What Can We Learn From the Sweetener and Gut Bug Study?
Last week, a paper by Jotham Suez and colleagues on the potential detrimental effect of artificial sweeteners (particularly saccharin) on glucose homeostasis, published in Nature grabbed media attention worldwide.
Using an elegant series of experiments, the research showed that saccharin not only appears to negatively affect glucose metabolism in mice, but does so through its effects on gut bugs.
Potential relevance to humans was demonstrated by exposing volunteers to 120 mg of saccharin a day for 7 days and then transplanting the stool of the four (out of seven) participants, who showed decreased glucose tolerance, to germ-free mice.
In their conclusions, the authors speculate that the widespread consumption of artificial sweeteners (as a means to prevent obesity and/or diabetes) may have played a paradoxical role in promoting these very health problems.
While that may or may not be the case (given that all we have is evidence in mice and short-term finding from a handful of humans), I find these observations most interesting for one simple reason alone and that is the demonstration that chemical composition of the diet can alter gut bacteriomes, which in turn can significantly affect metabolism.
Whether or not artificial sweeteners may have significantly altered the gut bacteria of people across the world (leading to obesity in Africa, India, South America and elsewhere) may not be entirely plausible but, if indeed sweeteners can do this, there are probably much more likely culprits in our modern diets.
For one, I would begin by suspecting the rather liberal use of antibiotics both in animal husbandry as well as human infection. Next, I would wonder about the widespread use of preservatives and pesticide. Finally, I’d wonder about the very likely impact of all the other chemicals including personal hygiene products and disinfectants in our environment on our intestinal flora (does washing your hands make you obese?).
If there is one thing that I learn from this study, it is the fact that we must now take into consideration a wide range of factors that can potentially alter our susceptibility to obesity and/or diabetes by changing our gut bugs.
Incidentally, the gut bugs are not just influenced by environmental or food-borne chemicals – the very foods we eat can substantially affect our gut bugs, which have now been implicated in everything from Alzheimer’s and autism to arthritis and cancer.
While every new area of research is often accompanied by considerable hype (promoted both by the media and the researchers themselves), this will probably be an interesting space to watch.
Suez J, Korem T, Zeevi D, Zilberman-Schapira G, Thaiss CA, Maza O, Israeli D, Zmora N, Gilad S, Weinberger A, Kuperman Y, Harmelin A, Kolodkin-Gal I, Shapiro H, Halpern Z, Segal E, & Elinav E (2014). Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature PMID: 25231862