Are fruits and vegetables good for me? Mostly yes, but there are some exceptions.
One of these exceptions is an intolerance of some sugars and starches in fruit and vegetables. This is evident as significant bloating and/or constipation/diarrhea after eating. I recall one athlete who loved apples dearly, but eating one apple ruined her day, until she figured out the real cause for that. For some apples (and other citrus fruits) are the worst, some do not tolerate cheeses, some struggle with cauliflower and/or other veggies.
This is because of a disruption in microbial balance in the gut. The bacteria ferment the fructose, and other sugars from the fruit and vegetables, leading to the symptoms. The bacteria should be in the large intestine, but travelled all the way up to the small intestine. In the small intestine the food is not as digested yet, and therefore the bacteria can ferment some sugars and starches (so called FODMAPS) in the small intestine. This leads to bloating and gas, but also to malabsorption, changes in the microbiome of the large intestine, and also immunological involvement (inflammation).
The situation where bacteria, which should be in the large intestine are present in the small intestine is called SIBO (small intestinal bacterial overgrowth), and a diet low in fermentable sugars (low FODMAP diet) will be an instant relief of symptoms.
There are lab tests to check for SIBO, but the best test is to leave FODMAP foods out of the diet and feel for a positive response. If a person feels better on a low-FODMAP diet, then she/he should NOT continue with a low-FODMAP diet, but undertake the necessary steps to treat the underlying SIBO. Many practitioners advice to stay on a low FODMAP diet forever. This is not smart.
A low-FODMAP diet is NOT a long-term solution. It is merely diagnostic for SIBO!
May the FLOW be with you brothers and sisters!
Gerrit Keferstein is a Medical Doctor specialised in Performance & Functional Medicine. He is most known for his work on the optimisation of recovery and adaptation in elite athletes.