Food Additive P-80 Impacts Mouse Gut Microbiota Promoting Intestinal Inflammation, Obesity and Liver Dysfunction

the globalization of unhealthy lifestyle.Key metabolic and physiological changes, including obesity, metabolic syndrome and Nonalcoholic Fatty Liver Disease (NAFLD) are commonly associated with chronic, non-communicable disease that are responsible for approximately 70% of the world's death.There are compelling arguments to include the composition of gut microbiota as a key risk factor for the development of obesity and obesity related metabolic disorders, including insulin resistance, type 2 diabetes, dyslipidemia and non-alcoholic fatty liver disease [3].The gut microbiota has been implicated in having both direct (i.e. through effect on nutrient uptake) and indirect effect on health [4,5].In mice, food additives have been demonstrated to affect the host microbiota interaction, leading to low-grade inflammation, adiposity and adiposity associated metabolic effect [6].We set out to elucidate whether alteration in the gut microbial community after P-80 ingestion is a causative agent of liver dysfunction.To explore this possibility, we setup an experiment to examine the impact of P-80 on gut microbiota using wild-type C57BL/ 6 mice.The experimental mice were gavaged with the amount of P-80 equal to 1% of their body weight.This amount correlates to the acceptable daily human intake of 1% per kg of polysorbate-80 to body weight [7]. Methods Mice and dietThe C57BL/6 (000664) mice were purchased from The Jackson Laboratory.The mice were maintained under specific pathogenfree conditions, on a 12-h light-dark cycle, and fed normal diet (12 kcal% fat, 29 kcal% protein, 59% kcal carbohydrate) ad libitum.For this study there were two groups: one control group (ingesting saline via gavage) and one experimental P-80 fed group (ingesting P-80 dissolve in saline, 1% per kg via gavage).This dose corresponds to the FDA Acceptable Daily Intake (ADI) in humans (1% per kg (body weight), adjusted to the mouse AbstractThe increasing prevalence of obesity has emerged as one of the most important global public health issue.The change to the human microbiome as a result of changes in the quality and quantity of food intake over the past several decades has been implicated in the development of obesity and metabolic syndrome.We administered polysorbate-80 to mice via gavage.The researchers monitor liver noninvasively using a bioluminescence imaging.For the liver dysfunction we measure the liver enzymes and PAS stain on liver, electron microscopy liver mitochondria.For the assessment of intestinal inflammation we measured fecal LCN2, LPS, MPO and flagellin by ELISA and qPCR.We use confocal microscopy to detect closet bacteria near the epithelium.16S sequence was used for the composition of microbiota.Compared with control mice, those receiving emulsifier, showed impaired glycemic tolerance, hyperinsulinemia, altered liver enzymes, larger mitochondria and increased gall bladder size.Additionally, mice in the experimental group showed higher levels of DCA, reduced Muc2 RNA expression, reduced mucus thickness in the intestinal epithelium and increased gut permeability.Intestinal bacteria of mice receiving P-80 were found deeper in the mucus and closer to the intestinal epithelium and had increased level of bioactive LPS, flagellin and LCN2 expression.The result of the study are supportive of evidence that emulsifier agents such as polysorbate-80, may be contributing to obesity related intestinal inflammation and progression of liver dysfunction and alternation of gut microbiota.