I still remember the day I realized I had digestive issues.  I was 30 years old living in San Francisco.  I had just finished my usual Saturday bagel and cream cheese, but for the fourth week in a row, my stomach started churning over.  It suddenly clicked: I could no longer tolerate dairy.

As the years progressed, an increasing number of foods were added to the list of “intolerables”: gluten, onions, legumes, corn chips…and more.  Until what was a minor annoyance solved by Lactaid bills became an all-consuming wrestling match with my gut.

Now 14 years later, after many experiments, countless dead ends, supplements, and books, I can confidently say that my gut is (mostly) back to normal.  Here are seven habits I recommend:

  1. Get enough Vitamin D  

Getting enough vitamin D is really important.  So important that it likely explains why Europeans have light colored skin and are more likely to be lactose tolerant.

Vitamin D usually comes from the sun.  We need very little sun to generate enough of for our bodies, but now that humans wear clothes, hang out inside, and live in places where the sun is weak in the winter…Vitamin D deficiency is incredibly common – depending on the population studied, somewhere between 24% and 82%.

Unfortunately vitamin D deficiency seems to kill people.  It is also related to poor gut health.  Studies have shown this, but it’s apparent from my personal experience as well.

Once I started actively trying to spend a little more time in the sun, and added Vitamin D supplements when I couldn’t get outside, my gut health improved remarkably.

  1. Reduce the diversity of the foods you eat

As Westerners, we are overwhelmed by food choice.  In the 1990s, the average supermarket had a mind boggling 7,000 foods to choose from.  By 2017, that number had exploded to over 40,000 unique items, including out of season berries, spices used by cultures thousands of miles away, and an endless array of packaged foods catering to your unique preference.  Although the diversity of food is a testament to capitalism and the ingenuity of mankind, it runs counter to how our ancestors ate. 

So when it comes to your gut, find the few foods you tolerate and eat them more frequently.  This has the side benefit of letting you easily control your portions.  When you wish to venture into a new food, do so in a controlled way – and take good notes about how your body reacts.

If you want excitement, find it somewhere else!

  1. Add resistant starch to your diet

Resistant starch refers to a carbohydrate that is resistant to digestion, and feeds your friendly gut bacteria.  In this respect, resistant starches lie somewhere in between fiber and regular carbohydrates.

The three easiest ways to get more resistant starch are to 1) cool cooked carbohydrates (e.g. rice and oats) overnight in the fridge before eating them, 2) eat green bananas, and 3) add potato starch to smoothies and other foods.

Another benefit is that resistant starch is lower in calories than other carbohydrates.

  1. Take probiotics

Probiotics restore the bacterial balance of your gut.  Here is a list of the Amazon bestsellers.

  1. Take Ox Bile

It’s gross, and not very animal rights friendly, but it works.  Really well.

I take it daily as part of a digestive enzyme complex.

  1. Intermittently Fast

Yes, it is the trend of now.  But there is some good research being done at highly respected universities like Cedars Sinai showing that after 12-16 hours of fasting the bacterial composition of your gut changes markedly.  My personal experience confirms this.

  1. Try the Low FODMAP diet

FODMAPs are complex carbohydrates that can cause upset stomach in many people.  Common high FODMAP foods include onions, mushrooms, dates, and anything containing wheat.

Although effective, it is not an intuitive diet.  Additionally, some people are sensitive to certain FODMAPs and not others.  Therefore, I recommend an elimination approach – start by following a strict low FODMAP diet and then adding items back in slowly and watching how your body reacts.  Here’s a great guide to getting started.


The good news is that you don’t have to do all seven of these things to fix your gut.  In fact, you may find that just one or two do the trick.  So, go back to the list above and pick the item that seems easiest.  And then gradually add in the other habits until your gut is back at its best.

Good luck!