March 06, 2019
By Anne Harding
NEW YORK (Reuters Health) - Prebiotics may have metabolic and anti-inflammatory benefits in type 2 diabetes, new research suggests.
"After a systematic review of the available evidence, prebiotics and substances with prebiotic properties can have beneficial effects on metabolic and inflammatory biomarkers in individuals with type 2 diabetes mellitus," said Dr. Melissa Brown of the University of Saint Joseph, in West Hartford, Connecticut.
"However, the overall number of studies are too few to draw a definitive conclusion and (it is) too soon to make wide-reaching generalized recommendations," she told Reuters Health by email.
The findings were published online February 28 in the Journal of the Academy of Dietetics and Nutrition.
Prebiotics are plant fibers that may reduce inflammation and improve gut health by promoting the growth of "good bacteria," or probiotics.
To investigate whether prebiotics could reduce inflammatory and metabolic biomarkers in type 2 diabetes patients, Dr. Brown and her team reviewed 27 randomized controlled trials of several different prebiotics. Most study participants were women, with disease duration ranging from six months to 11 years. Intervention duration ranged from four days to 12 weeks.
Twenty studies found a benefit of prebiotics over placebo on metabolic and/or inflammatory markers. Glycemia improved in 19 studies, cardiovascular markers in 15, body weight in nine and markers of inflammation in nine.
"Many different types of prebiotics or substances with prebiotic properties were investigated and for some of them, they were only examined in one or two studies," Dr. Brown said. "The prebiotics with the most evidence to date are resistant starch, resistant dextrin and oligofructose-enriched inulin due to the quantity and quality of the publications analyzed."
There are many food sources of prebiotics, the author noted, which can also be consumed in fortified processed foods and beverages or in supplements.
"While we always recommend a 'food first' approach, the optimal dose for prebiotics has not yet been established so it is still difficult to gauge just how much of these foods one would need to consume to achieve the optimal benefits," she said. "Optimal dose of these prebiotics and substances with prebiotic properties is an area of ongoing research and hopefully we will know more in the coming years."
"Doctors should be aware of the potential benefits of prebiotics for individuals with type 2 diabetes, especially females over the age of 18 years old which was the population most represented in our systematic review," Dr. Brown added. "Whether or not they recommend prebiotics to their patients should be determined on an individual basis as with all medical and nutrition therapy."
"The good thing about the evidence with prebiotics so far is that there really hasn't been any harmful adverse effects except for some individuals experiencing some gas and bloating and other minor gastrointestinal effects," she said. "So in many cases the potential benefits could outweigh the negatives."
Future research should include studies of longer duration, and studies that include both males and females, according to Dr. Brown.
J Acad Nutr Diet 2019.
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