Ah, probiotics. The supplement du jour.
It was only a matter of time. Just as we started wrapping our heads around the concept of consuming “live cultures” for gut health, the market spilled into the realm of baby products.
Would you deny your baby something that promises eternal tummy happiness?
WHAT ARE PROBIOTICS?
Is it me, or are probiotics one of those things that we nod our head in conversation and go “oh, sure, totally, it’s soooo important” without having a freaking clue what we are talking about?
Here’s a super quick summary of our belly bugs —
We eat stuff… let’s say kale. Our measly human machinery cannot break down the tough bits in kale. We simply do not have the tools.
You know who does have the tools? Bacteria. Specialized little worker bugs that hang out in our intestine with their tools all ready for the kale chunks that escape our ill-equipped stomach.
In exchange for room and board, those little worker bugs break down that kale and kick back some nutrients we would have missed. Kale-eatin’ bugs are only the start. Along with a range of other little bug friends, our gut is host to a beautiful little ecosystem that, when kept happy and in balance, can confer all kinds of health benefits.
Probiotics? Anything that you might ingest containing live microorganisms (bacteria) that pass through the digestive system to confer “benefits” once they reach the intestines. For example, a whole range of yogurt products have “live cultures” on board and are promoted as probiotics.
Here’s the problem — our gut is already jam packed with resident bacteria. After those “live cultures” brave the digestive passage to end up in your gut, they drop off the good stuff they already made while waiting out in the yogurt, and pass on through. The real estate landscape is already too crowded and the residents are not likely to make room for the new guys.
But you know whose gut does have a lot of open real estate?
COLONIZING THE BABY GUT
In order to establish residency, the microbes have to get there.
When they’re born, babies are rubbed all over by bacteria that may be important for gut colonization. The gut of a C-section babies compared to a vaginal birth babies shows profound differences. Babies that come out on their own have higher quantities of helpful microbes. Presumably, this is a result of spending time in the birth canal. But, this study cannot rule out another possible influence — C-section mamas went through major surgery and weren’t able to nurse immediately or effectively for the days before the test (samples taken on day 3 post-birth) .
Which brings us to that mama milk.
We all know that breast milk passes along important antibodies, but here’s another thing that breast milk may provide— gut bacteria.
Yes, helpful microbes may also be passed along in the milk .
More importantly, human breast milk contains a critical prebiotic to sustain the helpful bacteria.
PREBIOTICS ARE MORE IMPORTANT THAN PROBIOTICS
Ok, prebiotics, what are those?
Think of prebiotics as the food for the good bacteria. Without a prebiotic, the probiotic bacteria reaching the intestine realize that there is nothing for them to do and nothing for them to eat, and they wave goodbye to the other bacteria setting up shop and head on out the other end. They are probably not around long enough to confer any kind of benefit to that baby.
No food? No bugs.
Human breast milk has special complex sugars, called Human Milk Oligosaccharides. The human body cannot digest these sugars. Only specialized bacteria can digest them. By introducing this prebiotic, the bacteria that feast on this specific sugar flourish. They set up shop and multiply. They also kick back amazing benefits — immune system building, preparing a happy gut for adulthood, and the list goes on.
But these bacteria will only set up shop if they have those special mama sugars available. No sugars? No food. No bugs.
You can have a prebiotic without a probiotic, but a probiotic without a prebiotic is useless.
Adult side note:
One funny thing about this all is that a common probiotic on the market is a little posse of bacteria called Bifidobacteria. These bacteria were first isolated from baby poo and now they are the main health bug in a whole range of probiotic products aimed at adults.
The problem? Bifido prefers Human Milk Oligosaccharides as a prebiotic. Since I’m pretty sure no adult is taking a healthy swig of breast milk on a daily basis, it’s hard to say how much benefit our adult gut is getting from adding these fellas to our daily diet.
BACK TO THE BABIES! THE VERDICT?
First, here are my general concerns —
One, you are essentially feeding your baby bacteria. Where is this bacteria coming from? How is it controlled, isolated, tested?
Two, the baby gut is trying to do it’s thing. It is set up to do it’s thing. Do we need to play puppet master to a community that has evolved for beautiful symbiotic balance?
So, at first I would have said “NO, crazy!” but upon greater reflection I have softened my stance.
A few scenarios:
Natural birth, breastfeeding mama — why mess with nature? This is my category, and, personally, I will not be giving the wee one probiotics.
C-section, breastfeeding mama — Tough one. We still do not know how important the exit strategy is for setting up the important bacteria. Maybe they could use a boost?
Super early baby, breastfeeding mama — Ok, for this one there are some data. A recent study in a NICU, doctors gave babies born pre-term (< 32 weeks), daily doses of a carefully screened probiotic. There was a significant reduction in necrotizing enterocolitis (a super scary intestinal disease in preemies). Sure, the numbers went from 10% to 5% but when you are talking about babies, every baby counts. The authors conclusion was to adopt daily probiotic administration into the protocol of pre-term care .
See a pattern? Breastfeeding is key. The boobs make the prebiotic.
Even in the NICU study, 93% of the mothers were nursing.
FORMULA + PROBIOTICS?
Only human milk has the one true prebiotic to encourage the happy bugs to grow and establish their community.
To get around this, formula companies have tried to mimic Human Milk Oligosaccharides with a combination of complex, but not as complex, sugars: Galacto-oligosaccharides and Fructo-oligosaccharide (GOS/FOS). Some research suggests that having this GOS/FOS prebiotic is enough to get the happy bacteria established in the baby gut similar to the breast-fed baby (no probiotic necessary) . Other research warns that we don’t know enough about GOS/FOS to be messing around with it .
Research on everything involving the baby gut is still in its infancy (pun intended).
We haven’t mapped out every inch of bacterial real estate in the ever changing baby intestine. We don’t know the job description for every occupant. We don’t know the long-term effects of manipulating the landscape.
I say, leave ‘em be for now.
The baby will figure out how to walk.
The microbes will figure out how to flourish.
4. Bakker-Zierikzee, A.M., Alles, M.S., Knol, J., Kok, F.J., Tolboom, J.J.M., Bindels, J.G., 2005. Effects of infant formula containing a mixture of galacto- and fructo-oligosaccharides or viable Bifidobacterium animalis on the intestinal microflora during the first 4 months of life. Br J Nutr 94, 783–790.
I am a scientist. But I also work in Berkeley, CA. And it was only a matter of time before these worlds collided…
Let’s talk about the science behind a very popular pregnancy herbal supplement – Raspberry Leaf Tea.
(My prenatal yoga instructor is not going to be happy with me.)
Though I proudly bought my Prenatal Vitamins, Ovulation tests, and pregnancy pee sticks, I hid my “Mother to Be” tea underneath a red pepper on the supermarket conveyor belt the other day. Yes, I bought the tea but I am still conflicted about buying into the concept that a tea can magically (uh, I mean biologically) strengthen a uterus.
In addition to the gushing words from my yoga instructor, the internet offers up unlimited gems about the stuff. These words of wisdom range from the very appealing – “It strengthens the uterus and pelvic muscles which leads to shorter and easier labors” to the anecdotal – “…my sister’s sister took it at 35 weeks and had her baby within 48 hours” to the very confident “Has been shown to concentrate the effects of contractions to make them more effective”
Alright then, challenge accepted! Time to dig up some scientific evidence for these claims.
So, can raspberry leaf tea do all these amazing things the internet claims it can: strengthen the uterus, shorten labor, decrease assisted delivery, and so on?
Well, despite this supplement being a fan favorite over in the midwife community (63% of American midwives recommend this supplement to stimulate labor ), overall it seems like the jury is still out as to its pro’s and con’s.
A very comprehensive scientific literature search by Holst et al. in 2009  found only six studies testing the effects of the tea in a lab, with non-human or petri dish subjects, and only five studies that took place in the clinic. I do want to note that the small number of studies unveiled was not for lack of trying – these authors including an obscure paper from 1941 that only included three women! Anyway, the lab studies were mixed. Overall, raspberry leaf tea was shown to facilitate more rhythmic contractions in uterine tissue but also showed conflicted toning and relaxing effects. The five clinical studies did not reveal any strong effects of the elixir (positive or negative) in humans. Some studies did show a shorter first or second stage of labor but the tea only knocked off a few minutes (wow!) and one study showed shorter gestation length… but only by a couple of days (insert more sarcastic enthusiasm).
After Holst and colleagues published their efforts combing the literature, another lab study  was conducted to directly test uterine contractions in the presence of raspberry leaf tea in vitro (outside the body). When applied directly to uterine tissue from non-pregnant rats, raspberry leaf tea had no effect on uterine contractibility. However, when the researchers stuck a pregnant rat’s uterus in a petri dish with some the tea – BAM! – the cellular response rivaled that of Oxytocin. Oxytocin, among the many wonderful things it can do during birth, is the main hormone in charge of making sure the uterus steps up and does its job to help get baby out into the world. The researchers then tested whether raspberry leaf tea played Oxytocin’s little helper in this process. With only six test subjects, however, they found results split in two directions: half of the test subjects showed that oxytocin-induced contractions were augmented with raspberry leaf tea, but the other half showed the same augmentation followed by inhibition of contractions. Hmmmm. At the end of the day, though, the authors did not even want to put weight into their own findings (which I actually found quite promising so I was a bit bummed). They concluded that since humans are unlikely to get the same dose that they used on their rat uteri, this effect is probably not translatable to the intact, in vivo uterus of your average pregnant women.
Now for the potential adverse effects. Well, fortunately, there were mostly no adverse effects noted. However, there was one study that found odd trans-generational effects . That’s right, drinking raspberry leaf tea while pregnant may affect your baby and your baby’s baby. In this study, mother rats were fed raspberry leaf extract every day from conception to weaning. The babies of these mother rats showed signs of early puberty and the babies’ babies showed greater growth restriction. Important to point out, though, these rats were consuming raspberry leaf extract throughout the entire pregnancy. I cannot put a percentage on the number of female humans consuming the tea throughout pregnancy but I am guessing more women are taking it primarily when they start to hit that “holy crap, I have to push out a screaming child!” stage. My unscientific analysis of pregnant friends puts this stage somewhere between the second and third trimester but rarely during the first, when the developing womb baby is most likely to be affected by what we are putting into our bodies and when these effects may affect the womb baby’s egg babies. Of course, more studies are needed before we can conclude that this is or is not a scary potential result of raspberry leaf consumption.
As for those benefits –
Sorry, internet, but I have to side with the scientist buzzkills, Holst and colleagues, when they state – “The fact that the product has been in traditional use for decades does not constitute evidence”. There simply are not enough studies to back up the claims that raspberry leaf tea is a pregnancy super juice.
With that said, in honor of full disclosure, I must admit that I have a steaming pot of “Mother to Be Tea” sitting next to me as I write this.
Yup, there will always be a tiny part of me swayed by the fact that it worked for somebody’s sister’s sister.
1. McFarlin, B. L., M. H. Gibson, et al. (1999). “A national survey of herbal preparation use by nurse-midwives for labor stimulation: Review of the literature and recommendations for practice.” Journal of Nurse-Midwifery 44(3): 205-216.
4. Johnson, J. R., E. Makaji, et al. (2009). “Effect of Maternal Raspberry Leaf Consumption in Rats on Pregnancy Outcome and the Fertility of the Female Offspring.” Reproductive Sciences 16(6): 605-609.