(Press-News.org) URBANA, Ill. - Most Americans don't get the daily recommended amount of fiber in their diet, though research has shown that dietary fiber can cause a shift in the gut toward beneficial bacteria, reducing the risk of colon cancer, type 2 diabetes, and other diseases. A new study from the University of Illinois shows that two specific functional fibers may also have the potential to assist in weight loss when made part of a long-term, daily diet.
Kelly Swanson, a U of I professor of nutrition, and his team had previously been able to see a "snapshot" of what bacteria were present in the gut after a diet had been supplemented with polydextrose and soluble corn fiber. Using the samples from the same trial, Swanson and his lab used whole-genome sequencing to explore the full range of bacterial genomic information in the gut after fiber supplementation.
The new information is helping the researchers to understand more about the functional capabilities of the bacteria in the gut when these fibers are consumed as part of a regular diet.
"In the gut, bacteria have the capacity to do a lot of different things, such as fermenting proteins, carbohydrates, or other substrates," Swanson said. "We have already been able to identify what bacteria are there and the changes that occur with diet, and now we are asking if we can change the machinery or the capacity of what functions the bacteria have. Knowing what bacteria are there may matter, but it may not matter as much as identifying their function."
Hannah Holscher, a U of I postdoctoral researcher and registered dietitian in animal sciences, said what was most surprising and novel in the recent study was a shift in the Bacteroidetes:Firmicutes ratio toward more Bacteroidetes, something the researchers had not seen previously.
"This was of particular interest to us because other research has shown that having more Bacteroidetes may be beneficial because the higher that proportion is, the individual tends to be leaner. With higher Firmicutes, that individual tends to be more obese," Holscher said. "We don't know if there is any causality for weight loss, but studies have shown that having a higher fiber diet is protective against obesity. It's an exciting shift and helps to drive researchers to study these fibers as part of a weight loss diet."
Holscher added that the whole-genome sequencing data also revealed shifts in the functional capacity of the microbiome including modifications in nutrient metabolism. "We saw that there was a decrease in genes associated with protein metabolism, which correlated with the reduced protein fermentation that occurred in the study participants' guts when they consumed the fibers," she said "The information from this study, in combination with the results from the previous study, has allowed us to put together a more complete picture of what the bacteria in our gut are doing."
The samples sequenced for bacteria genomic information were part of a study Swanson and his lab conducted in 2012. In that study, 20 healthy men with an average fiber intake of 14 grams a day were given snack bars to supplement their diet. The control group received bars that contained no fiber; a second group ate bars that contained 21 grams of polydextrose, which is a common fiber food additive; and a third group received bars with 21 grams of soluble corn fiber.
Fecal samples were collected from the participants, and DNA was then subjected to 454 pyrosequencing, which provided a snapshot of all the bacterial types present. The previous study examined only one gene used for identification purposes, while the current study used whole-genome shotgun 454 pyrosequencing to examine the full range of bacterial genetic information in the fecal microbiome.
Holscher stressed that though there were significant shifts in the gut bacterial populations with fiber supplements, when the supplements were stopped populations seemed to go back to where they were before. "The take-home is if people want to make changes to their diet and have a healthier gut they need to be everyday changes.
"We need more fiber in our diets from lots of different sources," Holscher said. "These two fibers look like they could be beneficial when included in a balanced diet along with whole grains, fruits, vegetables, and legumes."
Holscher added that only 10 percent of Americans meet their daily fiber needs of 25 to 38 grams per day, with most only eating 12 to 14 grams per day.
Polydextrose and soluble corn fiber are often ingredients used in prepared foods such as cereals, cereal bars, baking mixes, and drinks. Holscher said food companies are interested in these fibers as ingredients in products because they are lower in calories and do not negatively affect the taste or texture of the product.
"These fibers also tend to be better tolerated, causing less gas, bloating, and discomfort. They can be provided at higher levels than other types of fiber, such as inulin," she added.
The researchers hope to continue studying these fibers for their potential use in disease prevention and weight loss.
"We're hoping this study helps people realize that diet--what you eat every day--does affect the bacteria in your gut. We saw these dramatic shifts in bacterial populations with fiber supplementation, but then those shifts went away when people stopped using the supplements," Holscher said.
"It's an important concept because we are not at the point of giving someone a single pill to change the microbiome; it's not like using an antibiotic to treat an infection. We want to make sure that diet stays in the conversation because there is a significant impact," she added.
INFORMATION:
"Fiber supplementation influences phylogenetic structure and functional capacity of the human intestinal microbiome: follow-up of a randomized controlled trial" was recently published in the American Journal of Clinical Nutrition and can be accessed online at http://ajcn.nutrition.org/content/early/2014/11/12/ajcn.114.092064.abstract. Co-authors of the study are Hannah D. Holscher, J. Gregory Caporaso, Seema Hooda, Jennifer M. Brulc, George C. Fahey Jr., and Kelly S. Swanson.
Funding in part was provided by General Mills, Inc.
When NASA's Terra satellite passed over the Southern Indian Ocean, the MODIS instrument aboard captured a picture of Tropical Cyclone Adjali that showed it developed a "tail," which is actually band of thunderstorms extending south of the center.
The Moderate Resolution Imaging Spectroradiometer, or MODIS instrument that flies aboard NASA's Terra satellite took a visible picture of Tropical Storm Adjali on Nov. 18 at 05:35 UTC (12:35 a.m. EST). The MODIS image showed a concentration of strong storms around the center of Adjali's circulation and a band of thunderstorms ...
A peek inside the brains of professional musicians has given University of Texas at Arlington psychology researchers what may be the first links between music expertise and advantages in long-term memory.
Heekyeong Park, assistant professor of psychology, and graduate student James Schaeffer used electroencephalography (EEG) technology to measure electrical activity of neurons in the brains of 14 musicians and 15 non-musicians and noted processing differences in the frontal and parietal lobe responses. The team will present initial results of their new research Tuesday ...
Motor vehicle crashes are the most common cause of unintentional life lost around the world, with about 30,000 deaths occurring annually in the U.S. due to motor-vehicle crashes.
A study by a doctoral student in epidemiology at the Indiana University Richard M. Fairbanks School of Public Health at Indiana University-Purdue University Indianapolis showed that vehicle inequities have a significant impact on survivability in head-on collisions.
Uzay Kirbiyik conducted a study of risk factors associated with drivers' survival in head-on vehicle collisions by examining ...
Chicago, November 18, 2014--The Associated Press-NORC Center for Public Affairs Research has released an issue brief containing results of a survey about Hispanics' experiences with long-term care in the United States. The issue brief provides new data on how Hispanics age 40 and older are, or are not, planning for long-term care, details how their experiences compare to those of non-Hispanics, and highlights ways in which demographic differences among Hispanics affect their experiences. The study also addresses how Hispanics' familial relationships are impacted by providing ...
This news release is available in French. Montreal, November 18, 2014 -- The next time you berate yourself for wasting an evening playing Farmville on Facebook, think again. If you were playing with Mom, Dad or Aunt Carmen, you were actually helping to strengthen family bonds.
New research from Concordia University, published in Information, Communication and Society, shows that, beyond being a fun distraction, social network games (SNGs) can offer family members a meaningful way to interact and meet social obligations.
"Maintaining those connections is especially ...
URBANA, Ill. - If an in-the-flesh Extension specialist isn't available to provide training, is a video of the specialist's presentation or a video of a new agricultural practice a good substitute? The answer, according to a University of Illinois study with farmers in rural Uganda, isn't simple, particularly when gender is factored into the equation.
"The literature in the field says communication materials like videos work best to support face-to-face communication," said U of I agricultural communications professor Lulu Rodriguez. "But if you don't have an Extension ...
CHICAGO - An important new study of men who have undergone testosterone replacement therapy has found that taking supplemental testosterone does not increase their risk of experiencing a major adverse cardiac event, such as a heart attack or stroke.
Researchers at the Intermountain Medical Center Heart Institute in Murray, Utah, which is the flagship facility for the Intermountain Healthcare system, studied 5,695 men between the ages of 53 and 71. The men, all patients at Intermountain Healthcare hospitals, had initial low testosterone levels.
Researchers found that ...
WASHINGTON, DC - November 18, 2014 - Certain subtypes of avian influenza viruses have the potential to cause more severe disease in humans than other avian influenza subtypes and should be monitored carefully to prevent spread of disease, according to a study published this week in mBio®, the online open-access journal of the American Society for Microbiology.
The work, directed by researchers at the National Institute of Allergy and Infectious Diseases in Bethesda, Md., found that flu viruses expressing the low pathogenicity avian H1, H6, H7, H10 or H15 hemagglutinins ...
(WASHINGTON, November 18, 2014) - New evidence suggests that therapeutic plasma exchange and appropriate blood testing could help patients who are in urgent need of heart surgery, but have a history of an adverse reaction to the blood thinner heparin, according to a study, published online today in Blood, the Journal of the American Society of Hematology (ASH).
Many patients who take blood thinners will eventually require some form of heart surgery, which requires the administration of large quantities of heparin to prevent clots. Some patients who have taken heparin ...
Mycoplasma gallisepticum causes chronic respiratory disease in birds. The illness particularly affects domestic chicken and turkey flocks. The bacteria are especially life-threatening for the animals when they occur in combination with other infections. In order to control the spread of the disease, poultry farms in the EU must be proven free from Mycoplasma gallisepticum or face being closed.
Mycoplasma gallisepticum is related to the human pathogen Mycoplasma pneumoniae, the causative agent of human bronchitis and pneumonia. Mycoplasmas are among the world's smallest ...
