Oral Health Prev Dent. 2024 Oct 24;22:525-540. doi: 10.3290/j.ohpd.b5795653.
Despite substantial evidence supporting the role of resident bacterial communities in therapeutic fasting outcomes, research has primarily focused on gut microbiota, leaving changes in oral microbiota largely unexplored. The clinical significance of oral health changes during fasting is nonetheless underscored by the documented development of halitosis in fasting individuals. However, no scientific studies have comprehensively examined the interplay between salivary microbiota alterations, inflammatory changes in the gingival crevice, and the production of malodorous volatile compounds. We examined volatile sulphur compounds (VSC) in breath during fasting, cytokine levels in the gingival crevice, and oral microbiota composition of the saliva in a single-arm interventional study involving 36 subjects who fasted for 10 ± 3 days.
Participants fasted according to Buchinger fasting guidelines. VSC were evaluated every morning before any food or drink intake using the OralChroma gas chromatography device. Saliva and gingival crevicular fluid (GCF) samples were collected at the clinical site before fasting, at the end of fasting, and at the end of food reintroduction. Follow-up saliva samples were sent to the patients after 1 and 3 months. Saliva samples were processed and analysed by targeted sequencing of 16S rRNA gene amplicons, whereas the expression of 6 inflammatory markers in the GCF were analysed using a multiplex fluorescent bead-based immunoassay.
The quantification of volatile compounds in the breath demonstrated a statistically significant increase in dimethylsulfide levels during fasting, which corroborates the occurrence of bad breath as a common side effect of fasting. Salivary microbiota profiling showed a shift in microbial composition, including reduction in the levels of Neisseria, Gemella and Porphyromonas spp., concomitant with an increase in the levels of Megasphaera, Dialister, Prevotella, Veillonella, Bifidobacteria, Leptotrichia, Selenomonas, Alloprevotella, and Atopobium. We further demonstrated a reduction in the levels of the pro-inflammatory cytokine interleukin-8 in the GCF.
Dimethylsulfide concentrations in the breath increased during fasting, and this was correlated to changes in the oral microbiota. Future studies are needed to illuminate the possible impact of these changes on oral and general health status.
尽管有大量证据表明常驻细菌群落对治疗性禁食的结果具有重要作用，但研究主要集中在肠道微生物群上，而口腔微生物群的变化在很大程度上仍未得到探索。尽管在禁食个体中出现口臭的情况已有记录，但禁食期间口腔健康变化的临床意义仍不容忽视。然而，没有科学研究全面检查唾液微生物群变化、牙龈沟内的炎症变化以及恶臭挥发性化合物的产生之间的相互作用。我们在一项涉及 36 名参与者的单臂干预研究中，检查了禁食期间呼吸中的挥发性硫化合物 (VSC)、牙龈沟中的细胞因子水平以及唾液中的口腔微生物群落组成。参与者按照 Buchinger 禁食指南禁食。使用 OralChroma 气相色谱仪，每天早上在摄入任何食物或饮料之前评估 VSC。在禁食前、禁食结束时和重新开始进食时，在临床现场采集唾液和龈沟液 (GCF) 样本。随访唾液样本在 1 个月和 3 个月后寄给患者。处理和分析唾液样本，通过靶向测序 16S rRNA 基因扩增子，而 GCF 中 6 种炎症标志物的表达则使用基于多重荧光珠的免疫分析进行分析。
呼吸中挥发性化合物的定量表明，在禁食期间二甲基硫醚水平呈统计学显著增加，这证实了口臭是禁食的常见副作用。唾液微生物群分析显示微生物组成发生变化，包括奈瑟菌、孪生球菌和卟啉单胞菌属水平降低，而巨球形菌属、Dialister、普雷沃氏菌属、韦荣球菌属、双歧杆菌属、脱硫弧菌属、唾液链球菌属、拟普雷沃氏菌属、和阿托波氏菌属水平升高。我们进一步证明 GCF 中促炎细胞因子白细胞介素-8 的水平降低。
禁食期间呼吸中的二甲基硫醚浓度增加，这与口腔微生物群的变化相关。需要进一步的研究来阐明这些变化对口腔和整体健康状况的可能影响。
