Relationships Between Diurnal Changes of Tongue Coating Microbiota and Intestinal Microbiota

Abstract

The oral cavity and the intestine are the main distribution locations of human digestive bacteria. Exploring the relationships between the tongue coating and gut microbiota, the influence of the diurnal variations of the tongue coating microbiota on the intestinal microbiota can provide a reference for the development of the disease diagnosis and monitoring, as well as the medication time. In this work, a total of 39 healthy college students were recruited. We collected their tongue coating microbiota which was collected before and after sleep and fecal microbiota. The diurnal variations of tongue coating microbiota are mainly manifested on the changes in diversity and relative abundance. There are commensal bacteria in the tongue coating and intestines, especially Prevotella which has the higher proportion in both sites. The relative abundance of Prevotella in the tongue coating before sleep has a positive correlation with intestinal Prevotella; the r is 0.322 (p < 0.05). Bacteroides in the intestine had the most bacteria associated with the tongue coating and had the highest correlation coefficient with Veillonella in the oral cavity, which was 0.468 (p < 0.01). These results suggest that the abundance of the same flora in the two sites may have a common change trend. The SourceTracker results show that the proportion of intestinal bacteria sourced from tongue coating is less than 1%. It indicates that oral flora is difficult to colonize in the intestine in healthy people. This will provide a reference for the study on the oral and intestinal microbiota in diseases.

The association between oral and gut microbiota in male patients with alcohol dependence

“…Colonization of the gut from oral bacteria may precipitate intestinal microbiota disturbance and barrier damage, resulting in low levels of systemic inflammation and distal spread ( Bull-Otterson et al, 2013 ; Imai et al, 2021 ). In addition, HC had a proportion of the intestinal microbiota which derived from the oral microbiota of less than 1% according to the Chinese study, which similar to the results of current study ( Guo et al, 2022 ).…”

Distribution characteristics of oral microbiota and its relationship with intestinal microbiota in patients with type 2 diabetes mellitus

“…To further explore whether there was ectopic colonization of oral flora in the intestinal tract in patients with T2DM, we used the Source Tracker method to analyze. The results showed that nearly 2.36% of intestinal flora came from the ectopic colonization of tongue-coating flora, which was higher than the results of healthy people (< 0.9%) in the previous study ( 49 ), Figure 5B .…”

“…T2DM is characterized by chronic low-grade inflammation ( 27 ), closely related to intestinal microflora change and intestinal permeability increase ( 84 ). In this study, the proportion of ectopia colonization of oral flora in the intestine reached 2.36%, significantly higher than the healthy ( 49 ), indicating that T2DM might correlate with the heterotopic colonization of oral flora in the intestine, which might provide an essential reference for the diagnosis and treatment of type 2 diabetes.…”

Regulatory effects of oral microbe on intestinal microbiota and the illness

“…However, frequently using 1% as the threshold for excluding the low-abundant organisms, some oral-origin microbiome species in the intestine may escape detection unconsciously. The SourceTracker results showed that the percentage of intestinal bacteria from the tongue-coated microflora was within 1% ( Guo et al., 2022 ). Moreover, diet and diurnal variation are independent variables that affect the composition of microbes in the GI tract, which needs further consideration while analyzing microbial communities.…”