Protein Links Gut Microbes, Biological Clocks, and Weight Gain

Fat calls with and without NFIL3

Caption: Lipids (red) inside mouse intestinal cells with and without NFIL3.
Credit: Lora V. Hooper, University of Texas Southwestern Medical Center, Dallas

The American epidemic of obesity is a major public health concern, and keeping off the extra pounds is a concern for many of us. Yet it can also be a real challenge for people who may eat normally but get their days and nights mixed up, including night-shift workers and those who regularly travel overseas. Why is that?

The most obvious reason is the odd hours throw a person’s 24-hour biological clock—and metabolism—out of sync. But an NIH-funded team of researchers has new evidence in mice to suggest the answer could go deeper to include the trillions of microbes that live in our guts—and, more specifically, the way they “talk” to intestinal cells. Their studies suggest that what gut microbes “say” influences the activity of a key clock-driven protein called NFIL3, which can set intestinal cells up to absorb and store more fat from the diet while operating at hours that might run counter to our fixed biological clocks.

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Creative Minds: New Piece in the Crohn’s Disease Puzzle?

Gwendalyn Randolph

Gwendalyn Randolph

Back in the early 1930s, Burrill Crohn, a gastroenterologist in New York, decided to examine intestinal tissue biopsies from some of his patients who were suffering from severe bowel problems. It turns out that 14 showed signs of severe inflammation and structural damage in the lower part of the small intestine. As Crohn later wrote a medical colleague, “I have discovered, I believe, a new intestinal disease …” [1]

More than eight decades later, the precise cause of this disorder, which is now called Crohn’s disease, remains a mystery. Researchers have uncovered numerous genes, microbes, immunologic abnormalities, and other factors that likely contribute to the condition, estimated to affect hundreds of thousands of Americans and many more worldwide [2]. But none of these discoveries alone appears sufficient to trigger the uncontrolled inflammation and pathology of Crohn’s disease.

Other critical pieces of the Crohn’s puzzle remain to be found, and Gwendalyn Randolph thinks she might have her eyes on one of them. Randolph, an immunologist at Washington University, St. Louis, suspects that Crohn’s disease and other related conditions, collectively called inflammatory bowel disease (IBD), stems from changes in vessels that carry nutrients, immune cells, and possibly microbial components away from the intestinal wall. To pursue this promising lead, Rudolph has received a 2015 NIH Director’s Pioneer Award.

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Nanojuice: Getting a Real-Time View of GI Motility

Nanojuice as it passes through the gut of the mouse

Caption: A real-time image of nanojuice as it passes through a mouse’s small intestine. A laser causes particles in the nanojuice to vibrate, creating vibrations picked up by an ultrasound detector that are then used to generate a black-and-white image. Rainbow colors are added afterward to reflect the depth of the intestine within the mouse’s abdomen: blue is closest to the surface and red is deepest.
Credit: Jonathan Lovell, University at Buffalo

For those of you who love to try new juices, you’ve probably checked out acai, goji berry, and maybe even cold-pressed kale. But have you heard of nanojuice? While it’s not a new kind of health food, this scientific invention may someday help to improve human health through its power to visualize the action of the gastrointestinal (GI) tract in real-time.

It’s true that doctors already have many imaging tools at their disposal to examine various parts of the GI tract—all the way from throat to colon. These include invasive techniques, such as upper endoscopy and colonoscopy; as well as non-invasive approaches, such as ultrasound, magnetic resonance imaging, and X-ray procedures that may or may not involve swallowing a chalky liquid containing barium or other materials that are radio-opaque. There’s even a wireless capsule that can shoot videos as it travels all the way through the GI tract. None of these techniques, however, provides a non-invasive, real-time view of the wave-like muscle contractions that move food through the gut—a crucial process called peristalsis.

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