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.