Scientists Reveal Diet That Fights Off Life-Threatening Infections

Eating a diet rich in fiber from beans, legumes, vegetables, fruit, whole grains, nuts and seeds could promote the growth of beneficial microbes in the gut and help the body fight potentially dangerous infections. A study by scientists at the U.K.'s University of Cambridge recently found that 135 species of gut bacteria were linked to the absence of Enterobacteriaceae, a group of bacteria that can cause life-threatening infections. "There is a lot of research showing how fiber affects our gut in a positive way," senior author Alexandre Almeida of Cambridge's Department of Veterinary Medicine told Newsweek. "First, it helps with digestion by keeping things moving smoothly through our intestines. "In addition, certain types of fiber act as food for the good bacteria living in our gut. These beneficial bacteria play important roles in digestion and immune function," he said. In the study, Almeida's team found these bacteria to be associated with lower levels of harmful bacteria in the gut.

Enterobacteriaceae are generally present in healthy guts at low levels—including some famous varieties such as Escherichia coli (E. coli), which is one of the top three leading causes of foodborne illness in the U.S. "However, an overgrowth of Enterobacteriaceae species and strains can lead to issues like inflammation, diarrhea and even systemic infections," Almeida said. Other varieties, such as Klebsiella pneumoniae, can cause pneumonia, meningitis and other infections at high levels. "Since these species tend to also have high rates of antibiotic resistance, if they cause an infection in other parts of the body this may be difficult to treat," Almeida said. His team used artificial intelligence to analyze the gut bacteria in the stool of more than 12,000 people from 45 different countries. The researchers discovered certain bacteria that were associated with healthier levels of Enterobacteriaceae, such as Faecalibacterium, which has been linked with a healthier gut. "Since fiber is not digested by our bodies, it can make its way to the colon, where gut bacteria break them down through a process known as fermentation," Almeida said. "Some of our gut bacteria, especially those commonly found in healthy people, use these fibers to produce chemicals known as short-chain fatty acids that can help reduce inflammation and strengthen the gut lining. These chemicals themselves can also create an environment in the gut that may make it more difficult for harmful bacteria to thrive," Almeida said. The researchers concluded that eating more fiber, such as that from vegetables, beans and whole grains, was likely to promote the growth of these helpful bacteria species, which could help prevent an overgrowth of harmful bacteria and reduce the risk of infection. They also found that 172 species of gut microbes were able to coexist with disease-causing Enterobacteriaceae, suggesting that taking probiotics—live cultures of bacteria in food or supplements—and hoping to crowd out harmful bacteria is unlikely to work. "It's too early to make very specific recommendations," Almeida said. "Our findings along with others suggest that our diet plays a role in gut health and that fiber could be important for keeping potentially harmful bacteria in check. However...more studies are needed to better understand which specific fibers and in what amounts may be more beneficial." The study was published Friday in the online journal Nature Microbiology.

Reference

Yin, Q., da Silva, A. C., Zorrilla, F., Almeida, A. S., Patil, K. R., Almeida, A. (2024). Ecological dynamics of Enterobacteriaceae in the human gut microbiome across global populations, Nature Microbiology. https://doi.org/10.1038/s41564-024-01912-6 Do you have a tip on a food story that Newsweek should be covering? Is there a nutrition concern that's worrying you? Let us know via science@newsweek.com. We can ask experts for advice, and your story could be featured in Newsweek.