**Acknowledgements**

*Oral Health by Using Probiotic Products*

genus were observed [33].

[28–30, 37].

**8. Conclusions**

the population.

tion or treatment of overweight and obesity.

and composition of the microbiota are the changes in the diet (high-fat diets) that

In order to demonstrate the aforementioned, it is convenient to point out two investigations carried out in 2015; Kasai et al. [32] conducted a study in Japanese population where they observed that bacterial diversity was significantly higher in obese subjects than in nonobese subjects. In the first group, there was a decrease of the *Bacteroidetes* species and increase of *Firmicutes* [31]. Angelakis et al. showed in a study performed in thin and obese subjects that the *Firmicutes* and *Actinobacteria* genera were the most predominant of the duodenal microbiota; however, in subjects with obesity, a higher proportion of anaerobic and lower proportions of aerobic

On the other hand, there are other authors such as Murugesan et al. that indicate in a study carried out in 190 Mexican children between 9 and 11 years old no significant differences between the different bacterial species of microbiota in the different evaluated subjects [34]. The same happens in Hu et al. In 2015, when 134 Korean adolescents from 13 to 16 years old were evaluated, no significant differences were found between the *Bacteroidetes*, *Firmicutes* and *Proteobacteria* populations [35]. It is widely recognised in the scientific community that diets with high-fat content favour the development of resistance to leptin, hyperphagia and therefore obesity. A study points out that the inclusion in the diet of the oligofructose prebiotic prevents the development of resistance to leptin and hyperphagia in rats; from this it is concluded that oligofructose reduces the energy of ingestion, and therefore

On the other hand, the use of probiotics is associated with multiple health benefits, which are highly endorsed by the scientific community. So far, the data that associate a specific type of microorganisms with human obesity are not conclusive, since they do not say whether it is the microbiota that plays a cause-effect function of obesity or whether it is the intestinal microbiota that is modulated in response to obesogenic diets and other factors related to the pathogenesis of this condition

Studies aimed at modulating the gut microbiota to prevent or control the obesity

With the reviewed bibliographic evidence, it is crucial to highlight the importance of including the gut microbiota as one of the factors involved in the management of obesity; however, more conclusive information must be analysed about it evaluating what happens even in other specific groups such as the child population.

As has been discussed in this chapter, multiple factors influence the development of obesity, including diet, a sedentary lifestyle, selection and an inadequate intake of nutrients such as simple carbohydrates and saturated fats. It has also been observed that obese individuals and those of a normal weight have different compositions of gut microbiota, with some bacterial families more predominate than others, which in turn modulates an individual's energy balance in some way and promotes the development of obesity. It has been established that a dietary supply of prebiotics and probiotics, for which there is scientific evidence demonstrating their benefits, could serve as an additional tool to curb the rising trend of obesity in

However, more studies using randomised, double-blind, controlled trials are necessary to demonstrate the efficacy of prebiotics and probiotics for the preven-

impact on the relationship between *Firmicutes* and *Bacteroidetes* [31].

it is suggested that it has the potential for the obesity treatment [36].

of the host, including the use of probiotics, show positive results [25, 30].

**102**

This work team is made up by academics from the Nutrition and Dietetics Department at the Technological University of Chile, INACAP, Concepción Talcahuano.
