At birth, we are all colonized by bacteria from our environment. Whichever colonies take hold first can have lifelong consequences, and in rare cases, can be deadly. The first reaction in hospitals to a potentially deadly (but rare) bacteria called Group B Streptococcus (GBS), was to give antibiotics and kill the bacteria in the mother's body. My childbirth class goes in-depth into all the options if you carry this bacteria in particular at birth, but let's concentrate on not having it in the first place.
The best way to combat GBS, E. coli (which can cause UTIs), and other dangerous microorganisms (like the ones that cause yeast infections) is to not give them room to grow in the first place. We can drive them out by doing things that encourage our beneficial bacterial populations.
Other fermented foods
Probiotic powders or capsules also deliver bacteria to our gut, but all of these foods need to be taken regularly for best results.
Feed Those Buggers!
Other measures than can help are feeding those good bacteria once they're there. Certain fibers and starches make great bacteria food, so eat healthy foods. Hey, you're doing that anyway, right? Interestingly, cooking and then refrigerating your beans and potatoes increases the amount of bacteria food.
Don't Kill Them
So you're eating lots of good bacteria and keeping them fed, so now make sure you don't kill them. Antibiotics kill beneficial bacteria as well as the bad ones, so try to avoid them pregnancy. Other things can kill them like essential oils (which can be in your shampoo and body wash), douches, and soaps. It's recommended to only wash your genitals with water, and this includes both partners.
Help Your Baby's Bacteria
Whatever bacteria your gut is colonized with your vagina will also have. Once you make sure your own intestines are full of these very helpful little guys make sure your baby gets them. In other words, do whatever you can to have a vaginal birth. If a Caesarean is needed, talk to your provider about swabbing your baby with good bacteria, explained here. The next very important step is to breastfeed your baby exclusively for six months. (If you need help, please contact me and I will sell you an awesome breastfeeding DVD.) Breast milk not only continues to give your baby bacteria and nutrition for those bacteria, but prevents harmful bacteria from getting a foothold through the water used to make formula. If you do have to bottlefeed, please sterilize the water and bottles every time to prevent this.
Now pat your tummy and thank those millions of bacteria inside for helping you digest your food and keeping you healthy!