'An apple a day keeps the doctor away'

‘An apple a day keeps the doctor away’, is a well-known proverb. This is mainly because the vitamins and fruit-sugars in apples, next to the organic fiber content. Other “healthy” compounds in fruit include flavonoids, an antioxidant, and pectin. Apples are currently the most produced fruit globally, with approximately 80 million metric tons of production per year. Apples consist of a stem, peel, pulp, seeds and calyx, and every of these areas has its own specific microbiome.

Especially raw fruits and vegetables contain a high density of bacteria. As such, when eating fruits, the human microbiome is supplemented by these extra bacteria, and as such the composition of the microbiome is altered.

Furthermore, it has been found that a plant microbiome is needed for fruit or vegetables to grow. The bacteria support the plant micro-environment, but yet still little is known about the types and functions of these bacteria. This is as such also a matter of food safety, with regards to the presence of potential pathogenic species.

One research has found that apples may contain around 100 million bacteria that we ingest per apple, and that the diversity and abundance of bacteria is especially high in raw and organic apples. Furthermore, the consumption of organic apples increases the need for production of organic apples, which has a lower carbon footprint than production at “regular” apple orchards.

https://www.frontiersin.org/articles/10.3389/fmicb.2019.01629/full