An apple carries about 100 million bacteria: Study

London (PTI): Besides containing fibre and vitamins, an apple also carries about 100 million bacteria, and whether these microbes are good or bad for health may depend on how the fruit was grown, according to a study.

The study, published in the journal Frontiers in Microbiology, shows that organic apples harbour a more diverse and balanced bacterial community -- which could make them healthier and tastier than conventional apples, as well as better for the environment. "The bacteria, fungi and viruses in our food transiently colonise our gut," said Professor Gabriele Berg, of Graz University of Technology, Austria.

"Cooking kills most of these, so raw fruit and veg are particularly important sources of gut microbes," Berg said. To help us choose our colonic colonists wisely, the team analysed the microbiome of one of the world's favourite fruits: the apple. "83 million apples were grown in 2018, and production continues to rise. But while recent studies have mapped their fungal content, less is known about the bacteria in apples," said Berg.

The researchers compared the bacteria in conventional store-bought apples with those in visually matched fresh organic ones. Stem, peel, flesh, seeds and calyx -- the straggly bit at the bottom where the flower used to be -- were analysed separately. Overall, the organic and conventional apples were occupied by similar numbers of bacteria.

"Putting together the averages for each apple component, we estimate a typical 240 gramme apple contains roughly 100 million bacteria," said Berg. The majority of the bacteria are in the seeds, with the flesh accounting for most of the remainder. So, if the core is discarded, the intake falls to nearly 10 million, researchers said.