The advice I got was all about being sensible, basic food hygeine, no raw meats or fish or undercooked eggs or poorly reheated ready meals/leftovers. However I have to point out that the baby won't build up any immunity while in the womb! Babies aren't born with the same immunities we have built up as adults and infections we get whether food poisoning or general illness are generally not passed on to them but can be devastating if they make us very ill! When baby is born they need protection as can easily succumb to illness as they don't have an established immune system, as they get older and start being independant enough to eat mud pies that's when they are better able to cope with the onslaught of bugs we all deal with every day with no trouble. I don't agree with the culture of anti-bacterial and anti viral everything (anti-viral tissues I saw yesterday - for goodness sake, whats wrong with using an ordinary tissue, throwing it away and washing your hands???) and research has show that a good was or clean with ordinary soap and water is just as effective as the antibacterial stuff we waste so much money on. However when pregnant it makes sense to be a bit more cautious - isn't morning sickness bad enough without adding a bit of the squits from that curry that tasted so good at the time?? Some food/water borne infections are actually very dangerous for you and bump so maybe you should regard potential sources with the same caution you would regard someone with chickenpox (even if you have already had it yourself). No need to get paranoid about it, just stick to simple principles, the list of stuff in the don't list is not actually that long!
xx