Background: Helicobacter pylori(H. pylori) colonize the stomach and are considered an etiological agent of gastric cancer. The oral cavity is a transmission route to the stomach, but the exact site of colonization has not yet been explicated. Our study investigated the association betweenH. pyloriinfection and presence in oral samples.Methods: Dental pulp, supragingival plaque, and saliva from 192 patients visiting the Dentistry’s outpatient clinic were collected for testing. TheH. pylori ureAgene was identified via Nested PCR. Urine anti-H. pyloriantibody test was utilized to detect infection.Results: Twenty-five subjects were found to be antibody-positive. PCR analysis of dental pulp revealed that 23 subjects possessed theureAgene. Twenty-one subjects were positive for both antibodies and genes in dental pulp. PCR testing revealed that 2 subjects were positive in dental plaque but negative for saliva. The subjects positive forH. pyloriin dental pulp expressed clinical signs of severe dental caries.Conclusions: H. pyloriinfected subjects expressedH. pyloriin samples from the oral cavity. The main reservoir for infection within the oral cavity was determined to be dental pulp. Moreover,H. pyloriare likely transmitted from dental caries to the root canal.

This cross-sectional study investigated the relationship between self-reported chewing status and glycemic control in 30,938 Japanese adults who participated in health checkups. Chewing status was evaluated using a self-reported questionnaire. We defined high hemoglobin A1c (HbA1c) levels as a HbA1c level ≥6.5%; 692 (2.2%) respondents met this criterion. After adjusting for gender, age, smoking status, exercise habits, body mass index and eating speed, high HbA1c levels was found to be associated with male gender (odds ratio (OR), 1.568; 95% confidence interval (CI), 1.310 to 1.878; p < 0.001), older age (OR, 1.077; 95% CI, 1.068 to 1.087; p < 0.001), higher body mass index (OR, 1.246; 95% CI, 1.225 to 1.268; p < 0.001), current smoker status (OR, 1.566; 95% CI, 1.303 to 1.882; p < 0.001) and chewing difficulty (OR, 1.302; 95% CI, 1.065 to 1.591; p < 0.05). In conclusion, self-reported chewing difficulty was associated with high HbA1c levels in Japanese adults.

The relationship between oral functions and dementia was examined in 7384 older adults (age ≥ 75 years) who visited a dental clinic in Gifu, Japan. Participants without dementia in a baseline survey in April 2018 were followed until March 2021. As oral functions, chewing function, tongue and lip function, and swallowing function were assessed by self-administered questionnaire, by oral diadochokinesis test, and by repetitive saliva swallowing test, respectively. The presence of systemic diseases was based on data obtained from the National Database of Health Insurance of Japan. At follow-up, 415 (6%) participants were diagnosed with dementia. Multivariate logistic regression analyses showed the presence of dementia at follow-up was associated with female (odds ratio [OR] 1.386; 95% confidence interval [CI] 1.117–1.719), age (OR 1.078; CI 1.056–1.101), regular dental checkups (absence; OR 1.452; CI 1.180–1.788), brushing frequency ≥ twice/day (absence; OR 1.510; CI 1.194–1.911), decayed teeth (presence; OR 1.328; CI 1.071–1.648), swallowing function (poor; OR 1.484; CI 1.135–1.939) at baseline. It was found that poor swallowing function was associated with the future onset of dementia.

The aim was to examine the relationships between oral functions and support/care-need certification in older people aged ≥ 75 years using the National Health Insurance (NHI) database system and data from Kani City, Gifu, Japan. In total, 732 older Japanese people aged ≥ 75 years who did not have support/care-need certification and underwent dental check-ups in Kani City in 2017 were followed up until 2020. Chewing state, tongue and lip function, and swallowing function were assessed by a self-administered questionnaire, an oral diadochokinesis test, and a repetitive saliva-swallowing test, respectively. The presence or absence of systemic diseases and of support/care-need certification was based on data collected by the NHI database. At follow up, 121 (17%) participants had support/care-need certification. The participants with support/care-need certification included more women (p < 0.001) and older people (p < 0.001); and had more hypertension (p = 0.003), musculoskeletal disorders (p < 0.001), pneumonia (p = 0.044), poor chewing state (p < 0.001), and poor swallowing function (p = 0.003) than those without support/care-need certification. Furthermore, the presence of support/care-need certification at follow up was associated with sex (woman: odds ratio [OR], 2.120; 95% confidence interval [CI], 1.354 to 3.317), age (OR, 1.203; CI, 1.139 to 1.270), chewing state (poor: OR, 2.534; CI, 1.409 to 4.557), and swallowing function (poor: OR, 2.372; CI, 1.248 to 4.510) at baseline. However, tongue and lip function were not associated with support/care-need certification. The results indicate that older Japanese people aged ≥ 75 years with a poor chewing state and poor swallowing function at baseline had a higher risk for support/care-need certification after three years.

This cross-sectional study investigated the relationship between chewing status and fatty liver among Japanese adults. Between April 2018 and March 2021, 450 individuals (352 males, 98 females; mean age 54.7 years) were recruited at the Asahi University Hospital Human Health Center. Chewing status was evaluated using a self-reported questionnaire. Liver/spleen (L/S) attenuation ratio < 0.9 on computed tomography was considered to indicate fatty liver, which was present in 69 participants (15%). Compared with participants without fatty liver, those with fatty liver had higher proportion of 25.0 (kg/m²) ≤ body mass index (BMI) (p < 0.001), higher serum hemoglobin A1c (HbA1c) (p < 0.001), higher systolic blood pressure (p < 0.001), higher diastolic blood pressure (p < 0.001), and lower serum high-density lipoprotein cholesterol (HDL cholesterol) (p = 0.011). Significant differences were also found in chewing status (p < 0.001) and eating speed (p = 0.011). Presence of fatty liver was positively associated with BMI (25.0 ≤; odds ratio [OR], 5.048; 95% confidence interval [CI], 2.550–9.992), serum HbA1c (OR, 1.937; 95% CI, 1.280–2.930), and chewing status (poor; OR, 8.912; 95% CI, 4.421–17.966) after adjusting for sex, age, BMI, serum HbA1c, systolic blood pressure, diastolic blood pressure, serum HDL cholesterol, chewing status, and eating speed. Poor chewing status was positively associated with L/S attenuation ratio. These results indicate a positive relationship between poor chewing status and fatty liver diagnosed by L/S attenuation ratio in Japanese adults.

Helicobacter pylori (H. pylori) infection is a cause of gastric disorders and is treated mainly by pharmacotherapy with antimicrobial agents. An association has been reported between dental caries and H. pylori infection. As antimicrobial agents are less effective inside dental caries because of impaired blood circulation, the presence of untreated dental caries (decayed teeth) may influence the success of H. pylori eradication treatment. In this cross-sectional study, we examined whether failed eradication of H. pylori was associated with decayed teeth in Japanese adults. Enrolled were 226 participants who received dental checkups among those treated for eradication of H. pylori at Asahi University Hospital between April 2019 and March 2021. Treatment efficacy was assessed by urea breath test. Eradication failed in 38 participants (17%), decayed teeth in 32 participants (14%), and number of 0.34 teeth per participants. Multivariate logistic regression analyses showed that failed eradication of H. pylori was associated with decayed teeth (presence: odds ratio, 2.672; 95% confidence interval, 1.093–6.531) after adjusting for gender, age, and brushing frequency. These results indicate that failed eradication of H. pylori was associated with decayed teeth and suggest that untreated dental caries may impact treatment for eradication of H. pylori.