Chapter 9 - The role of the intestinal microbiota in weight loss in overweight and obese humans

Abstract

Obesity is a multifactorial disease with a broad etiology and multiple comorbidities that represent a major public health problem. An emerging factor in obesity is the intestinal microbiota that, according to several studies, is directly implicated in obesity and its metabolic complications. However, it is an ongoing challenge for scientists to understand this relationship. This bibliographical review describes the influence of the intestinal microbiota on the weight loss of overweight and obese subjects. The obese phenotype is characterized by a lower microbial genetic variety, a higher proportion of Firmicutes, and a lower proportion of Bacteroidetes with respect to the normal weight phenotype. Also, it has been observed that the abundance of several bacterial species can be altered by means of nutritional intervention. Although the majority of the results that have been published to date suggest that the intestinal microbiota at the phylum level is related to obesity, there are several studies that show conflicting results. Therefore more research is needed to understand and confirm this connection and the underlying mechanisms, as targeting the microbiome could be a promising future approach, along with dietary intervention, to maintain significant weight loss.