Feeding good gut bacteria through fibre may enhance protection against infections

New research points out

A new study has highlighted the significant role of gut microbiome composition in determining an individual’s vulnerability to life-threatening infections caused by bacteria such as Klebsiella pneumonia, E. coli, and other harmful microbes.

The findings suggest that dietary changes, such as remarkably increasing fibre intake, can alter the gut environment and offer increased protection against these infections.

The human gut microbiome, a complex community of trillions of microbes, plays a crucial role in maintaining overall health. Among the various bacteria in the microbiome, members of the Enterobacteriaceae family, including Klebsiella pneumoniae, Shigella, and E. coli, are typically present in small quantities and are considered a normal part of the gut ecosystem.

However, when these bacteria proliferate due to inflammation or contamination from infected food, they can cause severe illness. In extreme cases, an overgrowth of Enterobacteriaceae in the gut can become life-threatening.

The study, which involved analysing gut microbiome data from over 12,000 individuals across 45 countries, utilised advanced computational techniques, including artificial intelligence, to identify the microbial signatures associated with increased susceptibility to Enterobacteriaceae infections.

The researchers found that an individual’s microbiome can effectively predict the likelihood of these harmful bacteria colonising the gut. Notably, these findings were consistent across various health conditions and geographical locations.

Consistent findings

In their study, the researchers identified 135 species of gut microbes that tend to be present when Enterobacteriaceae are absent, potentially offering protection against infections caused by these bacteria.

One group of bacteria, Faecalibacterium, stood out as particularly beneficial. These microbes are known for breaking down dietary fibre and producing short-chain fatty acids (SCFAs), which have anti-inflammatory properties and contribute to maintaining a balanced gut environment. These SCFAs play a key role in preventing the overgrowth of harmful Enterobacteriaceae bacteria, offering a protective effect.

Dr Alexandre Almeida, a researcher at the University of Cambridge’s Department of Veterinary Medicine and senior author of the paper, commented on the significance of the findings: “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.”

He added, “By eating fibre-rich 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.”

The study, published in Nature Microbiology, provides a new perspective on the relationship between diet, gut health, and infection risk. It reinforces the idea that a high-fibre diet supports the growth of beneficial gut bacteria and, in turn, helps reduce the risk of infection from harmful pathogens.

This is particularly important in light of the growing global concern about antibiotic resistance, especially to bacteria like Klebsiella pneumonia, which can cause pneumonia, meningitis, and other severe infections.

“With higher rates of antibiotic resistance, fewer treatment options are available. 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,” Dr Almeida explained.

New insights

The study also offers new insights into the interactions between different types of gut bacteria. Previous research often used mouse models to investigate these interactions, but the findings from this study challenge some of the earlier assumptions.

The researchers discovered that 172 species of gut bacteria can coexist with harmful Enterobacteriaceae species. Many of these bacteria share similar nutritional needs, previously thought to lead to competition and prevent the establishment of harmful bacteria in the gut. However, the new study indicates that this competition does not necessarily occur as scientists had imagined.

This has important implications for treatment strategies. For instance, while probiotics are often thought to help balance gut bacteria by competing for the same resources as harmful microbes, this approach may not effectively prevent infections caused by Enterobacteriaceae.

The researchers suggest that a more effective strategy would be to modify the gut environment—perhaps through diet—to make it less conducive to the survival and growth of pathogenic bacteria.

Dr Qi Yin, a visiting researcher at the University of Cambridge and first author of the study, highlighted the importance of considering pathogens in the broader context of the gut microbiome. “This study highlights the importance of studying pathogens not as isolated entities but in the context of their surrounding gut microbiome,” she said.

The findings from this study can potentially revolutionise how we approach the prevention of gut-related infections. By increasing dietary fibre intake, individuals may improve their overall health and bolster their gut’s defences against harmful bacterial infections, providing a simple yet effective strategy to safeguard against various infectious diseases.

Image: By increasing dietary fibre intake, individuals may improve their overall health and bolster their gut’s defences against harmful bacterial infections. Credit: Yaroslav Shuraev

Last Updated on 1 day by Dan Ngiam