A type 4 resistant potato starch alters the cecal microbiome and gene expression in mice fed a Western diet based on NHANES data

Authors: Smith, Allen; Chen, Celine; Cheung, Lumei; WARD, ROBERT - Utah State University; JONES, B. SKY - Utah State University; Pletsch, Elizabeth; Dawson, Harry

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2024
Publication Date: 3/5/2024
Citation: Smith, A.D., Chen, C.T., Cheung, L., Ward, R., Jones, B., Pletsch, E.A., Dawson, H.D. 2024. A type 4 resistant potato starch alters the cecal microbiome and gene expression in mice fed a Western diet based on NHANES data. Nutrients. 15,3141-3157. https://doi.org/10.1039/d3fo04512a.
DOI: https://doi.org/10.1039/d3fo04512a

Interpretive Summary: Four major types of resistant starch (RS1-4) are present in foods all of which can alter the microbiome and are fermented in the cecum and colon to produce short-chain fatty acids. Type 4 RSs are chemically modified starches, not normally found in foods but have become a popular food additive becasue they increase the amount of fiber in the food. Multiple studies, in humans and rodents have explored how different RS4 affect glucose metabolism, but fewer studies have examined the effects of RS4 consumption on the bacteria in the large intestine. In addition, many RS studies conducted in rodents use high-fat diets that do not represent what is typically consumed by people. To address this, mice were fed a Total Western Diet (TWD), based on NHANES data that mimics the composition of a typical American diet, for six weeks, and then supplemented with 0, 2, 5, or 10% of the RS4, Versifibe 1490TM (VF), a phosphorylated and cross-linked potato starch (RPS), for an additional three weeks. The contents of the cecums were analyzed for short chain fatty acid (SCFA) content and the composition of the bacteria in the large intestine. Butyrate, a SCFA, levels were increased while branched chain SCFA production decreased. The diversity of the large intestine bacteria decreased in mice fed the TWD with 10% VF 1490 added while the bacterial composition between groups fed the 5% and 10% VF groups were different from mice fed the TWD. Similarly, the largest changes in relative amounts of various types of bacteria were greatest in mice fed the 10% VF diet. Cecal and distal colon tissue gene expression levels were analyzed by a method called RNASeq. Gene expression changes were more prevalent in the cecum than the large intestine and in mice fed the 10% VF diet. These results providing additional evidence that the structure of the RS is a major factor determining its effects on the large intestine bacteria and gene expression in the cecum and colon.

Technical Abstract: Four major types of resistant starch (RS1-4) are present in foods all of which can alter the microbiome and are fermented in the cecum and colon to produce short-chain fatty acids. Type 4 RSs are chemically modified starches, not normally found in foods but have become a popular food additive as their addition increases fiber content. Multiple studies in humans and rodents have explored how different RS4 affect post-prandial glucose metabolism, but fewer studies have examined the effects of RS4 consumption on the microbiome. In addition, many RS studies conducted in rodents use high-fat diets that do not approximate what is typically consumed by humans. To address this, mice were fed a Total Western Diet (TWD), based on NHANES data that mimics the macro and micronutrient composition of a typical American diet, for six weeks and then supplemented with 0, 2, 5, or 10% of the RS4, Versifibe 1490TM (VF), a phosphorylated and cross-linked potato starch (RPS), for an additional three weeks. The cecal contents were analyzed for short chain fatty acid (SCFA) content and microbiota composition. Butyrate production was increased while branched chain SCFA production decreased. The alpha-diversity of the microbiome decreased in mice fed the TWD with 10% VF 1490 added while the beta-diversity plot showed that the 5% and 10% VF groups were distinct from mice fed the TWD. Similarly, the largest changes in relative abundance of various genera were greatest in mice fed the 10% VF diet. Cecal and distal colon tissue mRNA abundance was analyzed by RNASeq. Gene expression changes were more prevalent in the cecum than the colon and in mice fed the 10% VF diet, but the number of changes was substantially lower than we previously observed in mice fed RPS. These results providing additional evidence that the structure of the RS is a major factor determining its effects on the microbiome and gene expression in the cecum and colon.