According to a study published by scientists from the Agricultural Research Service and their colleagues from mBio.
Microbes that have resistance to various commonly used antibiotics such as tetracycline and aminoglycoside are a significant source of risk to people worldwide, with the widespread expectation that the problem of antimicrobial resistance (AMR) – the term that refers to bacteria, viruses and fungi resistant to antibiotics – is likely to worsen in the coming decades.
Antimicrobial resistance in humans is largely based on their gut microbiome, where microbes are known to carry genetically encoded strategies to survive contact with antibiotics.
“And the results lead directly to the idea that dietary modification has the potential to be a new weapon in the fight against antimicrobial resistance. And we’re not talking about eating an exotic diet either, but about a diverse, fiber-adequate diet that some Americans are already eating,” explained research molecular biologist Danielle Lemay of the ARS Center for Western Human Nutrition Research in Davis, Calif., and lead on the study.
In this study, the researchers looked for specific associations of antibiotic resistance gene levels in human gut microbes with both fiber and animal protein in the adult diet.
The researchers found that a regular diet with higher levels of fiber and lower levels of protein, especially beef and pork, was significantly correlated with lower levels of antimicrobial resistance genes (ARGs) among their gut microbes. Those who had the lowest levels of ARG in their gut microbiomes also had a greater abundance of strict anaerobes, which are bacteria that do not grow in the presence of oxygen and are a hallmark of a healthy gut with low inflammation. Bacterial species of the family Clostridiaceae were the most numerous anaerobes found.
But the amount of animal protein in the diet was not the best predictor of high ARG levels. The strongest evidence was for the association of higher amounts of soluble fiber in the diet with lower levels of ARG.
“Surprisingly, the most important predictor of low ARG levels, even more so than fiber, was diet diversity. This suggests that we may want to eat from a variety of food sources which tend to be richer in soluble fiber for maximum benefit,” added Lemay.
Soluble fiber, as the name suggests, dissolves in water and is the main type of fiber found in grains like barley and oats. legumes like beans, lentils and peas, seeds (like chia seeds) and nuts; and certain fruits and vegetables like carrots, berries, artichokes, broccoli and winter squash.
At the other end of the data, people who had the highest levels of ARG in their gut microbiomes were found to have significantly less diverse gut microbiomes compared to groups with low and medium levels of ARG.
“Our diets provide food for gut microbes. All of this suggests that what we eat could be a solution to reducing antimicrobial resistance by altering the gut microbiome,” Lemay said.
A total of 290 healthy adults participated in the study.
“But this is still early days because what we did was an observational study rather than one in which we provided subjects with a particular diet, which would allow for more direct comparisons,” Lemay said. . “Ultimately, dietary interventions may be useful in reducing the burden of antimicrobial resistance and could ultimately motivate dietary guidelines that will examine how nutrition might reduce the risk of antibiotic-resistant infections.”