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Tag: microbiome

When the gut’s internal ecosystem goes awry, could an ancient if gross-sounding treatment make it right?

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Lemur researchers make a case for fecal transplants to reduce the side effects of antibiotics. Photo by David Haring, Duke Lemur Center.

Dr. Cathy Williams knew something wasn’t right. The veterinarian had felt off for weeks after her 2014 trip to Madagascar.

At first she just felt bloated and uncomfortable and wasn’t interested in eating much. But eventually she developed a fever and chills that sent her to the emergency room.

When tested, doctors found that what she had wasn’t just a stomach bug. She was suffering from an infection of Clostridium difficile, a germ that causes severe diarrhea and abdominal pain and can quickly become life-threatening if not treated promptly.

“It was horrible,” Williams said.

The condition is often triggered when antibiotics disrupt the normal balance of bacteria that inhabit the gut, allowing “bad” bacteria such as C. difficile to multiply unchecked and wreak havoc on the intestines.

To get her infection under control, Williams asked her doctors if they could try an approach she and other veterinarians had used for decades to treat lemurs with digestive problems at the Duke Lemur Center. The procedure, known as a fecal microbiota transplant, involves taking stool from a healthy donor and administering it to the patient to add back “good” microbes and reset the gut.

At the time it was considered too experimental for clinical use in human cases like Williams’. She was prescribed the standard treatment and was sent home from the hospital, though she wouldn’t feel well enough to go back to work for another month. But now new research in lemurs is confirming what Williams and others long suspected: that this ancient if gross-sounding treatment can help an off-kilter gut microbiome get back to normal.

In a recent study in the journal Animal Microbiome, a research team led by Duke professor Christine Drea, former PhD student Sally Bornbusch and colleagues looked at the gut microbiomes of 11 healthy ring-tailed lemurs over a four-month period after receiving a seven-day course of the broad-spectrum antibiotic amoxicillin.

The lemurs were split into two experimental groups. One was a wait-and-see group, with continued follow-up but no further treatment after the antibiotics. The other group was given a slurry of their own feces, collected prior to antibiotic treatment and then mixed with saline and fed back to the same animal after their course of antibiotics was over.

“It sounds crazy,” Williams said. But she has used a similar procedure since the 1990s to treat illnesses in Coquerel’s sifaka lemurs, whose infants are known to eat their mother’s poop during weaning — presumably to get the microbes they’ll need to transition to solid food.

A baby Coquerel’s sifaka tries some of her first solid foods. Photo by David Haring.

Drea, Bornbusch and team used genetic sequencing techniques to track changes in the lemurs’ gut microbiome before, during and after treatment.

As expected, even a single course of antibiotics caused the numbers of microbes in their guts to plunge compared with controls, briefly wiping out species diversity in both experimental groups before returning to baseline.

“Antibiotics had dramatic effects, even in healthy animals,” Drea said.

But in terms of which types of bacteria bounced back and when, the patterns of recovery in the two groups were different. Lemurs that received the “poop soup” treatment started to stabilize and return to their pre-antibiotic microbiome within about two weeks. In contrast, the bacterial composition in the wait-and-see group continued to fluctuate, and still hadn’t quite returned to normal even after four months of observation.

This kind of therapy isn’t new. Reports of using fecal transplants to treat people suffering from food poisoning or diarrhea date back as far as fourth century China. The evidence for its effectiveness in captive settings has Bornbusch advocating for freezing stool at Smithsonian’s National Zoo, where she is now a postdoctoral fellow.

“If we can bank feces from animals when they’re healthy, that can be a huge benefit down the road,” Bornbusch said. “It can help the animals get better, faster.”

And now if any of her lemur patients were to get sick with C. difficile like she did, Williams said, “I would absolutely go with a fecal microbiota transplant.”

“People are put off by it,” Drea said, “But the disgust for this approach might actually have been holding up a fairly cheap and useful cure.”

Ring-tailed lemurs at the Duke Lemur Center in North Carolina. Photo by David Haring, Duke Lemur Center

This research was supported by the National Science Foundation (BCS 1749465), the Duke Lemur Center Director’s Fund, and the Duke Microbiome Center.

CITATION: “Antibiotics and Fecal Transfaunation Differentially Affect Microbiota Recovery, Associations, and Antibiotic Resistance in Lemur Guts,” Sally L. Bornbusch, Rachel L. Harris, Nicholas M. Grebe, Kimberly Roche, Kristin Dimac-Stohl, Christine M. Drea. Animal Microbiome, Oct. 1, 2021. DOI: 10.1186/s42523-021-00126-z.

By Robin Ann Smith

The Duke Dentist and her Research: Saving Children’s Teeth, One Tooth at a Time

Walking into our small meeting room with green scrubs and a white lab coat on, our special guest set her bag down in the front and stated “I fixed 60 teeth today and haven’t sat down since this morning.” To us, it sounds like a nightmare, but to Dr. Martha Ann Keels, working in her clinic and conducting dental research is a dream come true. 

Born and raised in North Carolina, Dr. Keels has kept her roots as she studied here at Duke. As a Duke undergrad, she received her bachelor’s degree in Chemistry and a minor in Art History, later choosing to become a pediatric dentist at UNC. It wasn’t long until she returned back to Duke to volunteer at Duke’s Children Hospital, and in 1986, she became the first pediatric dentist to get privileges to practice at Duke. She continues to run her own clinical practice alongside Duke Health System to this day, working for over 30 years!

“I get to feel the satisfaction that something I used my hands for helped alleviate pain in children,” Keels said. “I also get to watch them grow as they come in over the years. It feels super rewarding.”

With her passion and dedication, not only does she help those that enter her office, but she also conducts research on the side, wanting to help dentists all over.

Dr. Keels currently has her hands dirty with a major research project she has been working on for the past nine years. According to the National Institute of Dental and Craniofacial Research, 42% of children between the ages of two to eleven years old have at least one cavity in their primary teeth, and 23% of those children are untreated. With how high these numbers are, she and a group of other researchers are trying to develop tools that allow pediatricians and pediatric dentists to be able to identify high risk factors of cavities in children and care for them before they do occur; tools like questionnaires, surveys, and ‘top 5 predictors…’.

Table of percentages of children with cavities corresponding to age, sex, race, and poverty (National Institute of Dental and Craniofacial Research)

By observing a group of 1,300 children ever since birth, they have been analyzing all aspects of each child: collecting saliva, looking at biofilm (more commonly known as plaque), physical deformities in their teeth, and even social factors like parents’ dental experience. 

Despite the children still being fairly young, Dr. Keels reveals that a surprising amount of information has been found. “No one has ever looked at tight teeth– when your teeth are closely spaced– but we are seeing that it puts a child at high risk of cavities,” Keels said. She also adds that they have also begun to identify which types of bacteria help with reducing chances of getting a cavity, as well as bacteria that bring a high risk of creating a cavity.

 This also goes hand in hand with the microbiomes in our mouths. Dentists first believed that the microbiomes of the child’s caregiver affected the child’s microbiome, in the sense that their microbiomes would be similar from the beginning. Dr. Keels’s study says otherwise. It’s being shown that a child’s microbiome starts off as its own, unique microbiome, and it is over time that it begins to become similar to their caregiver’s microbiome.

With the vast amount of information already collected, Dr. Keels and her team continue to persevere, now wanting to push the study for another five more years. They want to start working with adolescents, wanting to also analyze mental states and how that might affect their dental hygiene and risks of cavities. 

Maybe in the near future, as you speak to your dentist at your next appointment, and they bring up a list of risk factors for cavities, who knows? That list or table could be coming from the one and only Dr. Martha Ann Keels.

Post by Camila Cordero, Class of 2025

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