Holstein cattle have become the dominant dairy breed worldwide. These black and white cows have become synonymous with dairy in many countries and they produce billions of liters of milk. This has been facilitated by artificial insemination technology that is the basis for herd replacement and genetic improvement programs around the world. With this in mind, Yue et al. conducted a study to examine how much genetic diversity exists in the male chromosomal lineages of modern cattle.
If you have a hard time digesting lactose from cow’s milk, you may want to avoid drinking monkey milk. Rhesus macaque monkeys produce milk with 8% lactose, almost twice the amount found in cow’s milk. With a barely detectable quantity of lactose, a better option for intolerant individuals would be milk from grey seals (that is, if you can get past that it is also 70% fishy-tasting fat and probably not the most appetizing choice for your morning bowl of cereal).
Saturated fatty acids (SFAs) have long been considered detrimental to cardiovascular health, with dietary guidelines advocating for a restriction of dietary SFAs to reduce the risk of cardiovascular disease (CVD). However, increased consumption of SFAs may not always be associated with increased CVD risk, and the effects of SFAs on CVD risk may instead depend on the food source.
In the past few months, Splash! has assessed how well Holder pasteurization, or HoP, kills viruses and bacteria, and the extent to which it affects the nutrients, immune proteins, and digestive aids in human milk. Because HoP is widely used by milk banks all over the world, these outcomes are potentially important for a huge number of infants, particularly those born prematurely. In this final article in the series, other methods of pasteurizing milk are brought into focus. Next to HoP, we know relatively little about their performance. Yet various studies show that they hold some promise towards achieving the ideal—a means of reliably preventing germs from proliferating in milk, while also retaining the function of human milk’s proteins.
The 14th International Symposium on Milk Genomics and Human Health was held in the warm and welcoming surrounds of Quebec City, Canada. This was the first time the consortium has been held in Canada, and it was a great opportunity to experience the hospitality and learn from the wonderful dairy science culture of the Canadians and the international program that the committee had assembled.
There is a laboratory in Rennes, the capital of Brittany, France that seeks to mimic the interior of the human gut. It has a machine with a compartment that pretends to be a stomach, full of acid and enzymes. Another compartment replicates the conditions of the small intestine. A computer modulates how food, in its various stages of digestion, flows through this system, by altering the activity of peristaltic pumps. In the past couple of years, scientists operating this system have put it to work digesting human milk. And because every aspect of digestion can be finely tuned, they can speed up gastric emptying, lower certain enzymatic activities, and raise gastric pH—as per a preterm (relative to a term-born) infant’s system. The main question these scientists seek to answer is how pasteurizing milk by heating to 62.5 °C for 30 minutes alters how well it is digested.
What we eat is known to influence our cognitive skills, and consuming dairy, in particular, has been associated with improved cognition. “There have been epidemiological studies or observational studies looking over the long term showing that people who ingest a higher amount of dairy products have better cognition in the long run,” says Professor Mary Beth Spitznagel of Kent State University.
The relationship between bacteria and the immune system is usually viewed as antagonistic, but bacteria and immune cells are not always on opposite teams. In fact, the bacteria that colonize the gastrointestinal tract during infancy actually shape the development of the immune system. Research in humans and nonhuman animals indicates that the types and quantities of immune cells that the infant produces are influenced by the strains of bacteria that take up residence in the infant’s gut. The infant’s diet is an important source of gut bacteria—does this mean that differences in early diet (i.e., mother’s milk vs. formula) could result in differences in immune function?
When you heat proteins, you very often ruin their function. This is because bonds that maintain a protein’s final structure start to rupture—that is, segments that have folded and wrapped around themselves, forming a fiddly and exact arrangement in three dimensions, come apart. “Denaturation,” as the process is called, is why Holder pasteurization (HoP)—heating milk to 62.5°C for 30 minutes—successfully removes the potential growth of germs such as bacteria when mother’s milk is stored, as in a milk bank. But in defanging some microorganisms through heating, HoP risks destroying the function of a suite of human proteins in milk that are thought to have beneficial effects on infants’ immunity. This third article in our series on HoP considers how well human proteins survive this type of pasteurization.
Recent research suggests a link between the infant’s gut bacterial community, or microbiome, and the adult microbiome; starting out with the right mix of beneficial bacteria in the gut influences health throughout the lifespan. The infant’s gut is initially colonized by bacteria that may come from different sources, such as breast milk, or worse, such as a hospital environment. Special carbohydrates in breast milk, such as free oligosaccharides or glycans attached to proteins, then selectively nurture the good bacteria.
What can a parent do to make sure their offspring’s gastrointestinal tract has the most beneficial strains of bacteria? The results of a new study out of UCLA and Children’s Hospital Los Angeles demonstrate that breast milk-derived microbes make up almost one-third of all beneficial bacteria in the infant’s gut. Far from contaminating, breast milk bacteria may be instrumental in getting the gut off to a good start.