniuys", a pudding made with colostrum. In Finland, a baked cheese called Leipäjuusto is traditionally made with either cow colostrum or reindeer milk.
A sweet cheese-like delicacy called 'Junnu' or 'Ginna' is made with colostrum in the south Indian states of Karnataka, Andhra Pradesh and Telangana. It is made with both cow and buffalo milk; in both cases milk produced on the second day after birth is considered ideal for preparing this pudding-like delicacy. Colostrum is in very high demand in these states, resulting in product adulteration.