THE HYGIENE HYPOTHESIS
MAKING OR BREAKING YOUR FAMILY'S HEALTH
Although people have been talking about similar for, well, centuries, the first person to actually coin the term 'Hygiene Hypothesis' was one David Strachan, a Professor of Epidemiology at London's St. George's University. His discoveries were published in a 1989 issue of the British Medical Journal (Hay Fever, Hygiene, and Household Size). Interestingly enough, he began that study by saying, "Hay fever has been described as a post-industrial revolution epidemic". In other words, Hay Fever was not an issue as long as people largely lived agrarian lifestyles (exposure to dirt, dust, manure, animals, etc, etc). He went on to say that, "infection in early childhood, transmitted by unhygienic contact with older siblings," prevented said allergic diseases (Hay Fever) in the younger siblings. Needless to say, in a society whose physicians basically promote cradle-to-grave germophobia, this idea went over like a proverbial lead balloon --- at least initially. But by Y2K momentum was shifting.
In the early 1990's (remember that The Wall came down in '89), Dr Erika Von Mutius, a German pediatrician, ran a series of experiments comparing the rates of ASTHMA and ALLERGIES between East German children who typically grew up poor and dirty under the effects of communism-induced poverty, and West German children, who on average had about as high a standard of living as you'll find anywhere in Europe. She expected to see that cleanliness really is next to Godliness; at least as far as allergies and asthma were concerned. She saw the exact opposite. The dirtier the children, the less likely they were to have A&A. Today there are literally thousands upon thousands of similar studies --- many having to do with autoimmune diseases (HERE'S ONE). To see where Dr. Erika's work has taken her over the past two decades, HERE is a cool study from last March's issue of the Journal of Allergy and Clinical Immunology that sums up this topic.
Are there legitimate physicians and researchers who actually know their way around this subject, yet still deny the Hygiene Hypothesis exists? Sure there are --- kind of. After reading last July's Perspectives in Public Health (Time to Abandon the Hygiene Hypothesis: New Perspectives on Allergic Disease, the Human Microbiome, Infectious Disease Prevention and the Role of Targeted Hygiene), I began to see what the "deniers" looked like and were really after. Despite having to admit that the premises of the HH are real --- "Evidence suggests a combination of strategies, including natural childbirth, breast feeding, increased social exposure through sport, other outdoor activities, less time spent indoors, diet and appropriate antibiotic use, may help restore the microbiome and perhaps reduce risks of allergic disease." --- the scientists went on to complain that the aspect of the HH they hated most was that one of their medical words (hygiene) had been hijacked. Thus, their demand that, "The term ‘hygiene hypothesis’ must be abandoned." I saw this same theme repeated in numerous articles and studies --- never denying that the phenomenon is real, but detesting the language used to describe it.
Case in point; writing for PNAS back in February (News Feature: Cleaning up the Hygiene Hypothesis), Megan Scudellari made essentially the same appeal, which carried two distinct points. The first is what I talked about in the last paragraph --- that the term "Hygiene Hypothesis" does not really explain what's going on because it's too broad, covers too much territory, and alters the common medical meaning of the word "hygiene". The second had to do with the fact that even though the data does not lie (there is an inarguable relationship between hygiene --- or the lack thereof --- and a slew of health-related factors and diseases), the Hygiene Hypothesis cannot be true because there is no one-size-fits-all probiotic "cure".
"The second major concern among researchers is a lack of evidence demonstrating how to reduce rates of allergic and autoimmune diseases. Although there are hundreds of observational and epidemiological studies supporting a more nuanced theory that moves beyond the hygiene hypothesis, there are only a few randomized, controlled prospective studies testing interventions to reregulate the immune system. These include an experimental infection with helminths to treat IBD, which met with mixed results, and probiotics treatments for illnesses ranging from severe acute pancreatitis to eczema. In some cases, probiotics alleviated symptoms, but, in others, they had no effect."
Scudellari's mistake is that she is looking at this problem through the lens of other medical treatments. Your testosterone is low? We'll just give you some testosterone (HERE). Not enough insulin to lower your blood sugar? We have drugs that do the same thing (HERE). Feeling a bit down because presumably your body is not making enough neurotransmitters (serrotonin / dopamine)? We'll start pumping the ANTIDEPRESSANTS. The problem is, not only does this short-sighted approach always fail over the long run, it suppresses your body's natural negative feedback loops, frequently leaving you worse off than ever (when's the last time insulin helped a TYPE II DIABETIC recover simply because they took insulin?). And here's the rub, there are only about a jillion studies showing that all three of these problems are INFLAMMATORY IN NATURE and intimately linked to one's microbiome. If that's really the case, why can't we just give everyone a probiotic? It's really quite easy to understand.
Scudallari is certainly right about one thing --- studies on PROBIOTICS are all over the map. For every study that "proves" a certain disease can be beneficially affected by taking a probiotic, another study "proves" otherwise. In other words, probiotics are the definition of a 'mixed bag'. Frankly, I'm not surprised, and you shouldn't be either. Depending on whose research you look at, a normal human microbiome contains something like 300 to 600 strains of bacteria, give or take. These bacteria must work in tandem with each other; like members of an orchestra. All it takes is one member out of tune or rhythm for things to not sound just right. Get a few more members off key and the whole thing starts to fall apart.
It's why even though I do not do them in my clinic, I have a DOZEN OR SO ARTICLES on FMT (Fecal Microbiota Transplants), one of them explaining why taking generic probiotic formulas with 1, 2, 8, or even 15 strains of bacteria, is not going to be enough to reestablish and heal the microbiota of many people --- especially really sick people (HERE). But when the alternate to probiotics is DANGEROUS DRUGS, what have you got to lose? Worst case scenario, it doesn't work. What are you out? A couple bottles of probiotics? Who cares! And as for the studies on people purposefully infected with HELMINTHS, there isn't "a" study as in one, there are dozens of such studies; many of which show promising results for those with IBS or IBD that has not responded to anything else.
Today, there are tens of thousands of studies concerning the HYGIENE HYPOTHESIS --- many, if not most, having to do with the MICROBIOME (on Pubmed, search for Gut Flora, Microbiome, Microbiota, Hygiene Hypothesis, Autoimmunity, etc, etc). The thing that's so astounding is that you can name virtually any disease that's NOT 100% GENETIC (something like Down's or Cystic Fibrosis), head on over to PubMed, and find studies linking it to GUT HYGIENE. You can also find thousands of studies showing how severely antibiotics affect your natural "hygiene" as well --- causing almost every disease you can imagine, including cancer (HERE).
WHAT'S THE POINT?
If you are interested in reading more on this topic, I put several posts together (HERE, HERE, HERE, HERE, and HERE). If you are chronically ill or dealing with CHRONIC PAIN, you might want to take a look at THIS POST as well.
Barefoot, dirty, taking a bath once a week (or maybe once a month). It's how the world's population has lived for most of recorded history. Today, however, it's not uncommon for people to bathe twice a day or more, using an array of antimicrobial and "hygienic" products. While I would never say that this is the only reason that today's population is sicker than at any point in the history of the world, it can't be overlooked. If you agree, share it on FACEBOOK.