What about antibacterial qualities of onion and garlic in low fodmap diet?

[IBSvictim]

As I understand it, the aim of low fodmap is to inhibit bad bacteria but depriving them of nutrition. Onion and garlic are to be avoided as they have nutrients that are supposed to be good for the bad bacteria. But what about the antibacterial qualities of onion and garlic? I always thought this would override any factor that helped bad bacteria. Has any research been done into whether onion and garlic have an overall positive or negative effect on bad intestinal bacteria?

[asbayford]

It's to do with the high amounts of fructans in onions and garlic, also in wheat and certain beans, grains. Fructans are good for the average person as they feed the good bacteria, however in ibs, it causes bad symptoms such as diarrhoea and unable to absorb vitamins, so the cons outweigh the good for us with onions&garlic. It's a 'low' fodmap diet, not a 'no fodmap' diet, so we do still get a small amount of fructans to feed the good guys.

Hope this helps!

Edit: it's the compound 'allicin' in garlic that gives the antibacterial benefits, allicin tablets are actually low fodmap

[Maureen1958 in reply to asbayford]

Very interesting reply. I have been wondering about fructans myself lately. I will have to look into this a bit more. Thanks.

[IBSvictim in reply to asbayford]

Thank you, that's useful to know. I didn't want to give up the antibacterial qualities of onion and garlic as if I have bacterial overgrowth I want to fight this on as many fronts as I can. So allicin tablets sounds like a great substitute.