Did you know that vegetables each have their own diverse microbiome? Just like humans have microbiomes that are uniques to their guts, nasal passages, ears, bellybuttons etc., vegetables all have unique species of organisms that call these plants their home. Species vary between different kinds of vegetables, and are influenced by farming and food processing practices (Source). Cabbage is one example of a vegetable, where humans have found a way to capitalize on its microbiome. If you have ever made a traditionally fermented sauerkraut or kimchi, then you might already be familiar with the fact that cabbage doesn't require the addition of a culture starter. Cabbage's culture starter is its own microbiome. The organisms that live on cabbage are the same organisms that allow cabbage to become sauerkraut. Just by adding water and salt, the conditions are set for fermentation to occur.
The organisms that turn cabbage into sauerkraut would be considered to be beneficial for our health, but what happens when the organisms on plants are pathogenic?
We know that pathogens such as Salmonella and E. coli are associated with disease, and that these species can be problematic when vegetables are eaten raw. An example would be spinach contaminated with Salmonella. You may be familiar with various recalls of spinach that have happened in recent years for this very reason. Similarly, E. coli outbreaks have been traced back to sprouts and lettuce.
Should you stop eating these vegetables? Does the risk of food poisoning outweigh the nutritional benefits of these foods?
IMPORTANCE OF MICROBIAL DIVERSITY
Microbial diversity in your gut is important for good health. Diversity helps us prevent disease and also ensures that pathogenic species are less likely to be able to infect the host (Source).
For a bit more information on diversity, just scroll down this page and read my blog on MICROBIAL DIVERSITY FOR GOOD HEALTH
FRIEND OR FOE?
Vegetables can harbour both beneficial and pathogenic species of organisms. Eating a variety of raw vegetables is one way to increase the diversity of your microbiome, but there is always the risk of being infected with a pathogenic species of organism. Your current state of health will largely determine whether a vegetable's microbiome is friend or foe.
The less diversity you have in your gut, the more likely it will be that these pathogenic species will be problematic (Source). This is especially the case if someone's immune system is compromised. Immune compromised individuals can include conditions such as cystic fibrosis, HIV, those undergoing chemotherapy, long-term antibiotic use and the elderly.
If you know you are immunocompromised, or you know you have dysbiosis, then it might be wise to consume your vegetables cooked to eliminate the risk of pathogenic infection. Beneficial species can be introduced by cultured foods or supplements rather than through raw vegetables. If you are confident that you have a healthy gut with a healthy, diversely populated microbiome, then you will be at little risk of pathogenic species being problematic for you.
One way to ensure you are able to benefit from consumption of a diversity of organisms without risking infection is to grow your own vegetables. Growing your own vegetables, allows you to control exactly what goes into your soil and what goes on the plants.
In my small vegetable plot, all I add each year is the compost I have created from fruit and vegetable scraps and leaves collected in the fall. My compost is quite distinct in that there are always pieces of eggshell that haven't broken down, so my garden soil is speckled with eggshell fragments. Eventually those pieces break down to add minerals to my soil. I am very comfortable eating the foods I grow straight from the garden with little or no washing. I know I'm getting the most benefit from the plant's microbiome this way, and that there is no risk of pathogenic species being introduced.
You can also talk to your local growers. Visit a farmer's market and chat with the people who are involved in growing. Any farmed vegetables will have been handled by people involved in harvesting, so there is some risk that infection can be passed on through the individual's handling the food. Produce should always be washed when purchased. Gentle washing can help remove surface contamination without removing all the beneficial organisms. Grocery store produce may have been irradiated, which removes both beneficial and pathogenic species, so there may be no benefits to from a microbial perspective. Additionally, it will have been handled by multiple people, so should always be washed thoroughly.
Happy, Healthy Eating and Gardening!