VANDERBILT STUDY EXAMINES BACTERIA’S ABILITY TO FIGHT OBESITY

VANDERBILT STUDY EXAMINES BACTERIA’S ABILITY TO FIGHT OBESITY

 From the FMS Global News Desk of Jeanne Hambleton

Released: 25-Jul-2014 9:00 AM EDT
Source Newsroom: Vanderbilt University Medical Center

 

Newswise — A probiotic that prevents obesity could be on the horizon.

Bacteria that produce a therapeutic compound in the gut inhibit weight gain, insulin resistance and other adverse effects of a high-fat diet in mice, Vanderbilt University investigators have discovered.

“Of course it’s hard to speculate from mouse to human,” said senior investigator Sean Davies, Ph.D., assistant professor of Pharmacology. “But essentially, we’ve prevented most of the negative consequences of obesity in mice, even though they’re eating a high-fat diet.”

Regulatory issues must be addressed before moving to human studies, Davies said, but the findings published in the August issue of the Journal of Clinical Investigation suggest that it may be possible to manipulate the bacterial residents of the gut — the gut microbiota — to treat obesity and other chronic diseases.

Davies has a long-standing interest in using probiotic bacteria — “friendly” bacteria like those in yogurt — to deliver drugs to the gut in a sustained manner, in order to eliminate the daily drug regimens associated with chronic diseases.

In 2007, he received a National Institutes of Health Director’s New Innovator Award to develop and test the idea.

“The NIH basically said, ‘we like this idea, now make it work,’” Davies said. “The New Innovator Award was critical to our success.”

Other studies have demonstrated that the natural gut microbiota plays a role in obesity, diabetes and cardiovascular disease.

“The types of bacteria you have in your gut influence your risk for chronic diseases,” Davies said. “We wondered if we could manipulate the gut microbiota in a way that would promote health.”

To start, the team needed a safe bacterial strain that colonizes the human gut. They selected E. coli Nissle 1917, which has been used as a probiotic treatment for diarrhea since its discovery nearly 100 years ago.

They genetically modified the E. coli Nissle strain to produce a lipid compound called NAPE, which is normally synthesized in the small intestine in response to feeding. NAPE is rapidly converted to NAE, a compound that reduces both food intake and weight gain. Some evidence suggests that NAPE production may be reduced in individuals eating a high-fat diet.

“NAPE seemed like a great compound to try — since it’s something that the host normally produces,” Davies said.

The investigators added the NAPE-producing bacteria to the drinking water of mice eating a high-fat diet for eight weeks.

Mice that received the modified bacteria had dramatically lower food intake, body fat, insulin resistance and fatty liver compared to mice receiving control bacteria.

They found that these protective effects persisted for at least four weeks after the NAPE-producing bacteria were removed from the drinking water. And even 12 weeks after the modified bacteria were removed, the treated mice still had much lower body weight and body fat compared to the control mice. Active bacteria no longer persisted after about six weeks.

“We still have not achieved our ultimate goal, which would be to do one treatment and then never have to administer the bacteria again,” Davies said. “Six weeks is pretty long to have active bacteria, and the animals are still less obese 12 weeks out.

“This paper provides a proof of concept,” he said. “Clearly, we can get enough bacteria to persist in the gut and have a sustained effect. We would like for that effect to last longer.”

Davies noted that the researchers also observed effects of the compounds in the liver, suggesting that it may be possible to use modified bacteria to deliver therapeutics beyond the gut.

The investigators are currently working on strategies to address regulatory issues related to containing the bacteria, for example by knocking out genes required for the bacteria to live outside the treated host. Zhongyi Chen, M.D., Ph.D., and Lilu Guo, Ph.D., are co-first authors of the JCI paper.

 

OBESITY LINKED TO LOW ENDURANCE, INCREASED FATIGUE IN THE WORKPLACE

From the FMS Global News Desk of Jeanne Hambleton

Released: 23-Jul-2014 9:00 AM EDT
Source : Virginia Tech  Citations Journal of Occupational and Environmental Hygiene

 

Newswise — U.S. workplaces may need to consider innovative methods to prevent fatigue from developing in employees who are obese. Based on results from a new study published in the Journal of Occupational and Environmental Hygiene (JOEH), workers who are obese may have significantly shorter endurance times when performing workplace tasks, compared with their non-obese counterparts.

The study, conducted at Virginia Tech in Blacksburg, Va., examined the endurance of 32 individuals in four categories (non-obese young, obese young, non-obese older, and obese older) who completed three distinct tasks that involved a range of upper extremity demands — hand grip, intermittent shoulder elevation, and a simulated assembly operation. Each task involved periods of work and rest, and included pacing demands similar to those experienced by workers in manufacturing settings.

“Our findings indicated that on average, approximately 40 percent shorter endurance times were found in the obese group, with the largest differences in the hand grip and simulated assembly tasks. During those tasks, individuals in the obese group also exhibited greater declines in task performance, though this difference was only evident among females,” said Lora A. Cavuoto, an assistant professor in the department of industrial and systems engineering at the University at Buffalo, SUNY, in Buffalo, New York.

In addition to examining how obesity affected physical demands and capacity, Cavuoto and her colleagues looked at the interactive effect of obesity and age on endurance times.

“Previous studies have indicated that both age and obesity lead to decreased mobility, particularly when it comes to walking and performing lower extremity tasks. However, we found no evidence of an interactive effect of obesity and age on endurance times, which is contrary to previous findings,” said Maury A. Nussbaum, a professor in the department of industrial and systems engineering at Virginia Tech, who also worked on the study.

Obesity is associated with physiological changes at the muscular level, including a decrease in blood flow, thereby limiting the supply of oxygen and energy sources. When performing sustained contractions, these physiological changes may lead to a faster onset of muscle fatigue. The prevalence of obesity has doubled over the past three decades and this increase has been associated with more healthcare costs, higher rates of workplace injury, and a greater number of lost workdays.

According to Cavuoto and Nussbaum, the results from this and related studies will contribute to a better understanding of the ergonomic impacts of obesity and age, which is important for describing the link between personal factors and the risk of workplace injury.

“Workers who are obese may need longer rest breaks to return to their initial state of muscle function. Based on the increased fatigue found among workers who are obese, workplace designers may need to consider adding fixtures and supports to minimize the amount of time that body mass segments need to be supported. We believe our results will help to develop more inclusive ergonomic guidelines,” said Cavuoto.

 

MISSING SLEEP MAY HURT YOUR MEMORY

From the FMS Global News Desk of Jeanne Hambleton 

Posted on July 21, 2014 by Stone Hearth News – Michigan State University.

EAST LANSING, Mich. — Lack of sleep, already considered a public health epidemic, can also lead to errors in memory, finds a new study by researchers at Michigan State University and the University of California, Irvine.

The study, published in the journal Psychological Science, found participants deprived of a night’s sleep were more likely to flub the details of a simulated burglary they were shown in a series of images.

Distorted memory can have serious consequences in areas such as criminal justice, where eyewitness misidentifications are thought to be the leading cause of wrongful convictions in the United States.

“We found memory distortion is greater after sleep deprivation,” said Kimberly Fenn, MSU assistant professor of psychology and co-investigator on the study. “And people are getting less sleep each night than they ever have.”

The Centers for Disease Control and Prevention calls insufficient sleep an epidemic and said it’s linked to vehicle crashes, industrial disasters and chronic diseases such as hypertension and diabetes.

The researchers conducted experiments at MSU and UC-Irvine to gauge the effect of insufficient sleep on memory. The results: Participants who were kept awake for 24 hours – and even those who got five or fewer hours of sleep – were more likely to mix up event details than participants who were well rested.

“People who repeatedly get low amounts of sleep every night could be more prone in the long run to develop these forms of memory distortion,” Fenn said. “It’s not just a full night of sleep deprivation that puts them at risk.”

Fenn’s co-investigators include Steven Frenda and Elizabeth Loftus from UC-Irvine.

Back tomorrow Jeanne mission lee

 

 

 

 

 

 

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