Study under review: a-Galacto-oligosaccharides Dose-Dependently Reduce Appetite and Decrease Inflammation in Overweight Adults
While it is generally acknowledged that fiber is good for us, different benefits come from different types of fiber. For example, viscous fibers (which have the ability to thicken or form gels when mixed with fluids) improve blood sugar control. Fermentable fibers can act as prebiotics and lead to favorable changes in the gut microbiota, in turn regulating appetite and food intake. But what in the world is a prebiotic?
The increasing awareness of probiotics and the importance of having healthy gut bacteria has been followed by an interest in prebiotics, which are foods for the bacteria in our gut. Specifically, a dietary prebiotic is a carbohydrate compound that resists digestion in the upper GI tract and is then fermented by the gut microflora in the colon. Prebiotics confer health benefits by causing specific changes in the composition and/or activity of the gastrointestinal microbiota.
One of the many different types of prebiotics are alpha galacto-oligosaccharides (a-GOS, pictured in Figure 1), which are made up of two to eight galactose units (galactose is a common dietary sugar and makes up half of the disaccharide lactose). They have not been studied nearly as much as other prebiotics, like inulin or fructooligosaccharides, but the prebiotic actions of a-GOS have shown benefits in animals and humans. The impact of oligosaccharides on the gut microbiome can be affected by a number of factors, including the dosage and degree of polymerization (i.e. the specific chemical configuration).
With all of that in mind, this study was designed to determine if a-GOS could reduce appetite, food intake, and inflammation in overweight but otherwise healthy participants.
Prebiotics are specific types of fiber that resist digestion in the upper GI tract and are fermented by microflora of the lower intestine, and in particular selectively feed bacteria potentially associated with health and well-being. One type of prebiotic with the potential to regulate food intake are alpha galacto-oligosaccharides (a-GOS).
Other Articles in Issue #13 (November 2015)
Breakfast: A disempowering nutritional dogma
By Martin MacDonald, Msc
Return of the globule: milk fat strikes back
Milk fat is structurally different than most other fats, and the milk fat globule membrane has been looked at previously (twice in Study Deep Dives, in fact) for its impact on chronic disease. But could it also impact response to exercise?
Studies have shown that supplement buyers generally trust the supplements they buy. That might not be the safest assumption, as dietary supplements that are presumed helpful or neutral may sometimes cause serious side effects, as quantified by this study.
Probiotics and the propensity for portliness
When you eat a meal, your gut bacteria also eats a meal. And gut bacteria are increasingly looked at for their influence on chronic disease. This study looks at the effect of a specific probiotic blend on weight gain.
The espresso effect: caffeine and circadian rhythm
Your daily rhythms are influenced by “zeitgebers” such as light and exercise. But until now, we haven’t known the exact impact of late-day caffeine intake on melatonin and circadian rhythms.
Money, time, and the science that suits us
By David Katz, MD, MPH
Human eating patterns ... there’s an app for that
Eating throughout the day has become quite normal, given the ubiquitous availability of snack foods. Partly due to this, diet research has been plagued by inaccurate self-reports. This study used an app to get around that issue.
Does marijuana actually boost creativity?
Ancedotally, weed has been claimed as a creativity booster for decades. With THC having an effect on dopamine, a plausible mechanism exists. This randomized trial puts marijuana to the test.
Diet and autism: no gluten, no casein, no difference?
Gluten and casein are two food components often linked with autism spectrum disorder symptoms. Hence the prevalance of wheat and dairy free diets. But will they work in a rigorously controlled trial?