Objective: Compare the gut microbiome composition among individuals with acute spinal cord injury (A-SCI), long-standing SCI (L-SCI), vs. able-bodied (AB) controls.
Abstract Background Studies have begun to investigate the complex relationship between host and microorganisms in non‐infectious pathologies such as acne, atopic dermatitis and psoriasis. Though the skin is exposed to environmental stressors such as ultraviolet radiation ( UVR ), no studies exist examining the effects of both UVA and UVB on the skin microbiome. Objective To test the effect of UVA and UVB on human skin microbiome. Methods To test whether UV will alter the cutaneous microbiome, participants were exposed to doses of UVA (22‐47 J/cm 2 ) or UVB (100‐350 mJ /cm 2 ) and samples were collected. DNA was isolated and sequenced to identify the microbial composition of each sample. Results There was vast intra‐ and inter‐subject variation at all time points, and phylum and species‐level differences were identified. These included an increase in the phylum Cyanobacteria and a decrease in the family Lactobacillaceae and Pseudomonadaceae. The sensitivity of microbes to UVR and their re‐colonization potential following exposure differed in UVA vs UVB samples. Limitations The sample size was small, and the study was limited to males. Conclusion The results demonstrate that UVR has profound qualitative and quantitative influences on the composition of the skin microbiome, possibly effecting skin pathology in which UVR is a factor.
Investigations into the causative role that western dietary patterns have on obesity and disease pathogenesis have speculated that quality and quantity of dietary fats and/or carbohydrates have a predictive role in the development of these disorders. Standard reference diets such as the AIN-93 rodent diet have historically been used to promote animal health and reduce variation of results across experiments, rather than model modern human dietary habits or nutrition-related pathologies. In rodents high-fat diets (HFDs) became a classic tool to investigate diet-induced obesity (DIO). These murine diets often relied on a single fat source with the most DIO consistent HFDs containing levels of fat up to 45-60% (kcal), higher than the reported human intake of 33–35% (kcal). More recently, researchers are formulating experimental animal (pre-clinical) diets that reflect mean human macro- and micronutrient consumption levels described by the National Health and Nutrition Examination Survey (NHANES). These diets attempt to integrate relevant ingredient sources and levels of nutrients; however, they most often fail to include high-fructose corn syrup (HFCS) as a source of dietary carbohydrate. We have formulated a modified Standard American Diet (mSAD) that incorporates relevant levels and sources of nutrient classes, including dietary HFCS, to assess the basal physiologies associated with mSAD consumption. Mice proffered the mSAD for 15 weeks displayed a phenotype consistent with metabolic syndrome, exhibiting increased adiposity, fasting hyperglycemia with impaired glucose and insulin tolerance. Metabolic alterations were evidenced at the tissue level as crown-like structures (CLS) in adipose tissue and fatty acid deposition in the liver, and targeted 16S rRNA metagenomics revealed microbial compositional shifts between dietary groups. This study suggests diet quality significantly affects metabolic homeostasis, emphasizing the importance of developing relevant pre-clinical diets to investigate chronic diseases highly impacted by western dietary consumption patterns.
