How the Sugars in Spit tame the Body’s Unruly Fungi ( [aka Spit or Sputum?]

Years ago, my pulmonologist spouse threatened to start a new journal called “Spit? or Sputum?”

The idea was rooted in our challenge, when we were medical interns, tasked with obtaining sputum (the thick mucus from deep in the lung that we needed) to spot the predominant organism responsible for a patient’s pneumonia. When done correctly, a patient would bring up a deeply-coughed sputum sample teeming with many copies of one species, that would jump out in technicolor when the correct stain was applied, and voila! We have a diagnosis under the microscope. When the patient gives us spit, however, we would see a veritable smorgasbord of organisms, and a disappointing lack of clarity.

So often, when collecting such sputum samples from patients (“Sir, please cough something up from deep inside”), we ended up with “spit”, the mucus that is generated in the mouth, home to millions of species of organism, and unhelpful in the diagnosis of pneumonia. When we run from the patient’s bedside to the closest microscope, we apply our stains and breathlessly wait to see: was it truly sputum? or just more spit?

Hence the burning question:

Is this SPIT or SPUTUM?

Not that funny? I guess you had to be there. Nevertheless, the title remains stuck in my head.

Reading this article brought that random thought out of the depths.

Fascinating read: researchers identified that Candida Albicans, a common fungus, is often present in our mouths. In this moist, seemingly ideal growth environment, does this organism not cause yeast infections in everyone?

It is a story worthy of Sherlock Holmes. From oral mucus to sugars to glycans to oxygen linking and then …

This is science AND science writing that educates and elevates. Worth a read.

Exercise: your organs are talking about you (nytimes)

How did I miss this the first time around? in a 2018 article, Gretchen Reynolds informs us that our organs are signaling each other with vesicles and communication molecules that change our physiology in response to exercise. This prompts more cooperation and health benefits and explains more of our internal workings.

We think we are one organism, walking and talking and stressing about our daily schedules. Instead, depending where you put your focus, you are: a human being OR a collection of organ systems (nervous system, respiratory system, cardiovascular, gastroenterological, etc) OR a bag of organs (heart, lungs, pancreas, liver, etc) OR a system of transport tubes (arteries, veins, lymphatics, nerves, or the most recently discovered: highways in the space outside of venules in the brain, activated during sleep!) OR a packed freeway of vehicles (red cells, white cells, platelets) OR a ghoulash of chemicals (thyroid hormone, insulin, interferon, cytokines that trigger fever or attract your immune defense, etc) OR a growing number of signaling vesicles (see the article above).

The rabbit hole goes very deep, my friends. And it is glorious.

“It’s like riding an escalator”: Burro racing isn’t likely to go mainstream, but it’s having a moment in Colorado (Colorado Sun)

I love living in Colorado. I’m not likely to do a burro race myself, but I totally enjoy the crazy friends and neighbors who do stuff like this. What are YOU doing this weekend for fun?

The rise of “BookTok”: 7 second emo sells books (nytimes)

Another sign of the times: older books getting a resurgence in sales from fans posting emotional reactions on TikTok.

Hmm. It seems that one can quickly change minds (and behavior!) on a population scale with super-short emotional appeal.

The good: Shows that Daniel Kahneman’s “Thinking, Fast and Slow” is an important pillar of modern online technology: emotions and story change more minds than just data. (link is to a blog post on The Undoing Project about Kahneman’s life and work).

The bad: Shows that Nicholas Carr’s book “The Shallows: what the internet is doing to our brains” is also right — we don’t have patience to read long-form fiction, except maybe when TikTok tells us to. (link to my mindfulness blog series, and a review of Carr’s book).

How ironic.

Things don’t make sense UNTIL THEY DO (mitochondria in the eye, from

John Ball via

In medical school, we all learned that the back of the eye, the retina that gathers and converts light from photons into electric signals in neurons, were cluttered with cell bodies and mitochondria that seemed to BLOCK light to the photo-receptors. We all sat around and puzzled “huh, why is that” and, in 1986, had no answer from the textbook.

Well, science progresses, and NOW there is an incredible answer, from the retinas of squirrels. Thanks to our brilliant basic science colleagues.

In a grand case of convergent evolution, birds circling high overhead, mosquitoes buzzing around their delicious human victims, and you reading this article have all independently evolved related optical functions—adaptations that bring a sharp and vibrant world to the eye of the beholder.

Yasemin Sapakoglu (

Using CRISPR gene editing to affect epigenetics?

Here’s another editing function that we humans now have over our own genes. Cool advances by scientists to advance the frontier.

Epigenetics is the study of the chemical changes that happen to DNA throughout a lifetime, which in turn affect the expression of genes. These changes can occur as a result of a person’s behavior (such as through diet or smoking) or environmental exposures (such as to toxins or ultraviolet rays). Epigenetics is a kind of molecular memory that reflects the experiences that we’ve encountered over many years. It’s the reason why, among identical twins who share the same DNA code, one may develop cancer while the other remains healthy.

Emily Mullen,

The ongoing remote vs return-to-work debate (nytimes)

What is your organization doing? We (as of early June) seeing a “test positivity rate” as high as 28% for COVID in our region (it was as low as 3% a couple months ago just before Omicron variant), but a low hospitalization rate.

The informatics team (my Large PIGs) are still exclusively meeting remotely.

We are actually writing this COVID pandemic textbook paragraph-by-paragraph together, my friends. There is no “playbook” for how to behave now.