Health Shot: the wild properties of b. infantis

How a random probiotic transformed my baby’s explosive poops

Illustration by Stephanie Davidson for Mood Health

My son was rushed to the NICU 30 minutes after birth due to excess fluid in his lungs that caused him to have trouble breathing. Needless to say, any experience rushing to the NICU with a baby who is struggling to breathe is really scary, but we were lucky that he stabilized within twelve hours, there was a clear-cut underlying cause, and the episode had no long-term impact. As part of the normal procedure, the NICU staff immediately administered a heavy dose of antibiotics in case his breathing difficulty was caused by an infection. He was fed via IV for the first 18 hours of his life, and stayed four days in a plastic box hooked up to all kinds of equipment.

If you have had any exposure to the “breastfeeding best practices,” or the “holistic start to baby’s life,” or the “best ways to ensure your baby’s microbiome is correctly seeded at birth” discussions, you will know that this situation is far from ideal. There was no golden hour, when the baby lies on the mother’s bare chest for the first hour of life to bond and feed, in fact there was minimal skin-to-skin contact of the first four days. Then there was the matter for the big A word, antibiotics, which were given liberally to my two-hour-old baby, a microbiome sin of epic proportions. Even though I believe in a lot of the wisdom behind the recommended best practices, I wasn’t particularly concerned about all this in the moment: once I knew he would live, the rest seemed unimportant.

But when we got home, he developed chronic diarrhea and, most concerning to us right then, an absolutely epic diaper rash. The bright red rash overtook his whole bottom causing him ongoing discomfort, and anytime he was changed he would scream in pain. A lactation consultant told us about a probiotic that she said really helps some babies with diaper rash, and it seemed like it couldn’t hurt, but it also struck me as a bit of a weak attack to mount on such a hefty rash. Probiotics are good, sure, but not, like, transformational. In the haze of early parenthood, we ordered the probiotic and gave it to our son mixed with breast milk in a syringe.

The day after his first dose, the diarrhea disappeared. Within another day the diaper rash was gone. It was a stunning transformation, and perhaps at any other time of life I would have dwelled on it and tried to understand it. But I had a two week old, so eff that. Life went on.

Fast forward to a couple months ago, when I finally read Ed Yong’s I Contain Multitudes: The Microbes Within Us and a Grander View of Life (long overdue for someone interested in the microbiome). Unawares, I came upon a section about the development of the infant microbiome. With classic Yong storytelling artistry, he had me hooked in the narrative. Human breast milk contains a huge amount of certain sugars called oligosaccharides, far more than any other mammal, and they make up third biggest component of our breast milk. But when researchers started studying these sugars, they realized that babies actually can’t digest them. So why the hell are they there? They must be important, given our species’ outsized investment in making them, so scientists started looking at gut microbes, assuming that the human milk oligosaccharides (HMOs) must feed an ecosystem of good gut bacteria. But not so, in fact almost all gut bacteria are terrible at digesting HMOs, except for one particular strain of bifidobacteria, b. infantis, which is a superstar HMO digester. According to Yong’s survey of the research, it looks like the infant gut, human breast milk, and b. infantis have evolved together to create the perfect circumstances for b. infantis to thrive. Moreover, it appears that the presence of b. infantis sets the stage for stable colonization of the infant gut by other good gut bacteria, like more of the bifido family and strains of lactobacillus. But, and this is the kicker, most infants born in the developed world have no b. infantis present in their guts at all.

As I read this, a question slowly dawned…that probiotic I gave to my son in a haze of confusion…what was in it? I don’t think I ever bothered to look, or I didn’t remember (because honestly, what do I remember from that time). I dug through the recesses of my brain for the name…what the hell was it called…Viva? Vivo? Evivo! I Googled and quickly found it: Evivo is a probiotic that contains only on thing: b. infantis.

Look, I’m not going to tell you that this supplement works miracles and you should all give it to any forthcoming infants in order to save their immune systems and souls (that’s exactly the kind of internet shit that I hate). I had only my one little experience, with its own particular context. But I have rarely ever seen any medication work on anyone so quickly and so completely, let alone a measly probiotic, so when I accidentally read some science behind it, I was suddenly sitting up and paying attention.

So for this week’s research roundup, I wanted to share three studies from the past few years for those who want to learn more about b. infantis and the infant gut. Much of the research in this area, it turns out, is funded by or connected with the company that makes Evivo. While that’s definitely a flag to watch, I believe the research is still high integrity. It is being published in top peer-reviewed journals, and the company was originally spun out of academic research being done at UC Davis. Still, I will note the corporate connections below.

3 studies on b. infantis

1. Infants in industrialized nations are losing b. infantis

This study, published in Science in 2022, compared stool samples from infants around the world. They found that b. infantis dominates the guts of infants in non-industrialized countries, but in industrialized countries other strains of bifidobacteria dominate, whether or not the baby is breast fed. B. breve is the most common strain the guts of babies in industrialized countries, and this strain has limited ability to break down HMOs. This is important because it suggests that the evidently longstanding symbiosis between b. infantis and breast milk is occurring less and less in the babies of industrialized countries.

2. Lack of b. infantis in infants is associated with gut inflammation

(Researchers included scientists employed by and affiliated with Infinant, the company that makes Evivo)

This study, published in Pediatric Research in 2019, looked at stool samples from full-term, breast fed infants, some of whom were given supplements of b. infantis. The supplemented infants had lower proinflammatory cytokines, signaling proteins that help control inflammation, and lower levels of pathogenic gut bacteria. This suggests that absence of b. infantis could play a role in the rise of big modern ailments, like allergies and autoimmune disease.

3. The effects of early b. infantis supplementation last

(Researchers included scientists employed by and affiliated with Infinant, the company that makes Evivo)

One of the well-known shortcomings of probiotic supplementation is that, even if they change gut composition temporarily, changes rarely stick once the supplementation ends. This study, also from Pediatric Research in 2021, followed up with breast-fed babies who had been supplemented with b. infantis for days 7-28 of their lives. Researchers took stool samples at multiple points up to one year, and found that higher levels of b. infantis persisted in the supplemented infants through the 1 year mark, and correlated with higher levels of beneficial bacteria and lower levels of pathogenic bacteria, even after the babies had started solid foods.

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Obviously, given my interest in the microbiome, my experience with my son and the imminent birth of my daughter, I find this all fascinating. I am trying to walk the line. I am trying not to fall into a line of thinking that goes, “fantastic, I found the magic bullet, all my children will be the most rubust and health children thanks fo b. infantis!” But I am also trying not to be cynical. “Oh, whatever, these things, never really true, funded by companies…” and so on. Somewhere in the middle there is the place I want to land. Hm. This is really interesting. The research that exists seems compelling. My personal experience was really notable. I’d like to keep an eye on this. And I’ll probably give my daughter Evivo.

***UPDATE*** This week one of the Evivo products was recalled after a preterm baby was given the product in the hospital and died of sepsis, a truly awful story. You can find a discussion about this in the comments section, and I would love to hear your thoughts on using baby and kid probiotics, which are all experimental to various degrees.

Get forthcoming personal dispatches on life as a highly sensitive person, new research on the microbiome, chronic illness, and autoimmunity, plus next week’s Lady’s Illness Library interview with Russell Nohelty. Don’t miss a thing - become a paid subscriber to Inner Workings.