Saliva and salivary antimicrobial proteins play important roles in the innate immunity, which prevents infections of orally invading bacteria and viruses. In this study, we compared the secretion rates of salivary lactoferrin (Lac) and lysozyme (Lys) in heat-not-burn (HNB) cigarette smokers and non-smokers. The analysis population for this study included 212 members of the fire department, including 32 HNB cigarette smokers, 17 paper cigarette smokers, 14 combined HNB and paper cigarette smokers, and 149 non-smokers. Salivary Lac and Lys concentrations were assessed using enzyme immunoassay. Saliva secretion was significantly lower among HNB cigarette smokers (p < 0.01) than among non-smokers. Accompanying this result, salivary Lac and Lys secretion rates were significantly lower among smokers, particularly HNB cigarette smokers, than among non-smokers (all p < 0.01). Our findings suggest a possible adverse effect of HNB cigarette on the amount of Lac and Lys released into the oral cavity.

Background: Cactus contains dietary fiber and minerals and is expected to have preventive effects against diabetes, arteriosclerosis, and other diseases. Additionally, cactus intake induces the production of short-chain fatty acids derived from the gut microbiota, which might influence immune functions. In this study, we examined the effects of a cactus (Nopalea cochenillifera: NC)-supplemented diet on lipopolysaccharide (LPS)-induced immune responses and intestinal barrier function. Methods: Male C3H/HeN mice were randomly divided into three groups—no fiber (NF), cellulose-containing fiber (Cellu), and cactus-added (NC) diets—for 6 weeks. The TNF-α and IL-10 responses to LPS, antibody titers, and intestinal barrier function, as well as the fecal microbiota, were analyzed. Results: The plasma TNF-α but not the IL-10 concentrations were significantly higher in the NC group than in the NF and Cellu groups. Furthermore, the plasma IgG antibody titers were significantly higher in the NC group than in the other groups. The NC group showed higher mucin content and IgA antibody titers in their feces compared with the Cellu group. The succinate and lactate contents, which induce a reduction in TNF-α secretion by macrophages, in the cecum of the NC group were significantly lower than those in the Cellu and NF groups. In contrast, the butyrate content was significantly higher in the cecum of the NC group compared to that of the Cellu group, with a significantly higher relative abundance of butyrate-producing bacteria. Conclusions: Taken together, we found that cactus intake regulates innate and adaptive immune function via the gut microbiota in mice. Therefore, cactus supplementation might serve as a strategy to develop novel functional foods with dietary fiber.

The coronavirus disease 2019 (COVID-19) pandemic has decreased bystander cardiopulmonary resuscitation (BCPR) intervention rates. The purpose of this study was to elucidate the willingness of university freshmen to provide BCPR during the COVID-19 pandemic and the predictors thereof. A cross-sectional survey of 2789 newly enrolled university students was conducted after the end of the sixth wave of the COVID-19 epidemic in Japan; predictors of willingness to provide BCPR were assessed by regression analysis. Of the 2534 participants 1525 (60.2%) were willing to intervene and provide BCPR during the COVID-19 pandemic. Hesitancy due to the anxiety that CPR intervention might result in poor prognosis was a negative predictor of willingness. In contrast, anxiety about the possibility of infection during CPR intervention did not show a negative impact. On the other hand, interest in CPR and willingness to participate in a course, confidence in CPR skills, awareness of automated external defibrillation, and knowledge of CPR during the COVID-19 pandemic, were also positive predictors. This study suggests that the barrier to willingness to intervene with BCPR during a COVID-19 pandemic is not fear of infection, but rather hesitation due to the possibility of poor prognosis from the intervention. The significance of conducting this study during the COVID-19 epidemic is great, and there is an urgent need for measures to overcome hesitation regarding BCPR.

This study investigated nicotine dependence among Japanese university students who had reached the smoking age (20 years or older) by the time of the coronavirus disease 2019 (COVID-19) pandemic and examined factors that encourage early smoking cessation. Social dependence on nicotine was evaluated using the Kano Total Social Nicotine Dependence Level (KTSND), and physiological dependence was evaluated using the Fagerström Nicotine Dependence Index (FTND). Of the 356 college students who smoked (4.4% of the total), 182 (51.1%) stated that they were not interested in quitting. Furthermore, 124 (68.1%) of those with no interest in quitting smoking were aware that smoking is a high-risk factor for COVID-19, and 58 (31.9%) were unaware. The group not aware of this risk had significantly higher KTSND scores than the group aware of it. The examination of cigarette type that indicated the users of non-conventional cigarette products and dual-user groups scored significantly higher than the cigarette group on FTND items. Overall, the smokers scored above the normal range for social nicotine dependence, suggesting the need to reduce nicotine dependence to encourage college students who continue to smoke to quit smoking.

Since the novel coronavirus disease 2019 (COVID-19) pandemic, educational institutions have implemented measures such as school closures, raising concerns regarding the increase in psychological distress among university students. The purpose of this study is to identify factors that have influenced psychological distress among college freshmen during the COVID-19 pandemic. A questionnaire survey was conducted at the conclusion of the sixth wave of COVID-19 in Japan. Psychological distress was measured using the six-item Kessler Psychological Distress Scale (K6). Factors affecting psychological distress were calculated using regression analysis. Of the 2536 participants, 1841 (72.6%) reported having no psychological distress, while 695 (27.4%) reported having psychological distress. Factors that were identified to contribute to psychological distress were lack of sleep, weight gain or loss, worsening of interpersonal relationships, and physical symptoms and illnesses. A willingness to join an athletic club and having an environment in which it is easy to discuss worries and anxieties with others were factors that were identified to hinder psychological distress. It is necessary for universities to offer enhanced supports for physical and interpersonal activities. Additionally, it is imperative to encourage students to look after their physical health and to actively utilize university-based consultation systems.