Aim: To evaluate the effect of religious Bahá'í dry fasting (BF) or 16:8 time‐restricted eating (TRE) compared with a regular diet (CG) on periodontal parameters during a modified experimentally induced gingivitis. Material and Methods: All participants were asked to refrain from oral hygiene (3 sextant) for 9 days (T1–T2) and were followed for a total of 19 days (T3) while adhering to fasting or a regular diet and resuming oral hygiene. The primary outcome was bleeding on probing in the test sextant (BOP_s), Rustogi plaque index (RPI), gingival crevicular fluid (GCF), blood pressure (BP), body weight (BW), HbA1c and C‐reactive protein (CRP) were measured (T1–T3) and ANCOVA and post hoc comparison were applied. Results: Sixty‐six healthy participants were recruited. Forty‐three were randomly assigned to TRE ( n = 22) and CG ( n = 21), while 23 followed BF, avoiding food and drinks during the day. At T2, BF demonstrated significantly less increase in BOP_s, and GCF increased in CG only. Analysis revealed significant differences in change for BOP_s between BF and CG (−9.48% [−17.18; −1.79]) and BF and TRE (−9.19% [−15.07; −3.32]) as well as for GCF between BF and CG (−0.06 μL [−7.22; −0.66]) and TRE and CG (−0.08 μL [−0.17; −0.00]). Conclusion: This study indicates beneficial effects of different fasting protocols on oral experimental gingivitis and metabolic parameters, but results are limited by randomisation issues and potential bias in the BF group.

Background: This study investigated the effect of a 4‐week free‐sugar avoidance on periodontal parameters during periodontal therapy.Methods: Twenty‐one patients with untreated periodontitis and daily free‐sugar intake were allocated to a sugar avoidance group (SAG) and a control group (CG). The SAG received a 45‐min dietary consultation and was instructed to avoid free sugars during the following 4 weeks after subgingival instrumentation, while the CG continued with their regular diet. Bleeding on probing (BOP), plaque control record, body weight (BW), visceral fat (FATv), and a food frequency questionnaire (FFQ) were collected at baseline (T1), 4 weeks (T2), and 8 weeks (T3) after subgingival instrumentation.Results: The main outcome parameter BOP was significantly reduced at T2 by 40.3% ± 15.54 in the SAG and 34% ± 12.47 in the CG (intra‐p value both <0.001, inter‐p value 0.361). A linear regression analysis of changes at patient level adjusted for age and FATv revealed a significant group difference for BOP (regression coefficient = –6.8; p = 0.019). Significant reductions were observed in BW, FATv and mean daily intake of free sugars (–14.4 g/day), and a significant increase of vitamin C derived from fruits (75.89 mg/day) at T2 in the SAG only.Conclusion: This study may indicate additional beneficial effects of a sugar avoidance on periodontal and metabolic parameters, and nutritional intake during periodontal therapy.German Clinical Trials Register (DRKS00026699).Plain Language Summary: The current widespread free‐sugar consumption is linked to an increasing incidence of chronic non‐communicable diseases. Data indicate a relationship between sugar intake and a higher prevalence of periodontitis and increased gingival inflammation.This study showed that free‐sugar avoidance after periodontal therapy had additional beneficial effects on periodontal and metabolic parameters in 10 test and 11 control patients. After 4 weeks of avoiding free sugars like sweets, processed white flour, juice, and so forth, periodontal bleeding was significantly reduced in both groups (–40.3% test group, –34% control group). Further regression analysis revealed a significant difference between groups favoring the intervention. Additionally, body weight and visceral fat were significantly reduced in the intervention group, only. To avoid sugar, patients were allowed to replace it with whole fruit, which led to increased levels of micronutrients such as vitamin C. Therefore, free‐sugar avoidance may be of therapeutic benefit in addition to periodontal therapy. Further research is needed to investigate this effect in larger cohorts.

Intermittent religious fasting increases the risk of hypo- and hyperglycemia in individuals with diabetes, but its impact on those without diabetes has been poorly investigated. The aim of this preliminary study was to examine the effects of religious Bahá’í fasting (BF) on glycemic control and variability and compare these effects with time-restricted eating (TRE). In a three-arm randomized controlled trial, 16 subjects without diabetes were assigned to a BF, TRE, or control group. Continuous glucose monitoring and food intake documentation were conducted before and during the 19 days of the intervention, and the 24 h mean glucose and glycemic variability indices were assessed. The BF and TRE groups, but not the control group, markedly reduced the daily eating window while maintaining macronutrient composition. Only the BF group decreased caloric intake (−677.8 ± 357.6 kcal, p = 0.013), body weight (−1.92 ± 0.95 kg, p = 0.011), and BMI (−0.65 ± 0.28 kg, p = 0.006). Higher maximum glucose values were observed during BF in the within-group (+1.41 ± 1.04, p = 0.039) and between-group comparisons (BF vs. control: p = 0.010; TRE vs. BF: p = 0.022). However, there were no alterations of the 24 h mean glucose, intra- and inter-day glycemic variability indices in any group. The proportions of time above and below the range (70–180 mg/dL) remained unchanged. BF and TRE do not exhibit negative effects on glycemic control and variability in subjects without diabetes.

Aim: To investigate the effect of a 16‐week whole‐food plant‐based diet (WPBD) on periodontal parameters in patients with increased cardiometabolic risk.Materials and Methods: A total of 36 participants from a randomized clinical trial received additional periodontal assessment. The intervention group (n = 17) followed a WPBD for 16 weeks, whereas the control group (CG) (n = 19) was instructed not to change their diet. Measurements were assessed at baseline (t1), week 8 (t2) and week 16 (t3). Periodontal examination included bleeding on probing (BOP), periodontal inflamed surface area (PISA) and plaque index (PI) on six index teeth, salivary pH and matrix‐matalloproteinase‐8 (MMP‐8).Results: At t3, the mean PISA of the index teeth was reduced by 32 mm² (53.8) in the WPBD group and increased by 22.6 mm² (45.1) in the CG group (intra‐group p = 0.255 and p = 0.977, respectively), BOP changes were similar (intra‐group p = 0.89 and p = 0.839, respectively). MMP‐8 values reduced in the WPBD group by 50.73 ng/mL (117) and in the CG by 5.40 ng/mL (96.6) (intra‐group p = 0.066, p = 0.837, respectively). Difference in change (t3 − t1) between the groups was p = 0.001, p = 0.003 and p = 0.032, respectively. Saliva pH increased in the WPBD group only (intra‐group p = 0.007).Conclusion: A trend towards stabilization of the inflammatory parameters (BOP, PISA) was observed in the WPBD group. Because of the non‐significant changes within the groups, this study highlights the imperative for future studies.ClinicalTrials.gov identifier: NCT03901183.

Aim: To evaluate the effect of prolonged fasting on the oral microbiome in patients with metabolic syndrome (MetS).Materials and Methods: This follow‐up study evaluated changes in the oral microbiome in a sub‐cohort of 42 patients with MetS during prolonged fasting. Periodontal parameters such as bleeding on probing (BOP), plaque index (PI) and gingival crevicular fluid (GCF) measured in Periotron units (PU) as well as supra‐ and subgingival plaque samples were taken at baseline (T1), after 5–10 days of prolonged fasting (T2) and at 4–5‐month follow‐up (T3). Sequencing of the V4 hypervariable region of the 16S rRNA gene was performed to analyse the microbiome composition.Results: Significant reductions were observed in BOP: 36.4% ± 18.2% to 30.4% ± 15.6% (p = 0.01), PI: 66.9% ± 19.5% to 58.8% ± 23.4% (p < 0.01) and GCF: 83.6 ± 27.8 PU to 67.9 ± 30.3 PU (p < 0.01) post fasting. Microbiome α‐ and β‐diversity did not change significantly. However, significant changes in specific bacterial genera were noted: Lachnospiraceae [G‐3] increased only in subgingival samples; Eikenella and Peptostreptococcaceae [XI][G‐7] increased; while Mitsuokella and Atopobium decreased in both sub‐ and supra‐gingival samples.Conclusion: Within the constraints of this analysis, prolonged fasting was found to be associated with reduced periodontal inflammation and selected shifts in the oral microbial composition. Larger controlled trials are needed to confirm these exploratory findings and determine their clinical relevance.

Intermittent religious fasting increases a risk of hypo- and hyperglycemia in individuals with diabetes, but its impact in those without diabetes is poorly investigated. The study aim was to examine the effects of religious Bahá'í fasting (BF) on glycemic control and variability and compare these effects with time-restricted eating (TRE). In a three-arm randomized controlled trial, 16 subjects without diabetes were assigned to a BF, 16:8 TRE or control group. Continuous glucose monitoring and food intake documentation was conducted before and during the 19 days of intervention, and 24-hour mean glucose, glycemic variability indices, and glucotypes were assessed. BF and TRE groups, but not the control group, markedly reduced the daily eating window while maintaining macronutrient composition. Only the BF group decreased caloric intake (-677.8 ± 357.6 kcal, p=0.013), body weight (-1.92 ± 0.95 kg, p=0.011) and BMI (-0.65 ± 0.28 kg, p=0.006). Higher maximum glucose values were observed during BF in the within-group (+1.41 ± 1.04, p=0.039) and between-group comparison (BF vs. Control: p= 0.010 and TRE vs. BF: p= 0.022). However, there were no alterations of 24-hour mean glucose, intra- and inter-day glycemic variability indices, or glucotypes in any group. Proportions of time above and below range (70-180mg/dl) and HbA1c values remained unchanged. BF and TRE do not exhibit negative effects on glycemic control and variability in subjects without diabetes.