It wasn’t long ago that genetics explained everything that went on in the body. If you had the genes for a particular disease, that was your future. We now know that environmental conditions and stresses factor in – a science called epigenetics. But the most cutting edge research now shows that health or disease may largely be due to the health and diversity of your gut microbiome.
A recently published study in the journal Cell Host & Microbes, explored the question of whether it is genetics or diet that drives changes to the gut microbiome.
An interesting question.
Peter Turnbaugh et al carried out studies with different strains of genetically identical mice. They also studied four lines of mice deficient for key genes involved in immunity and obesity. Additionally, there were more than 200 “outbred” mice — bred to yield offspring with easy-to-trace genes.
They offered two different diets: One a low fat, high plant polysaccharide diet (LFPP) and the other a high fat, high sugar diet (HFHS).
I would have been interested to see a couple of other diets studied, such as a high saturated fat (from good clean sources), low sugar diet and a moderate fat, moderate carb diet.
I always wonder what they consider high fat and where they source the fat. The same goes for the high plant diet – where do they get the plants from – are they GMO corn and soy?
But I digress and the study was really not all about the particulars of the diet.
The researchers found that diet was the more important driver of microbiome diversity – not the genetics.
Furthermore, when the mice were reverted back to their original diets, the majority of their microbiome reverted back as well, although this did not happen to all the subjects.
Additionally, they found that it took only 3 days to change the community of microbes in the gut and that this was independent of genetics.
The researchers concluded that,
These new results emphasize that, unlike a mammalian genome — which is relatively constant — the microbial genomes that comprise the gut microbiome are relatively plastic… It may someday be possible to design diets that shape the gut microbiome in a way that is therapeutically beneficial. The good news is that the microbial response to a given diet may be similar for many people’s microbial communities, suggesting that we might not need to tailor interventions differently for every single person. (source)
Interestingly, fecal analysis revealed that the high-fat, high-sugar diet increased the abundance of members of the Firmicutes phylum and decreased the abundance of members of the Bacteroidetes phylum.
It has already been shown in the literature that increases in the Firmicutes phylum contributes to obesity. There is a lot of research that shows gut bacteria have a certain amount of control over appetite.
In another recent study in humans, Turnbaugh et al showed that diet can rapidly and reproducibly alter the human gut. This study showed that the animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii).
Well, although we have not had the benefit of double blind, multi-clinic studies, many of us who have changed our diets for therapeutic benefit have already experienced a change in the gut microbiome in a positive direction.
Read more about changing your diet for better health here.
I’m looking forward to the time when a conventional doctor will instruct a patient on the specific diet necessary as a therapeutic tool instead of just writing a handful of prescriptions.
Have you experienced benefits from changing your diet? Leave a comment and let us know!