All posts for the month November, 2014

Hello readers! Just last month an interesting paper was published on links between the composition of bacteria in the guts of alcoholics seeking treatment, and psychological or physiological symptoms that are associated with relapse. The paper is by Leclercq et al. and comes from a variety of European labs, and is published in the Proceedings of the National Academy of Sciences of the USA (find it here).

Essentially, the authors found that some, but not all, alcohol-dependent subjects developed gut leakiness, which was associated with higher scores of depression, anxiety, and alcohol cravings after a short period (three weeks) of abstinence in a treatment program. These may be important indicators of the potential for relapse. Subjects with gut leakiness had an altered composition of the gut bacterial community, and the bacteria were differently active (this was measured by studying the metabolic compounds that were present in feces).

What does this mean? It means that in some people, changes in gut bacterial community composition (dysbiosis) can lead to physical and psychological changes that affect mood, and possibly behavior. In this particular study, dysbiosis in the guts of some alcoholics resulted in effects that might make it more difficult for them to stay away from alcohol.

It may be possible in future to help people with substance abuse problems manage these problems with changes in diet and exercise! In fact, there’s no reason why a person can’t try to help manage these problems now by eating a healthy diet, getting regular sleep, and getting regular exercise. Probiotics may, in future, assist with problems like these but at the moment no products have been tested for helping with behavioral problems like alcohol abuse.

A while ago, I came across this interesting and very important review in Cell (a very reputable journal), on how gut microbes (part of your microbiome) can affect the aging process. Ten years ago people would have thought this was impossible!

The review, published in January 2014, is by Caroline Heintz and William Mair, both from Harvard. The article can be found here: “You are what you host: microbiome modulation of the aging process.“. To summarize, the microbes living in symbiosis with invertebrates, and possibly other animals (mostly in the gut, but also in other places, like the mouth or on the skin), can affect the rate at which aging occurs. This could occur by the microbial production of compounds that affect the expression of genes, or possibly by the microbes metabolizing compounds into products that have direct effects on host physiology. There is also evidence to suggest that different microbial species may have different effects. It makes sense if you think of how long digestive systems have existed in symbiosis with microbes- maybe we and they have co-evolved.

Most of the work cited in this review has been done with invertebrates, particularly nematodes, which have been intensively studied for many years as model organisms. How exciting if the results from these studies are supported by work done with mammals!  Until we know more about how microbes interact with mammals, the best thing you can do is try to make sure you eat a healthy, balanced diet with lots of fruits and vegetables, get regular sleep (disrupting circadian rhythms can lead to changes in your gut microfloral composition and changes in your body, like a tendency to gain weight), and get regular exercise (in addition to health benefits, most cardio exercise helps your gut move food along by peristalsis- there’s a reason why for many years people would take walks after meals to help with digestion!). If you want to take a probiotic, I can’t recommend a specific product, but you may be able to find more information at sites like

Have a great day!