Probiotics breastmilk: fewer allergies and slimmer too!

Giving babies probiotic bacteria - harmless bacteria normally found in our bodies, notably our digestive systems - has long been theorized to be a method of preventing allergies. From a theoretical standpoint, It certainly makes sense. According to the hygiene hypothesis, we develop allergies in part because our immune systems are under-challenged by a “too clean” environment, devoid of our natural microbes and parasites. Without the proper stimulation, it goes a bit haywire and starts attack all sorts of otherwise benign molecules, such as peanut proteins or egg whites. So if you feed babies lots of probiotic-rich foods, cultured milks and yogurt, they should have plenty of bacteria, the immune system should keep healthily occupied.

A multitude of clinical trials have tested probiotics for both the prevention and treatment of allergies. This review from January 2008 from The Journal of Allergy and Clinical Immunology found that, yes, probiotics do indeed help prevent allergies, but not actually treat them. Fair enough.

It’s possible that breastfed babies get more probiotics from their mother’s milk, which might explain why breastfed babies are less likely to develop allergies. Another theory on the breast-allergy relationship is that eating food proteins (peanut, pollen, egg, dairy) via breast milk (ie mother eats it and it is transmitted to baby through breast milk) might actually help the baby become tolerant as opposed to allergic to the protein (Here is a neat little study from Nature Medicine on mice that showed just that).

Of course the studies here can be a bit conflicting. The most recent suggest that breastfeeding for 4 to 6 months decreases risk of allergies and asthma, but continuing after that seems to increase risk. Weirdly.

Now another prong to the “Breast Is Best” movement is emerging: the added probiotics from breastfeeding might help babies regulate their weights. A follow up of 49 babies from a large Finnish study that was originally testing the probiotics-allergy connection has revealed that those who had higher levels of Bifidobacteria (good and found in many yogurts) and lower levels of Staphylococcus aureus (bad) were less likely to be overweight at 7 years old. Which kind of fits with the observation that allergies and obesity are linked...any may even provide the mechanism that everyone is searching for…

Now you might get all fusty and dig up this paper, which found little connection between childhood obesity and adult obesity (only significantly predicted adult fatness after age 13..), but all told, the story that is emerging on the potential importance of healthy gut bacteria, even from a very early age, is enough to make you wanna feed your child with and then bathe them in raw milk (errr, sort of).