DIETARY INTERVENTION IMPACT ON GUT MICROBIAL GENE RICHNESS

Editors Note: The following submission was written by Campbell P. (’14), and it summarizes an interesting article he read for his AP Biology class.

            The purpose of this study is to see whether or not it is possible to change microbial gene richness to ward off the epidemic of obesity. This article explains the relationship between food intake, gut microbiota and metabolic and inflammatory phenotypes. In this a study of microorganisms, the authors hypothesized that a dietary intervention could change the gene richness in the gut of an individual to prevent obesity and other diseases that LGC (low gene count) could lead to like pre-diabetes, type 2 diabetes, cardiovascular disorders and cancer. Forty nine obese subjects were recruited with a mix of HGC (high gene count) individuals and LGC individuals. The subjects ate a six week high protein diet then a six week weight maintenance diet. The individuals were subject to physical activity scores, observation of food intake and analysis of gut microbiota. During the first week the subjects noticed a loss in body fat. During the next six weeks nutrient intake returned to normal values. The LGC individuals had high insulin resistance, high LDL cholesterol and higher inflammation than HGC individuals. Prior to the study, the LGC individuals consumed less fruits and vegetables and less fishery products than HGC which suggests long term dietary habits affect gene richness. Gut microbiota differ from LGC to HGC because 14 out of 18 species found in the gut were differentially abundant in LGC and HGC individuals. Gene richness in LGC individuals increased after energy-restricted diet and while there was almost no change in gene richness in HGC individuals. Increase of abundance of gene clusters in energy-restricted diet abundance decreased in maintenance phase in LGC. Gene richness may help to predict efficacy on dietary interventions on inflammatory variables. The intake of fruits and vegetables before intervention lead to HGC. Dietary intervention could lead to microbial changes but because the intervention was so short there were no full permanent change of gene richness in LGC individuals.