High-amylose maize starch with chemical add-ons prevented diabtes in susceptible mice in an Australian study.
A chemically-modified starch used to increase fiber content in foods may serve as a prophylaxis of type 1 diabetes (T1D).
High-amylose maize starch — often found in nutrition bars and gluten-free snacks — with chemically linked acetate or butyrate has shown in mouse studies to be capable of helping subjects protect against autoimmune diseases including T1D.
A team of researchers — lead by senior author Charles Mackay (pictured), PhD, professor of immunology at Monash University in Melbourne, Australia — fed nonobese diabetic (NOD) mice the modified starch in combination diets with high levels of acetate and butyrate.
Mackay reported the mice’s gut bacteria fermented the modified starch in the mice’s colons, producing higher levels of short-chain fatty acids (SCFAs) acetate and butyrate than the process would with nonmodified starch.
The modified starch improved the mice’s colon lining, reduced proinflammatory factors, and promoted immune tolerance. None of the mice on a combination diet developed T1D — which is developed by T cells mistaking insulin-producing pancreas beta cells as foreign invaders and destroy them.
The positive results suggest there are different actions taken by acetate and butyrate, with the former reducing the rate of autoreactive T cells in the NOD mice, and the latter serving as an energy source for the colon lining cells.
Mackay called the discovery “the beginning of an era of the use of medicinal foods to treat human disease.”
Though Mackay and researchers theorized shaping the gut microbiota with a substantial production of SCFAs could prevent and treat human diseases, there is a significant leap in testing its efficacy on mice to humans.
Julia Greenstein, PhD, vice president of discovery research at the Juvenile Diabetes Research Foundation — a funding source for the mice study — noted the NOD mouse model is different than human T1D diagnoses.
Nearly every mouse of the NOD strain develops T1D, while only 50-60% of genetically predisposed humans develop T1D, Greenstein said.
“We don’t know what would happen if we gave [the SCFA-enriched starch] to people,” Greeinstein said. “[Acetate- and butyrate-enriched starch] has a big impact on these animals. No question.”
There is also expressed concern as to whether the starch prevents diabetes from ever occurring, or if it simply serves as a delaying factor in its progression. Long-term clinical studies on its effects would be necessary to know, Greenstein said.
Mackay has expressed interest in beginning clinical trials within a year to test whether the modified starch helps prevent T1D development in at-risk patients — or, those related to T1D patients and with an above-average risk of development, according to screening.
Study coauthor Julie Clarke, PhD, described the chemically-modified treatment as “sort of halfway between being a medicine and being a food,” with capsules unavailable for human patient consumption. She suggested patients would be treated to a tasty combination therapy.
“It’s a research product,” she said. “We recommend to our participants that they mix it with something like chocolate milk.”
The study, "Gut microbial metabolites limit the frequency of autoimmune T cells and protect against type 1 diabetes," was published online in the journal Nature.
An article regarding the study was made available.