What do your intestines have in common with a sewer pipe?


I’m not being funny but…

Did you ever stop to think about how much poop you produce in a year?

Unless you have too much time on your hands, probably not.

So let me tell you.

The average individual pops out about an ounce a day for each 12 pounds of body weight, so do the math and this suggests you flush away almost twice your own weight each year.

Now, to you that’s just waste matter, but to the uBiome labs it’s our bread-and-butter.

I know. An unpleasant metaphor, but I hope you get my point.

Fortunately we need only the smallest sample of your poop to analyze your microbiome.

Just a Q-tip’s worth collected from your used toilet paper in fact.

So you have our blessing to carry on happily flushing the rest away.

However, while our laboratory is content to test your microbiome using mere smears, other researchers are getting down and dirty with the more prodigious volumes you and I dispatch into the void each day.

A current project, appropriately called Underworlds, in Cambridge, Massachusetts, is experimenting with smart sewers that enable public health experts to study a city’s collective microbiome.

They can detect foodborne pathogens, enabling them to pick up localised outbreaks of food poisoning, and also look for biomarkers that flag up other diseases and health conditions.

The work is being done in conjunction with Kuwait, where officials are anxious to learn more about childhood obesity. More than a third of Kuwaiti children are obese.

But what does obesity have to do with sewage?

Surprisingly, quite a bit.

A remarkable University of Wisconsin-Milwaukee study earlier this year analyzed bacteria from sewage collected in 71 cities in 31 U.S. states, and could predict whether it had been gathered from a community categorized as either lean or obese with close to 90% accuracy.

Lean and obese individuals typically have differing intestinal bacterial profiles (more of this, less of that etc.) and the study showed that this same differential was also reflected down in the sewers.

Sewage sleuthing has been a thing for some time.

European studies have studied the stuff in sewers to monitor population-level trends in illicit drug-use, showing for example that cocaine and ecstasy are big at the weekends in major metropoles, while cannabis and methamphetamine use is pretty constant throughout the week.

Impressive, huh? There’s clearly a lot to be discovered by looking into effluent.

And a lot to be grateful for, too, when you consider the sewage systems of developed countries.

In fact readers of the British Medical Journal voted sanitation the greatest medical advance since 1840, comfortably beating antibiotics, anesthesia, widespread vaccinations, and even the discovery of DNA.

Although we don’t have time to go into how sewage is processed, I couldn’t leave you without brief mention of a project in India, in which the job is done by allowing sewage to sit in pools of duckweed and fish for five days.

Apparently it does the job brilliantly, but somewhat uncomfortably the whole operation is then funded by selling the fish.

I’m sure it’s just a coincidence that you can rearrange the letters of the particular species they use to spell something else altogether.


Have a great week!
Alexandra 🙂

Alexandra Carmichael
Director of Product, Community, and Growth


Further reading

Poop Health – Everything You Want to Know But Haven’t Asked

Sanitation rated the greatest medical advance in 150 years

Sewage Reflects the Microbiomes of Human Populations

Smart Sewer Project Will Reveal a City’s Microbiome

Smart Sewers Will Reveal What’s in Cambridge Citizens’ Guts

Spatial differences and temporal changes in illicit drug use

Sewage Treatment: All The Pooey Facts