‘Antibiotic diets’ as a possible approach
A compromise between the two sides may be the so-called antibiotic diet. The theory behind such diets is that foods and beverages with biome-boosting properties may be a risk-free intervention that patients can adopt to alleviate antibiotic-related side effects.
“You want your diet to include more soluble fibers to help support the good bacteria, particularly when you’re taking antibiotics,” said Dr. Cresci. “You can get this through eating fresh fruits and vegetables, whole grains, and foods that have more prebiotic, like potatoes. You can also eat fermented food, such as kefir, kombucha, kimchi, and yogurt, so you’re adding more beneficial bacteria into your intestinal tract.”
There is ample published evidence that such foods can boost microbiome diversity and decrease inflammation, including a July 2021 study in Cell. However, the protection this may confer while taking antibiotics isn’t known. Establishing a clear role for the efficacy of such interventions is made additionally difficult by the well-established limitations of conducting dietary clinical trials.
Dr. Merenstein said that there is no compelling evidence that antibiotic-related complications can be offset by changing what goes onto our dinner plates. He joked: “We can’t say, ‘Here’s amoxicillin for your ear infection, now make sure you increase your fermented food, fiber, and water.’ ”
Dr. Johnson said he’s intrigued by studies of prebiotics – fibers that boost beneficial bacteria in the GI system.
“I would love to have more findings about prebiotic identification; that is, things we could do in a healthy way to keep the gut balanced while it’s subject to a change with antibiotics,” he said. “We’re just not there yet.”
Dr. Johnson added that he generally recommends that patients taking antibiotics eat “a bland diet, avoiding things that may have been provocative in the past.”
If patients are already enjoying foods with microbiome-boosting reputations, Dr. Johnson sees “very little downside to continuing that [while on antibiotics].” However, he noted that the period in which you’re taking antibiotics isn’t ideal for trying new foods, given the lack of experience with how the gut bacteria will react.
There are data about foods to avoid while taking antibiotics, which generally fall in line with common dietary knowledge. Many patients may know not to drink grapefruit juice with certain medications, but it’s worth a reminder. Certain antibiotics may also require delaying or avoiding dairy products, although this does not apply to yogurt.
A fiber-deficient diet can aggravate microbiota collapse following antibiotics. In a 2020 study, researchers showed that people on a high-fat diet who were using antibiotics were 8.6 times more likely to have preinflammatory bowel disease than those eating low-fat foods and who had no recent history of antibiotic use. Mouse model data from the same study indicated that poor diet and antibiotics may have worked in conjunction to reduce oxygen in the gut.
Dr. McFarland noted that building a healthy microbiome is a lifelong pursuit and that several factors (for example, environmental or genetic) are out of individuals’ hands. The general public might want a quick fix – ironically, one of the main drivers behind their requesting and receiving antibiotics when they’re not indicated – but it’s likely not available to them.
“You can’t eat one salad and suddenly have a healthy gut, unfortunately.”
A version of this article first appeared on Medscape.com.