Too Many of Our Plates Are Missing Immune-Boosting Microbes

Lisa Rapaport

June 22, 2022

What we eat affects the trillions of bacteria, fungi, viruses, and other germs that live in our digestive tract and our diet shapes what scientists call our gut microbiome. The microbes inside our bodies change how the immune system functions and influences physical and mental health.

Scientists know that certain dietary options like fermented foods, yogurt, and non-starchy fruits and vegetables help create a healthy mix of organisms in our gut.

But one thing about the gut microbiome has remained a mystery: How many immune-boosting microorganisms do people actually eat with all the different foods they consume?

To figure this out, investigators estimated the number of microorganisms per gram in more than 9000 different foods. Foods with the highest levels of microbes included things known to promote a healthy microbiome like yogurt, pickles, and kimchi. Foods with medium microbe levels included a wide variety of raw fruits and vegetables.

Then, to see how many people ate foods packed with microorganisms, scientists looked at detailed dietary data collected from 2001 to 2018 for almost 75,000 adults and children.

Overall, 26 percent of adults and 20 percent of children consumed foods with high levels of microorganisms in their diets, researchers report in The Journal of Nutrition .

"When we think of microbes in our food, we often think of either foodborne pathogens that cause disease or probiotics that provide a documented health benefit," study co-author Colin Hill, PhD, of APC Microbiome Ireland at the University of College Cork, said in a statement.

But it's important to also explore dietary microbes that we consume in fermented and uncooked foods, Hill says.

"It is very timely to estimate the daily intake of microbes by individuals in modern society as a first step towards a scientific evaluation of the importance of dietary microbes in human health and wellbeing," Hill adds.


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