Is Cleanliness Making Us Sick?

Stop taking showers. Keep the dirt under your fingernails. Say “No” to hand sanitizer and antibiotics. These are words I’ve heard and read recently from people who have embraced the “Hygiene Hypothesis.”

This hypothesis states that lack of early childhood exposure to good bacteria suppresses the development of one’s immune system and makes one more susceptible to disease. This is not the same as the idea of building our immune systems by more exposure to bad bacteria, getting sick and thus having more antibodies (humoral immunity).

Is cleanliness making us sick?

Dr. Robynne Chutkan writes about the Hygiene Hypothesis in her book Gutbliss. As a board-certified gastroenterologist, Dr. Chutkan discusses the epidemic of digestive bloating and distress she sees clinically, and which is virtually always explained by frequent antibiotic usage.

The hypothesis is backed up by Dr. Paolo Lionette’s work, which compared gut bacteria of children in Florence, Italy with those of healthy African children in Burkina Fasa. He noted that the children had nearly identical gut bacteria at birth, but very different bacteria as they got older, due to very different diets. Children in Africa have much more diversity in their bacteria (which is good) than those in Florence and Dr. Lionette attributed this to diet: legumes and vegetables vs. high sugar and meats.  The theory within the world of microbiome science is that more diversity in gut bacteria composition is a good thing.

The hypothesis is further bolstered by seeing the high distribution of Crohn’s, ulcerative colitis, asthma, and autoimmune disorders in developed countries and low distribution in developing ones.

So, what can you and I do about this information?  

Well, a landmark study out of Harvard in 2014 showed not only that the food you eat determines the bacteria you grow, but also that the composition of the bacteria in your gut can change within days as you shift what you eat. This is significant because our bacteria can turn on and off disease-causing genes.

The Hygiene Hypothesis is just that—a hypothesis.  But there seems to be something to it.  And much still needs to be learned about the microbiome.  The good news is, if you think diversity of microbiome is a good thing, improving your composition is relatively easy to do. Changing to a diet that is comprised of 80-90% plants is really the quickest step to shift to a more diverse microbiome.  Here are six additional steps to take to improve the health of your microbiome:

1. Limit or eliminate sweets.  Simple carbohydrates are known to be food for bad types of bacteria.  Stop eating and drinking things with refined sugar.
2. Eat more veggies. More variety of veggies means more variety of gut bacteria.  If you’re not sure where to start, eat veggies of different colors. 
3.  Get your hands dirty. This could be through gardening or other activities outside.
4. Eat fermented foods. Sauerkraut, pickles, and kefir are our favorites.
5. Eat prebiotics.  These are foods with fiber called inulin that are food for the good gut bacteria.  Chicory root, onion, garlic, banana and asparagus are common.
6. Cautious use of pharmaceutical drugs. Use less antibiotics, steroids, hormones and NSAIDS like ibuprofen.