While it is not a commonly understood concept that wheat or gluten can cause blood sugar disorders, and certainly not as serious as type 1 diabetes, which involves the autoimmune destruction of the insulin producing beta cells in the pancreas, a sizable body of animal and human data points to exactly this causal link. [i]
Gluten, after all, is well known for adversely affecting gut health, and in the case of celiac disease, destroying the absorptive surface of the intestine through a hallmark autoimmune triggered process. In many ways, gluten opens up a 'pandora's box' of autoimmunity by both triggering intestinal permeability – so-called 'leaky gut' – as well as providing over 23,000 unique, digestion resistant polypeptides which are capable of infiltrating the body causing systemic inflammation and the loss of immunological self-tolerance, i.e. the ability to distinguish self from non-self.
Adding to this increasingly dismal picture of what was once considered the ultimate poster child for 'healthy food,' a new study published in the PloS One may have uncovered a 'missing' link in understanding how wheat exerts its toxic effects.
Mayo Clinic researchers sought to elucidate the mechanism at play within the long observed link in both animal and human studies between dietary gluten and the pathogenesis of type 1 diabetes (T1D), focusing on the role of the gut microflora in mediating its diabetes promoting properties.
In the new study titled, "Low Incidence of Spontaneous Type 1 Diabetes in Non-Obese Diabetic Mice Raised on Gluten-Free Diets Is Associated with Changes in the Intestinal Microbiome",[ii] they sought to confirm "whether changes in the intestinal microbiome could be attributed to the pro- and anti-diabetogenic effects of gluten-containing and gluten-free diets, respectively." They noted recent research showing that intestinal microflora have a major influence on the incidence of T1D, and theorized that since "diet is known to shape the composition of the intestinal microbiome," they might find an important link by testing changes in the gut flora of animals fed either gluten or gluten-free diets.
The study design was described as follows:
"NOD [non-obese diabetic] mice were raised on gluten-containing chows (GCC) or gluten-free chows (GFC). The incidence of diabetes was determined by monitoring blood glucose levels biweekly using a glucometer. Intestinal microbiome composition was analyzed by sequencing 16S rRNA amplicons derived from fecal samples."
The researchers observed the following results:
- "First of all, GCC-fed [gluten-containing chow fed] NOD mice had the expected high incidence of hyperglycemia [elevated blood sugar] whereas NOD mice fed with a GFC [gluten-free chows] had significantly reduced incidence of hyperglycemia.
- "Secondly, when the fecal microbiomes were compared, Bifidobacterium, Tannerella, and Barnesiella species were increased (p = 0.03, 0.02, and 0.02, respectively) in the microbiome of GCC [gluten-containing chow fed] mice, where as Akkermansia species was increased (p = 0.02) in the intestinal microbiomes of NOD [non-obese diabetic] mice fed GFC [gluten-free chows].
- "Thirdly, both of the gluten-free chows that were evaluated, either egg white based (EW-GFC) or casein based (C-GFC), significantly reduced the incidence of hyperglycemia."