I thought it did, but don't know for sure. I haven't had to take it as much this time round, but I did alot more when DS1 was feeding. His poos were more orange colour on days after i'd take it and i'd also find when there were days when he hadn't pooped, if i took metamucil he would poo shortly after.

I learnt that berocca goes through to the milk though, but i didn't feed DS1 the following day (it was after a night out for my best friends hens night so i pumped and dumped- mainly for comfort), as the milk was a strange shade of orange. So if that goes through i couldn't see why metamucil wouldn't.

Will be interested to know the correct answer to this though.