The impact of California table grapes on intestinal inflammation and microbiota in mice fed an american type diet

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Brian Collins (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Michael McIntosh

Abstract: Obesity is a growing health concern in the United States and worldwide. The chronic, low grade inflammation associated with increased white adipose tissue mass has been linked to chronic metabolic disorders such as insulin resistance, hypertension, and hyperlipidemia. Consumption of high fat diets leads to intestinal disorders such as microbial dysbiosis and gut barrier dysfunction that can adversely impact systemic metabolism. One potential dietary strategy to alleviate the high fat-induced chronic inflammation is increased consumption of fruits and vegetables rich in polyphenols due to their antioxidant and anti-inflammatory properties. Notably, several studies have demonstrated that supplementation with grape products or anthocyanins found in grapes reduced inflammation systemically and increased the abundance of beneficial bacteria such as Lactobacillus, and Bifidobacterium in culture. However, the beneficial properties of whole grape powder and one or more of its fractions on intestinal inflammation, microbial populations, and barrier function in mice fed an American type diet rich in saturated fat are unclear. Therefore, the specific aims of this research were to; (i) determine the impact of consuming California table grapes on intestinal health in mice fed an American type diet rich in one type of saturated fat (Aim 1), and (ii) identify a key fraction (i.e., extractable polyphenol (EP) or non-extractable polyphenol (NEP) fractions) of California table grapes that improves markers of intestinal inflammation in mice fed an American type diet rich in four types of saturated fats (Aim 2). In Aim 1, consumption of at least one of the powder grape diets; (i) reduced body fat percentage, the total weight of all four fat depots, and inguinal fat depot weight, (ii) increased localization of a tight junction protein linked to improved barrier function, (iii) reduced the abundance of a deleterious sulfidogenic bacteria, and (iv) increased the abundance of beneficial bacteria (e.g., Akkermansia muciniphila, Bifidobacterium, and Lactobacillus), compared to high fat controls. However, the high fat diet did not significantly increase the abundance of inflammatory markers in the intestine nor did the powdered grapes significantly decrease their abundance. Taken together, these data acquired in Aim 1 demonstrate that whole powdered California table grapes improved a marker of gut barrier function and a metabolic profile that was positively correlated with changes in microbiota in mice fed a butter-rich diet. In Aim 2, the polyphenol-rich EP fraction alone or in combination with NEP (EP+NEP), but not powdered grapes; (i) decreased body fat percentage, body fat depot weights, and liver triglyceride levels, (ii) improved insulin sensitivity and glucose disposal, (iii) decreased the mRNA levels of several inflammatory genes in WAT, (iv) decreased the expression of the proinflammatory gene Cluster of differentiation 68 in the colon, and (v) increased expression of G-protein receptor 43 in the ileum compared to high fat controls. Taken together, these data demonstrate that the; (i) potential health benefits of consuming grape powder are dependent on the type and amount of fat in the diet, and (ii) extraction of polyphenols from powdered grapes results in improved metabolic profile and decreased systemic inflammation in conjunction with consuming a rich in saturated fats. Collectively, these findings are expected to contribute insight for the development of dietary strategies using table grapes for decreasing obesity and some of its metabolic complications, possibly by altering populations of gut microbes. However, clinical trials are needed to determine the extent to which these findings are applicable to humans.

Additional Information

Language: English
Date: 2015
Grapes, Intestine, Microbiota, Obesity
Obesity $x Physiological aspects
Table grapes $x Therapeutic use
Intestines $x Microbiology
Obesity $x Treatment

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