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Natural Antioxidant Prevents Severe Flu



Microbes that live in the gut don't just digest food. They also have far-reaching effects on the immune system. Now, a new study shows that a particular gut microbe can prevent severe flu infections, likely by breaking down naturally occurring compounds -- called flavonoids -- commonly found in foods such as black tea, red wine and blueberries.



Strong evidence from several studies have shown that individuals consuming fruits and vegetables rich in different flavonoids have a reduced risk of overall mortality and of several chronic diseases.

The research, conducted by scientists at Washington University School of Medicine in St. Louis, also indicates that this strategy is effective in staving off severe damage from flu when the interaction occurs prior to infection with the influenza virus. This work also could help explain the wide variation in human responses to influenza infection.
"For years, flavonoids have been thought to have protective properties that help regulate the immune system to fight infections," said first author Ashley L. Steed, MD, PhD, an instructor in pediatrics who treats intensive care patients at St. Louis Children's Hospital. "Flavonoids are common in our diets, so an important implication of our study is that it's possible flavonoids work with gut microbes to protect us from flu and other viral infections. Obviously, we need to learn more, but our results are intriguing."
Influenza -- characterized by fever, cough and body aches -- is a common and sometimes deadly viral infection of the upper respiratory tract. Older adults, pregnant women, young children and people with chronic health problems such as asthma and heart disease are most prone to serious flu complications. Since 2004, an average of 113 children have died from influenza in the U.S. each year, according to the Centers for Disease Control and Prevention. Around the world, the World Health Organization estimates there are 250,000 to 500,000 flu-related deaths annually.
Previous evidence suggests that the gut microbiome may be important in protecting against severe influenza infections, so in this study, the researchers aimed to identify just what gut microbes might provide that protection. In addition, for years, nutritionists have explored potential health benefits linked to foods loaded with flavonoids.
"It's not only having a diet rich in flavonoids, our results show you also need the right microbes in the intestine to use those flavonoids to control the immune response," said the study's senior author, Thaddeus S. Stappenbeck, MD, PhD, the Conan Professor of Pathology & Immunology. "We were able to identify at least one type of bacteria that uses these dietary compounds to boost interferon, a signaling molecule that aids the immune response. This prevented influenza-related lung damage in the mice. It is this kind of damage that often causes significant complications such as pneumonia in people."
As part of the study, the researchers screened human gut microbes looking for one that metabolized flavonoids. Stappenbeck and Steed identified one such microbe that they suspected might protect against flu damage. The microbe, called Clostridium orbiscindens, degrades flavonoids to produce a metabolite that enhances interferon signaling.
"The metabolite is called desaminotyrosine, otherwise known as DAT," Steed said. "When we gave DAT to mice and then infected them with influenza, the mice experienced far less lung damage than mice not treated with DAT."
Interestingly, although the lungs of DAT-treated mice didn't have as much flu damage, their levels of viral infection were identical to those in mice that didn't get the treatment.
"The infections were basically the same," Stappenbeck said. "The microbes and DAT didn't prevent the flu infection itself; the mice still had the virus. But the DAT kept the immune system from harming the lung tissue."
That's important because annual flu vaccines aren't always effective at preventing infections.
"But with DAT, it may be possible to keep people from getting quite as sick if they do become infected," Steed said. "This strategy doesn't target the virus. Instead, it targets the immune response to the virus. That could be valuable because there are challenges with therapies and vaccines that target the virus due to changes in the influenza virus that occur over time."
Next steps include identifying other gut microbes that also may use flavonoids to influence the immune system, as well as exploring ways to boost the levels of those bacteria in people whose intestines aren't adequately colonized with those microbes. As those future studies are planned, the researchers said it might not be a bad idea to drink black tea and eat foods rich in flavonoids before the next flu season begins.

This first appeared in Prevent Disease

Intense Physical Activity Can Be Done Safely At Any Age With Incredible Results



Growing older may not have to mean growing frail. A preclinical study has revealed that brief periods of intense physical activity can be safely administered at advanced age, and that this kind of activity has the potential to reverse frailty.



High intensity workouts
 strengthen the body to not only decrease the risk of developing diseases such as heart disease and diabetes, but it can also reduce the symptoms of those who are already suffering from some conditions.
Studies have found these intervals of exercise that push people to their limit can improve their:
  1. Cardiovascular system
  2. Respiratory health
  3. Metabolic functioning
  4. Other mechanical functions
  5. Cycling
  6. Swimming
  7. Walking
  8. Jogging

Published in the Journal of Gerontology A in June by University at Buffalo researchers, the study is the first to investigate whether a novel, short-session regimen of high-intensity interval training (HIIT) can be safe and effective in older populations.
The study was conducted on two groups of a dozen mice, each 24 months old, which correlates roughly to 65 years old in human terms. All the mice had been sedentary up until that age. While cautioning that the study was done in mice, the authors state that the results could have significant application to humans.
"We know that being frail or being at risk for becoming frail puts people at increased risk of dying and comorbidity," said Bruce R. Troen, MD, senior author on the study with Kenneth L. Seldeen, PhD, who is first author.
Troen is professor and chief of the Division of Geriatrics and Palliative Medicine in the Department of Medicine, Jacobs School of Medicine and Biomedical Sciences at UB, a geriatrician with UBMD Internal Medicine, and a physician-investigator with the Veterans Affairs Western New York Health Care System. Seldeen is research assistant professor of medicine at UB.
"These results show that it’s possible that high-intensity interval training can help enhance quality of life and capacity to be healthy," Troen said.
The results were striking with mice exhibiting "dramatic" improvements in numerous measurements, including strength and physical performance.
No longer frail
One of the most significant findings was that by the end of the study, five of six mice found to be frail or pre-frail at baseline improved, and four were no longer frail.
"Those four mice who had exhibited the kinds of deficits that correlate to frailty in humans improved to a completely robust level," said Troen. "The HIIT actually reversed frailty in them."
Troen and Seldeen developed mouse equivalents for measures that assess human frailty, including ways to evaluate grip strength, endurance and gait speed, so that they could establish baseline levels and then compare those with results once the study was complete.
"Because the performance measures for the mice are directly relevant to clinical parameters, we think this program of exercise is quite applicable to humans," said Troen. "We’re laying a foundation so we can do this in people and so we can understand how to tailor it to individuals so they can successfully implement this."
Similar to the way that an athletic trainer might individualize a fitness program for a client, Troen and Seldeen tailored intensity levels to each mouse.
"While the mice are genetically identical, they aren’t phenotypically identical," Seldeen explained, "so we customized the exercise program to each mouse, first finding out what each one was capable of at baseline, and then increasing or decreasing the intensity depending on the performance of the mouse during the study."
HIIT was well-tolerated
The 10-minute exercise program involved a three-minute warm-up, three intervals of one minute of high intensity and one minute at lower intensity, and a final minute of higher intensity on an inclined treadmill. The exercises were done three times a week over 16 weeks. All exercises were well-tolerated by the mice.
There were dramatic improvements in grip strength, treadmill endurance and gait speed. The mice showed greater muscle mass and an increase in total mitochondria, the energy factories of cells.
"Increased mitochondrial biomass allows you to utilize oxygen more efficiency," Troen explained. "With HIIT, we saw both mitochondrial increase and an improvement in muscle quality and fiber size in these mice."
As to why HIIT results in such significant benefits to those who engage in it, Troen said that it has to do with the stress to which it subjects the body.
"Exercise stresses the system and the body can respond beneficially," he explained. "We believe that the intensity of individualized HIIT provides a more significant but manageable stress so the body responds more robustly to these short, vigorous periods of exercise.
"In other words, you get more bang for your buck."
Troen and Seldeen cautioned that anyone considering HIIT should check with their physician first.

This first appeared in Prevent Disease