An apple a day is a good bet for health—especially the health of your gut…and especially if that apple is organic, a recent study has confirmed. The bacteria you consume from eating raw fruits and vegetables support a healthy community of microorganisms (microbiome) of the digestive tract. Raw is the best way to go because cooking kills the healthy microbes that protect your gut.

A balanced and healthy microbiome is key for digestive health and for a healthy immune system. Healthy bacteria—such as Lactobacillus found in probiotics—need to balance out harmful bacteria that can cause digestive disorders, such as food poisoning.

The researchers, from the Institute of Environmental Biotechnology at Graz University in Graz, Austria, wanted to see if bacteria in raw fruit differed between organically and conventionally grown fruit. They chose apples because they are among the most common fruits eaten worldwide. Their findings were published in Frontiers in Microbiology.

Study details: The researchers picked four organically grown apples and compared their bacterial components with four conventionally grown apples matched for size, color and flawlessness. Although both types of apples had about the same number of bacteria—about 100 million cells—the organic apples had more bacterial variety. The conventional apples had more harmful bacteria, such as E. coli and shigella, which are associated with food poisoning. The organic apples had more probiotic bacteria.

To be labeled as organic, a fruit or vegetable needs to meet certain standards that include avoiding the use of pesticides and chemical fertilizers. [1] The researchers found that although all parts of the apple had bacteria, a large portion of it was found in the seeds and core. To get up to 100 million bacterial cells, you would need to eat the whole apple. Apples provide other health benefits, such as antioxidant flavonoids and heart-healthy fiber from pectin.

Takeaway: This is one more study that points to the importance of including raw fruits and vegetables in your diet. The investigators conclude that organically grown fruit may offer a wider variety and more probiotic types of bacteria that could lead to a healthier, more balanced gut microbiome. And a healthy gut usually means a strong immune system.

Source: Study titled “An Apple a Day: Which Bacteria Do We Eat With Organic and Conventional Apples?” by researchers at Institute of Environmental Biotechnology, Graz University, Graz, Austria, published in Frontiers in Microbiology.