Field Notes

Study Finds Physical Activity Reduces Chronic Disease Risk

University of Iowa researchers are recommending that all patients be surveyed about their physical activity levels after a new study underscores the link between physical activity and chronic disease.

The study, led by Lucas Carr, PhD, an associate professor in the department of health and human physiology, examined responses from more than 7,000 patients at University of Iowa Health Care Medical Center who noted their level of physical activity in a questionnaire.

From patients’ answers to the questionnaire, the researchers found that those who reported the highest level of physical activity—meaning they exercised moderately to vigorously at least 150 minutes per week—were at a statistically significantly lower risk of having 19 chronic conditions, including CVD, cancer, respiratory disease, and diabetes.

The findings further suggest that patients who are least active—meaning they reported little to no exercise in a given week—are at increased risk of developing a chronic disease.

Based on those results, the Iowa researchers also recommend that health care systems provide information on health and wellness services for physically inactive patients who are at most risk.

“In our health care environment, there's no easy pathway for a doctor to be reimbursed for helping patients become more physically active,” Carr says. “And so, for these patients, many of whom report insufficient activity, we need options to easily connect them with supportive services like exercise prescriptions and/or community health specialists.”

Most hospitals in the United States don’t ask patients about their physical activity, and no hospital system in the Midwest has done so, according to the researchers. In this study, Carr partnered with Britt Marcussen, MD, a family medicine physician in University of Iowa Health Care, to offer the questionnaire to patients visiting for annual wellness exam appointments. The study period was from November 2017 to December 2022.

The Exercise Vital Sign survey, as the questionnaire is called, asked patients the following two questions that they answered on a tablet:

• “On average, how many days per week do you engage in moderate to vigorous exercise (like a brisk walk)?” (zero to seven days) 
• “On average, how many minutes do you engage in exercise at this level?”

Carr and his team propose making the survey available to all patients.

“This two-question survey typically takes fewer than 30 seconds for a patient to complete, so it doesn’t interfere with their visit. But it can tell us a whole lot about that patient’s overall health,” Carr says.

The researchers also compared results from patients who completed the surveys with more than 33,000 patients who weren’t offered the survey in other areas of the hospital. The researchers found that patients who took the survey were younger and in better health than the patient population who weren’t given the questionnaire, based on analyzing all patients’ EMRs.

While the link between physical activity and reduced risk of chronic disease has been known, the researchers say the study underscores the value of surveying patients about their physical activity levels.

“We believe this finding is a result of those patients who take the time to come in for annual wellness exams also are taking more time to engage in healthful behaviors, such as being physically active,” Carr says.

In a related study published recently in the Journal of Physical Activity and Health, Carr’s team found that when health care providers billed for providing exercise counseling to patients, those invoices were reimbursed by insurance providers nearly 95% of the time.

“Our findings suggest the recommended physical activity billing codes are reimbursed at a high rate when providers submit them for reimbursement, which reinforces the idea to make physical activity surveys and counseling services available,” Carr says.

— Source: University of Iowa

 

Fiber in Diet May Boost Body Against Infections

The group of bacteria called Enterobacteriaceae, including Klebsiella pneumoniae, Shigella, E. coli, and others, is present at low levels as part of a healthy human gut microbiome. But at high levels—caused, for example, by increased inflammation in the body or by eating contaminated food—these bugs can cause illness and disease. In extreme cases, too much Enterobacteriaceae in the gut can be life-threatening.

Researchers have used computational approaches, including artificial intelligence, to analyze the gut microbiome composition of over 12,000 people across 45 countries from their stool samples. They found that a person's microbiome “signature” can predict whether a person's gut is likely to be colonized by Enterobacteriaceae. The results are consistent across different states of health and geographic locations.

The researchers identified 135 gut microbe species that are commonly found in the absence of Enterobacteriaceae, likely protecting against infection.

Notable among the protective gut species is a group of bacteria called Faecalibacterium, which produce beneficial compounds called short-chain fatty acids by breaking down the fiber in the foods we eat. This seems to protect against infection by a range of disease-causing Enterobacteriaceae bugs.

The researchers suggest that eating more fiber in our diet will support the growth of good bacteria—and crowd out the bad ones to significantly reduce the risk of illness.
In contrast, taking probiotics—which don't directly change the environment in the gut—is less likely to affect the likelihood of Enterobacteriaceae infection.

The results are published in the journal Nature Microbiology.

"Our results suggest that what we eat is potentially very important in controlling the likelihood of infection with a range of bacteria, including E.coli and Klebsiella pneumonia because this changes our gut environment to make it more hostile to invaders," says Alexandre Almeida, PhD, a researcher at the University of Cambridge's department of veterinary medicine and senior author of the paper.

He adds: "By eating fiber in foods like vegetables, beans, and whole grains, we can provide the raw material for our gut bacteria to produce short-chain fatty acids—compounds that can protect us from these pathogenic bugs."

Klebsiella pneumonia can cause pneumonia, meningitis, and other infections. The alarming global rise in antibiotic resistance to this bacterial pathogen has led scientists to look for new ways of keeping it, and other similar infectious bacteria, under control. "With higher rates of antibiotic resistance, there are fewer treatment options available to us. The best approach now is to prevent infections occurring in the first place, and we can do this by reducing the opportunities for these disease-causing bacteria to thrive in our gut," Almeida says.

A New Understanding of Gut Microbe Interactions
Earlier research to understand interactions between the different bacteria in the gut has used mouse models. However, some of these new results are at odds with previous findings.

The new study revealed that 172 species of gut microbes can coexist with disease-causing Enterobacteriaceae bugs. Many of these species are functionally similar to the bugs: They need the same nutrients to survive. Previously, it was thought that competition for resources would stop the disease-causing bacteria from getting established in the gut.

This has important implications for treatment: taking probiotics that compete for the same nutrients with the bad bacteria to try and starve them out isn't going to work. The researchers say that it will be more beneficial to change the environment in the gut, for instance, through diet, to reduce the risk of infection with Enterobacteriaceae.

"This study highlights the importance of studying pathogens not as isolated entities, but in the context of their surrounding gut microbiome," says Qi Yin, PhD, a visiting researcher at the University of Cambridge's Department of Veterinary Medicine and first author of the report.

— Source: University of Cambridge