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Truth in Fiction

A few months ago I did a two-week elective with our hospital’s Emergency Medical Services. Over those two weeks I saw all manner of medical “emergencies”.  Some were true emergencies, but plenty were BS calls where first responders and ambulances were called into action when what was really needed was an $8 taxi ride to the emergency room (or even better, $8 worth of broth and a couple days in bed to get over the flu, but I digress).


I met some wonderful first responders on this rotation. People that really want to help others and who obviously get a high from the adrenaline of being called to duty in an emergency.  As I saw bits of the recent Boston and Texas events unfold I imagined how the EMTs and medics I worked with would have jumped to duty in these situations.  Indeed, many of them did 11.5 years ago when they responded to the attacks on the World Trade Centers.  One of the women I worked with lost a friend who was responding that day.


Unlike the hospital environment, where people usually avoid any controversial conversations, I frequently found the topics of religion, politics, taxation, healthcare reform, and gun-control being discussed. The disagreement was sometimes vehement, and the conversations often heated, but there were never any hard feelings at the end of the day.


I worked with a number of EMTs and medics on my 2-week elective, but I bonded with one in particular. I think we had matching (or perhaps complementary) streaks of cynicism and optimism (yes, you can be both a cynic and an optimist. In my case, I think my cynicism protects my optimism from being snuffed out by reality).  He asked if I had read The House of God [1], by Samuel Shem, (the nom de plume of psychiatrist Stephen Bergman), and when I said I had not he insisted that I must.


I ordered the book right away, but like so many excellent book recommendations, it took me a while to get around to reading it.  I finally started a couple weeks ago, and quickly devoured the whole book.


The House of God is a satirical novel that portrays the life of a medical intern in the early 1970s.  A lot of things have changed for interns since this book was published- the most notable (for the sake of this novel) is work hour restrictions. Nonetheless, there is much about this novel that made me, even as a mere medical student, laugh, cringe, and nearly cry.  I have since recommended it to many other medical students and residents with the description that it is “brilliant, hilarious, and terrifying”.


The book is, of course, fiction, but it is, in essence, true.  It is as poignant today as when it was first published in 1978.


Some of the scenes are things that I can relate to, if not describe verbatim, from my experience as a third year medical student.  Some of the patients I have seen are the embodiment of the caricatures described in this novel. “The Yellow Man” with his failing liver, the (relatively rare) young patient who invariably has some condition we can not treat and who sadly dies, the (common) old patient that we can not treat effectively but that we can patch up well enough to carry on… These are patients I know, even though they are fictional.


I won’t write a review of the book- it is brilliant, and I think everyone involved in the medical community should read it. I find myself wondering what non-medical people think of the book… I suspect it would be hard to decipher satire from actuality- the line is definitely not clear, even for those who work in the medical community.


The House of God uses terms that are familiar to those who work in a hospital- and I’m not talking about words you find in a medical dictionary. The term “turfed” is when a patient is moved from one medical team to another (such as from a general team to a specialty team, or vice versa), a “bounce back” is a patient that your team treated who was then transferred to another team or discharged from the hospital, only to “bounce back” to your service.  The term “gomer” is one that I write with some reluctance.  It is a word that I have never heard uttered in the hospital, and have only heard in “humanism” lectures (in which it was made clear that no one should ever use the term), which describes “a human being who has lost-often through age-what goes into being a human being”.  The House of God is how this term first became well known, a term that is an abbreviation for “Get Out of My Emergency Room”.


The same author, again under his pen name, published a piece in 2002 in the Annals of Internal Medicine entitled “Fiction as resistance” [2], in which he describes using storytelling to illustrate, and retaliate against, the brutality and inhumanity of medical training and the practice of medicine. Fiction makes reality palatable.


In this article Shem writes about how he encourages people to resist the inhumanities of medicine. The keys, he believes, lie in (1) learning our trade and being aware of the world around us and our patients, (2) avoiding isolation, (3) speaking up, and (4) learning empathy. I am not sure how one learns empathy.  Sadly, some aspects of medical practice almost seem designed to dispatch it.


Just as I finished The House of God, my mother sent me a book for my upcoming birthday.  I’ve quickly read about half of On Call: A Doctor’s Days and Nights in Residency [3], written by Emily Transue, an internist on faculty at the University of Washington.


Reading these books in immediate succession is powerful.  One is satirical fiction while the other is reality, but if you changed the writing styles you could easily swap the real stories for the fiction.  Both write of the dehumanization that occurs during medical training, but Shem follows the adage “if you want to tell people the truth, make them laugh, otherwise they’ll kill you”.


Sometimes I think I’m too young, too “wet behind the ears”, to write about dehumanization in medicine.  I’m only a fourth year medical student, how much have I really seen.  Other times (well, most of the time), I worry that expressing my feelings, especially in writing especially on the internet, is just asking to have things I say come around and bite me at some point in the future…


Another part of me, however, thinks that medical students are best positioned to recognize dehumanization in medicine.  We are the least indoctrinated, the least hardened.  As students, we also know that there’s a lot we can’t do. The idea, of course, is that with training we will be able to fix people, heal people, make things better.  Sometimes we can; frequently we cannot.


As students, we know that we are fairly powerless in the management of a patient’s medical care.  This can be frustrating when you think there is something that could be done that might help a patient, but also leaves you in a position where you don’t feel like you’re personally failing a patient when there is little to be done (at least medically speaking).  When those with more medical clout, more medical ability, are faced with a situation where the best medicine we can offer will do little good, they sometimes have a hard time letting go.  As if saying “there are no more medical options we can try” or “this isn’t going to get any better” is admitting defeat.


Perhaps it is defeat. But maybe in this circumstance admitting defeat makes you better.  When you realize that you have exhausted your medical options, perhaps you can finally treat the person, not the disease.  It’s just a shame that we don’t always treat the person first.


1.            Shem, S., The House of God. 1978, New York, New York: Dell Publishing.

2.            Shem, S., Fiction as resistance. Ann Intern Med, 2002. 137(11): p. 934-7.

3.            Transue, E.R., On Call: A Doctor’s Days and Nights in Residency. 2005: St. Martin’s Griffin.

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Road Trip!

I have more to write about lipids and liver (consider yourselves warned!), but I likely won’t have a post out on that subject for a little while.

During the last month I have been enjoying my Family Medicine Clerkship. I am very fortunate to be working with an excellent and enthusiastic physician, with whom I have had fantastic patient interactions both in the office and on house calls (Yes, house calls- who knew physicians still did those?!). Not only is this physician an enthusiastic practitioner and teacher, but she is also very supportive of my (not so main-stream) academic interests. This was evident in the office, where she was keen to push me towards patients whose medical conditions I was particularly interested in and where she encouraged me to talk about nutrition with many of the patients (Yes- evolutionarily appropriate nutrition- not some American Diabetic Association or “My Plate” nonsense”).  This physician was also keen that I pursue my academic interests outside of the clinic, so she has worked with me and my schedule so that I can attend the 2nd annual Ancestral Health Symposium in Boston at the end of this week.

This time last year I was in the throes of writing my thesis, and I was forced to watch the inaugural Ancestral Health Symposium from the sidelines (you can watch the videos from last years symposium here). I’m very excited to participate in person this year!  (If you’re unable to attend but want to be kept up to date, you can follow the twitter feed @Ancestry2012)

While I am looking forward to a number of the lectures on offer this year, I am equally excited about catching up with other people interested in Ancestral Health.  I’ve been fortunate to cultivate a number of friendships within this community over the last couple years, though because of distance I’ve only met a couple people in person.  While I’ve come to know some quite well through the powers of e-mail, Skype, and Twitter, there’s nothing quite like some face time with friends who share (arguably very nerdy) interests.

Anyway- this is a drawn out way of saying “Hey- I’m headed to Boston for AHS 2012. If you’ll be there and want to say ‘Hi’, please do!”.

Pic- for identification purposes!

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Physical rehabilitation is an important part of medicine. When I was on the stroke team on my Neurology clerkship, the main goal of our team (after we identified and localized the stroke) was to make sure our patients were medically cleared so they could go to rehab (The second I wrote that I heard the Amy Winehouse song “Rehab” in my head- I’m sorry if I’m responsible for putting this earworm in your head too!).

Physical rehabilitation was also a significant portion of patient care on my surgical trauma clerkship. Indeed, one of the tasks of the med students was to do “PT rounds”, in which we tracked down our patients’ charts (yes, our hospital still uses paper charts) and checked for progress in their therapy. This became quite time consuming when our list grew to 40 patients, including 1 on almost every floor of the hospital! Each afternoon, as we tracked down charts, we would pore over the PT/OT (Physical therapy/Occupational therapy) notes. This was challenging not only because of the almost illegible handwriting of some of the therapists, but also because of the litany of abbreviations and symbols that they utilize (though with time, their interpretation became much easier). Over the weeks we would track the range of motion of our patients’ various joints, and the relative amount of assistance needed to go from lying to sitting and from sitting to standing. We would see how far they could walk (and with what type of assistance) and how many stairs they could climb up and down.  The process- both the types of movements done and the assistance that is provided- is very delineated and mechanistic.

Meanwhile, in a seemingly totally different world…

Last weekend I attended a MovNat one-day workshop in Central Park. I’ve been aware of MovNat for a while now (I can’t remember my original introduction, but the name, and the general concept of ‘natural human movement’, is definitely something I came across as part of my journey in evolutionary health and wellness), but it’s something I’ve been interested in for a while, and I was enthusiastic to attend the workshop.

For those that are not familiar, MovNat is a concept of fitness based on the full range of natural human movements. It is the pursuit of fitness based on “man in the wild” not “man in the zoo”.

Through the day, we talked about and practiced 7 of the 13 MovNat movement skills. People do some interesting things in Central Park, but we definitely drew interesting looks as we explored different ways of walking, running, balancing, jumping, crawling, climbing, and lifting (the remaining 5 skills of swimming, carrying, throwing, catching, striking, and grappling were left for another day…). Many of the movements we explored were familiar, if not as things that we do on a regular basis now, then perhaps more reminiscent of a day outside as a child. Running around barefoot, tumbling in the grass, trying to nimbly walk along curbs and park benches: these skills weren’t exactly new, they were just things we needed to rediscover.

Throughout the day, the emphasis for these movements was not one of rigorous perfection, but more one of practice and experimentation. Through a variety of positions and movements, we explored our balance and flexibility, all with a focus of being mindful, both of our body and mind, and also of the environment around us.  Through this practice, one could recognize the efficiency of natural movement and the (at least to me) instinctive nature of basic human movements.

As I mentioned above, many of the things we explored were not really “new”, but instead were a reawakening of movements and skills of childhood. It is great to watch a child play and realize that (at least to my rather untrained eye) they have great form in almost everything they do. Watch a child squat, pick up a rock, and play with it. Watch them as they stand up, carry, and run around with it- they don’t have to be taught how to do these movements correctly, they learn it through a process of trial and error- figuring out how do it as efficiently as possible.

Rediscovering these movements, with the help of guidance and tips from an instructor, is (at least from my take) what MovNat is all about (at least for the basic skills of balancing, walking, running, and lifting… I’d be a bit concerned if I was impressed with the grappling skills of a small child!).

So where does rehabilitation tie into all this? 

As I mentioned above, the process by which people receive physical therapy in our medical system is (at least from my experience) rather rigid and mechanized. Could the instinctive and practical elements of a “natural movement” regime (such as MovNat) offer a new approach to rehabilitation?

MovNat has gained respect from many in the fitness world and beyond. Indeed the founder of MovNat, Erwan Le Corre, has given a talk on the subject at NASA. The emphasis I have seen thus far has been of general fitness and wellbeing for “normal” humans as well as athletes, but could a return to “natural human movements” be an appropriate approach to rehab? Would it help those who have lost their knowledge of how to move like a human, such as those who have suffered a stroke or a traumatic brain injury? When someone has well-and-truly forgotten how to move like a human (versus those of us who might just need to dust off those skills from childhood), can rebuilding this knowledge from an evolutionary and adaptive approach bring more success than a purely mechanistic approach? And what of those who are recovering from a long period of convalescence? Would a program that focused on the evolutionary “natural” movement of humans have greater success at returning appropriate balance and strength?

I definitely don’t have any solid answers, but it’s an interesting idea to ponder… 

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Pop a squat

I lied.


I said I was going to take a break from writing about bowels and microbiota (I was, I really was), but then my awesome chief resident (the head of my surgery team) distracted me with bowels again.  After I revealed my interest in evolutionary medicine (followed by a brief rant on the appendix, gut microbiota, and the general tenets of evolutionary medicine) he said “Cool- let’s see what kinds of patients I can find for you”.  He then assigned me a few patients with some thoughts of things I should look up and get back to the team on.  I was thrilled.  The patients were interesting and the things he suggested I look up were spot-on… He totally ‘gets it’.


Diverticula are out-pouches of the colon, and can either be “true” diverticula, consisting of all layers of the bowel wall, or “false” (AKA pseudodiverticula), where the thin layers of the bowel balloon out through gaps in the muscular layer.  Diverticula can occur on the right side of the colon (the part closest to the small intestine) but are much more common (at least in the Western world) on the left side, particularly in the sigmoid colon (the last bit of the colon before the rectum).  These are almost always “pseudodiverticula” though are generally referred to as “diverticula” and are the type I will discuss in this post.


Diverticula were once considered so rare that surgical textbooks from the early 1900s didn’t even mention them.  It is now thought to be one of the most common colonic conditions in the developed world, though the prevalence is difficult to determine as most cases are asymptomatic.  Current estimates, however, are that more than 40% of people in industrialized nations develop diverticula by the age of 60, and more than 60% develop them by the age of 80.  As I mentioned, diverticula are frequently asymptomatic, but we become aware of them when they become inflamed, infected, or abscessed, leading to a condition known as diverticulitis (interestingly, diverticula on the right are more prone to bleed, while the ones on the left are more likely to become infected).


The pathogenesis of diverticula is generally believed to be dependent on the intraluminal pressure of the colon, specifically increased pressure during defecation.  While straining to ‘perform’, the pressure in the colon greatly increases, especially in the areas closest to the rectum.  Exaggerated contractions with spasmodic bowel movements cause increases in bowel pressure that may lead to diverticula.  Conventional wisdom would have you believe that increased peristaltic activity is caused by our industrialized low-fiber diet, which leads to low-bulk stool, which cause our colon to work extra hard to expel their payload.  You might suspect, however, that I am a little skeptical of conventional wisdom (refreshingly, so is my chief resident!).


The thought process that led to a ‘fiber-deficiency’ model of diverticular disease is actually rather encouraging for those of us who appreciate an ancestral approach to health.  The argument was initially made by Burkitt and Painter [1] who in 1975 compared the stool transit time and volume of native Ugandans (a population virtually devoid of diverticula) with that of native Britons (importantly, while native Africans do not develop diverticula, those of African descent living in the developed world do).  Burkitt and Painter realized that Ugandans had much larger (450g/day vs. 110g/day) stools and a much shorter transit time (34 hours vs. 80 hours) than UK natives.  It was reasoned that these differences were caused by decreased fiber consumption in the developed world.


Alas, while this argument has gained substantial credence through years of reinforcement, the case for diverticula being a disease of a fiber deficiency fails to hold up.  In fact, a paper recently published in the Journal of Gastroenterology is just the most recent take down of the fiber-based model of disease [2].  This paper adds to the library of references that have failed to show a link between low-fiber diets and diverticula.  In fact, this paper actually suggests that the inverse is true, with those that consumed the most fiber having the highest incidence of diverticula.  This paper also took a look at other factors often implicated in diverticular disease, specifically infrequent bowel movements, high-fat diets, diets with a lot of red meat, and physical inactivity.  None of these factors were associated with diverticulosis (indeed, people with few bowel movements had fewer diverticula than those with many!).


So if a lack of fiber doesn’t cause diverticula, what does? In their 1975 paper, Burkitt and Painter focused on the fiber content of the native diet of Ugandans.  Their focus on diet, I fear, has led astray those who seek to prevent diverticular disease.  While it is true that native Ugandans ate an evolutionary-appropriate diet, they ALSO utilized evolutionary appropriate behavior… For lack of a more tactful explanation- they squat to defecate and only go when they feel the need!  Shocking, I know.


The hypothesis that diverticula could be prevented by squatting and urge-driven bowel habits was put forth in a 1988 paper (in one of my favorite journals, Medical Hypotheses), which pointed out that underdeveloped nations (which have an exceptionally low prevalence of left sided diverticular disease) utilize latrine pits.  They went on to point out that bowel emptying in a sitting position, as caused by a western toilet, requires multiple straining efforts, while bowel empting upon urge in a squatting position usually only requires one [3].  This suggestion has been followed up with a couple of recent studies that show that straining to defecate is greatest in the standing or lying position and minimized in the squatting position [4, 5].  Anatomically, this is explained by the change in the recto-anal angle, which becomes aligned in the squatting position and is obstructed as the flexion of the hips is decreased.


An interesting aside at this juncture is a quick look at the prevalence of diverticular disease in Japan.  As an Asian country, Japan used to have a higher prevalence of right-sided diverticular disease, with left-sided being fairly uncommon.  This trend, however, started to change with the westernization of Japan.  Following Burkitt and Painter, the increase in left sided diverticular disease has been attributed to a decrease in fiber in the westernized Japanese diet [6], but is the blame duly placed?  My brother has lived in Japan for many years and I’ve visited a number of times, and I’ve often been impressed by the spectrum of toilets available in Japan.  They range from the  ‘traditional’ Japanese squatting toilet (a ceramic latrine set in the ground) through to the modern toilet which is an amazing feat of engineering (perhaps you’ve seen one on TV somewhere- they come complete with jets that direct warm water and warm air at various body parts, play music to hide unwanted sound effects, and may, in fact, be able to tell you the answer to the ultimate question of life, the universe, and everything).  Is it fair to blame a lack of fiber on the increase in diverticular disease in Japan?  Or might it actually be due to a conversion from the traditional squatting toilets to westernized seated ones?


“Seated-stooling” has also been implicated in other conditions of the bowel.  There’s another Medical Hypotheses paper that names sitting as a mechanism underlying primary constipation [7], and another communication from the Israel Medical Journal describing a neat little trial conducted on patients with hemorrhoids [8].  This small trial, consisting of only 20 patients, showed interesting results.  Of the 20 patients, 17 had tried (with minimal success) conservative treatment for hemorrhoids, including the ‘all-curing’ high-fiber diet, as well as suppositories, salves, and laxative preparations.  The remaining 3 patients had undergone ligation for severe hemorroids.  Throughout the course of this study (conducted over 1 year) the patients were asked to defecate in a squatting position only and to defecate only in response to a strong urge (no straining to perform!).  The result of these interventions was alleviation of symptoms in most patients.  Alas, 2 of the 3 who had undergone ligation did not experience significant improvement, which may have been a result of fibrous tissue development at the site of ligation.


The conclusion of this last paper seems particularly fitting in consideration of the overlying evolutionary-based interests of this blog: “that a program may be needed to reacquaint man with his natural habits.”[8](No, you don’t need a pit latrine- there are little stools available designed to fit around toilets that allow you to squat over the pot! (Here’s an example, with the option to ‘build your own’)



1.            Painter, N.S. and D.P. Burkitt, Diverticular disease of the colon, a 20th century problem. Clin Gastroenterol, 1975. 4(1): p. 3-21.

2.            Peery, A.F., P.R. Barrett, D. Park, A.J. Rogers, J.A. Galanko, C.F. Martin, and R.S. Sandler, A high-fiber diet does not protect against asymptomatic diverticulosis. Gastroenterology, 2012. 142(2): p. 266-72 e1.

3.            Sikirov, B.A., Etiology and pathogenesis of diverticulosis coli: a new approach. Med Hypotheses, 1988. 26(1): p. 17-20.

4.            Sikirov, D., Comparison of straining during defecation in three positions: results and implications for human health. Dig Dis Sci, 2003. 48(7): p. 1201-5.

5.            Rao, S.S., R. Kavlock, and S. Rao, Influence of body position and stool characteristics on defecation in humans. Am J Gastroenterol, 2006. 101(12): p. 2790-6.

6.            Nakaji, S., K. Sugawara, D. Saito, Y. Yoshioka, D. MacAuley, T. Bradley, G. Kernohan, and D. Baxter, Trends in dietary fiber intake in Japan over the last century. Eur J Nutr, 2002. 41(5): p. 222-7.

7.            Sikirov, B.A., Primary constipation: an underlying mechanism. Med Hypotheses, 1989. 28(2): p. 71-3.

8.            Sikirov, B.A., Management of hemorrhoids: a new approach. Isr J Med Sci, 1987. 23(4): p. 284-6.

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‘Breast is best’ is the rallying cry of many who want to encourage mums to breastfeed their children, though some think the slogan should be banished. To those who wish to do away with the slogan, it’s not a matter of what is ‘best’ but a matter of ‘biologically normal’. I’ll admit to being rather nonplussed about slogans, but I am rather adamant that one should put trust in basic biology when possible.


Over the years, studies have shown correlations suggesting many benefits of breastfeeding, including increased IQ, decreased obesity, and a decrease in several pediatric ailments such as gastritis and ear infections in the offspring (I think those last two are particularly interesting). While these studies are interesting, they are just correlations, and I hate to put too much weight on correlative studies (though they can be fun to look at).


Biology is marvelously complex. As a result, studying it and then mimicking it is time consuming and tricky. I think breastfeeding is a wonderful example of a fascinating bit of biology that shows us how tricky it is to properly and fully study complex biology, and also shows us how humans have evolved to thrive on the ‘evolutionary norm’ (breastfeeding).


Breast milk is interesting stuff- though to be honest, some species have much more interesting milk than humans, with some species producing milk that changes in composition from day to day (and even different compositions from different nipples to feed different offspring!). While breast milk provides sustenance for an infant, it also helps develop the immune and metabolic systems of the offspring. The composition of breast milk can pass along information from mother to child, relaying information about the relative abundance or paucity of the environment in which the offspring will develop. This transfer of information, and the relative role of this communication in growth and development, is a fascinating area of research.


If people think about breast milk in the context of immunity, they generally think of the active transfer of antibodies from mother to child. The earliest milk produced by a mother, colostrum, is particularly rich in antibodies, and imparts great benefits to an infant. Even mothers that don’t wish to breastfeed extensively are encouraged to at least nurse in the early days of a neonate’s life so as to transfer these important antibodies. But is that it on the breast milk/immune system link?


In my last few posts I’ve touched on the importance of the gut in a number of immune mediated responses. The gut is actually rather rich with immune tissue, and fosters a number of bacteria (hopefully helpful and health-promoting ones) that help keep out nasty pathogenic invaders (and also helps keep the gut healthy in other ways, such as producing short chain fatty acids to nourish cells and producing Vitamin K). In my last few posts, I’ve talked about the appendix, and how it appears to have evolved as a safe house for our native microbiota in times of duress. But where do these bacteria come from?


Before birth, the intestinal tract of the fetus is thin and immature- lacking any significant lymphoid tissue. The intestine of a newborn develops substantial lymphoid tissue, which indicates the active bacterial colonization of the gut, altering its structure and function. There appear to be three phases of normal gut colonization in an infant starting with whatever flora are picked up during a normal vaginal delivery. The process of breast-feeding ushers in a second phase of colonization, with the third and final stage occurring at weaning. During colonization, it appears that infants generally inherit their mother’s microflora [1], and if all goes well- this is what will populate your appendix!


Any one with an eye to evolution might suspect that breast milk is exquisitely effective at producing healthy offspring- we’ve been making this stuff for hundreds of thousands of years… it is nuanced in ways we’ve yet to even think about. One thing we are starting to understand is that the composition of breast milk fosters a healthy microbiome in infants. In addition to the protein, fats, and carbohydrates that make up breast milk and nourish the child, there are a number of products present in breast milk that can’t be actively digested by the infant, but that are excellent fodder for a blossoming gut microbiome. These compounds are known as human milk oligosaccharides (HMOs- not the annoying health insurance type), and we’re nowhere close to identifying all the different types, though we know there are more than 100 different molecular structures. These molecules are resistant to gastric acid and aren’t absorbed or metabolized by the baby, and instead make it to the large intestine where they can be fermented by intestinal microflora. 


The gut microbiome of infants that are breast fed is quite a bit different from that of formula-fed babies. A number of studies have looked into this, and I don’t want to go into details of different studies, but there appear to be significant differences in the type and number of bacteria in the gut of these populations. Depending on the study, findings showed babies that had been breast-fed tended to have the same amount or more ‘good’ bacteria (Lactobacillus sp. and Bifidobacterium sp.) and less ‘bad’ bacteria (E. coli and C. diff (remember that guy from my last post?)). Breastfeeding probably helps set the microbiome up for success in a number of ways, including the direct transfer of bacteria from mother to child and also the transfer of maternally produced prebiotics that encourage appropriate bacterial growth. There’s also evidence that there is a significant difference in the pH of the large intestines of breast-fed vs formula-fed infants (an acidic pH in breast-fed infants vs a fairly neutral pH in those fed formula). I’m not sure how much of this is a result of appropriate bacterial growth, and how much that acidic pH then encourages more appropriate bacterial growth, but it’s fun to think about (it’s probably a nice little positive feedback loop).


Setting the neonatal microbiome up for success is just one of the many roles that breast milk has evolved to excel at. As mentioned above, breast milk is incredibly complex, and we are only starting to understand the many ways in which is sets an infant up to thrive (and not just survive). In the ideal world, all mothers would breast feed exclusively for 6 months, and then continue to breast feed while foods are introduced, but unfortunately, reality is not this easy. For some, formula is a necessity.  So how can we take what we know about breast milk and the infant microbiome and put this into practice?


In addition to the digestible micronutrients that are important for the proper growth of an infant, breast milk contains a vast array of non-digestible (but fermentable!) oligosaccharides that promote the development of a robust commensal microbiome. Knowing this, it seems appropriate to supplement formula with prebiotics that might equally foster the growth of appropriate microflora. There are a number of well-known prebiotics (perhaps the best known being inulin), but as we have yet to identify all the complex molecules in breast milk, we are unlikely to recreate the full spectrum of prebiotics offered by the ‘evolutionarily appropriate’ diet of an infant. Nonetheless, it appears that formula fortified (gosh I hate that word- if something needs to be fortified, I tend to think there’s a better, naturally more nutritious, option you should be consuming instead) with prebiotics might improve the gut microbiome in comparison to that of a regular formula-fed baby. A number of researcher groups have studied the effects of supplementation, with mixed results. Some have found positive effects of supplementation [2] (I’ll admit I’ve just read the abstract as I can’t read Chinese!) and some showing no difference [3]. This is not surprising, considering the complex nature of maternally produced prebiotics, but it does suggest that this is an avenue of investigation that should be further explored.


We are a long way off from making a formula that adequately and completely replaces breast milk. Like the gut microbiome (and growing infant!) that it nourishes, breast milk is extraordinarily complex, and we are only just exploring the tip of the iceberg of this massive subject. Nonetheless, realizing that breast milk helps promote a healthy microbiome (that you will hopefully keep for life!), which in turn helps develop a robust and appropriately directed immune system, should encourage researchers to further pursue this avenue of exploration. The more we learn about modern diseases, the more it appears that the integrity of the gut, and the functionality of the associated immune tissue, should be a central point of exploration for understanding disease.


1.            Kulagina, E.V., A.N. Shkoporov, L.I. Kafarskaia, E.V. Khokhlova, N.N. Volodin, E.E. Donskikh, O.V. Korshunova, and B.A. Efimov, Molecular genetic study of species and strain variability in bifidobacteria population in intestinal microflora of breast-fed infants and their mothers. Bull Exp Biol Med, 2010. 150(1): p. 61-4.

2.            Cai, J.W., Y.D. Lu, and X.M. Ben, [Effects of infant formula containing galacto-oligosaccharides on the intestinal microflora in infants]. Zhongguo Dang Dai Er Ke Za Zhi, 2008. 10(5): p. 629-32.

3.            Xia, Q., T. Williams, D. Hustead, P. Price, M. Morrison, and Z. Yu, Quantitative Analysis of Intestinal Bacterial Populations From Term Infants Fed Formula Supplemented With Fructo-Oligosaccharides. J Pediatr Gastroenterol Nutr, 2012.



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