Next time you chomp into a crunchy apple, in addition to enjoying the sweet taste, you can think about all the possibly beneficial bacteria you are consuming. New research suggests an apple is teeming with about 90 million bacteria.
And if you're looking for the best "bugs" for your gut, you may want to go organic. The researchers found that fresh, organic apples may harbor a more diverse and well-balanced microbiome than conventionally produced apples.
The study also suggests a rethink on throwing out that apple core. The team used gene sequencing to analyze the bacterial communities living in different parts of the golden delicious-type apple in Austria (called the arlet). [5 Tips for Getting More Fruit into Your Diet]
Most of the bacteria, they found, live in the core of the apple, which includes the seeds (about 38 million), the calyx end (22 million) and the stem end (10 million). The fruit pulp holds about 20 million bacterial cells, while the peel is host to just 1.6 million.
That's why the researchers suggest eating the entire apple, including the bacteria-packed core, said Birgit Wassermann, first author of the paper, which was published June 24 in the journal Frontiers in Microbiology. Wassermann is a doctoral student in the lab of Gabriele Berg at Graz University of Technology in Austria.
The organic apples also bested conventional ones in terms of how "diverse" their microbiomes were, something that could impact the fruit's taste.
"Methylobacterium, [a bacterium] known to enhance the biosynthesis of strawberry flavor compounds, was significantly more abundant in organic apples," Berg, a biologist and biotechnologist, said in a statement. The tasty compounds accumulate in the fruit's peel and pulp.
The organic apples tested also contained a wide variety of bacteria types in fairly balanced proportions, which may help prevent any one species from overtaking the rest.
"The highly diverse microbiome of organically managed apples might probably limit or hamper the abundance of human pathogens," the researchers wrote in their paper.
Many of the organic apples contained the probiotic Lactobacilli, a gut bug completely absent from the conventionally grown and managed apples. Most of those conventional apples contained a group of bacteria that includes known pathogens, which could harm human health.
"The microbiome and antioxidant profiles of fresh produce may one day become standard nutritional information, displayed alongside macronutrients, vitamins and minerals to guide consumers," Wassermann said. Future research may also reveal how microbiomes differ between apple varieties and how exactly fruit-borne microbes support bacterial diversity in the gut, the authors said.
Because the apples tested were produced in Austria, the results may not hold for apples in other regions.
The study was funded by a program within the Austrian Federal Ministry of Education, Science and Research. The authors stated that they have no financial or commercial relationships that could pose conflict-of-interest concerns.
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Originally published on Live Science.
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Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.