Does the Gut Microbiota Modulate Host Physiology through Polymicrobial Biofilms?

Microbes inhabit various environments, such as soil, water environments, plants, and animals. Humans harbor a complex commensal microbial community in the gastrointestinal tract, which is known as the gut microbiota. The gut microbiota participates not only in various metabolic processes in the human body, it also plays a critical role in host immune responses. Gut microbes that inhabit the intestinal epithelial surface form polymicrobial biofilms. In the last decade, it has been widely reported that gut microbial biofilms and gut microbiota-derived products, such as metabolites and bacterial membrane vesicles, not only directly affect the host intestinal environment, but also indirectly influence the health of the host. In this review, we discuss the most recent findings from human and animal studies on the interactions between the gut microbiota and hosts, and their associations with various disorders, including inflammatory diseases, atopic dermatitis, metabolic disorders, and psychiatric and neurological diseases. The integrated approach of metabologenomics together with biofilm imaging may provide valuable insights into the gut microbiota and suggest remedies that may lead to a healthier society.

Soy ß-conglycinin improves obesity-induced metabolic abnormalities in a rat model of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) has a variety of causes including calorie over-intake, an unbalanced diet, and/or genetic dysfunction of lipid metabolism. We hypothesized that NAFLD symptoms could be mitigated by specific nutritional factors. Here, we show that the potential for soy ß-conglycinin (ßCG) to improve obesity-induced metabolic abnormalities in the Otsuka Long Evans Tokushima fatty (OLETF) rat model of NAFLD. Long Evans Tokushima Otsuka (i.e., wild-type) and OLETF rats were provided a normal diet containing 20% casein for 4 weeks as a control. In a third (ßCG) group, OLETF rats were fed a diet in which half of the casein was replaced by ßCG. There was no difference in food intake between groups. Rats in the ßCG group had decreased liver weight and lipid content (triglycerides, cholesterol, and phospholipids) compared to controls. In addition, ßCG consumption decreased fatty acid synthase gene expression and enzymatic activity. These findings indicate that dietary intake of ßCG can improve obesity-induced metabolic dysfunction, possibly via suppression of de novo fatty acid synthesis.

Soy ß-conglycinin improves glucose uptake in skeletal muscle and ameliorates hepatic insulin resistance in Goto-Kakizaki rats.

Although the underlying mechanism is unclear, ß-conglycinin (ßCG), the major component of soy proteins, regulates blood glucose levels. Here, we hypothesized that consumption of ßCG would normalize blood glucose levels by ameliorating insulin resistance and stimulating glucose uptake in skeletal muscles. To test our hypothesis, we investigated the antidiabetic action of ßCG in spontaneously diabetic Goto-Kakizaki (GK) rats. Our results revealed that plasma adiponectin levels and adiponectin receptor 1 messenger RNA expression in skeletal muscle were higher in ßCG-fed rats than in casein-fed rats. Phosphorylation of adenosine monophosphate-activated protein kinase (AMP kinase) but not phosphatidylinositol-3 kinase was activated in ßCG-fed GK rats. Subsequently, ßCG increased translocation of glucose transporter 4 to the plasma membrane. Unlike the results in skeletal muscle, the increase in adiponectin receptor 1 did not lead to AMP kinase activation in the liver of ßCG-fed rats. The down-regulation of sterol regulatory element-binding factor 1, which is induced by low insulin levels, promoted the increase in hepatic insulin receptor substrate 2 expression. Based on these findings, we concluded that consumption of soy ßCG improves glucose uptake in skeletal muscle via AMP kinase activation and ameliorates hepatic insulin resistance and that these actions may help normalize blood glucose levels in GK rats.

Optical coherence tomographic assessment of dynamic macular changes in patients with Vogt-Koyanagi-Harada disease.

To determine the relationship between visual acuity and three-dimensional optical coherence tomographic (3D-OCT) findings of the macula in eyes with Vogt-Koyanagi-Harada (VKH) disease. Twelve eyes of six patients (three men and three woman, average age 53.2 years) in the acute phase of VKH disease were examined with a 3D-OCT instrument. All of the eyes had a serous macular detachment. The height of the sensory retinal detachment (SRD) and the sensory retinal thickness (SRT) were measured by OCT before treatment (acute stage) and at the convalescent stage. The correlation between the retinal morphology and visual acuity was evaluated. The height of the SRD and the SRT were 612.5 ± 371.2 and 136. 7 ± 22.0 µm, respectively. The initial visual acuity was significantly worse in eyes with a higher SRD (P = 0.014, r = 0.68) but the correlation between initial visual acuity and SRT was not significant. The recovery of visual acuity was attained in 50.7 ± 44.1 days and the complete resolution of the SRD was attained in 30.5 ± 23.2 days. The final visual acuity was attained several days after the complete resolution of the SRD in all four eyes of patients over 60 years of age, but the recovery of visual acuity often preceded the complete resolution of the SRD. The OCT images provided a noninvasive indicator of the severity of the disease and dynamic changes in the macular morphology, reflecting the effect of treatment in association with the improvement in visual acuity. Monitoring the SRD by 3D-OCT may guide the tapering of systemic corticosteroid treatment.

Severe acute ocular ischemia associated with spontaneous internal carotid artery dissection.

A healthy 40-year-old man developed unilateral ocular ischemic syndrome as the only manifestation of a spontaneous internal carotid artery dissection.

Primary conjunctival epithelial cyst of the orbit.

BACKGROUND: A primary conjunctival epithelial cyst is an uncommon lesion that consists of nonkeratized, stratified squamous epithelium without dermal appendages. METHODS: Case report. RESULTS: A 57-year-old woman presented with a soft mass in the anterior portion of the nasal orbit. Magnetic resonance imaging demonstrated a rounded, cystic lesion between the right eye and the nasal bone. Histopathological examination following complete surgical excision disclosed a conjunctival epithelial cyst lined by nonkeratinized cuboidal epithelium without goblet cells and adnexal structures. CONCLUSION: A conjunctival epithelial cyst should be considered in the differential diagnosis of a mass in the anterior portion of nasal or superonasal orbit.