What’s in your gut? Termites, for example

Science News has a fascinating short story, Gut bacteria reflect dietary differences, by Gwyneth Dickey, that highlights one of the ecological dimensions of ‘enculturation’ that I think some symbolic models of culture have a hard time grasping. It turns out that a Western diet produces a less-varied gut ecology in Italian children than was found in African children. Moreover, the old adage ‘you are what you eat’ could apply in a particularly interesting way to those who eat termites.

The original article, Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe (urban Florence) and rural Africa (Boulkiemde province, Burkina Faso), by Carlotta De Filippo and colleagues, is open access on the Proceedings of the National Academy of Sciences website, so you should definitely surf over there if you find this interesting.

De Filippo and colleagues discuss the microbiome, the ‘complex consortium of trillions of microbes, whose collective genomes contain at least 100 times as many genes as our own eukaryote genome’ (see also Gill et al. 2006). This enormous, varied ecosystem in the gut, a symbiotic community, supplements human metabolic capabilities, provides a first line of defense against pathogens, modulates gastrointestinal development and even informs the configuration of the immune system (paraphrased from De Filippo et al. 2010).

Different gut ecologies brought about both by environmental factors and by food production techniques, dietary preferences, and even food handling practices are one way that human groups might inadvertently induce biological variation in our species, a subtle culture-biology link through the populations in our gastrointestinal tracts. Now De Filippo and colleagues has gone out and actually demonstrated this variation empirically, using high-throughput 16S rDNA sequencing and biochemical analyses of fecal microbiota.

Continue reading

Live healthy, turn on your genes

For all those out there who still think that ‘it’s all in the genes,’ here’s a recent news story on the way that changes in lifestyle can affect genetic activity. Will Dunham at ABC News brings us, Healthy Lifestyle Triggers Genetic Changes: Study (I also pulled it off the Reuters feed). The study was small, and I doubt that it was nearly as rigorous as really necessary, but the findings are interesting.

In a small study, the researchers tracked 30 men with low-risk prostate cancer who decided against conventional medical treatment such as surgery and radiation or hormone therapy.

The men underwent three months of major lifestyle changes, including eating a diet rich in fruits, vegetables, whole grains, legumes and soy products, moderate exercise such as walking for half an hour a day, and an hour of daily stress management methods such as meditation.

As expected, they lost weight, lowered their blood pressure and saw other health improvements. But the researchers found more profound changes when they compared prostate biopsies taken before and after the lifestyle changes.

After the three months, the men had changes in activity in about 500 genes — including 48 that were turned on and 453 genes that were turned off.

Continue reading