Thursday, April 28, 2016


In September of 2013 I gave up dairy products and suddenly it was like someone put a pin in my belly and deflated it--I began to lose weight quickly and easily. I was pretty impressed because most days the only dairy I had was the milk in my coffee. I thought the explanation was the insulinotrophic action of whey–a tripling of insulin output by the pancreas, a situation that stalls weight loss. But that was before I took a course on gut microbes from the University of Colorado. After that, I wondered if dairy consumption might significantly change my gut microbiome in a way that related to weight. So I decided to test that last August.

First I consumed about two servings of dairy products a day--milk, cheese, ice cream, and yogurt--for several weeks and sent my first sample into uBiome (cost: $89, method: simple, go to their site for more info). Then I quit dairy and retested six weeks later. The results were interesting though inconclusive since only I was doing the experiment, and it was by no means a controlled experiment either. That said, there certainly was a difference in my gut microbiome between the two analyses.

My first sample was in the 62nd percentile for diversity, and my second sample in the 88th, meaning it was more diverse than 88 percent of the samples in the uBiome database and quite a bit more diverse than my first sample. Could there be something in dairy that destroys diversity? That would be sad.

Two other big differences were in my amounts of bacteroidetes and firmicutes.

According to the uBiome site, bacteroidetes are the most prominent gut microbes in much of the world. They are thought to help protect against obesity because they do not digest fat well. After giving up dairy, my bacteroidete count went up by over two and a half times, whereas my firmicute count decreased by a quarter.

According to the uBiome site, firmicutes help us digest fat and are among the most common microbes in our gut. But an oversupply of firmicutes has been linked to a higher risk of obesity.

Could it be that dairy consumption promotes the growth of firmicutes and/or destroys bacteroidetes? Wouldn't that be interesting to know. I will have to try the experiment again. But even better would be for other people to try it because then we could see if there is a common pattern.

My first sample looked most similar to the omnivores in the uBiome database and my second sample--even though I was eating some meat and eggs--looked more like the vegans, although more diverse.

I think I owe the diversity to making half of what I eat each day vegetables. I've followed that rule for over five years. From what I've learned, plant foods feed good gut microbes, and good microbes equal good health. Regardless of what I weigh or how big my belly is, I feel quite healthy and all my vital statistics support that I am. Still, I'm always curious about the ways different foods affect me, and dairy and wheat so far have had the biggest effects. Now I want to know why. uBiome helps me with that quest.

One of the many charts and graphs that uBiome provides 

What I like about uBiome's product is that, besides being simple to use, once they've processed your sample they give you loads of information (which you access on-line) about the various microbial communities you host. Some of the information is over my head, but other info is quite accessible like how my microbiota compares with various groups like vegetarians, paleo dieters, omnivores, vegans, heavy drinkers, all women, all men, etc.

Two other things I like about uBiome: Once you're in their database, if you have questions, you can contact them easily and get quick answers (which I've done a number of times), and they send an e-newsletter out weekly to help you learn more about microbes in general.

Here are the three best books I've read that got me hooked on this subject:
AN EPIDEMIC OF ABSENCE by Moises Velasquez-Manoff
HONOR THY SYMBIONTS (A collection of essays) by Jeff Leach
MISSING MICROBES by Martin J. Blaser, MD

And here's the course I took offered by Coursera and the University of Colorado, Gut Check: Exploring Your Microbiome. It's taught by Rob Knight one of the world's foremost authorities in this area. The course is FREE on-line, and it's self-paced so you can start it any time.

A few weeks ago, uBiome sent me an email offering anyone I refer a 10% discount. So if you're interested in learning what microbes are in your gut, or doing your own microbiome experiments, here's the link to the discount code: (I'm not sure how long the offer lasts.)

Here's the blog post about when I gave up dairy: Milk: Lactose, Whey, Casein, Calories, It's Complicated!

Note: When I do the dairy experiment again--and I probably will this summer--first I'll do a baseline sample while on my regular diet which includes only occasional dairy and no milk. Once I get my results, I'll consume 8 oz. of regular, commercial milk a day for a week or two and retest to see if there's a significant change in my microbiome and a difference that's similar to my first experiment. (Since my first experiment, I've learned that microbial communities in our guts react to changes in our diets within days. So no need to wait six weeks to test.) I'll report the results. 

1 comment:

  1. Testing my own microbiome makes sense to me because each person's microbiome is unique, so reading about what's true about other people's guts may or may not relate to mine. See Atlantic article:


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