Depending on the individual and the severity of IBS, it may not be necessary to eliminate all the FODMAP foods completely. The amount and the type of food consume matters. So a person may be fine eating an apple by itself. But may not be when eating an apple along with a dish containing broccoli together. Both apple and broccoli are on the high FODMAP list.
One person may have no problems with apples, but problems with milk. Another person fodmaps diet may be the exact reverse. Some may find that wheat, onions, apples, and pears are the most problematic. But others may not.
For some who are only lactose-intolerant, elimination of only lactose may be enough. There is a hydrogen breath test that can determine lactose-intolerance. For those who do not have lactose intolerance, they can safely consume lactose. But then they may or may not have problems with the other oligosaccharides.
People who do not have enough of the lactase enzyme will be lactose-intolerant. Whereas, people without enough hydrolases in the small intestine to break the fructose-fructose bond would be intolerant to oligosaccharides.
Then for others, it may require near total elimination to see any beneficial effect. So it gets complicated and people with IBS should work with a trained dietitian to eliminate not all FODMAP foods, but only those foods that one is particularly intolerant to.
The ironic thing is that FODMAP may be due to imbalance of gut flora, and eating fibers and fruits and vegetables (some of which are FODMAP foods) is supposed to balance and improve the gut flora over the long run because fiber is the food for the good bacteria as well.
On a Chris Kresser podcast, he says ...
"All prebiotics are FODMAPs, so when youre on a low FODMAP diet, youre avoiding prebiotics, but the thing is, prebiotics are what have the most profound effect on the gut flora over time. So, if you always avoid prebiotics and you dont make any effort to work them back into your diet even at low levels, then you might feel better for as long as you avoid those foods, but you may never regain your ability to eat those foods because the changes in the gut microbiota are what led to that inability in the first place."
But the good thing is that FODMAP sensitivity can go away, unlike gluten sensitivity. So it might help to not avoid FODMAPs entirely, but work them back slowly into low fodmap foods one's diet up to one's individual tolerance.
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