N = 1; Probiotic’s and my mood.

by Paleo Rob on 17/03/2011

The super doc Emily Deans (Evolutionary Psychiatry and now Psychology Today) recently posted on the affects of leaky gut and depression. It got me thinking about one of my many personal experiments (n=1). Reading through all the literature, I am becoming more convinced that keeping your gut healthy may be one of the single most important things you can do to keep healthy.

What do I mean by keeping your gut healthy? Well I mean keeping a good population of healthy gut flora and not eating foods that may cause gut permeability (leaky gut). For the latter, the single greatest thing you can do is cut grains from your diet, which I have done. For the former, I endeavoured for the past few months to actively add more probiotics into my diet, and I think it has positively affected my health and mood.

What I did.

So how did I do it? Well I upped the fermented food count. I started drinking 1 glass of home made kefir water every day. I started chowing down the sauerkraut. I started lapping up fresh raw milk yogurt every other day. I even took some over the counter pro-biotic supplements. As each type of probiotic source has a different spectrum of good bacteria, I tried to diversify the species of my gut bacteria.


I keep a daily mood tracker. It essentially is a 1-10 reading at various times during the day of how I feel. Looking at the data, I am seeing a slight linear progression of mood over the past 3 months. Now of course there are hundreds of factors that play into this, the placebo effect alone is enough to completely skew the data, but the data is there.


This experiment was n=1. In other words, even calling it a ‘scientific’ experiment is a rape of the definition. However I am seeing benefits, and the amount of real scientific data to support the thesis that a healthy gut will help with your mood amongst other things is growing. I’m really starting to think that everyone should include a gut flora routine in there journey for optimal health, and pumping up the probiotics is a great way to do so.

{ 3 comments… read them below or add one }

Natalie March 17, 2011 at 6:45 pm

I totally feel the different with taking probiotics. I remember feeling quite grim one day and taking probiotics after a long period of NOT taking them. I only took them because I was rummaging through my cupboards for honey and I found them WAAAY in the back. Within literally 15 minutes of taking them my mood brightened and cleaning my house, rocking out to heavy metal and dancing around. The days I don’t take them I’m just meh moodwise – not down, but low energy – but the days I DO take them I enjoy music more, have more energy and laugh more easily. Who cares if it’s just n=1 experimentation, probiotics FEEL good, so I’m continuing with them!


Mike Gale March 24, 2011 at 11:28 am

For a lot of work n=1 is all that you’ve got, so don’t knock it.

Maybe 80% of peer reviewed medical papers are untrue. I’m pretty sure that if you’re thorough and persistent you can beat that batting average with your personal research. (To see more about the unreliability of published research read papers by a guy called Ioannidis. There’s an interesting article at “The Atlantic” and some tecnical papers at PLoS. He seems to be very popular in some of the medical community!)

In addition the sort of thing that you’re measuring (mood) is considered unmeasurable by a lot of researchers. For good reason if you take a random untrained person and ask him. However to tune up your own life you’ve got to tackle that and find a usable way to measure it. Seems you have. Well done.

The scary bit is that, in my opinion, it’s a huge impact on mood and mental performance. BUT there’s no data. How do we know which strain of which lactobacillus makes us a better programmer, blog writer or rocket scientist. As far as I know nobody knows this stuff. How do we figure it – I don’t know (yet).

For an interesting take on this basic idea there’s a Science Fiction book called “Blood Music”. If you have a taste for hard SF and don’t get too weirded out by disturbing ideas it’s worth a look. (If you’re not into hard SF and get disturbed by thinking about brain manipulation avoid it!)


GeeBee March 26, 2011 at 11:08 am

Hi Rob

I’m a follower of the Perfect Health Diet (ex long-term very-low-carber) and live in Perth. I was wondering how you made your kefir water. Were you able to source kefir grains locally?


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