The effects of sweeteners on the intestinal microbiota among individuals with eating disorders

Abstract: In today's society, the number of people who fall ill with various eating disorders is growing at a furious pace, the queues for treatment are getting longer at the same time as younger people are affected. In addition, it is a common phenomenon with ineffective treatments, where setbacks and relapses are common. Sometimes the affected individuals lose many valuable years or even an entire life dedicated to the hard grip of the eating disorder. Concurrently, the options on the food shelves are increasing with low-calorie options in the form of sweeteners. Studies show that individuals diagnosed with an eating disorder tend to choose those options to satisfy the craving for sweets, prevent weight gain, or because of the laxative effect. Due to the extent usage of sweeteners, sweeteners may have a major impact on the microbiota in individuals with eating disorders. It has been partly investigated how sweeteners, sugar, and eating disorders affect the intestinal microbiota separately, but they have not been linked to each other. This literature review aims to answer the following questions: How do sweeteners affect the intestinal microbiota and how do individuals with eating disorders consume sugar and other types of sweeteners? Previous research clearly shows that eating disorders affect the microbiota and bring it into the state of dysbiosis. The most research has been focused on one eating disorder, namely anorexia nervosa. Regarding sweeteners, it has been found that some affect the microbiota and others do not. For instance, aspartame is absorbed quickly, which leads to almost no calories, while the majority of sugar alcohols are slow and fermented further in the colon, which have an effect on the microbiota. Sugar has an inflammatory effect in higher intakes than recommended. The Nordic recommendations advise a diet with less than 10% sugar to avoid an inflammatory effect. The results of the literature study showed clear dysbiosis in both eating disorder studied. In the case of binge-eating disorder, this might be linked to irregular eating habits and episodes of binge eating which can lead to increased intake of sugar and sugar alcohols, resulting in low-grade inflammation. Regarding bulimia nervosa, further research is needed to draw some conclusions. However, there are 12 published studies regarding the microbiota in individuals with anorexia nervosa that indicate dysbiosis, either caused or consequence of malnutrition and starvation. Decreased serotonin levels and depression enchanted the pathways to synthesize serotonin even without the precursor. How sweeteners interact with the microbiota in individuals with eating disorders are also discussed in this thesis. Henceforth more studies are needed about the effect of sugar and sweetener consumption on the intestinal microbiota in individuals with eating disorders.