Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Global Health (Page 1 of 6)

Long-Term Study Sees the Big Picture of Cannabis Use

Seventy percent of the United States population will have tried marijuana by the age of 30. As the debate on the legalization of the most commonly used illicit drug continues throughout the country, researchers like William Copeland, PhD, and Sherika Hill, PhD, from the Duke Department of Psychiatry and Behavioral Sciences are interested in patterns of marijuana use and abuse in the first 30 years of life.

Marijuana is the most commonly used illicit drug.

The Great Smoky Mountain Study set out in 1992 to observe which factors contributed to emotional and behavioral problems in children growing up in western North Carolina. The study included over 1,000 children, including nearly 400 living on the Cherokee reservation. In addition to its intended purpose, the data collected has proven invaluable to understanding how kids and young adults are forming their relationship with cannabis.

The Great Smoky Mountains Study collected extensive medical and behavioral research from 11 counties in western North Carolina.

Using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and patterns of daily use of the drug, Copeland and Hill found some unsurprising patterns: peak use of the drug is during young adulthood (ages 19-21), when kids are moving out of the home to college or to live alone.

But while most people adjust to this autonomy and eventually stop their usage of the drug, a small percentage of users (7%) keep using into their adulthood. Hill and Copeland have observed specific trends that apply both to this chronic user group as well as an even smaller percentage of users (4%) who begin using at a later stage in life than most people, termed the delayed-onset problematic users.

Looking at the demographics of the various types of users, Hill and Copeland found that males are twice as likely to engage in marijuana use to any extent than females. Of those who do use the drug, African Americans are five times more likely to be delayed-onset users, while Native Americans are twice as likely to decrease their use before it becomes problematic.

For both persistent and delayed-onset problematic users, family instability during childhood was 2-4 times more likely than in non-problematic users.

Persistent users were more likely to have endured anxiety throughout childhood, and delayed-onset users were more likely to have experienced some kind of trauma or maltreatment in childhood than other types of users.

The identification of these trends could prove a vital tool in predicting and preventing marijuana abuse, and the importance of this understanding is evidenced in the data collected that elucidates outcomes of marijuana use.

Looking at various measures of social and personal success, the team identified patterns with a resounding trend: recent use of marijuana is indicative of poorer outcomes. Physical health and financial or educational outcomes displayed the worst outcomes in chronic and delayed-onset users. Finally, criminal behavior was increased in every group that used; in other words, regardless of the extent of use, every group with use of marijuana fared worse than the group that abstained.

The results of Copeland and Hill’s work has important implications as legislators debate the legalization of marijuana. While understanding these patterns of use and their outcomes can provide useful insight on the current patterns of usage, decriminalization will certainly change the way marijuana is manufactured and consumed, and will thus also affect these patterns.
By Sarah Haurin

Opportunities at the Intersection of Technology and Healthcare

What’d you do this Halloween?

I attended a talk on the intersection of technology and healthcare by Dr. Erich Huang, who is an assistant professor of Biostatistics & Bioinformatics and Assistant Dean for Biomedical Informatics. He’s also the new co-director of Duke Forge, a health data science research group.

This was not a conventional Halloween activity by any means, but I felt lucky to be exposed to this impactful research surrounded by views of the Duke forest in fall in Penn Pavilion at IBM-Duke Day.

Erich Huang

Erich Huang, M.D., PhD. is the co-director of Duke Forge, our new health data effort.

Dr. Huang began his talk with a statistic: only six out of 53 landmark cancer biology research papers are reproducible. This fact was shocking (and maybe a little bit scary?), considering  that these papers serve as the foundation for saving cancer patients’ lives. Dr. Huang said that it’s time to raise standards for cancer research.

What is his proposed solution? Using data provenance, which is essentially a historical record of data and its origins, when dealing with important biomedical data.

He mentioned Duke Data Service (DukeDS), which is an information technology service that features data provenance for scientific workflows. With DukeDS, researchers are able to share data with approved team members across campus or across the world.

Next, Dr. Huang demonstrated the power of data science in healthcare by describing an example patient. Mr. Smith is 63 years old with a history of heart attacks and diabetes. He has been having trouble sleeping and his feet have been red and puffy. Mr. Smith meets the criteria for heart failure and appropriate interventions, such as a heart pump and blood thinners.

A problem that many patients at risk of heart failure face is forgetting to take their blood thinners. Using Pillsy, a company that makes smart pill bottles with automatic tracking, we could record Mr. Smith’s medication taking and record this information on the blockchain, or by storing blocks of information that are linked together so that each block points to an older version of that information. This type of technology might allow for the recalculation of dosage so that Mr. Smith could take the appropriate amount after a missed dose of a blood thinner.

These uses of data science, and specifically blockchain and data provenance, show great opportunity at the intersection of technology and healthcare. Having access to secure and traceable data can lead to research being more reproducible and therefore reliable.

At the end of his presentation, Dr. Huang suggested as much collaboration in research between IBM and Duke as possible, especially in his field. Seeing that the Research Triangle Park location of IBM is the largest IBM development site in the world and is conveniently located to one of the best research universities in the nation, his suggestion makes complete sense.

By Nina Cervantes        

Global Health Research from Zika to Economics

Brazil, Kenya and China: this week, the sixth annual Global Health Research Showcase proved that Global Health majors truly represent global interests.

This past summer, Duke PhD student Tulika Singh explored complementary diagnosis techniques for Zika virus pregnant women in Vitoria, Brazil. Zika is difficult to diagnose “because the PCR-based test can only tell if you’ve had Zika virus within about ten days of the infection,” Singh said. “That’s a big problem for enrolling pregnant women into our study on Zika transmission and maternal immunity.”

To combat this issue, Singh and her thesis advisor Sallie Permar trained collaborators to use the whole virion ELISA (WVE) laboratory technique which may reveal if an individual has been exposed to Zika. ELISA detects Zika through testing for the antibodies that most likely would have been produced during a Zika infection. Singh’s work allows the research team to better assess whether women have been exposed to Zika virus during pregnancy, and will ultimately guide Zika vaccine design. 

Master of Science in Global Health candidate Carissa Novak examined why some HPV positive women in Western Kenya are not seeking preventive measures against cervical cancer. All the women diagnosed with HPV were referred to the Country Hospital but only “33 to 42 percent actually sought treatment” leading to Novak’s main research question, “Why did so few women seek treatment?” To answer this question, she sent out quantitative questionnaires to 100 women and then followed up by interviewing 20 of them. She surveyed and interviewed both women who had and had not sought treatment. Her results showed that transportation and cost hinder treatment acquirement and that the women who did seek treatment were often directed to by a health worker or actively trying to prevent cervical cancer. Novak believes that increasing women’s trust and understanding of the health care system will assist in improving the percentage who seek treatment.

In Kunshan, China, Brian Grasso evaluated the development of Kunshan’s health system in relation to its economic development. “Kunshan is now China’s richest county-level city and it used to be a small farm town…My main take away was that economic growth has strengthened Kunshan’s health systems while also creating new health challenges,” Grasso said. What are some of these new health challenges? Some of them include air pollution, increased stress in manufacturing jobs and more car accidents. Grasso determines that other developing health systems should learn from Kunshan that without proper regulations poor health can result in the midst of progress.

Post by Lydia Goff

Smoking Weed: the Good, Bad and Ugly

DURHAM, N.C. — Research suggests that the earlier someone is exposed to weed, the worse it is for them.

Very early on in our life, we develop basic motor and sensory functions. In adolescence, our teenage years, we start developing more complex functions — cognitive, social and emotional functions. These developments differ based on one’s experience growing up — their family, their school, their relationships — and are fundamental to our growth as healthy human beings.

This process has shown to be impaired when marijuana is introduced, according to Dr. Diana Dow-Edwards of SUNY Downstate Medical Center.

Sure, a lot of people may think marijuana isn’t so bad…but think again. At an Oct. 11 seminar at Duke’s Center on Addiction & Behavior Change, Dow-Edwards enlightened those who attended with correlations between smoking the reefer and things like IQ, psychosis and memory.

(https://media.makeameme.org/created/Littering-and-SMOKIN.jpg)

Dow-Edwards is currently a professor of physiology and pharmacology and clearly knows her stuff. She was throwing complicated graphs and large studies at us, all backing up her primary claim: the “dose-response relationship.” Basically the more you smoke (“dose”), the more of a biological effect it will have on you (“response”).

Looking at pot users after adolescence showed that occasionally smoking did not cause a big change in IQ, and frequently smoking affected IQ a little. However, looking at adults who smoked during adolescence correlated to a huge drop of around 7 IQ points for infrequent smokers and 10 points for frequent smokers. Here we see how both age and frequency play a role in weed’s effect on cognition. So if you are going to make the choice to light up, maybe wait until your executive functions mature around 24 years old.

Smoking weed earlier in life also showed a strong correlation with an earlier onset of psychosis, a very serious mental disorder in which you start to lose sense of reality. Definitely not good. I’m not trynna get diagnosed with psychosis any time soon!

One perhaps encouraging study for you smokers out there was that marijuana really had no effect on long-term memory. Non-smokers were better at verbal learning than heavy smokers…until after a three week abstinence break, where the heavy smokers’ memories recovered to match the control groups’. So while smoking weed when you have a test coming up maybe isn’t the best idea, there’s not necessarily a need to fear in the long run.

(Hanson et al, 2010)

A similar study showed that signs of depression and anxiety also normalized after 28 days of not smoking. Don’t get too hyped though, because even after the abstinence period, there was still “persistent impulsivity and reduced reward responses,” as well as a drop in attention accuracy.

A common belief about weed is that it is not addicting, but it actually is. What happens is that after repetitively smoking, feeling high no longer equates to feeling better than normal, but rather being sober equates to feeling worse than normal. This can lead to irritability, reduced appetite, and sleeplessness. Up to 1/2 of teens who smoke pot daily become dependent, and in broader terms, 9 percent of people who just experiment become dependent.

In summary, “marijuana interferes with normal brain development and maturation.” While it’s not going to kill you, it does effect your cognitive functions. Plus, you are at a higher risk for mental disorders like psychosis and future dependence. So choose wisely, my friends.

By Will Sheehan

Will Sheehan

Rare Cancers and Precision Medicine in Southeast Asia

Data collected through genomics research is revolutionizing the way we treat cancer. But a large population of cancer patients are being denied the benefits of this research.

Patrick Tan MD, PhD is a professor of cancer and stem cell biology at Duke-NUS Medical School in Singapore.

In 2016, less than one percent of all the existing genomic data came from the 60% of the world population living outside of the US, Europe, and Japan. Furthermore, 70% of patients who die from cancer this year will come from Asia, Africa and Central and South America.

Patrick Tan, M.D., Ph.D., and the Duke-National University of Singapore (Duke-NUS) Medical School are key players in an effort to rectify this discrepancy, specifically as it exists in Southeast Asia.

In his talk, sponsored by the Duke Center for Applied Genomics and Precision Medicine, Tan focused specifically on his work in northeast Thailand with cholangiocarcinoma (CCA), or bile duct cancer.

Liver fluke

Liver flukes like this are parasites of fish that migrate to human hosts who eat the fish raw, leading to a form of bile duct cancer.

While CCA is rare in most of the world, it appears at 100 times the global rate in the region of Thailand where Tan and his colleagues work. Additionally, CCA in this region is of a separate and distinct nature.

CCA in this region is linked with a parasitic infection of the bile ducts called a liver fluke.  Residents of this area in Thailand have a diet consisting largely of raw fish, which can be infected by the liver fluke and transmitted to the person who eats the fish.

Because of the poverty in this area, encouraging people to avoid eating raw fish has proven ineffective. Furthermore, healthcare is not readily available, so by the time most patients are diagnosed, the disease has progressed into its later and deadly stage.

The life cycle of liver flukes. (Graphic U.S. Centers for Disease Control)

Tan’s genomic research has discovered certain factors at the gene level that make liver-fluke positive CCA different from other CCA. Thus genomic data specific to this population is vital to improve the outcomes of patients with CCA.

Duke-NUS Precision Medicine (PRISM) has partnered up with the National Heart Research Institute Singapore (NHRIS) in SPECTRA, a program designed to create a database of genomic data from the healthy Asian population. SPECTRA is sequencing the genomes of 5,000 healthy Asians in order to create a baseline to which they can compare the genomes of unhealthy individuals.

These and other programs are part of a larger effort to make precision medicine, or healthcare tailored to an individual based on factors like family history and genomic markers, accessible throughout southeast Asia.

By Sarah Haurin

 

New Blogger Ameya Sanyal: Freshman Inspired by 'Kitchen Experiments'

Hello! My name is Ameya Sanyal and I’m an incoming Trinity Freshman. While I’ve lived in Madison, WI for the past 12 years, I was born in Roswell, NM. I use she/her/hers pronouns and live with my parents, Amit and Paulomi, my younger sister, Anika, and my goldendoodle, Zain.

When I was little, my dad used to host “Science Sundays.” From vinegar volcanoes to Dr. Seuss’s “oobleck,” I was captivated. These hands-on-activities — which I fondly called “kitchen experiments” — were only the beginning of my interest in science.

A man and three woman smiling.

My family and I experimenting with our camera.

Throughout elementary and middle school, I eagerly awaited science class. I loved to learn about real-life examples; projectile motion came alive with classroom rocket demonstrations and nitrogen fixation took on meaning with a field trip to a teacher’s farm.

In high school, I became frustrated as the science classes seemed to only cover core concepts. Although I recognized the importance of building a strong foundation in biology, chemistry and physics, I wanted to know more about the applications of basic scientific principles.

At this juncture, my interest in social studies began to grow. I joined various activist and leadership groups and explored the link between people and social change. In electives such as Government & Politics and Psychology, I could immediately see how skills such as knowing my rights and understanding my behavior in a nature-nurture context were valuable.

In the future, I’d like to become an activist-doctor and interact directly with patients while uniting with other physicians to pursue social change. Consequently, I hope to pursue an interdisciplinary major combining political science and medicine.

Three women in traditional Indian clothing.

My family and I celebrating Diwali, the festival of lights.

At Duke, I’d like to explore how communication across disciplines can result in increased health and wellness. As an aspiring Global Health and Biology double major, I am excited to think critically about the driving forces between social inequities and brainstorm how new scientific discoveries can be utilized in finding a solution to public health crises.

I am looking forward to writing about the impact of social determinants on health and wellness and emerging healthcare research and technologies. Apart from being a member of the research team, I hope to get involved with GlobeMed and the Hindu Students Association. If you see me volunteering in the Durham community or at Hindu celebrations, please say hi!

Post by Ameya Sanyal

Disaster Plans and the Mentally Ill

Houston, Miami, San Juan — Category 5 hurricanes, the most destructive storm systems, have made a record-breaking 6 landfalls this year. This represents a quarter of the total category 5 hurricane landfalls that the Atlantic has seen since 1851.

With statistics like these, disaster relief plans are becoming more important than ever. But do these plans do enough for marginalized groups, specifically the mentally ill?

Allan K. Chrisman, M.D., believes more can be done. As a career psychiatrist who has been deployed by the Red Cross in the aftermath of storms like Katrina and Matthew, Chrisman has seen and experienced the importance of including the mentally ill in disaster relief plans.

At his talk to physicians in Duke’s Hospital on Sept. 28, Chrisman, an emeritus  professor at Duke, highlighted specific aspects of disaster relief that are not doing enough for the one in four U.S. adults suffering from mental illness each year.

According to Chrisman, this part of the population is often less prepared for impending storms. When storms do hit, existing symptoms can be exacerbated, or new symptoms can appear.  Disruption of routine, inconsistency of taking medication and the overall stress that comes with emergencies all contribute to this exacerbation of mental illness.

While the Red Cross has an “everyone is welcome,” policy for their shelters, not being able to identify the needs of the mentally ill seeking sanctuary limits the organization’s ability to help. As a deployed psychiatrist, Chrisman worked with displaced mentally ill people to ensure they continued to get the care they needed even during the stress of a weather emergency.

One tool used by Chrisman and his colleagues to help these groups is the C-MIST framework. This system categorizes “functional-based needs” based on communication, maintaining health, independence, service and support, and transportation. It seeks to ensure not only that individuals are being given an option for a safe space in the wake of emergencies, but also that these spaces offer them the specific services they require.

Chrisman emphasized the need “to provide round-the-clock access to qualified mental health resources.”

He said that by following these inclusive protocols, disaster relief programs can do even more to protect the most vulnerable parts of the population.

By Sarah Haurin

New Blogger Nirja Trivedi: Neuroscience Junior with Infinite Curiosity

My name is Nirja Trivedi and I’m a junior from Seattle interested in the intersections between health, technology and business. At Duke, I’m the co-president of P.A.S.H., a writer for the Standard and a member of B.O.W.

Nirja Trivedi blocking the sun with her hand

Nirja Trivedi

During high school, I considered liberal arts and scientific research to be separate disciplines: if technology was my strength then philosophy must be my weakness. In my two years at Duke, I have experienced the duality of these fields through participating in the Global Health Focus Program, developing my own research projects, working with professors and now applying to write for Duke Research. Science truly is for everyone; no matter your field, interests or opinion. Research and discovery are conduits for every mind. Research isn’t just the forefront of innovation, it paves the way for the future.

Growing up with a passion for service and influenced by my family in the medical field, the research I leaned towards combined aspects of community and health. My senior project in high school examined traumatic brain injury (TBI) in youth sports, which provided the research-based approach for designing my own Concussion Prevention Program. After my first semester, I wanted to discover what kinds of research I wanted to fully integrate myself in. I began research with the Duke Institute of Brain Sciences and spent my summer volunteering for the Richman Lab, which examines the effects of psychosocial factors like discrimination, social hierarchies and power. After I declared my Neuroscience major, I spent the year assisting in studies at the Autism Clinic, sparking my interest in technology.

Nirja Trivedi on a mountain top

Nirja Trivedi on a mountain top.

Now going into my third year, my interests in scientific discovery have only grown. From insight into the human psyche and social economic behavior to medical advances, I love the complexity of the human mind and how it fuels innovation.

My unrestricted interests guided me to the Innovation & Entrepreneurship Certificate as well as this writing position, both which foster an environment of curiosity and inspiration. Through writing, I hope to connect with faculty, discover areas of research I never knew existed, widen my breadth of scientific knowledge, and connect students to research opportunities. The threshold of knowledge is where you draw the line – why not make it infinite?

Post by Nirja Trivedi

Mapping Electricity Access for a Sixth of the World's People

DURHAM, N.C. — Most Americans can charge their cell phones, raid the fridge or boot up their laptops at any time without a second thought.

Not so for the 1.2 billion people — roughly 16 percent of the world’s population — with no access to electricity.

Despite improvements over the past two decades, an estimated 780 million people will still be without power by 2030, especially in rural parts of sub-Saharan Africa, Asia and the Pacific.

To get power to these people, first officials need to locate them. But for much of the developing world, reliable, up-to-date data on electricity access is hard to come by.

Researchers say remote sensing can help.

For ten weeks from May through July, a team of Duke students in the Data+ summer research program worked on developing ways to assess electricity access automatically, using satellite imagery.

“Ground surveys take a lot of time, money and manpower,” said Data+ team member Ben Brigman. “As it is now, the only way to figure out if a village has electricity is to send someone out there to check. You can’t call them up or put out an online poll, because they won’t be able to answer.”

India at night

Satellite image of India at night. Large parts of the Indian countryside still aren’t connected to the grid, but remote sensing, machine learning could help pinpoint people living without power. Credits: NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA’s Goddard Space Flight Center

Led by researchers in the Energy Data Analytics Lab and the Sustainable Energy Transitions Initiative, “the initial goal was to create a map of India, showing every village or town that does or does not have access to electricity,” said team member Trishul Nagenalli.

Electricity makes it possible to pump groundwater for crops, refrigerate food and medicines, and study or work after dark. But in parts of rural India, where Nagenalli’s parents grew up, many households use kerosene lamps to light homes at night, and wood or animal dung as cooking fuel.

Fires from overturned kerosene lamps are not uncommon, and indoor air pollution from cooking with solid fuels contributes to low birth weight, pneumonia and other health problems.

In 2005, the Indian government set out to provide electricity to all households within five years. Yet a quarter of India’s population still lives without power.

Ultimately, the goal is to create a machine learning algorithm — basically a set of instructions for a computer to follow — that can recognize power plants, irrigated fields and other indicators of electricity in satellite images, much like the algorithms that recognize your face on Facebook.

Rather than being programmed with specific instructions, machine learning algorithms “learn” from large amounts of data.

This summer the researchers focused on the unsung first step in the process: preparing the training data.

Phoenix power plant

Satellite image of a power plant in Phoenix, Arizona

Fellow Duke students Gouttham Chandrasekar, Shamikh Hossain and Boning Li were also part of the effort. First they compiled publicly available satellite images of U.S. power plants. Rather than painstakingly framing and labeling the plants in each photo themselves, they tapped the powers of the Internet to outsource the task and hired other people to annotate the images for them, using a crowdsourcing service called Amazon Mechanical Turk.

So far, they have collected more than 8,500 image annotations of different kinds of power plants, including oil, natural gas, hydroelectric and solar.

The team also compiled firsthand observations of the electrification rate for more than 36,000 villages in the Indian state of Bihar, which has one of the lowest electrification rates in the country. For each village, they also gathered satellite images showing light intensity at night, along with density of green land and other indicators of irrigated farms, as proxies for electricity consumption.

Using these data sets, the goal is to develop a computer algorithm which, through machine learning, teaches itself to detect similar features in unlabeled images, and distinguishes towns and villages that are connected to the grid from those that aren’t.

“We would like to develop our final algorithm to essentially go into a developing country and analyze whether or not a community there has access to electricity, and if so what kind,” Chandrasekar said.

Electrification map of Bihar, India

The proportion of households connected to the grid in more than 36,000 villages in Bihar, India

The project is far from finished. During the 2017-2018 school year, a Bass Connections team will continue to build on their work.

The summer team presented their research at the Data+ Final Symposium on July 28 in Gross Hall.

Data+ is sponsored by Bass Connections, the Information Initiative at Duke, the Social Science Research Institute, the departments of mathematics and statistical science and MEDx. This project team was also supported by the Duke University Energy Initiative.

Writing by Robin Smith; video by Lauren Mueller and Summer Dunsmore

Lemur Research Gets a Gut Check

Baby Coquerel’s sifaka

Clinging to her mom, this baby Coquerel’s sifaka represents the only lemur species at the Duke Lemur Center known to fall prey to cryptosporidium, a microscopic parasite that causes diarrhea that can last for a week or more. The illness wipes out much of the animals’ gut microbiome, researchers report, but fecal transplants can help them recover. Photo by David Haring, Duke Lemur Center.

DURHAM, N.C. — “Stool sample collector” is not a glamorous way to introduce oneself at a party. But in the course of their research, gut microbiologists Erin McKenney and Lydia Greene have spent a lot of time waiting for animals to relieve themselves.

They estimate they have hundreds of vials of the stuff, from a dozen primate species including lemurs, baboons and gorillas, sitting in freezers on the Duke University campus.

The researchers aren’t interested in the poop per se, but in the trillions of bacteria inhabiting the gastrointestinal tract, where the bugs help break down food, produce vitamins and prevent infection.

A few years ago, McKenney and Greene started collecting stool samples at the Duke Lemur Center to see how the microbial makeup of lemurs’ guts varies from birth to weaning, and as their diets change over the seasons. And what happens when they get sick?

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Between 2013 and 2016, ten of the lemurs they were studying contracted cryptosporidium, or “crypto” for short, a waterborne parasite that causes diarrhea in people, pets, livestock and wildlife worldwide.

All of the infected animals were Coquerel’s sifakas — the only lemur species out of roughly 20 at the Duke Lemur Center known to fall prey to the parasite — and most of them were under five years old when they fell ill.

Animals that tested positive were moved into separate holding areas away from other animals and visitors. Keepers wore protective suits, gloves, face masks and booties while working in the animals’ enclosures to prevent infection.

All of the animals eventually recovered. Along the way, six of the affected animals were treated with antibiotics, and three were also fed a slurry of saline and feces from a healthy relative.

McKenney and Greene collected stool samples before, during and after infection for up to two months. They used a technique called 16S ribosomal RNA sequencing to identify the types of bacteria in the samples based on their genes, and compared the results with those of 35 unaffected individuals.

In a healthy gut microbiome, “good” bacteria in the gut compete with “bad” microbes for space and nutrients, and secrete substances that inhibit their growth.

The guts of sick and recovering sifakas are host to a very different assortment of microbes than those of unaffected animals, the researchers found.

Not surprisingly, both crypto infection, and antibiotic treatment, wiped out much of the animals’ gut flora — particularly the bacterial groups Bifidobacterium, Akkermansia, Succinivibrio and Lachnospiraceae.

Even after the infections cleared, most animals took another several weeks to stabilize and return to normal levels of gut biodiversity, with younger animals taking longer to recover.

The only animals that made a full comeback within the study period were those that received a fecal transplant, suggesting that the treatment can help restore gut bacterial diversity and speed recovery.

The patterns of gut recolonization following crypto infection mirrored those seen from birth to weaning, said McKenney, now a postdoctoral researcher at North Carolina State University.

The researchers hope their findings will help control and prevent crypto outbreaks in captive primates. Because lemurs are more closely related to humans than lab mice are, the research could also help scientists understand how the gut microbiome protects humans from similar infections and facilitates recovery.

“Thanks to bioinformatics and advances in sequencing, the microbiome gives us a window into the health of these animals that we’ve never had before,” said Greene, a graduate student in ecology at Duke.

They published their findings June 15, 2017, in the journal Microbial Ecology in Health and Disease.

Duke evolutionary anthropology professors Christine Drea and Anne Yoder were senior authors on this study. This research was supported by the National Science Foundation (1455848) and the Duke Lemur Center Directors Fund.

CITATION:  “Down for the Count: Cryptosporidium Infection Depletes Gut Microbiota in Coquerel’s Sifakas,” Erin McKenney, Lydia Greene, Christine Drea and Anne Yoder. Microbial Ecology in Health and Disease, June 15, 2017. http://dx.doi.org/10.1080/16512235.2017.1335165

Post by Robin Smith, science writer, Office of News & Communications

Page 1 of 6

Powered by WordPress & Theme by Anders Norén