Tag Archives: intestines

Stone toilet in Israel shows that the rich and powerful in antiquity were suffering from parasites

Despite their advanced sanitation systems, the ancient elites of Jerusalem were plagued by intestinal parasites, new research reports.

The 2,700 year-old toilet. Image credits Yoli Schwartz / The Israel Antiquities Authority.

The findings are drawn from an archaeological site at the ancient Armon Hanatziv royal estate in Jerusalem. The site lies close to the Dead Sea, to the north of today’s Bethlehem. Analysis of soil samples taken from an ancient toilet found that residents of the estate harbored several intestinal parasites, as evidenced by the discovery of parasitic eggs in the samples.

The findings of this study are among some of the earliest discoveries ever made in Israel up to now.

Egg surprise

“These are durable eggs, and under the special conditions provided by the cesspit, they survived for nearly 2,700 years,”  said Dafna Langgut of Tel Aviv University and the Steinhardt Museum of Natural History, a leading researcher in the emerging field of archeoparasitology, and sole author of the study. “Intestinal worms are parasites that cause symptoms like abdominal pain, nausea, diarrhea, and itching. Some of them are especially dangerous for children and can lead to malnutrition, developmental delays, nervous system damage, and, in extreme cases, even death.”

The findings can go a long way towards helping us understand the daily habits of people who once lived in this area, and of how ancient people dealt (or suffered with) infectious disease. This site is particularly valuable in this regard as it showcases the lives of the very rich and wealthy, who were most likely to enjoy the best lifestyle — in regards to resources, practices, and habits — of the time. Sites like this are also relatively hard to get this type of evidence from.

For example, Langgut explains that prior research had compared fecal parasites in hunter-gatherer and farming communities here and elsewhere, helping us better understand what this transition looked like for the people at the time.

One particularly important event for archeoparasitology (the study of parasites throughout human history) is the domestication of animals. At this time, the number of parasitic infections throughout farming communities rose sharply. Hunter-gatherers were generally exposed to fewer parasites and infectious diseases on account of living nomadic lifestyles — this, Langgut adds, is still the case today.

According to the paper, the area Israel occupies today — known as the Fertile Crescent in history — was probably one of the first where human populations suffered from wide-scale intestinal parasitic infection. Various ancient texts have been found throughout Israel referencing such diseases.

Excavation works at the ruins of Armon Hanatziv, or the Commissioner’s Palace, which dates back to the mid-7th century BCE, sometime between the reigns of King Hezekiah and King Josiah, started in 2019-2020.

Pollen found in samples taken from the site suggest that a garden of fruit trees and decorative plants existed around or next to the estate. Together with the lavish architecture and evidence of quality furnishings found at the site, this showcases the sheer level of wealth that was concentrated at the Armon Hanatziv.

During excavations in the garden, archaeologists from the Israel Antiquity Authority also discovered the remains of a primitive toilet: this consisted of a large water reservoir and a cubical limestone slab with a hole drilled in the center. Pollen was found in this structure as well, so the team believes that it was built either in a small room with windows, or in one without a roof, to ensure better ventilation. It was likely constructed in the garden, away from the main building, in an effort to have the plants mask some of the smell.

Toilets were quite a luxury during this time. The earliest examples of toilets in Israel all date to the Late Bronze Age and have been located in palace areas, indicative of their rarity and cost. Due to this, there is a relative lack of opportunities to study the contents of toilets for parasites. Only two such studies had been carried out before according to Langgut, one of which reported the presence of intestinal parasites.

Archaeologists collected 15 samples from the Armon Hanatziv, alongside a few controls from the area. The parasitic eggs were chemically extracted and studied under a microscope to determine their species and measure them. Langgut found eggs of four different species in six of the samples — whipworm, beef/pork tapeworm, roundworm, and pinworm. She adds that it’s the single earliest record of roundworm and pinworm in Israel.

Whipworm and roundworm eggs were the most common in the samples. None of the four control samples yielded any eggs, which ruled out the possibility of outside contamination into the toilet.

“It is possible that as early as the 7th century BCE, human feces were collected systematically from the city of Jerusalem in order to fertilize crops grown in the nearby fields,” Langgut wrote. “The inhabitants were forced to farm inhospitable rock terrain and were told which type of crop to grow. Additionally, the type of fertilizer used might have also been dictated by the Assyrian economy [at this time, Israel was under Assyrian rule].”

Human feces can act as useful and efficient fertilizer. Today, however, they are composted for a few months before use to limit the risk of any viable parasite eggs surviving. It’s very likely that people living in the area at that time were not using this practice, which allowed for the spread of parasites throughout the community. Langgut adds that the presence of tapeworm eggs is indicative that the inhabitants of the palace were eating poorly cooked or raw beef or pork, as these are “the only meats that carry the parasite”.

“While the mere existence of something as rare as a toilet installation seems to indicate that at least some ancient Jerusalemites enjoyed a relatively high level of sanitation, the evidence of intestinal parasite eggs suggests just the opposite,” she concludes. “The presence of indoor toilets may have been more a matter of convenience than an attempt to improve personal hygiene. A toilet was a symbol of wealth, a private installation that only the rich could have afforded.”

The paper “Mid-7th century BC human parasite remains from Jerusalem” has been published in the International Journal of Paleopathology.

Sharks have spiral-like intestines that resemble one of Nikola Tesla’s inventions

A CT scan image of the spiral intestine of a Pacific spiny dogfish shark (Squalus suckleyi). The structure is similar to the design of the Tesla one-way valve. Credit: Samantha Leigh/California State University Dominguez Hills.

Despite years of research, the exact structure and mechanics of shark intestines have been poorly understood until now. In a new study, researchers employed modern imaging tools to peer through the guts of various sharks, revealing that the spiral-shaped intestines remarkably function in a similar way to a Nikola Tesla patent for an unusual valve with no moving parts.

Marine biologists have had to rely on 2D sketches in order to study sharks’ digestive systems. Understanding how sharks’ intestines function has far-reaching consequences because these top-of-the-food-chain apex predators impact other species through what they eat and excrete.

Researchers at California State University Dominguez Hills, the University of Washington, and the University of California, Irvine embarked on a new study to fill in gaps in our knowledge that have eluded scientists for more than a century.

The reason why shark intestines are difficult to study has to do with their complex structure, with many overlapping layers. Dissecting a shark can destroy the context and connectivity of the tissue, which would be like “trying to understand what was reported in a newspaper by taking scissors to a rolled-up copy. The story just won’t hang together,” said Adam Summers, a professor at the University of Washington’s Friday Harbor Labs and co-author of the new study.

But this is where modern tools come in. The researchers used computerized tomography (CT) scanner to create 3D scans of intestines from nearly three dozen shark species. This machine takes X-ray images from different angles, then a computer algorithm stitches these different images together to create a 3-D image without harming or disturbing the tissues in any way or form. Before scanning them, the researchers made sure to fill the intestines and freeze-dried them in order to preserve their natural shape.

“It’s high time that some modern technology was used to look at these really amazing spiral intestines of sharks,” said lead author Samantha Leigh, assistant professor at California State University Dominguez Hills. “We developed a new method to digitally scan these tissues and now can look at the soft tissues in such great detail without having to slice into them.”

These scans serve to explain the odd shape of the shark’s intestines. Unlike most animals that have tubular intestines, sharks have spiral-shaped intestines that slow down the food as it moves downward through the gut due to gravity and peristalsis (the contraction of the gut’s smooth muscles). This shape allows food to move in only one way aided by gravity with virtually no energy expenditure.

That’s a very similar design to the “valvular conduit”, also known as a “Tesla valve”, patented by Nikola Tesla in 1920. Tesla’s invention is a one-way fluid valve with no moving parts consisting of a pipe with an intricate series of diverting teardrop-shaped loops.

Not all shark intestines are the same, though. There are four different kinds of spiral intestines, the researchers found. These organs can be columnar (like a spiral staircase), scroll (like a rolled-up sheet of paper), and either upward-facing or downward-facing funnels.

A CT scan image of a dogfish shark spiral intestine, shown from the top looking down. Credit: Samantha Leigh/California State University Dominguez Hills.

Sharks have wacky intestines for a reason. The researchers believe the spiral-shaped intestines allow sharks to hold food in their system for a longer time and absorb more nutrients than animals with tube-shaped digestive systems. Sharks are known to go days or even weeks without food if they have to, and their Tesla-valve-like intestines may play an important role.

The researchers also performed experiments to see with their own eyes how this spiral structure works. Intestines from five recently euthanized Pacific spiny dogfish sharks (Squalus suckleyi) were filled with colored liquids with different thicknesses. This allowed them to observe that the intestines “mix and churn” the liquids rather than pushing them along.

Beyond learning more about how sharks function, these findings have important implications for marine ecology. As top predators of the open ocean, sharks eat anything from fish and mammals to seagrass.

“The vast majority of shark species, and the majority of their physiology, are completely unknown. Every single natural history observation, internal visualization and anatomical investigation shows us things we could not have guessed at,” Summers said. “We need to look harder at sharks and, in particular, we need to look harder at parts other than the jaws, and the species that don’t interact with people.”

The researchers claim that this research could also inspire new technology that mimics shark intestine function, which may prove useful in certain industries where matter needs to flow in one direction with only minimal energy use. Potential applications include filtering microplastics from the water and industrial fluid-pump technologies.

The findings appeared in the journal Proceedings of the Royal Society B.