The occasional indulgence in a sweet treat can be harmless, but researchers are now urging caution over eating sugar while on certain antibiotics.
A new study by City of Hope researchers in California found that eating less sugar could protect the body’s microbiome – the collection of beneficial bacteria – while taking antibiotics, which are known to disrupt the delicate balance of good and bad bacteria.
In turn, this may lead to better outcomes in cancer patients on the medications.
‘Antibiotics disrupt the diversity of our gut bacteria, or microbiomes, which play an essential role in supporting our immune systems and overall health,’ said co-senior author Dr Marcel van den Brink, president of City of Hope Los Angeles and City of Hope chief physician executive.
‘Our research supports emerging evidence that avoiding sugary foods during antibiotic treatment may protect the microbiome. Preserving microbiome diversity has previously been linked with improved clinical outcomes for patients with cancer.’
Antibiotics throw the body’s microbiome out of balance because they don’t exclusively kill just the bacteria causing the infection they are prescribed to treat.
Depending on the medication, antibiotics can also kill off the body’s beneficial bacteria, which can lead to uncomfortable side effects, such as diarrhea, bloating, gas, abdominal discomfort, infections with other pathogens and out of control growth of harmful bacteria already present in the microbiome.
In the new study, researchers followed patients with blood cancer who were undergoing an intensive treatment and who were at high risk for severe gut microbiome disruption.
The combination of high-sugar foods and broad-spectrum antibiotics appeared to exacerbate the disruption of the microbiome (stock image)
To prevent and treat infections, each patient took at least one antibiotic during treatment, with 80 percent taking one or more of the broad-spectrum antibiotics that have the strongest effect on the microbiome.
To track the patients’ meals, the researchers had them complete a questionnaire every time they ate or drank
The team tracked 9,400 meals eaten by 173 patients and analyzed the microbiome diversity in stool samples from 158 of them. The data included more than 40,000 individual food items and 1,000 stool samples.
Van den Brink noted: ‘Unlike past nutrition studies that rely on patients’ memories of what they ate or other imprecise surveys, we had meticulous dietary records collected in real time. This enabled us to look for patterns that otherwise might be impossible to detect.’
After analyzing the data, researchers said what they found surprised them.
‘No matter how we analyzed the data, the same strong signal kept appearing,’ van den Brink said.
‘The patients who consumed more sweets while taking antibiotics were more likely to experience a loss of microbiome diversity as aggressive microbes crowded out other strains of bacteria.’
Researchers wrote that the combination of high-sugar foods and broad-spectrum antibiotics appeared to exacerbate the disruption of the microbiome.
This led to a 24 percent decline in bacterial diversity for every 100-gram increase in sweets – the equivalent to the amount of sugar in a large milkshake.
And one potentially dangerous organism stood out among the rest: Enterococcus.
When this organism grows in the microbiome, patients undergoing transplants face higher risks of bloodstream infections and life-threatening complications.
The researchers then tested sugar’s impact on the microbiome in mice taking broad-spectrum antibiotics, feeding them a high-sucrose diet. This quickly led to an overgrowth of enterococcus in their guts.
Van den Brink said the confirmation seen in the animal study ‘provides a compelling rationale for future clinical trials’ evaluating sugar intake during antibiotic usage.
But based on the results already seen in the mice and humans, van den Brink said the results reinforce diet as a strong factor in recovery and as a practical way hospitals can support recovery during certain treatments.
He added: ‘The microbiome is emerging as an important factor in cancer care.
‘The better we understand what supports and disrupts it, the more opportunities we have to reduce treatment side effects while improving how patients respond to and recover from therapy.’
