Neolithic ceramics reveal dairy processing from milk of multiple species

A new study has found evidence of cheesemaking, using milk from multiple animals in Late Neolithic Poland.

The research suggests that early farmers reduced the lactose content in milk by making it into cheese or other dairy products like yoghurt, and used dairy products from a number of different animals, such as cows, sheep or goats.

Lactose intolerance was a common condition in almost everyone in Europe during the Neolithic and until the Late Bronze Age when the genetic mutation became widespread, enabling adults to produce lactase, the enzyme which breaks down lactose in the body.

Researchers looked at the practice of dairy processing in the Late Neolithic, identifying high curd-content residues in pottery indicating cheesemaking, and revealing that multiple dairy species were utilised.

Dr Harry Robson, from the Department of Archaeology at the University of York, said: "These results contribute significantly to our understanding of the use of dairy products by some of the earliest farmers of Central Europe.

"Whilst previous research has shown that dairy products were widely available in some European regions during this period, here, for the first time, we have clear evidence for a diversified dairy herd, including cattle, sheep and goats, from the analysis of ceramics."

The scientists and archaeologists from the Universities of York, Cambridge, Toru? and Kraków used a multi-stranded proteomic and lipid-analysis approach to investigate ceramics and deposits on their surface, from the site of S?aw?cinek in central Poland.

The new development provides evidence that cheesemaking (and other curd-enriching dairy processing) can be directly detected by scrutinising the proportion of curd proteins, by comparing proteomic data. The results are also the first of their kind in Europe.

Despite widespread lactose intolerance in the period, there is evidence of dairy being consumed during the Neolithic, such as animal bones with kill patterns expected for dairy herds, dairy lipids in ceramic vessels, and dairy proteins in ancient dental calculus or plaque.

Lead author, Miranda Evans, PhD student at Cambridge's Department of Archaeology, said: "The proteomic results showed that the ancient residues closely resembled both the modern cheesemaking residues and cheese itself and not whole milk. This reveals that the people of S?aw?cinek practised cheesemaking or another form of curd-enriching dairy processing."

Evidence of multiple species used for cheesemaking was backed up by the presence of both cow and sheep or goat bones on the site."

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Study reveals the dynamics of human milk production

For the first time, MIT researchers have performed a large-scale, high-resolution study of the cells in breast milk, allowing them to track how these cells change over time in nursing mothers.

By analyzing human breast milk produced between three days and nearly two years after childbirth, the researchers were able to identify a variety of changes in gene expression in mammary gland cells. Some of these changes were linked to factors such as hormone levels, illness of the mother or baby, the mother starting birth control, and the baby starting daycare.

"We were able to take this really long view of lactation that other studies haven't really done, and we showed that milk does change over the entire course of lactation, even after years of milk production," says Brittany Goods, a former MIT postdoc who is now an assistant professor of engineering at Dartmouth College, and one of the senior authors of the study.

The researchers hope that their findings will lay the groundwork for more in-depth studies of how breast milk changes over time. Such studies could eventually yield new ways to boost mothers' milk production or to improve the composition of infant formula.

Bonnie Berger, the Simons Professor of Mathematics at MIT and head of the Computation and Biology group at the Computer Science and Artificial Intelligence Laboratory (CSAIL), is a senior author of the study, as is Alex Shalek, an associate professor of chemistry at MIT and a member of the Institute for Medical Engineering and Science (IMES); the Koch Institute for Integrative Cancer Research; the Ragon Institute of MGH, MIT and Harvard; and the Broad Institute of Harvard and MIT.

MIT graduate student Sarah Nyquist is the lead author of the paper, which appears this week in the Proceedings of the National Academy of Sciences.

Cellular changes

Human mammary glands can produce more than a liter of milk in a day, for months or years after childbirth. Studying how mammary gland cells accomplish this feat has been difficult in humans because the tissue itself can't be biopsied or otherwise accessed during lactation. However, recent studies have shown that breast milk contains many cells from the mammary gland, offering a noninvasive way to study these cells.

For this study, the MIT team collected breast milk samples from 15 nursing mothers. Each donor provided samples at multiple time points, ranging from three to 632 days after giving birth. The researchers also collected information about health and lifestyle changes that occurred throughout the lactation period.

The researchers isolated more than 48,000 cells from 50 samples and analyzed them using single-cell RNA-sequencing, a technology that can determine which genes are being expressed in a cell at a given moment in time. This analysis revealed 10 types of cells -- a population of fibroblast cells, two types of epithelial cells, and seven types of immune cells.

More than half of the immune cells that they found were macrophages. These cells appear to express genes that help make the mammary gland more tolerant of the milk proteins that they are producing, so they don't trigger an immune response. The researchers also found populations of B cells, T cells, and other immune cells, but their numbers were too small to do any in-depth studies of their functions.

By far the most abundant cells that they found were lactocytes, which are a type of epithelial cell. These cells expressed many genes for proteins that are found in breast milk, such as lactalbumin, as well as transporters needed to secrete milk proteins, micronutrients, fat, and other breast milk components.

Among the lactocytes, the researchers identified one cluster of cells that appears to be the primary producer of milk, and another that plays more of a structural role in the mammary gland. Each of these cell types could be divided into further subtypes, which the researchers hypothesize may be specialized for particular roles.

As time went on, the researchers found that the proportion of lactocytes involved in milk production went down, while the proportion involved in structural support went up. At the same time, genes involved in responding to the hormone prolactin became more active in the milk-producing lactocytes but dropped off in structural lactocytes. The researchers theorize that these changes may be related to the changing nutritional needs of infants as they grow.

"This study, along with some other studies that are out there, paves the way for mapping out and better understanding some of the pathways that these cells use to accomplish the tremendous amount of work that they do," Goods says.

Milk composition

The researchers also found links between the composition of cells in breast milk and events such as babies starting to go to daycare, starting formula, or the mother starting to use hormonal birth control.

"There are clearly changes in the composition of breast milk that are related to these lifestyle and health changes, such as infant illness or maternal hormonal birth control," Nyquist says. "These changes in lactation don't necessarily have a positive or negative impact on anyone's health, but they do occur and they may lead us to insights into how mammary epithelial cells are producing milk and the types of components that they may be producing."

The researchers now hope to do larger studies that could help them find stronger links between environmental factors and milk composition, and also discover more about how milk naturally changes over time. This could eventually help scientists devise better infant formulas or create formulas adapted to different stages of infancy. The researchers also hope to find ways to help nursing mothers boost their milk production or slow it down when babies are being weaned.

Other follow-up studies may explore how pumping affects milk composition and breast health, or how to prevent conditions such as mastitis.

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Geneticists’ new research on ancient Britain contains insights on language, ancestry, kinship, milk

New research revealing a major migration to the island of Great Britain offers fresh insights into the languages spoken at the time, the ancestry of present-day England and Wales, and even ancient habits of dairy consumption.

The findings are described in Nature by a team of more than 200 international researchers led by Harvard geneticists David Reich and Nick Patterson. Michael Isakov, a Harvard undergraduate who discovered the existence of the 3,000-year-old migration, is one of the co-first authors.

The analysis is one of two Reich-led studies of DNA data from ancient Britain that Nature published on Tuesday. Both highlight technological advances in large-scale genomics and open new windows into the lives of ancient people.

"This shows the power of large-scale genetic data in concert with archaeological and other data to get rich information about our past from a time before writing," said Reich, a professor in the Department of Human Evolutionary Biology and a professor of genetics at Harvard Medical School. "The studies are not only important for Great Britain, where we now have far more ancient DNA data than in any other region, but also because of what they show about the promise of similar studies elsewhere in the world."

The researchers analyzed the DNA of 793 newly reported individuals in the largest genome-wide study involving ancient humans. Their findings reveal a large-scale migration likely from somewhere in France to the southern part of Great Britain, or modern-day England and Wales, that eventually replaced about 50 percent of the ancestry of the island during the Late Bronze Age (1200 to 800 B.C.).

The study supports a recent theory that early Celtic languages came to Great Britain from France during the Late Bronze Age. It challenges two prominent theories: that the languages arrived hundreds of years later, in the Iron Age, or 1,500 years earlier at the dawn of the Bronze Age.

Previous research has shown that large-scale movement often accompanied language changes in pre-state societies. The Reich team argues that this untold migration event makes more sense for the spread of early Celtic languages into Britain.

"By using genetic data to document times when there were large-scale movements of people into a region, we can identify plausible times for a language shift," Reich said. "Known Celtic languages are too similar in their vocabularies to plausibly descend from a common ancestor 4,500 years ago, which is the time of the earlier pulse of large-scale migration, and very little migration occurred in the Iron Age. If you're a serious scholar, the genetic data should make you adjust your beliefs: downweighting the scenario of early Celtic language coming in the Iron Age [and early Bronze Age] and upweighting the Late Bronze Age."

As part of the genetic analysis, the researchers found that the ability to digest cow's milk dramatically increased in Britain from 1200 to 200 B.C., which is about a millennium earlier than it did in central Europe. These findings illuminate a different role for dairy consumption in Britain during this period compared with the rest of mainland Europe. More study is needed to define that role, the researchers said. Increased milk tolerance would have provided a big advantage in the former of higher survival rates among the children of people carrying this genetic adaptation.

The newly discovered ancestry change happened around 3,000 years ago, more than a millennium and a half before the Saxon period. The team was aware of a migration into England at some point during this gap because of an observation they made in research published in 2016. That study showed that contemporary English people have more DNA from early European farmers than people who lived in England about 4,000 years ago. The team set out to collect DNA from later periods to detect the shift.

The discontinuity -- a specific point in time when the percentage of farmer ancestry in English genomes changed -- was first noticed in the summer of 2019 by Isakov, an applied mathematics concentrator. He had started working as a researcher in Reich's lab the summer after his first year and was able to increase the statistical power of the group's ancestry tests. When he noticed some outliers in the data from people living 3,000 years ago, he led a closer analysis and discovered the migration.

"It's an extraordinary outcome and I'm very happy that I was able to get through it," said Isakov, who will graduate in May.

The second paper looks at kinship practices of 35 individuals who lived about 5,700 years ago and were buried in a tomb at Hazleton North in Gloucestershire, England. The researchers found a 27-person family -- three times larger than the second-largest documented ancient family -- whose kin relationships could be precisely determined by analyzing their DNA. The team created a family tree that covered five generations and found examples of polygyny, polyandry, adoption, and a key role for both patrilineal and matrilineal descent.

The lab's research illustrates the interdisciplinary collaborations that are required to tell the richest stories of the ancient past, Isakov said.

"It's sort of incredible that we have geneticists, we have statisticians, we have archaeologists, linguists, and even chemical analysis coming together. I think that the fact that we're able to like merge all these fields and have an actual insight that's culturally important is a great example of interdisciplinary science."

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Milk enabled massive steppe migration

The long-distance migrations of early Bronze Age pastoralists in the Eurasian steppe have captured widespread interest. But the factors behind their remarkable spread have been heavily debated by archaeologists. Now a new study in Nature provides clues regarding a critical component of the herders' lifestyle that was likely instrumental to their success: dairying.

From the Xiongnu to the Mongols, the pastoralist populations of the Eurasian steppe have long been a source of fascination. Amongst the earliest herding groups in this region were the Yamnaya, Bronze Age pastoralists who began expanding out of the Pontic-Caspian steppe more than 5000 years ago. These Bronze Age migrations resulted in gene flow across vast areas, ultimately linking pastoralist populations in Scandinavia with groups that expanded into Siberia.

Just how and why these pastoralists travelled such extraordinary distances in the Bronze Age has remained a mystery. Now a new study led by researchers from the Max Planck Institute for the Science of Human History in Jena, Germany has revealed a critical clue and it might come as a surprise. It appears that the Bronze Age migrations coincided with a simple but important dietary shift -- the adoption of milk drinking.

The researchers drew on a humble but extraordinary source of information from the archaeological record -- they looked at ancient tartar (dental calculus) on the teeth of preserved skeletons. By carefully removing samples of the built-up calculus, and using advanced molecular methods to extract and then analyse the proteins still preserved within this resistant and protective material, the researchers were able to identify which ancient individuals likely drank milk, and which did not.

Their results surprised them. "The pattern was incredibly strong," observes study leader and palaeoproteomics specialist Dr. Shevan Wilkin, "The majority of pre-Bronze Age Eneolithic individuals we tested -- over 90% -- showed absolutely no evidence of consuming dairy. In contrast, a remarkable 94% of the Early Bronze Age individuals had clearly been milk drinkers."

The researchers realized they had uncovered a significant pattern. They then further analysed the data in order to examine what kind of milk the herders were consuming. "The differences between the milk peptides of different species are minor but critical," explains Dr. Wilkin. "They can allow us to reconstruct what species the consumed milk comes from." While most of the milk peptides pointed to species like cow, sheep and goat, which was not surprising in light of the associated archaeological remains, calculus from a couple of individuals revealed an unexpected species: horse.

"Horse domestication is a heavily debated topic in Eurasian archaeology," notes Dr. Wilkin. One site where early Central Asian milk drinking had been proposed was the 3500-year-old site of Botai in Kazakhstan. The researchers tested calculus from a couple of Botai individuals, but found no evidence of milk drinking. This fits with the idea that Przewalskii horses -- an early form of which were excavated from the site -- were not the ancestors of today's domestic horse, as shown by recent archaeogenetic study. Instead, horse domestication -- and the drinking of horse milk -- likely began about 1500 kilometers to the west in the Pontic Caspian steppe.

"Our results won't make everyone happy, but they are very clear," says Professor Nicole Boivin, senior author of the study and Director of the Department of Archaeology at the MPI Science of Human History. "We see a major transition to dairying right at the point that pastoralists began expanding eastwards." Domesticated horses likely had a role to play too. "Steppe populations were no longer just using animals for meat, but exploiting their additional properties -milking them and using them for transport, for example," states Professor Boivin.

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From milk protein, a plastic foam that gets better in a tough environment

A new high-performance plastic foam developed from whey proteins can withstand extreme heat better than many common thermoplastics made from petroleum. A research team in Sweden reports that the material, which may be used for example in catalysts for cars, fuel filters or packaging foam, actually improves its mechanical performance after days of exposure to high temperatures.

Reporting in Advanced Sustainable Systems, researchers from KTH Royal Institute of Technology in Stockholm say the research opens the door to using protein-based foam materials in potentially tough environments, such as filtration, thermal insulation and fluid absorption.

The basic building blocks of the material are protein nanofibrils, or PNFs, which are self-assembled from hydrolyzed whey proteins -- a product from cheese-processing -- under specific temperature and pH conditions.

In tests the foams improved with aging. After one month of exposure to a temperature of 150C, the material became stiffer, tougher and stronger, says the study's co-author, Mikael Hedenqvist , professor in the Division of Polymeric Materials at KTH.

"This material only gets stronger with time," he says. "If we compare with petroleum-based, commercial foam materials made of polyethylene and polystyrene, they melt instantly and decompose under the same harsh conditions."

Proteins are often water-soluble, which poses a challenge when developing protein-based materials. Despite this, the material proved water-resistant after the aging process, which polymerized the protein, creating new covalent bonds that stabilized the foams. The foam also resisted even more aggressive substances -- such as surfactants and reducing agents -- that normally decompose or dissolve proteins. The crosslinking also made the foam unaffected by diesel fuel or hot oil.

The material also showed better fire resistance than commonly used polyurethane thermoset.

"This biodegradable, sustainable material can be a viable option for use in aggressive environments where fire resistance is important," Hedenqvist says.

Potential applications include providing support for catalytic metals that operate at higher temperatures, such as platinum catalysts for automobiles. The material could conceivably work as a fuel filter, too.

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Researchers develop simple method to 3D print milk products

 Researchers from the Singapore University of Technology and Design (SUTD) developed a method to perform direct ink writing (DIW) 3D printing of milk-based products at room temperature, while maintaining its temperature sensitive nutrients.

3D printing of food has been achieved by different printing methods, including the widely used selective laser sintering (SLS) and hot-melt extrusion methods. However, these methods are not always compatible with temperature-sensitive nutrients found in certain types of food. For instance, milk is rich in both calcium and protein, but as these nutrients are temperature sensitive, milk is unsuitable for 3D printing using the aforementioned printing methods which require high temperature. While the cold-extrusion is a viable alternative, it often requires rheology modifiers or additives to stabilize printed structures. Optimizing these additives is a complex and judicious task.

To tackle these limitations, the research team from SUTD's Soft Fluidics Lab changed the rheological properties of the printing ink and demonstrated DIW 3D printing of milk by cold-extrusion with a single milk product -- powdered milk. The team found that the concentration of milk powder allowed for the simple formulation of 3D-printable milk inks using water to control the rheology. Extensive characterizations of the formulated milk ink were also conducted to analyse their rheological properties and ensure optimal printability.

"This novel yet simple method can be used in formulating various nutritious foods including those served to patients in hospitals for their special dietary needs," said the lead author and Ph.D. candidate from SUTD, Mr Lee Cheng Pau.

"Cold-extrusion does not compromise heat-sensitive nutrients and yet offers vast potential in 3D printing of aesthetically pleasing, nutritionally controlled foods customized for individual requirements," added Assistant Professor Michinao Hashimoto, the principal investigator of the study.

From Science Daily

Study reveals lactose tolerance happened quickly in Europe

 The ability for humans to digest milk as adults has altered our dietary habits and societies for centuries. But when and how that ability -- known as lactase persistence or lactose tolerance -- occurred and became established is up for debate. By testing the genetic material from the bones of people who died during a Bronze Age battle around 1,200 BC, an international team of scientists including Krishna Veeramah, PhD, of Stony Brook University, suggest that lactase persistence spread throughout Central Europe in only a few thousand years, an extremely fast transformation compared to most evolutionary changes seen in humans. Their findings are published in Current Biology.

Despite the prominence of milk drinking in Europe and North American today, approximately two-thirds of the world's population remains lactose intolerant. Generally, no mammal digests milk as an adult, which is why for example people should not give adult cat or dog pets milk. However, a subset of humans have a genetic mutation that enables the enzyme lactase to digest the lactose sugar found in milk throughout an individual's lifetime. Many of these people are from Central or Northern Europe.

The battle occurred on the banks of the Tollense, a river in present day Germany, and is the most significant that we know about from Bronze Age Europe, probably consisting of about 4,000 warriors, almost a quarter of which died during the fighting. Despite being more than three thousand years old, the researchers were able to sequence DNA from some of the bone fragments recovered from the battle site.

Veeramah, Associate Professor in the Department of Ecology and Evolution in the College of Arts and Sciences, led part of the research that involved analyzing how the overall genetic ancestry of the battlefield population compared to other modern and ancient populations, and then compared the frequency of the lactase-persistent allele to other modern and ancient populations, particularly medieval European populations.

The research team, led by Joachim Burger and colleagues at Johannes Gutenberg University Mainz (JGU), found that despite the battle occurring more than 4,000 years after the introduction of agriculture in Europe -- which in part would have involved the consumption of dairy from early cattle, goats and sheep domesticates -- only one in eight of the warriors had a genetic variant that enabled them to break down lactose.

"When we look at other European genetic data from the early Medieval period less than 2,000 years later, we find that more than 60 percent of individuals had the ability to drink milk as adults, close to what we observe in modern Central European countries, which ranges from 70 to 90 percent" said Veeramah. "This is actually an incredibly fast rate of change for the gene that controls milk digestion. It appears that by simply possessing this one genetic change, past European individuals with the ability to digest lactose had a six percent greater chance of producing children than those who could not. This is the strongest evidence we have for positive natural selection in humans."

Joachim Burger of JGU, lead author on the study, added that there still is not definitive answer to the question: Why did being able to digest the sugar in milk after infancy provide such a big evolutionary advantage?

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5,000-year-old milk proteins point to the importance of dairying in eastern Eurasia

Today dairy foods sustain and support millions around the world, including in Mongolia, where dairy foods make up to 50% of calories consumed during the summer. Although dairy-based pastoralism has been an essential part of life and culture in the eastern Eurasian Steppe for millennia, the eastward spread of dairying from its origin in southwest Asia and the development of these practices is little understood. The current study, led by Shevan Wilkin and Jessica Hendy of the Max Planck Institute for the Science of Human History, presents the earliest evidence for dairy consumption in East Asia, circa 3000 BCE, and offers insights into the arrival and evolution of dairy pastoralism in prehistoric Mongolia.

Earliest dairy consumption & a possible path of entry

The highly mobile nature of pastoralist societies and the severe winds of the Eastern Steppe make detecting occupied sites with direct evidence into the lives and culture of ancient Mongolians exceedingly rare. Instead, the researchers looked for clues in ritual human burial mounds, often marked by stone monuments and occasionally featuring satellite animal graves.

In collaboration with the National University of Mongolia, researchers analyzed dental calculus from individuals ranging from the Early Bronze Age to the Mongol Period. Three-quarters of all individuals contained evidence that they had consumed dairy foods, which demonstrates the widespread importance of this food source in both prehistoric and historic Mongolia. The study's results include the earliest direct evidence for dairy consumption in East Asia, identified in an individual from the Afanasievo site of Shatar Chuluu, which dates to roughly 3000 BCE. Previous DNA analysis on this individual revealed non-local genetic markers consistent with Western Steppe Herder populations, presenting Early Bronze Age Afanasievo migrations westward via the Russian Altai as a viable candidate for the introduction of dairy and domestic livestock into eastern Eurasia.

Multiple different animal species were used for their milk

By sequencing the milk proteins extracted from the dental calculus, the scientists were able to determine which animal species were being used for dairy production, and thereby help to trace the progression of domestication, dairying, and pastoralism in the region. "Modern Mongolians use cow, sheep, goat, yak, camel, horse and reindeer for milk today, yet when each of these species were first utilized for dairy in Mongolia remains unclear," says Shevan Wilkin, lead author of the study. "What is clear is that the crucial renewable calories and hydration made available through the incorporation of dairying would have become essential across the arid and agriculturally challenging ancient Eastern Steppe."

The earliest individuals to show evidence of dairy consumption lived around 5000 years ago and consumed milk from ruminant species, such as cattle, sheep, and goats. A few thousand years later, at Bronze Age sites dated to after 1200 BCE, the researchers find the first evidence of horse milk consumption, occurring at the same time as early evidence for horse bridling and riding, as well as the use of horses at ritual burial sites. In addition, the study shows that during the Mongol Empire circa 1200-1400 CE, people also consumed the milk of camels. "We are excited that through the analysis of proteins we are able to see the consumption of multiple different animal species, even sometimes in the same individual. This gives us a whole new insight into ancient dairying practices" says Jessica Hendy, senior author of the study.

Millenia after the first evidence of horse milk consumption, horses remain vital to the daily lives of many in modern Mongolia, where mounted pastoralists rely on them to manage large herds of livestock, transport people and supplies, and provide a primary source of meat and milk. "Our findings suggest that the incorporation of horses into dairy pastoralism in Eastern Eurasia was closely linked to a broader economic transformation in the use of horses for riding, movement, and diet," says William Taylor of the University of Colorado-Boulder, one of the study's coauthors.

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