People who are obese tend to have an irregular mix of bacteria in their colon, which can impair their ability to feel full after a meal and promotes chronic inflammation—eventually leading to type 2 diabetes and ‘metabolic syndrome.’ The health benefits of apples have been well documented, but a new study has taken the research a step further by looking specifically at how the nondigestible components of apples influence the kinds of bacteria that live in the gut.

Researchers from Washington State University and the University of Idaho compared the major strains of apples grown in the Pacific Northwest—Braeburn, Fuji, Gala, Golden Delicious, Granny Smith, McIntosh and Red Delicious—and found that they significantly differed in their levels of dietary fiber and polyphenols (phenolics and proanthrocyanidins), with Granny Smith having the most of these beneficial components. When they compared fecal samples from normal mice and mice with experimentally induced obesity, they found that apples (Granny Smith were the only variety they tested) restored the abnormal bacterial profile of obese mice to resemble that of normal mice.

More research is needed to translate these findings to human patients, but they suggest that apples could be a simple way for people struggling with obesity to help prevent low-grade inflammation and long-term consequences.

(Source: Food Chemistry, 2014; DOI: 10.1016/j.foodchem.2014.03.122)