Blog editor shift

This is partly a temporary good-bye and partly an introduction to Wayne Drash. Wayne will be filling in for Quinn Eastman, who has been the main editor of Lab Land. Wayne is a capable writer. He spent 24 years at CNN, most recently within its health unit. He won an Emmy with Sanjay Gupta for a documentary about the separation surgery of two boys conjoined at the head. Wayne plans to continue writing about biomedical research at Read more

Some types of intestinal bacteria protect the liver

Certain types of intestinal bacteria can help protect the liver from injuries such as alcohol or acetaminophen overdose. Emory research establishes an important Read more

Can blood from coronavirus survivors save the lives of others?

Donated blood from COVID-19 survivors could be an effective treatment in helping others fight the illness – and should be tested more broadly to see if it can “change the course of this pandemic,” two Emory pathologists say. The idea of using a component of survivors’ donated blood, or “convalescent plasma,” is that antibodies from patients who have recovered can be used in other people to help them defend against coronavirus. Emory pathologists John Roback, MD, Read more

hepatology

Some types of intestinal bacteria protect the liver

Certain types of intestinal bacteria can help protect the liver from injuries such as alcohol or acetaminophen overdose, according to Emory scientists led by pathologist Andrew Neish and physiologist Dean Jones.

The research was published on March 25 in Cell Metabolism.

“The composition of the microbiota, because of natural variation, dysbiosis, or supplementation with probiotics, can strongly affect how the liver processes both toxins and pharmacological agents, and thus have clinical consequences on how individuals respond to such exogenous chemicals,” Neish says.

While pretreatment with bacteria is needed for the observed effect in acute liver injury, probiotics or small molecule substitutes may be useful in the treatment of chronic liver diseases, the authors suggest.

In mice, oral administration of Lactobacillus rhamnosus or LGG could protect against liver damage brought on by alcohol or acetaminophen. Several labs had already observed a beneficial effect from LGG against liver injury, but the Emory research establishes an additional mechanism.

The protection comes from a small molecule metabolite produced by the bacteria called 5-MIAA (5-methoxyindoleacetic acid), activating the mammalian transcription factor Nrf2. Other types of bacteria did not produce 5-MIAA or activate Nrf2. While LGG is also known to improve the barrier function of the gut and dampen inflammation, liver-specific depletion of Nrf2 prevented LGG’s beneficial effects, suggesting that this is the primary mechanism of action. Read more

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The unsweetened option

Pediatric hepatologist Miriam Vos is starting a new study testing the effects of a low-sugar diet in children with NAFLD (non-alcoholic fatty liver disease). The study is supported by the Nutrition Science Initiative and conducted in a partnership with UCSD/Rady Children’s Hospital, San Diego. See below for more on NUSI.

While there are no medications approved for NAFLD – a healthy diet and exercise are the standard of care – plenty of drugs are under development, as a recent article from Mitch Leslie in Science illustrates. As a reality check and benchmark, the NUSI study will address whether the low-tech intervention of altering diet can be effective.

Lab Land has delved into NAFLD and its increasing prevalence in previous posts. Plenty of correlational data shows that sugar intake is linked to NAFLD (a recent paper from the Framingham Heart Study), but Vos points out that there are no studies showing that reducing sugar is sufficient to drive improvement in the disease.

Diet is a challenge to examine in humans rigorously. In observational studies, investigators are always bumping up against the limits of memory and accurate reporting. In an interventional study with adults, it’s possible to provide them a completely defined menu for a short time in a closed environment, but that’s less practical for longer periods or with children.

The press release announcing the NUSI study says: half of the families will eat and drink what they normally do while the rest will be put on sugar-free meals and snacks, all of which will be provided for the participants and their families for eight weeks.

Miriam Vos, MD

I was curious about how this would work, especially for boys aged 11 to 16 (the participants in her study), so I asked Vos more about it for Lab Land.

“We try to provide them a diet that is otherwise similar to what the family is used to,” she says. “For example, if they’re accustomed to home-cooked meals, our team of nutritionists will work with them to find different recipes.” Read more

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