IDRR APRIL -MAY -JUNE 2020 - Flipbook - Page 66
INTERDISCIPLINARY
DISCUSSION:
In addition to bacteraemia and metastatic
inflammation , another possible pathway associating
periodontal diseases to systemic inflammatory
diseases may be through alterations in the gut
microbiome. In individuals with periodontal diseases,
the long-term swallowing of high doses of periodontal
pathogenic microorganisms could induce a dysbiosis
of the intestinal microbiota, favouring the
establishment of an ‘inflamed’ microbiome in terms
of composition and or function. In turn, this altered
gut microbiota could modulate periodontal diseases
by contributing to the progression and severity of
periodontal tissue destruction. As a first approach to
support this concept, we focused on determining the
composition profile of the gut microbiome of individuals
with periodontal diseases in comparison to periodontally
healthy controls. We also searched for correlations
between periodontal inflammation and attachment
lost with specific microorganisms of the gut
microbiota.
Along with our line of thought, some studies have
addressed the possible association between
periodontal disease oral pathogens and the gut
microbiota . Through oral administration of high doses
of this pathogen in mice. It is reported that there is an
increase in local and systemic inflammation, glucose
blood levels, insulin resistance, systemic endotoxemia,
and a decrease in gut barrier function. Although no
major changes in diversity were seen, significant
changes in the gut microbiota composition of P.
gingivalis-administered mice were observed, with an
increase in Bacteroidetes, a decrease in Firmicutes,
and an increase in Prevotella. The proportions of
Porphyromonadaceae were still very low in these
animals, suggesting that the pathobiont P. gingivalis
may alter the gut microbiome not by outgrowing in
the gut but by indirectly inducing endotoxemia.
In contrast to those previous studies in animal models
our findings showed that patients with periodontal
July-August-September 2019
diseases tend to present lower diversity in the gut
microbiota. In relation to beta diversity, it was not
possible to clearly distinguish individuals with distinct
clinical status based on the composition of the gut
microbiota.
Differences among clinical groups were observed in
the composition of the gut microbiome at the phylum
level. Considering the two major phyla commonly
observed in the human gut microbiota, there was a
tendency of Bacteroidetes to decrease and
Firmicutes to increase with disease severity. In
accordance with these data, a high Firmicutes/
Bacteroidetes ratio in the gut microbiome has been
reported in many other systemic inflammatory
conditions Other investigations, however, have either
reported a significant decrease in this ratio or no
changes at all in systemic inflammatory conditions.
Although the ratio Firmicutes/Bacteroidetes was high
in our diseased population, these phyla varied widely
in abundance among patients within the same clinical group.
ORAL MICROBIOME MODULATED
BY DIETARY HABITS
The members of the oral microbiome in health or
disease appear to select depending on the availability
of nutrients .Diet of the human host appears to shape
the symbiosis of the microbiota residing on the mucosa and on the non-shedding surfaces of teeth. Use
of refined carbohydrates in the diet of modern humans. Sucrose contributes to increased risk of caries.
Shifts in the diet of early human ancestors to modern
foods have contributed to subtle changes in the oral
microbial community . Interestingly, periodontal
disease-associated taxa, including Porphyromonas
gingivalis and members of the Tannerella . The decrease
in microbial diversity culminated in dramatic shifts in
the proportional composition of the microbial
communities of humans of the industrial revolution. In
contrast, from medieval to modern times, the oral
microbiome associated with the gingival sulcus and
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