Optimization and Application of Metabolomic Assays for Analyzing Diet-induced and Gut Microbiota-derived Short-chain Fatty Acids in Mice and Humans

Introduction: In recent decades, the obesity epidemic worldwide has prompted the need for research targeting disease prevention, treatment, and maintenance. Dietary interventions are one of the primary methods to instill positive nutrition habits into one’s lifestyle. Thus, resistant starch type 4 (RS4), a prebiotic dietary fiber, has been proposed to induce beneficial immunometabolic health outcomes. Currently there is a lack of knowledge on the health outcomes of RS4 in adults with metabolic syndrome (MetS). Goal: The goal of this research was to optimize a metabolomic assay to quantify fecal short chain fatty acids (SCFAs), a byproduct of microbial fermentation in the gut, and to apply this assay to health outcomes of RS4 intervention in an adult population with MetS as well as genetically induced obese mice. Methods: An assay was optimized to extract and derivatize fecal SCFA from human stool samples followed by quantification using gas chromatography – mass spectrometry (GC-MS). Retrospective analysis of fecal samples from adults including both men (n=4) and women (n=12) with signs of MetS, collected at four time points throughout an ad libitum dietary intervention of RS42, were processed and quantified. This method was also retrospectively applied to cecum samples of KK.Cg-Ay/a, genetically induced obese mouse model, to quantify the effects of RS4 on cecum SCFA concentrations. 16S rRNA sequencing was performed to study the effect of RS4 on gut microbial composition. Blood biomarkers, glycemic, and lipid viariables, anthropometric measurements, and diet nutrient composition were also studied. Results: GC-MS analysis revealed significantly increased SCFAs following RS4 consumption including butyrate, propionate, valerate, isovallerate, and hexanoate. 16S-rRNA gene sequencing revealed a differential abundance of 71 bacterial operational taxonomic units, including the enrichment of three Bacteroides species and one each of Parabacteroides, Oscillospira, Blautia, Ruminococcus, Eubacterium, and Christensenella species in the RS4 group. RS4-specific associations were found between gut microbial composition and SCFA concentrations. Cholesterols, fasting glucose, glycosylated haemoglobin, and proinflammatory markers in the blood as well as waist circumference and % body fat were lower post intervention in the RS4 group compared with the control group. In KK.Cg-Ay/a mice, butyrate was significantly enriched in RS4 fed mice intestinal tissue. Discussion: An optimized method to quantify intestinal and fecal SCFA was created. The biological function of RS4 on gut microbiota in inidividuals with MetS was also identified. Larger studies are needed to fully understand the mechanistic action of RS4 in individuals with metabolic dysfunction for future implications on dietary guidelines

Impact of Dietary Resistant Starch Type 4 on Human Gut Microbiota and Immunometabolic Functions

Dietary modulation of the gut microbiota impacts human health. Here we investigated the hitherto unknown effects of resistant starch type 4 (RS4) enriched diet on gut microbiota composition and short-chain fatty acid (SCFA) concentrations in parallel with host immunometabolic functions in twenty individuals with signs of metabolic syndrome (MetS). Cholesterols, fasting glucose, glycosylated haemoglobin, and proinflammatory markers in the blood as well as waist circumference and % body fat were lower post intervention in the RS4 group compared with the control group. 16S-rRNA gene sequencing revealed a differential abundance of 71 bacterial operational taxonomic units, including the enrichment of three Bacteroides species and one each of Parabacteroides, Oscillospira, Blautia, Ruminococcus, Eubacterium, and Christensenella species in the RS4 group. Gas chromatography-mass spectrometry revealed higher faecal SCFAs, including butyrate, propionate, valerate, isovalerate, and hexanoate after RS4-intake. Bivariate analyses showed RS4-specific associations of the gut microbiota with the host metabolic functions and SCFA levels. Here we show that dietary RS4 induced changes in the gut microbiota are linked to its biological activity in individuals with signs of MetS. These findings have potential implications for dietary guidelines in metabolic health management

Poród a schorzenia narządu wzroku

There are many controversies among ophthalmologists and obstetricians regarding indications for caesarean section due to preexisting eye diseases. Many ophthalmologists still believe myopia, retinal detachment, glaucoma or diabetic retinopathy to be indications for a caesarean section. There is a discrepancy between clinical practice and evidence-based medicine, as none of the published trials have reported any retinal changes after vaginal delivery. This report provides information on the infl uence of physiological changes on eye diseases during the fi nal stage of the delivery. We conclude that an eye disease is not an indication for a caesarean section.Wskazania do skrócenia drugiego okresu porodu z powodu współistniejących schorzeń okulistycznych stanowią wciąż źródło wielu kontrowersji zarówno wśród okulistów, jak i ginekologów. Schorzenia narządu wzroku, takie jak: krótkowzroczność, odwarstwienie siatkówki, retinopatia cukrzycowa oraz jaskra są nadal uważane przez wielu okulistów za wskazanie do cięcia cesarskiego. Istnieje rozbieżność pomiędzy praktyką kliniczną a doniesieniami naukowymi, nie istnieją bowiem żadne udokumentowane publikacjami badania potwierdzające pogorszenie stanu narządu wzroku będące wynikiem porodu siłami natury. Niniejsza praca przedstawia zmiany fizjologiczne zachodzące w oku podczas końcowych etapów porodu. Wnioskujemy, że choroby narządy wzroku nie są wskazaniem do cięcia cesarskiego

Solitary Sarcoid Granuloma of the Iris Mimicking Tuberculosis: A Case Report

Introduction. We report a case of a male patient presented with sarcoid lesions of the iris and conjunctiva, mimicking tuberculosis due to epithelioid cell granulomas with small central necrosis in conjunctival biopsy. Patient. A 25-year-old man was referred to our department for further management of an “iris tumor with iridocyclitis” in his right eye. Initial examination showed an isolated vascular tumor of the iris and ciliary body with anterior uveitis and mutton-fat keratic precipitates, suggesting the diagnosis of a granulomatous disease. Conjunctival biopsy revealed granulomatous epithelioid cell inflammation with small central necrosis without acid-fast bacilli. Extensive systemic examination, including bronchoscopy and transbronchial biopsy, provided the diagnosis of sarcoidosis stage 2 with pulmonary involvement, thus ruling out tuberculosis. Systemic and local steroid therapy was initiated, leading to complete recovery of our patient with complete disappearance of the iris lesion and improvement of the pulmonary function. Conclusion. Although noncaseating epithelioid cell granulomas are typical for sarcoidosis, small central necrosis can be found in some granulomas, leading to presumption of tuberculosis. Extensive systemic checkup in cooperation with other specialists is essential to confirm the correct diagnosis and to initiate the appropriate therapy

Time Course of Induced Astigmatism After Canaloplasty

Purpose:To study the changes in astigmatism after canaloplasty and to analyze its correlation with long-term intraocular pressure (IOP) results.Methods:Twenty-six eyes of 26 consecutive patients with primary open-angle glaucoma (n=14) and pseudoexfoliative glaucoma (n=12) undergoing canaloplasty were included in this retrospective study. Canaloplasty comprised of 360-degree catheterisation of Schlemm canal by means of a flexible microcatheter with distension of the canal by 2 tensioning 10-0 polypropylene sutures. Primary outcome measures included IOP, glaucoma medication usage, astigmatism, and adverse events at 2, 4, 12, and 24 weeks postoperatively.Results:The mean preoperative IOP was 21.15.8 mm Hg. The mean IOP decreased to 14.25 +/- 4.3 mm Hg at 6 months. Mean astigmatism preoperatively was 0.77 +/- 0.5 D, which increased to 3.3 +/- 1.7 D at 2 weeks postoperatively (P0.05; Wilcoxon-test). Thereafter, the astigmatism underwent a spontaneous decline, reaching 1.9 +/- 0.8 D at 4 weeks and 1.2 +/- 0.74 D at 12 weeks postoperatively. Best-corrected visual acuity did not change significantly. Six months after canaloplasty, mean astigmatism reached the preoperative range of 0.86 +/- 0.52 D. Astigmatism at 2 weeks correlated significantly and inversely with IOP at 6 months (r=0.59, P=0.005; Spearman).Conclusions:The change of astigmatism after canaloplasty follows a clear time course with a maximum at 2 weeks reaching preoperative values at 6 months. The amount of surgically induced astigmatism might be helpful to predict outcome of canaloplasty in terms of IOP reduction