It's a seed.

I admit, it's not easy to do, and was a bit of a shock at first. You would be surprised how much stuff has yeast extract in it, like Samboy plain chips. They're plain chips, why do they need yeast extract in them! But I bet, even if you applied just some of the principles you'll see a huge difference. Things like eating natural homemade yogurt everyday, reducing your sugar and gluten intake because they feed yeast; removing yeast - you can get yeast free breads from woolies (admittedly they are $5 for a half loaf and the plain white is very dense, the soy linseed one is nicer) or you could make soda bread which uses natural yogurt instead of yeas, or corn wraps; taking a probiotic, taking a vitamin C that hasn't had the acid stripped from it because yeast prefer an alkaline stomach, and increasing your vegetable/fruit intake, and eating lots of homemade soup!! Honestly, it's the easiest thing in the world to chuck a whole chicken in a pressure cooker with 2 litres of water, boil for 30 minutes, take the chicken out while retaining the now stock, and pull off the meat to put aside to be used in a meal (or even put some back into the soup) - done. I do normally put the carcass back into the stock with some vegetables and lentils, with another 1/2 litre of water and reboil for 30 minutes to make it stronger and really get the marrow out of the bones but you don't have to, and can just put the veg in the first time. But apart from pulling the meat off, it literally takes 5 minutes and I can have it as is or add other veg to it to make it different - broccoli and leek - yummy! Admittedly, if I didn't have a pressure cooker I might not be as keen, and it's less fitting in summer.

Other little detox changes you could make would be eating more onion and garlic - they're natural chelation foods -- and having baths with 1/2 cup of epsom salts a couple of times per week. Toxins are about load, so the odd take away in the wake of these changes isn't going to make a huge difference, and you could always double your dose of probiotics to compensate - it's the hidden stuff that's the problem. Yeast extract is in so many things where it simply doesn't make sense to be...