Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years.

Yacold also partners with nature portfolio to advance gut microbiome science through the global grants for gut health, an investigator-led research program.

To learn more about Yachtolt, visit yawcult.co.

J-P. That's Y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacolt.

This is Scientific American's 60-second science.'m Christopher Entagata. Got a minute?

Homo sapiens may dominate Europe and Asia today, but hundreds of thousands of years ago,

long before we got there, the land was ruled by our now extinct cousins, the Neanderthals and Denisovans.

I think one important thing to realize is that given that Neanderthals and Denisovans had lived in Europe and Asia for such an extended time, they were probably quite well adapted to the local conditions.

Janet Kelso, a computational biologist at the Max Planck Institute for evolutionary anthropology. So they were well adapted to the pathogens, to the foods that were available to the

climate. The invading newcomers probably found themselves less well adapted to the local

conditions. So when Homo sapiens shacked up with their close evolutionary relatives, it gave

him a shot at picking up some advantageous genes. Kelsso and her colleagues hunted modern human genomes for strings of DNA that closely resembled

those known to be from Neanderthals and Denisovans. And indeed, on human chromosome number

four, they found a stretch of archaic DNA, 140,000 bases long. The genomes of many non-African humans today have this sequence,

which includes a cluster of genes that code for toll-like receptors, or TLRs, a type of immune

protein that sniffes out pathogens. And it turns out that archaic variants of that gene are associated

with lower microbial loads in present-day humans,

a trait that may have been quite valuable to our ancestors as they settled new lands.

The study appears in the American Journal of Human Genetics.

Problem is that increased immune vigilance, it has a side effect, allergies.

Our speculation is this is some kind of trade-off, right?

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