Low Gut Bacterial Richness Linked to Obesity
(HealthDay News) – Individuals with low gut bacterial richness have more adiposity and a more pronounced inflammatory phenotype; and weight loss intervention can improve bacterial gene richness, according to two studies published in the Aug. 29 issue of Nature.
Emmanuelle Le Chatelier, from the Institut National de la Recherche Agronomique in Jouy en Josas, and colleagues examined the human gut microbial composition in 123 non-obese and 169 obese Danish individuals. The researchers found that the groups differed with respect to the number of gut microbial genes. Twenty-three percent of the population were individuals with low bacterial richness and were characterized by more marked overall adiposity, insulin resistance, and dyslipidemia, and by a more marked inflammatory phenotype, compared to those with high bacterial richness. Within the low arterial richness group, obese individuals also gained more weight over time. A few bacterial species were able to differentiate between lean and obese participants.
Aurélie Cotillard, from the Centre de Recherches des Cordeliers in Paris, and colleagues examined the temporal relationship between food intake, gut microbiota, and metabolic and inflammatory phenotypes during a diet-induced weight-loss and weight-stabilization intervention conducted in 38 obese and 11 overweight individuals. The researchers found that more pronounced dys-metabolism and low-grade inflammation was present in individuals with reduced microbial gene richness (40%). Low gene richness and clinical phenotypes were improved with dietary intervention, but the intervention was less efficient for inflammation variables in those with lower gene richness.
"This finding, although exploratory in nature and requiring replication, supports a recently reported link between long-term dietary habits and the structure of gut microbiota and suggests that a permanent change of microbiota may be achieved by appropriate diet," Cotillard and colleagues write.