Dynamic Alteration in Cerebral Total Hemoglobin Concentration Measured Using Portable Near-infrared Spectroscopy in Orthostatic Hypotension and Intolerance

A portable near infrared spectroscopy (NIRS) system was used to evaluate alterations in cerebral total hemoglobin concentration (HbT) in individuals with orthostatic hypotension (OH) and orthostatic intolerance (OI) symptoms. We enrolled 238 healthy participants (mean age, 47.9 years) and assessed the presence of OH (orthostatic blood pressure (BP) drop of systolic BP ≥ 20 mmHg or diastolic BP ≥ 10 mmHg within 3 minutes of supine-to-stand) and OI symptoms using the OH questionnaire. The participants were categorized into three groups based on the presence of OH and OI symptoms: the classic OH (OH-BP) group, symptom alone (OH-Sx) group, and control group. Random case-control matching sets (age, sex, hypertension, and diabetes mellitus) were constructed consisting of 16 OH-BP and 69 OH-Sx-control sets. We measured the time-derivative of HbT change in the prefrontal cortex during the squat-to-stand maneuver. There were no differences in demographics, baseline BP, and heart rate among the matched sets. Among the NIRS parameters, the peak-time of maximum slope variation was significantly longer in the OH-Sx and OH-BP groups than in the matched control groups during transition to the standing position after squatting. Our results suggested that OH and OI symptoms are associated with dynamic alteration in cerebral HbT.

Dynamic alteration in the gut microbiota and metabolome during the pregnancy

Background Gut microbiota and their metabolites were associated with obesity. Our previous study showed that maternal body fat percentage increased from days 45 to 110 of gestation in a Huanjiang mini-pig model. Thus, 16S rRNA sequencing and metabonomic techniques were used to investigate the changes of maternal gut microbiota composition and microbial metabolite profile from days 45 to 110 of gestation. Results The abundances of Clostridium_sensu_stricto_1, Romboutsia, Turicibacter, and Streptococcus in jejunum contents were higher in day 110 than those in day 45 or 75 of gestation. In ileum, the abundance of Streptococcus was the highest (P < 0.05) at day 110 of gestation, as well as the metabolism function of jejunal and ileal microbiota. The ileal butyrate and acetate concentrations were the highest at day 45 and day 110 of gestation, respectively. In colon, the concentrations of cadaverine and spermine were the highest (P < 0.05) at days 45 and 110 of gestation, respectively. Metabonomic analysis demonstrated that metabolic pathways including glutamine and glutamate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and alanine, aspartate, and glutamate metabolism changed during gestation. Conclusions Microbiota composition and metabolites changed dramatically from the early to the late pregnancy, which might be associated with the maternal fat accumulation.

Salivary microbial changes during the first 6 months of orthodontic treatment

Background Orthodontic treatment is widely used to treat malocclusion. However, the influence of treatment on the oral microbiome remains unclear. In this study, we investigated salivary microbial changes in patients undergoing orthodontic treatment. Methods In total, 19 orthodontic patients participated in this study. Saliva samples were collected at the following three timepoints: before (T0) and 3 months (T1) and 6 months (T2) after the placement of orthodontic appliances. High-throughput sequencing was performed based on the 16S rRNA gene V4 region. Results The phyla of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Fusobacteria were predominant. Observed Species, Chao1 and ACE, which represent α diversity, were significantly decreased at T1 and subsequently increased at T2. In addition, the β diversity at T1 based on the Bray-Curtis distances differed from T0 and T2. The relative abundances of Prevotella, Porphyromonas and Peptostreptococcus were decreased with treatment, whereas those of Capnocytophaga and Neisseria exhibited the opposite results. In total, 385 of 410 operational taxonomic units were shared at T0, T1 and T2. The co-occurrence networks with hub nodes at T1 were the most complex. Conclusion Orthodontic treatment temporarily affected the saliva microbial community. This dynamic alteration in species did not induce deterioration in oral health. Oral hygiene instructions were necessary and should be emphasized during each visit. Further studies with longer observation periods and more participants are required.