Data Dump: 11,000 Donate Stool Samples to Gut Microbiome Project

By Greg Watry

The American Gut Project has just produced the largest study yet of microbial diversity in human poop. With “contributions” from more than 11,000 citizen scientists, the team led by researchers at UC San Diego has compiled a public reference database on the human gut microbiome, published May 15 in the journal mSystems. The study is a step forward in understanding how factors such as diet, antibiotics and mental health relate to the microbes living in the human gut.

Biology Researchers Make Cell Metabolism “Best of 2017”           

Two different teams of researchers from the College of Biological Sciences are represented in the “Best of 2017” issue of the prominent journal Cell Metabolism. Their papers, on insulin-producing beta cells and on the effects of a low-carb diet on longevity in mice, are among just five research articles chosen to appear in the special issue along with two clinical reports and four review articles.

Pancreatic islet

Pancreatic islets make insulin in response to blood glucose. Mark Huising/UC Davis

Breast Milk Nourishes Probiotics for Healthy Babies

Earlier this week NPR broadcast a story about growing interest in giving probiotics – beneficial bacteria that live in the gut – to babies. Mark Underwood, professor of pediatrics, explained that in UC Davis neonatal care unit, all premature babies under a certain weight are given a probiotic to prevent necrotizing enterocolitis (NEC),a potentially deadly inflammation of the intestine. It’s becoming a common practice in premature infants, and Underwood and colleagues have carried out a clinical trial in full-term infants. They showed that newborns fed a supplement containing Bifidobacterium bacteria (thought to be beneficial) had more “good bacteria” and fewer “bad bacteria” in their guts two months later.

Chemical Messengers, Calcium and Neutrophils

Neutrophils are the most abundant type of white blood cell. They play a vital role in defending us from infections, by engulfing and destroying bacteria and viruses or cancerous cells. A new study by UC Davis engineering student Emmet Francis, working with Professor Volkmar Heinrich in the Department of Biomedical Engineering, adds to our knowledge of how neutrophils are drawn towards infection sites and how they can attack their targets.

First, Francis and Heinrich looked at how isolated neutrophils respond to chemical messengers called anaphylatoxins. These molecules guide immune cells to their targets but can cause severe illness in excessive amounts.

Receptors Key to Strong Memories

When we create a memory, a pattern of connections forms between neurons in the brain. New work from UC Davis shows how these connections can be strengthened or weakened at a molecular level. The study is published Feb. 27 in the journal Cell Reports.

AMPA-type glutamate receptors are responsible for fast synaptic transmission in the brain. (Wikipedia image)

Neurons branch into many small fibers, called dendrites, that connect to other neurons across tiny gaps called synapses. Messages travel across synapses as chemical signals: A molecule, or neurotransmitter, is released on one side of the synapse and connects with a receptor on the other side, a bit like tossing a ball and a fielder catching it in a mitt.

Looking for New Pollutants in the Ashes of Sonoma

In this month’s episode of Three Minute Egghead, UC Davis graduate student Gabrielle Black talks about collecting samples of ash from neighborhoods burned by last year’s northern California wildfires. The intense heat on a wide range of household items from insulation to electronics may have created new chemical pollutants. Thanks to modern analytic technology, Black plans to search for both known pollutants and new compounds, and compare them to the ashes of burned wild land.

Listen to the podcast here.

More information

Testing Sonoma Ash and Air for Fire-Formed Pollutants

WHAT-NOW Survey (UC Davis Environmental Health Sciences Center)

Multi-state E. coli Outbreak Linked to Romaine Lettuce

 By Heidi Meier and Ann Filmer

The U.S. Centers for Disease Control and Prevention (CDC) released a media statement in late December profiling a multi-state outbreak of food poisoning caused by the bacteria E. coli O157:H7 with 17 reported illnesses. Romaine and leafy greens are among the suspected sources of contamination, but no definitive source or location has been confirmed at this time, according to the CDC.

A lettuce field in California (photo by Trevor Suslow, UC Davis)

Prozac Use in Children: Studying Side Effects of Fluoxetine in a Monkey Model

Fluoxetine (Prozac) is widely prescribed for depression, anxiety and other behavioral and psychiatric disorders and is approved for use in children. But little is known about the side effects of fluoxetine, part of a class of drugs called Selective Serotonin Reuptake Inhibitors (SSRIs) in pre-teen children.

Young monkeys

Rhesus macacque monkeys have a relatively long period of development before they reach sexual maturity. That makes them a useful model to study the possible side effects of Fluoxetine (Prozac) in children. (Photo by K. West, CNPRC)

Mice Help Find Gene for Bad Breath

An international team of researchers has identified a cause for chronic bad breath (halitosis), with the help of gene knockout mice from the UC Davis Mouse Biology Program. The results are published Dec. 18 in the journal Nature Genetics.

Prof. Kent Lloyd, director of the UC Davis Mouse Biology Program, in the lab. Gene-edited and “knockout” mice have become a vital tool in biomedical research. (Karin Higgins/UC Davis photo)

While most cases of bad breath are linked bacteria growing in the mouth, up to 3 percent of the population have chronic halitosis of no obvious cause.

Targeted Action Group Marks 20 Years in Fight Against HIV/AIDS

By Larkin Callaghan

A recent meeting at UC Davis marked 20 years of effort towards a vaccine for HIV/AIDS. When the Targeted Action Group on Vaccines was founded twenty years ago, the HIV epidemic was in a very different place – politically, socially, scientifically, and emotionally. Known as TAG, this program has brought together researchers, students, advocates, and industry, who are invested in and working towards an HIV vaccine.