Unfermented ß-fructan Fibers Fuel Inflammation in Select Inflammatory Bowel Disease Patients.

BACKGROUND & AIMS: Inflammatory bowel diseases (IBD) are affected by dietary factors, including nondigestible carbohydrates (fibers), which are fermented by colonic microbes. Fibers are overall beneficial, but not all fibers are alike, and some patients with IBD report intolerance to fiber consumption. Given reproducible evidence of reduced fiber-fermenting microbes in patients with IBD, we hypothesized that fibers remain intact in select patients with reduced fiber-fermenting microbes and can then bind host cell receptors, subsequently promoting gut inflammation. METHODS: Colonic biopsies cultured ex vivo and cell lines in vitro were incubated with oligofructose (5 g/L), or fermentation supernatants (24-hour anaerobic fermentation) and immune responses (cytokine secretion [enzyme-linked immunosorbent assay/meso scale discovery] and expression [quantitative polymerase chain reaction]) were assessed. Influence of microbiota in mediating host response was examined and taxonomic classification of microbiota was conducted with Kraken2 and metabolic profiling by HUMAnN2, using R software. RESULTS: Unfermented dietary ß-fructan fibers induced proinflammatory cytokines in a subset of IBD intestinal biopsies cultured ex vivo, and immune cells (including peripheral blood mononuclear cells). Results were validated in an adult IBD randomized controlled trial examining ß-fructan supplementation. The proinflammatory response to intact ß-fructan required activation of the NLRP3 and TLR2 pathways. Fermentation of ß-fructans by human gut whole microbiota cultures reduced the proinflammatory response, but only when microbes were collected from patients without IBD or patients with inactive IBD. Fiber-induced immune responses correlated with microbe functions, luminal metabolites, and dietary fiber avoidance. CONCLUSION: Although fibers are typically beneficial in individuals with normal microbial fermentative potential, some dietary fibers have detrimental effects in select patients with active IBD who lack fermentative microbe activities. The study is publicly accessible at the U.S. National Institutes of Health database (clinicaltrials.gov identification number NCT02865707).

Intestinal microbial and metabolite profile in infants with small bowel stomas after bowel resection.

BACKGROUND: Infants with small bowel stomas (SBstoma) frequently struggle with absorption and rely on parenteral nutrition (PN). Intestinal absorption is difficult to predict based solely on intestinal anatomy. The purpose of this study was to characterize the microbiota and metabolic by-products within stoma effluent and correlate with clinical features and intestinal absorption. METHODS: Prospective cohort study collecting stoma samples from neonates with SBstoma (N = 23) or colostomy control (N = 6) at initial enteral feed (first sample) and before stoma closure (last sample). Gut bacteriome (16S ribosomal RNA [rRNA] sequencing), short-chain fatty acids (SCFAs) and bile acids (BAs) were characterized along with volume and energy content of a 48 h collection via bomb calorimetry (last sample). Hierarchical clustering and linear regression were used to compare the bacteriome and BAs/SCFAs, to bowel length, PN, and growth. RESULTS: Infants with ≤50% small bowel lost more fluid on average than those with >50% and controls (22, 18, 16 mL/kg/day, p = 0.013), but had similar energy losses (7, 10, 9 kcal/kg/day, p = 0.147). Infants growing poorly had enrichment of Proteobacteria compared to infants growing well (90% vs. 15%, p = 0.004). An increase in the ratio of secondary BAs within the small bowel over time, correlated with poor prognostic factors (≤50% small bowel, >50% of calories from PN, and poor growth). CONCLUSION: Infants with SBstoma and poor growth have a unique bacteriome community and those with poor enteral tolerance have metabolic differences compared to infants with improved absorption.

'Key skills' building in schools as a possible approach to reducing and preventing challenging behaviour.

BACKGROUND: Building 'key skills' may help prevent the development of challenging behaviour in children with an intellectual disability. The aim of this paper was to extend the current limited evidence in this area. METHOD: We undertook two studies with children with an intellectual disability in school settings: (1) a cross-sectional replication study exploring the relationship between 'key skills' and challenging behaviour. (2) a longitudinal study follow-up exploring change in 'key skill' levels and challenging behaviour. RESULTS: The replication study recruited 74 participants, those scoring lowest in 'key skill' had a 94% chance of having challenging behaviour; those with the highest scores had a 6% chance. The follow-up study recruited 39 participants, we found a significant increase in children's 'key skill' level (p < .001) and a decrease in their challenging behaviour (p = .046). CONCLUSION: Building 'key skills' in children with an intellectual disability may help reduce or prevent challenging behaviour.

Three-site screening for STIs in men who have sex with men using online self-testing in an English sexual health service.

OBJECTIVES: Among men who have sex with men (MSM) in the UK,Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) infections commonly occur asymptomatically at extragenital sites. Therefore, MSM seeking sexual health services are offered three-site (oropharyngeal, rectal and urogenital) STI screening. To increase access to screening, some UK sexual health services enable asymptomatic service users to order free STI screening kits online for self-sampling at home. We sought to assess prevalence of overall and extragenital CT/NG infection among asymptomatic MSM who used online self-testing in Hampshire, UK. METHODS: We assessed prevalence of CT/NG infections from non-pooled samples among asymptomatic cisgender MSM using an administrative database with results from 5601 STI screening kits returned between 20 December 2016 and 31 January 2020. We compared number of diagnoses of extragenital infection with urogenital results of the same individuals to determine prevalence of infection that would have been missed with urine testing alone. RESULTS: Among 5051 valid CT and 5040 valid NG asymptomatic test results, overall prevalence was 5.9% (298/5051) and 4.5% (228/5040), respectively. Among MSM with asymptomatic CT, 71.8% (214/298) had extragenital infection only, χ2 (1, n=298)=56.71, p<0.001. Among those with asymptomatic NG, 89.9% (205/228) had extragenital infection only, χ2 (1, n=228)=145.281, p<0.001. CONCLUSIONS: Overall, most CT/NG infections among asymptomatic MSM who used online self-testing were extragenital. Given this and the likelihood of onward transmission from asymptomatic infection, it is recommended that three-site testing remain standard for MSM and free screening services be expanded in easily accessible ways.

Novel Biomarkers for Inflammatory Bowel Disease and Colorectal Cancer: An Interplay between Metabolic Dysregulation and Excessive Inflammation.

Persistent inflammation can trigger altered epigenetic, inflammatory, and bioenergetic states. Inflammatory bowel disease (IBD) is an idiopathic disease characterized by chronic inflammation of the gastrointestinal tract, with evidence of subsequent metabolic syndrome disorder. Studies have demonstrated that as many as 42% of patients with ulcerative colitis (UC) who are found to have high-grade dysplasia, either already had colorectal cancer (CRC) or develop it within a short time. The presence of low-grade dysplasia is also predictive of CRC. Many signaling pathways are shared among IBD and CRC, including cell survival, cell proliferation, angiogenesis, and inflammatory signaling pathways. Current IBD therapeutics target a small subset of molecular drivers of IBD, with many focused on the inflammatory aspect of the pathways. Thus, there is a great need to identify biomarkers of both IBD and CRC, that can be predictive of therapeutic efficacy, disease severity, and predisposition to CRC. In this study, we explored the changes in biomarkers specific for inflammatory, metabolic, and proliferative pathways, to help determine the relevance to both IBD and CRC. Our analysis demonstrated, for the first time in IBD, the loss of the tumor suppressor protein Ras associated family protein 1A (RASSF1A), via epigenetic changes, the hyperactivation of the obligate kinase of the NOD2 pathogen recognition receptor (receptor interacting protein kinase 2 [RIPK2]), the loss of activation of the metabolic kinase, AMP activated protein kinase (AMPKα1), and, lastly, the activation of the transcription factor and kinase Yes associated protein (YAP) kinase, that is involved in proliferation of cells. The expression and activation status of these four elements are mirrored in IBD, CRC, and IBD-CRC patients and, importantly, in matched blood and biopsy samples. The latter would suggest that biomarker analysis can be performed non-invasively, to understand IBD and CRC, without the need for invasive and costly endoscopic analysis. This study, for the first time, illustrates the need to understand IBD or CRC beyond an inflammatory perspective and the value of therapeutics directed to reset altered proliferative and metabolic states within the colon. The use of such therapeutics may truly drive patients into remission.

Factors associated with transactional sex among a cohort of gay, bisexual, and other men who have sex with men in Vancouver, Canada.

Background Gay, bisexual, and other men who have sex with men (GBM) who engage in transactional sex (sex in exchange for drugs, money, or goods) experience increased risk of sexually transmitted infections (STI), including HIV. This study explored additional psychosocial and health-related factors associated with transactional sex among GBM. Methods Respondent-driven sampling was used to recruit GBM in Vancouver, Canada, from 2012 to 2015, with follow up every 6months until July2019. We examined factors associated with transactional sex using multivariable three-level mixed-effects modelling. Results Among 698 GBM, 22.1% reported ever receiving drugs, money, or goods for sex. Transactional sex was more likely to be reported by GBM who were younger (<30years) and who had lower incomes, less education, and insecure housing. GBM reporting transactional sex were more likely to report substance use (i.e. crystal methamphetamine, poppers, GHB, and non-steroid injection drugs) and higher risk sexual behaviours (i.e. more sex partners, sex party attendance, and condomless anal sex with serodifferent or unknown HIV status partners); however, they were no more likely to be living with HIV or to report a recent bacterial STI diagnosis. GBM who reported higher loneliness, anxiety, and cognitive escape were also more likely to report transactional sex. Conclusions More than one-fifth of GBM in Vancouver reported transactional sex and those who did were more likely to also experience psychosocial stressors, increased substance use, and higher risk sexual behaviours. Programs which consider the interconnections of personal, social, and structural challenges faced by GBM engaging in transactional sex are necessary to support improved mental, physical, and sexual health for these men.

Undetectable or Unknown? A Longitudinal Event-Level Analysis of Disclosure of HIV Serostatus and Undetectability Among Gay, Bisexual, and Other Men Who have Sex with Men (gbMSM) in Metro Vancouver.

We examined temporal trends and factors associated with reporting partner's serostatus and viral load among a sample of gay, bisexual and other men who have sex with men (gbMSM) in Vancouver, Canada. Participants were recruited using respondent-driven sampling and we collected prospective cohort data from 09/2014 to 02/2017 using a computer-assisted questionnaire and nurse-administered STI/HIV testing. Our study included 481 participants reporting on 3780 sexual events. Among HIV-negative/unknown gbMSM we found a trend towards decreased proportions of sexual events reporting an unknown HIV-status partner (42-19%; p = < 0.001) and found increased proportions among gbMSM living with HIV (11-27%; p = 0.043). More participants living with HIV reported sex with undetectable partners, compared to HIV-negative/unknown participants (14.8% versus 5%). Our multivariable model found that compared with unknown status partners, undetectable partners were older, were from longer sexual relationships and were more likely to engage in condomless anal sex. Findings indicate that HIV-negative gbMSM seem more aware of the serostatus of their partners over time, but knowledge of partners' viral load over time was not significant. Further research should assess the degree to which new campaigns such as Undetectable = Untransmittable (U = U) are associated with discussions about HIV disclosure and viral load status.

Longitudinal Analysis of HIV Risk and Substance Use Patterns for Men Who Have Sex with Men and Women and Men Who Have Sex with Men Only.

Men Who Have Sex with Men and Women (MSMW) experience discrimination from same-sex and heterosexual communities partially because of perceptions they feature high-risk sexual behavior, elevated polysubstance use levels, and constitute an HIV bridge population. We used a longitudinal multivariate generalized linear mixed model comparing sexual risk and substance use patterns for Men Who Have Sex with Men Only (MSMO) with MSMW in the same cohort study. Data consisted of 771 men reporting 3,705 sexual partnerships from 2012-2017. For high-risk sexual behavior multivariate results showed non-significant (p>0.05) differences for partner number and commercial sex work, and significantly less (p<0.05) HIV prevalence and condomless anal sex. However, MSMW had significantly higher levels of hallucinogen and prescription opioid use, and substance treatment histories. Only one HIV-positive MSMW had a transmittable viral load, negating the concept of an HIV bridge population. Results indicate the need for additional longitudinal studies comparing MSMO and MSMW.

Population-Level Sexual Mixing According to HIV Status and Preexposure Prophylaxis Use Among Men Who Have Sex With Men in Montreal, Canada: Implications for HIV Prevention.

Using cross-sectional survey data (Engage, 2017-2018) from 1,137 men who have sex with men, ≥16 years old, in Montreal, we compared observed human immunodeficiency virus (HIV) seroconcordance in previous-6-months' sexual partnerships with what would have been observed by chance if zero individuals serosorted. Of 5 recent partnerships where both individuals were HIV-negative, we compared observed concordance in preexposure prophylaxis (PrEP) use with the counterfactual if zero individuals selected partners based on PrEP use. We estimated the concordance by chance using a balancing-partnerships approach assuming proportionate mixing. HIV-positive respondents had a higher proportion of HIV-positive partners (66.4%, 95% confidence interval (CI): 64.0, 68.6) than by chance (23.9%, 95% CI: 23.1, 24.7). HIV-negative respondents (both on and not on PrEP) had higher proportions of HIV-negative partners (82.9% (95% CI: 81.1, 84.7) and 90.7% (95% CI: 89.6, 91.7), respectively) compared with by chance (76.1%, 95% CI: 75.3, 76.9); however, those on PrEP had a higher proportion of HIV-positive partners than those not on PrEP (17.1% (95% CI: 15.3, 18.9) vs. 9.3% (95% CI: 8.3, 10.4). Those on PrEP also had a higher proportion of partners on PrEP among their HIV-negative partners (50.6%, 95% CI: 42.5, 58.8) than by chance (28.5%, 95% CI: 27.5, 29.4). The relationship between PrEP and sexual-mixing patterns demonstrated by less population-level serosorting among those on PrEP and PrEP-matching warrants consideration during PrEP roll-out.

Escape expectancies and sexualized substance use among gay, bisexual, and other men who have sex with men.

McKirnan's Cognitive Escape Theory (1996) is often characterized by the hypothesis that drugs are used during sex by gay, bisexual, and other men who have sex with men (gbMSM) to relieve internal cognitive conflict over safe-sex norms and sexual desire. We examined how McKirnan's Cognitive Escape Scale (CES) is related to other widely used constructs relevant to sexualized substance use with hopes of better situating the theory within the evolving landscape of HIV-prevention. Associations between CES and trait anxiety, depression, treatment optimism, sexual altruism, sexual sensation seeking, and self-perceived risk for HIV transmission/acquisition were tested. Mediation analyses tested whether associated psychological measures mediated the effect of CES on the proportion of events in which participants reported co-occurrent substance use and condomless anal sex. Results indicated that CES is associated with higher sexual sensation seeking, treatment optimism, trait anxiety, and perceived likelihood of HIV transmission/acquisition. Mediation analyses suggest that CES is related to but operates independently of treatment optimism, sensation seeking, and trait anxiety. Nevertheless, the intersection of HIV-related worries and substance use expectancies are clearly more nuanced than is widely reported is discussions on cognitive escape.

What Does Research Tell Us About Women's Experiences, Motives and Perceptions of Masturbation Within a Relationship Context?: A Systematic Review of Qualitative Studies.

This systematic review provides an overview of what qualitative research has revealed about partner-related factors around women's masturbation and explores how these factors relate to women's behavior, perceptions, and motives toward masturbation. Eleven studies were identified and secondary thematic analysis was used for synthesis. Women's perceptions often focus on the (potential) negative influences of masturbation on current or future relationships. Motivations some women reported for masturbating due to partner-related factors were diverse. Findings suggested that some women modify their masturbation behavior when in a relationship. The implications of these findings for sexual health educators and clinicians are discussed.

Vesicouterine Fistula and Fetus in Bladder: A Case Report.

BACKGROUND: Vesicouterine fistulas are the rarest of all urogenital fistulas, with most cases occurring after cesarean section. CASE: A 38-year-old woman in rural Zimbabwe presented at 20 weeks gestation with a suspected fetus in the urinary bladder by transabdominal ultrasonography. This finding was confirmed intraoperatively together with a vesicouterine fistula. Cesarean section 20 years earlier was the only risk factor. Diagnosis was delayed for lack of access to appropriate imaging and a tertiary facility. CONCLUSION: A vesicouterine fistula is a rare presentation in the context of an advanced health care system. To our knowledge, this is the fourth case report of a fetus in the bladder secondary to vesicouterine fistula. Patient morbidity in this case possibly could have been avoided with earlier diagnosis and access to care.

Crystal Methamphetamine Use and Initiation among Gay, Bisexual, and Other Men Who Have Sex with Men Living with HIV in a Treatment as Prevention Environment.

BACKGROUND: Risk compensation in an HIV Treatment as Prevention (TasP) environment may increase high-risk sexual and substance use behaviors among people living with HIV. Objective: To examine recent crystal methamphetamine (CM) use/initiation in a longitudinal cohort of gay, bisexual, and other men who have sex with men (GBMSM) living with HIV in Metro Vancouver, Canada. Methods: Eligible participants were GBMSM aged >15 years who reported sex with another man in the past six months. Participants were recruited using respondent-driven sampling and self-completed a computer questionnaire every six months. We used multi-level generalized mixed-effect models to evaluate trends in recent CM use (past six months), multivariable logistic regression to identify covariates of recent CM use, and multivariable survival analysis to identify predictors of CM initiation. Results: Of 207 GBMSM living with HIV at enrollment, 44.3% reported recent CM use; there was a statistically non-significant decrease over the study period (41% in first period to 25% in final period, p = 0.087). HIV treatment optimism was not associated with CM use/initiation. CM use was positively associated with depressive symptomology, sexual escape motivation, transactional sex, number of anal sex partners, condomless anal sex with seroconcordant partners, STIs, and other substance use. Recent CM use was negatively associated with viral load sorting. CM initiation was predicted by escape motivation, transactional sex, and group sex participation. Conclusion: Results suggest that CM use among GBMSM living with HIV is prevalent and increased CM use/initiation is not a consequence of TasP public policy.

Factors Associated with Cessation or Reduction of Methamphetamine Use among Gay, Bisexual, and Other Men Who Have Sex with Men (gbMSM) in Vancouver Canada.

Background: Methamphetamine (MA) use among gay, bisexual, and other men who have sex with men (gbMSM) is a pervasive issue, associated with detrimental health outcomes. We identified factors associated with discontinuation or reduction in MA among a subset of gbMSM reporting frequent (at least weekly) use, with a specific focus on symptoms of anxiety and depression. Methods: We recruited sexually-active gbMSM aged ≥16 years in Vancouver, Canada into a prospective-cohort study using respondent-driven sampling. Participants completed study visits once every six months. We used generalized linear mixed models to identify factors associated with reductions in MA use following a visit where participants previously reported using MA at least weekly. Results: Of 584 cohort participants with at least one follow-up visit, 67 (11.5%) reported frequent MA use at baseline or in follow-up visits. Of these, 46 (68.7%) had at least one subsequent study visit where they transitioned to less frequent (monthly or less) or no MA use. In multivariable models, reduced MA use was less likely for those who spent >50% of social time with other gbMSM (aRR = 0.49, 95%CI:0.28-0.85), gave or received drugs in exchange for sex (aRR = 0.34, 95%CI:0.13-0.87), injected drugs (aRR = 0.35, 95%CI:0.18-0.68), or used gamma-hydroxybutyrate (GHB) (aRR = 0.41, 95%CI:0.21-0.78). Symptoms of anxiety or depression were not associated with reductions in MA use. Conclusions: Social connection and drug-related factors surrounding MA use were associated with reductions, but anxiety and depressive symptomatology were not. Incorporating socialization and polysubstance-related components with MA reduction may help in developing efficacious interventions toward reducing MA use for gbMSM.

HIV Testing Among a Representative Community Sample of Gay, Bisexual, and Other Men Who Have Sex with Men in Vancouver, Canada.

Earlier HIV diagnosis allows for improved treatment outcomes and secondary prevention. It is recommended that all individuals know their HIV status and that those at higher risk test more frequently. Using a representative community sample of gay, bisexual, and other men who have sex with men (GBMSM), we aimed to: (1) determine the proportion of GBMSM who have tested in the past 2 years, (2) determine reasons for testing and never having tested, and (3) explore correlates of testing. Of 535 eligible participants, 80.0% reported having had an HIV test in the past 2 years, most commonly as part of a regular testing schedule. The most common reason for not testing was low perceived HIV risk. Bisexual and older GBMSM, as well as those who lived outside of Vancouver, were less likely to have tested in the past 2 years. Rapid point-of-care testing may help improve testing rates and was shown to effectively engage some hard-to-reach GBMSM (e.g., those who had not tested for other STIs) in this sample.

"Condoms are like public transit. It's something you want everyone else to take": Perceptions and use of condoms among HIV negative gay men in Vancouver, Canada in the era of biomedical and seroadaptive prevention.

BACKGROUND: The emergence of biomedical and seroadaptive HIV prevention strategies has coincided with a decline in condom use among gay men. METHODS: We undertook a social ecological analysis of condom use and perceptions using nineteen semi-structured interviews with HIV negative gay men in Vancouver, Canada who used HAART-based prevention strategies. RESULTS: Contributors to inconsistent condom use were found at various levels of the social ecological model. Ongoing concern regarding HIV transmission and belief in the proven efficacy of condoms motivated contextual use. When condoms were not used, participants utilized seroadaptive and biomedical prevention strategies to mitigate risk. CONCLUSIONS: These findings indicate that notions of "safety" and "risk" based on consistent condom use are eroding as other modes of prevention gain visibility. Community-based and public health interventions will need to shift prevention messaging from advocacy for universal condom use toward combination prevention in order to meet gay men's current prevention needs. Interventions should advance gay men's communication and self-advocacy skills in order to optimize these strategies.

HIV leadership programming attendance is associated with PrEP and PEP awareness among young, gay, bisexual, and other men who have sex with men in Vancouver, Canada.

BACKGROUND: Young gay, bisexual, and other men who have sex with men (YGBM) may have reduced engagement and knowledge of HIV care and biomedical HIV prevention strategies, such as pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), and Treatment as Prevention (TasP), compared with adult GBM. We sought to understand differences in HIV prevention awareness, health care access, and service utilization between youth (16-29 years) and adult (≥30 year) GBM, as well as factors associated with attendance in HIV leadership programming among YGBM living in the publicly funded PrEP setting of Vancouver, Canada. METHODS: Sexually-active GBM were recruited using respondent-driven sampling (RDS) from February 2012 to February 2015. Participants completed an in-person computer-assisted self-interview every 6 months, up to February 2017, with questions on sociodemographic factors, awareness of biomedical HIV prevention strategies, and an HIV treatment optimism-skepticism scale. Participants were asked if they had ever attended either of two HIV-leadership programs designed for YGBM. Both programs involve multiple GBM-led education and social networking sessions operated by community-based organizations in Vancouver. Multivariable Glimmix confounder models assessed differences between youth and adult GBM. Among younger men, bivariate analyses examined factors associated with HIV-leadership program attendance. RESULTS: Of 698 GBM who enrolled in the longitudinal study, 36.8% were less than 30 years old at the first study visit. After controlling for gender identification, sexual orientation, HIV status, and income in the past 6 months, younger GBM (n = 257/698) had lower awareness of biomedical HIV prevention strategies and less HIV treatment optimism compared with older GBM (n = 441/698). Among younger GBM who attended HIV-leadership programs (n = 50), greater awareness of biomedical HIV prevention strategies and higher HIV treatment optimism were reported, compared with non-attendees. CONCLUSION: Younger GBM, who are disproportionately affected by the HIV epidemic, are less aware of new prevention technologies than older GBM, but attending peer-based HIV-leadership programs ameliorates age-disparities in HIV-prevention knowledge and treatment optimism.

Substance Use as a Mechanism for Social Inclusion among Gay, Bisexual, and Other Men Who Have Sex with Men in Vancouver, Canada.

Background: Previous research demonstrates that substance use preferences and social-sexual environments are highly interrelated for gay, bisexual, and other men who have sex with men (gbMSM). Objective: We conducted a qualitative study to explore the socio-cultural context of substance use among local gbMSM communities in Metro Vancouver, Canada. Methods: Twenty gbMSM were purposively sampled from the larger Momentum Health Study cohort, a sexual health study of gbMSM in Greater Vancouver. Participants were demographically diverse in terms of HIV serostatus, age, income, ethnicity, and area of residence within the city and neighboring suburbs. Community maps generated by participants during formative research served as prompts for semi-structured interviews which were audio recorded and transcribed verbatim. Thematic analysis identified three themes of common experience. Results: First, participants indicated that substance use is intrinsically social in Vancouver gbMSM communities and that it functions as both a means of social inclusion and exclusion. Second, a distinction was made between types of substances and the location and context of their use, with specific substances having particular uses and meanings. Third, analysis suggested that gbMSM change their substance use over the life course and that this is affected by shifting priorities as people age. Discussion: For Vancouver gbMSM communities, substance use serves several social-cultural functions and can simultaneously serve as both a potential facilitator and barrier for community connection. Future research and health programing should consider venue and context specific messaging and recognize the heterogeneity of substance use within the larger gbMSM population.

Generational differences in sexual behaviour and partnering among gay, bisexual, and other men who have sex with men.

INTRODUCTION: Given that different generations of gay, bisexual, and other men who have sex with men (gbMSM) have been influenced by substantially different life course events and cultural contexts, we explored differences in sexual behaviour between millennials, Gen-Xers, and baby boomers. METHODS: Sexually active gbMSM from Metro Vancouver, ≥16 years, were recruited using respondent-driven sampling between 2012-2015 and completed computer-assisted self-interviews every 6 months, up to 2017. To explore differences between generations (millennials born ≥1987, Gen-Xers born 1962-1986, baby boomers born <1962) we used multivariable logistic regression models using baseline, RDS-weighted data. We also examined 6-month trends, stratified by generation, in partner number, prevalence of high-risk sex, and relationship status using hierarchical mixed-effects models. RESULTS: Among 774 gbMSM (190 millennials, 469 Gen-Xers, 115 baby boomers), median age of first anal sex with a male partner decreased from 20 (aQ1,aQ3:17,25) among baby boomers to 18 (aQ1,aQ3: 16,20) among millennials (x 2 (DF=2, N=764)=12.920, p=0.002). After controlling for relevant demographics, differences were observed for some sexual behaviours (i.e., anal sex positioning, giving oral sex, sex toys, masturbation, sexual app/website use, transactional sex) but not others (i.e., receiving oral sex, rimming, fisting, watersports, group sex). At baseline, millennials reported less high-risk sex than other generations but all trended toward less high-risk sex, fewer partners, and regular partnering over the course of the study. CONCLUSIONS: While there was notable similarity across generations, millennial gbMSM reported earlier age at first anal intercourse and less high-risk sex. However, all generations trended towards less high-risk sex, fewer partners, and regular partnering over time.