Obesity Associated with Reduced Levels of Intestinal Microbiota


Obesity is an energy disorder and something that more and more of us are becoming familiar with. Obesity is measured using a person’s body mass index (BMI) which is a proportion of a person’s height and weight. Obesity, defined as having a BMI of greater than 30, is related to many health conditions such as cardiovascular disease, type 2 diabetes, stroke, hypertension, and cancer. Studies have shown that the amount of “good” bacteria in the human intestinal tract has a positive effect on normal bodily functions. Lately, more research is being conducted to determine the presence and role of these good and bad bacteria on health conditions, obesity included.


To determine if reduced levels of intestinal microbiota are associated with obesity.


One of two groups of people included 68 obese patients, with a BMI of greater than 30. The control group was made up of 47 people with normal BMI’s in the 19-25 range. All patients were male and of the same height but had various ages.


Stool samples were collected in sterile plastic containers. These samples were then cultured to see how much of each of numerous strains of bacteria were contained in each sample. The cultures of the obese and the control groups were compared against each other to determine, if any, the differences in the amounts of microbiota.


When comparing the two groups it was found that the “normal” weight control subjects had higher amounts of many intestinal bacteria than the obese subjects did. The control group had higher quantities of the species B. animalis, M. smithii, and L.casei/paracasei when analyzed against the obese. The only strain of bacteria to be found in higher amounts in the obese was L. reuteri.


The participants in this study were mostly Caucasian. In addition, the number of subjects studied was small.


It was found that obese patients had reduced levels of certain bacteria in their intestinal tract compared to the patients of normal weight, who had higher levels of these same bacteria. The higher levels of bacteria in the normal weight patients are associated with a healthy gut and necessary for proper function.


The full report is titled “Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevib-acter smithii.” It is in the 2 July 2011 issue of International Journal of Obesity (pages 1-9). The authors are M. Million, M. Maraninchi, M. Henry, F. Armougom, H. Richet, P. Carrieri, R. Valero, D. Raccah, B. Vialettes, and D. Raoult.


Written by Carrie Ficuciello,
Dept. Nutritional Sciences, Rutgers University-NewBrunswick
Edited by SA Shapses PhD, RD