written by dietitian Hazel Clark
Look, us mere mortals never really get to find out what is going on in the world of science. Well, not unless it’s (sometimes) sensationalised in the press. So, we wanted to bring you a snapshot of the latest science to whet your appetite to find out more if it’s something that piques your interest. Or, simply to keep you all in the “gut world” loop. Remember most of the studies are VERY new science, so keep your critical thinking cap on!
Background
You’ve probably heard the saying “an apple a day keeps the doctor away” but what are the health benefits of apples? Aside from being a good source of fibre, polyphenols, and nutrients. The microbes living on and in apples may also boost this humble fruit’s health credentials. A recent study reported that apples are home to around 100 million bacteria! Could this be one of the many reasons why apples have purported health benefits? With apples being one of the most consumed fruits worldwide, this is a really interesting study. It looks at external exposure to bacterial communities (and not just the ones in your gut).You can find the full research here.
Types of Study
Using DNA sequencing, researchers from the Graz University of Technology in Austria analysed the bacteria strains and quantity in different parts of the apple (stem, peel, fruit pulp, seeds, and calyx). And then compared conventionally grown apples to organically grown apples.
Study Findings Of The Bacteria Profile Of Apples
Researchers found over 100 million bacteria had set up home in each apple. Most bacteria were found in the seeds, stem, and calyx (the bottom), stem and pulp. Interestingly, the skin of the apple contained the least bacteria. The bacteria profile of apples, comparing prganic and conventionally grown apples contained the same amount of bacteria but the organic apples had a more diverse range of bacteria and more of the beneficial species, such as Lactobacillus (check out our video about probiotic strains).
Study Limitations
This is an interesting piece of research looking into the bacteria composition of apples, but what we don’t know is how this translates across different species of apples in different parts of the world and how the bacteria in the apple interacts and has an effect on the human gut microbiota.
Conclusions
Apples are a great source of fibre, flavonoids and nutrients. This study gives an insight into their potential probiotic properties too, with organic apples having a greater diversity of beneficial bacteria than conventionally grown.
About the Author
Monica Mischie obtained an Msci in Human Genetics from University College London in 2018. She is now doing a Ph.D. on the gut microbiome and dietary fibres at Imperial College London. She loves cooking, discovering new flavour combinations, and visiting farmers’ markets.