#microbiome

Playing through the greenery and litter of a mini forest's undergrowth for just one month may be enough to change a child's immune system, according to an experiment in Finland. When daycare workers rolled out a lawn, planted forest undergrowth (such as dwarf heather and blueberries), and allowed children to care for crops in planter boxes, the diversity of microbes in the guts and on the skin of the young kids appeared healthier in a very short space of time. Compared to other city kids who play in standard urban daycares with yards of pavement, tile, and gravel, 3-, 4-, and 5-year-olds at these greened-up daycare centers in Finland showed increased T-cells and other important immune markers in their blood within 28 days.

This prehistoric "chewing gum" was discovered during excavations on the Danish island of Lolland.

According to this article:

At the dawn of the Neolithic era, a young woman discarded a lump of ancient chewing gum made from birch tar into a shallow, brackish lagoon that drew fishers to the coast of southern Denmark. Nearly 6,000 years later, researchers excavating the site spotted the gum amid pieces of wood and wild animal bone and from it have reassembled her complete DNA and so painted the broadest strokes of her portrait.

The strands of DNA preserved in the gum point to a hunter-gatherer from continental Europe who had dark skin, dark hair and blue eyes. She lived near the lagoon, itself protected from the open sea by shifting sand barriers, about 5,600 years ago, according to carbon dating of the birch tar.

Alongside her DNA, the researchers found genetic material from duck and hazelnuts – presumed remnants of a recent meal – and at least 40 types of microbes.

Above: an artist's interpretation of "Lola," the young woman or girl who chewed the birch tar nearly 6,000 years ago (image created by Tom Björklund)

Hannes Schroeder, a molecular anthropologist at the University of Copenhagen, said: “This is the first time anyone has got a full ancient genome from anything other than bone or teeth. The preservation of the gum is quite extraordinary. We didn’t expect to get the whole genome.”

Birch tar, made by heating the tree’s bark, has been used as a natural adhesive for hundreds of thousands of years. In the stone age, the material was extracted on a mass scale to haft arrowheads and other tools. But it had other applications too. Lumps of the tar found at archaeological sites often contain juvenile tooth marks, and given that it contains antiseptic substances, it may have served as a prehistoric tooth brush.

The scientists found they had enough ancient DNA to reconstruct a full human genome. It showed that the person was female and had dark skin, dark hair and blue eyes. She was also more closely related to hunter-gatherers from mainland Europe than those who lived in central Scandinavia at the time, according to a report in Nature Communications. It is impossible to know her age, but given that children seemed to chew birch tar, the scientists suspect she was young.

Further DNA revealed her oral microbiome, the collection of microbes that live, often harmlessly, in the mouth. Among tens of bacterial species were three linked to severe periodontal disease, and Streptococcus pneumoniae, a major cause of pneumonia. The scientists also spotted the Epstein-Barr virus, which can cause glandular fever. While she may well have been ill, all can be present without causing disease or illness.

Sources & More Info:

The Guardian: Neolithic Chewing Gum Helps Recreate Image of Ancient Dane

Nature: A 5700 Year-Old Human Genome and Oral Microbiome from Chewed Birch Pitch

National Geographic: DNA from Stone Age 'Chewing Gum' Tells an Incredible Story

I have a poem in a biology textbook!

I’m really delighted by this.

(Thanks to Margaret Riley and Princeton University Press for reaching out.)

A skeleton is not a more "efficient" body.

All other parts are needed for it to function.

Even "foreign bodies" live in symbiosis to form the flora on our skin and in our guts. Protecting us from infection and helping us better digest food. They are part of the body.

Even just bone and muscle is not enough when the means to sustain our energy needs are stripped out.

Reduction is not efficiency.