Comparative diet-gut microbiome analysis in Crohn's disease and Hidradenitis suppurativa.

Introduction: The chronic inflammatory skin disease Hidradenitis suppurativa (HS) is strongly associated with Crohn's Disease (CD). HS and CD share clinical similarities and similar inflammatory pathways are upregulated in both conditions. Increased prevalence of inflammatory disease in industrialised nations has been linked to the Western diet. However, gut microbiota composition and diet interaction have not been compared in HS and CD. Methods: Here we compared the fecal microbiota (16S rRNA gene amplicon sequencing) and habitual diet of previously reported subjects with HS (n = 55), patients with CD (n = 102) and controls (n = 95). Results and discussion: Patients with HS consumed a Western diet similar to patients with CD. Meanwhile, habitual diet in HS and CD was significantly different to controls. Previously, we detected differences in microbiota composition among patients with HS from that of controls. We now show that 40% of patients with HS had a microbiota configuration similar to that of CD, characterised by the enrichment of pathogenic genera (Enterococcus, Veillonella and Escherichia_Shigella) and the depletion of putatively beneficial genera (Faecalibacterium). The remaining 60% of patients with HS harboured a normal microbiota similar to that of controls. Antibiotics, which are commonly used to treat HS, were identified as a co-varying with differences in microbiota composition. We examined the levels of several inflammatory markers highlighting that growth-arrest specific 6 (Gas6), which has anti-inflammatory potential, were significantly lower in the 40% of patients with HS who had a CD microbiota configuration. Levels of the pro-inflammatory cytokine IL-12, which is a modulator of intestinal inflammation in CD, were negatively correlated with the abundance of health-associated genera in patients with HS. In conclusion, the fecal microbiota may help identify patients with HS who are at greater risk for development of CD.

Persistence with urate-lowering therapy in Australia: A longitudinal analysis of allopurinol prescriptions.

AIM: Gout is the most common form of inflammatory arthritis in men. Despite the availability of effective urate-lowering therapies (ULT), the management of gout is suboptimal due to poor persistence with ULT. This study examined national prescribing patterns of ULT to determine persistence with allopurinol in Australia. METHODS: A 10% sample of the Australian Pharmaceutical Benefits Scheme dispensing claims database was used to identify individuals initiated on allopurinol between April 2014 and December 2019. The number of allopurinol scripts dispensed was used to estimate persistence with allopurinol. Persistence was defined as the number of months from initiation until discontinuation (last prescription with no further scripts acquired for a period thereafter). Kaplan-Meier curves were used to examine persistence, while Cox regression analysis was used to examine the influence of gender, concomitant colchicine and age. RESULTS: The largest drop in persistence occurred immediately after initiation, with 34% of patients discontinuing allopurinol 300-mg therapy in the first month. Median persistence with allopurinol 300 mg was 5 months (95% confidence interval 4.76-5.24), with around 63% of individuals not persisting with this therapy for more than 12 months. Concomitant prescription of colchicine on the day of allopurinol initiation only occurred in 7% of allopurinol initiations. No increase in persistence was observed for those co-prescribed colchicine. CONCLUSION: Persistence with allopurinol was poor. More effective methods targeting prescribers, patients and systems are required to promote persistence with allopurinol. Improving persistence to allopurinol is an important public health goal given the proven potential of this medication to eliminate gout.

Colorectal microbiota after removal of colorectal cancer.

The colonic microbiome has been implicated in the pathogenesis of colorectal cancer (CRC) and intestinal microbiome alterations are not confined to the tumour. Since data on whether the microbiome normalises or remains altered after resection of CRC are conflicting, we studied the colonic microbiota of patients after resection of CRC. We profiled the microbiota using 16S rRNA gene amplicon sequencing in colonic biopsies from patients after resection of CRC (n = 63) in comparison with controls (n = 52), subjects with newly diagnosed CRC (n = 93) and polyps (i = 28). The colonic microbiota after surgical resection remained significantly different from that of controls in 65% of patients. Genus-level profiling and beta-diversity confirmed two distinct groups of patients after resection of CRC: one with an abnormal microbiota similar to that of patients with newly diagnosed CRC and another similar to non-CRC controls. Consumption levels of several dietary ingredients and cardiovascular drugs co-varied with differences in microbiota composition suggesting lifestyle factors may modulate differential microbiome trajectories after surgical resection. This study supports investigation of the colonic microbiota as a marker of risk for development of CRC.

Dietary Fibre Modulates the Gut Microbiota.

Dietary fibre has long been established as a nutritionally important, health-promoting food ingredient. Modern dietary practices have seen a significant reduction in fibre consumption compared with ancestral habits. This is related to the emergence of low-fibre "Western diets" associated with industrialised nations, and is linked to an increased prevalence of gut diseases such as inflammatory bowel disease, obesity, type II diabetes mellitus and metabolic syndrome. The characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as high plasma cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Gut microbial signatures are also altered significantly in these cohorts, suggesting a causative link between diet, microbes and disease. Dietary fibre consumption has been hypothesised to reverse these changes through microbial fermentation and the subsequent production of short-chain fatty acids (SCFA), which improves glucose and lipid parameters in individuals who harbour diseases associated with dysfunctional metabolism. This review article examines how different types of dietary fibre can differentially alter glucose and lipid metabolism through changes in gut microbiota composition and function.

Comorbidity Medications Are Dispensed to More People Receiving Antiretroviral Therapy for HIV Compared with the General Population in Australia.

Medical comorbidities occur in more persons with HIV than without HIV. We used a nationally representative 10% sample of 2016 Pharmaceutical Benefits Scheme (PBS) dispensing data to compare the proportions of antiretroviral therapy (ART)-purchasing and non-ART-purchasing patients who also purchased prescriptions for medical comorbidities. Each patient who purchased ART was compared with two gender- and age group-matched patients who did not purchase ART in the same year. We calculated the proportions of patients who also purchased coprescriptions used for hypertension, dyslipidemia, diabetes, cancer, low bone mineral density, and mental health, defined using PBS medication coding categories, and the resulting odds ratios. A total of 1,973 ART-purchasing patients in our sample were matched to 3,946 non-ART-purchasing patients. Compared with non-ART-purchasing patients, a greater proportion of ART-purchasing patients also purchased medications for dyslipidemia (19.8% vs. 16.6%; p-value = .003), low bone mineral density (1.5% vs. 0.8%; p-value = .02), and mental health (29.1% vs. 15.3%; p-value < .0001); a lower proportion purchased diabetes medications (4.8% vs. 6.5%; p-value = .009). These differences remained when our analysis was restricted to persons >55 years of age. Rates of multimorbidity (dispensed ≥2 medications for chronic conditions) were also higher among ART-purchasing patients (19.0% vs. 15.9%; p-value = .003). Using a nationally representative sample of prescription dispensing data, we found that higher proportions of ART-purchasing patients purchased coprescriptions for common comorbidities compared with non-ART-purchasing patients. Our finding that ART-purchasing patients purchased fewer diabetes medications is surprising, but may reflect differences in population characteristics between our two groups.

HIV treatment regimens and adherence to national guidelines in Australia: an analysis of dispensing data from the Australian pharmaceutical benefits scheme.

BACKGROUND: Treatment guidelines for antiretroviral therapy (ART) have evolved to emphasize newer regimens that address ageing-related comorbidities. Using national Australian dispensing data we compare ART regimens with Australian HIV treatment guidelines in the context of treated comorbidities. METHODS: The study population included all individuals in a 10% sample of national data from the Australian Pharmaceutical Benefits Scheme (PBS) who purchased a prescription of ART during 2016. We defined each patient's most recently dispensed ART regimen and characterized them to evaluate regimen complexity and adherence to national HIV treatment guidelines. We then analyzed ART regimens in the context of other co-prescriptions purchased for defined comorbidities. RESULTS: The 1995 patients in our sample purchased 212 different ART regimens during 2016; 1524 (76.4%) purchased one of the top ten most common regimens of which 62.3% were integrase strand transfer inhibitor-based. Among the 1786 (90%) patients that purchased the most common regimens, 83.7% purchased a regimen recommended by the guidelines for initial antiretroviral therapy and 11.4% purchased antiretrovirals that are not recommended for initial therapy; < 1% of the entire cohort purchased medications not recommended for use. While most patients purchased optimal ART regimens with low potential for significant drug interactions, regimen choices in the setting of risk factors for heart disease, renal disease and low bone mineral density appeared suboptimal. CONCLUSIONS: Australian HIV providers are prescribing ART regimens in accordance with updated treatment guidelines, but could further optimize regimens in the setting of important medical comorbidities.

Circadian alterations during early stages of Alzheimer's disease are associated with aberrant cycles of DNA methylation in BMAL1.

INTRODUCTION: Circadian alterations are prevalent in Alzheimer's disease (AD) and may contribute to cognitive impairment, behavioral symptoms, and neurodegeneration. Epigenetic mechanisms regulate the circadian clock, and changes in DNA methylation have been reported in AD brains, but the pathways that mediate circadian deregulation in AD are incompletely understood. We hypothesized that aberrant DNA methylation may affect circadian rhythms in AD. METHODS: We investigated DNA methylation, transcription, and expression of BMAL1, a positive regulator of the circadian clock, in cultured fibroblasts and brain samples from two independent cohorts of aging and AD. RESULTS: DNA methylation modulated rhythmic expression of clock genes in cultured fibroblasts. Moreover, rhythmic methylation of BMAL1 was altered in AD brains and fibroblasts and correlated with transcription cycles. DISCUSSION: Our results indicate that cycles of DNA methylation contribute to the regulation of BMAL1 rhythms in the brain. Hence, aberrant epigenetic patterns may be linked to circadian alterations in AD.

Epigenetic alterations in the brain associated with HIV-1 infection and methamphetamine dependence.

HIV involvement of the CNS continues to be a significant problem despite successful use of combination antiretroviral therapy (cART). Drugs of abuse can act in concert with HIV proteins to damage glia and neurons, worsening the neurotoxicity caused by HIV alone. Methamphetamine (METH) is a highly addictive psychostimulant drug, abuse of which has reached epidemic proportions and is associated with high-risk sexual behavior, increased HIV transmission, and development of drug resistance. HIV infection and METH dependence can have synergistic pathological effects, with preferential involvement of frontostriatal circuits. At the molecular level, epigenetic alterations have been reported for both HIV-1 infection and drug abuse, but the neuropathological pathways triggered by their combined effects are less known. We investigated epigenetic changes in the brain associated with HIV and METH. We analyzed postmortem frontal cortex tissue from 27 HIV seropositive individuals, 13 of which had a history of METH dependence, in comparison to 14 cases who never used METH. We detected changes in the expression of DNMT1, at mRNA and protein levels, that resulted in the increase of global DNA methylation. Genome-wide profiling of DNA methylation in a subset of cases, showed differential methylation on genes related to neurodegeneration; dopamine metabolism and transport; and oxidative phosphorylation. We provide evidence for the synergy of HIV and METH dependence on the patterns of DNA methylation on the host brain, which results in a distinctive landscape for the comorbid condition. Importantly, we identified new epigenetic targets that might aid in understanding the aggravated neurodegenerative, cognitive, motor and behavioral symptoms observed in persons living with HIV and addictions.

A gender comparison of postobstructive injury in the rat kidney.

BACKGROUND/AIMS: Unilateral ureteral obstruction (UUO) results in renal injury. Studies report increased injury indices in male rats following UUO. Our study examined whether this gender-based renal response to UUO was reflected in sustained differences following relief of obstruction. METHODS: Adult male/female rats (200-400 g) were subjected to either sham surgery (S/RN) or UUO (UUO/RN). At 24 h, obstruction was relieved and all animals underwent contralateral nephrectomy. Five days after initial surgery, animals were placed in metabolic cages and given water ad libitum for 24 h followed by a 24-hour period of complete water restriction. On day 7, animals were euthanized and samples harvested. Tubular injury, urinary volume/osmolality, creatinine clearance, plasma arginine vasopressin, renal medullary V2 receptor and aquaporin 2 (AQP2) expression were measured. RESULTS: Male UUO/RN rats showed increased renal apoptotic injury and reduced creatinine clearance rates (glomerular filtration rate) vs. females. No gender-dependent differences were observed in urinary osmolality or concentrating ability. AQP2 expression increased post-obstruction. CONCLUSION: Increased injury in males following UUO remains manifest during early recovery after release of obstruction. Despite this, the grade of postobstructive diuresis is not significantly altered between sexes. This may reflect reduced glomerular filtration rate and elevated AQP2 in male rats.