Viral infections have afflicted human health and despite great advancements in scientific knowledge and technologies, continue to affect our society today. The current coronavirus (COVID-19) pandemic has put a spotlight on the need to review the evidence on the impact of nutritional strategies to maintain a healthy immune system, particularly in instances where there are limited therapeutic treatments. Selenium, an essential trace element in humans, has a long history of lowering the occurrence and severity of viral infections. Much of the benefits derived from selenium are due to its incorporation into selenocysteine, an important component of proteins known as selenoproteins. Viral infections are associated with an increase in reactive oxygen species and may result in oxidative stress. Studies suggest that selenium deficiency alters immune response and viral infection by increasing oxidative stress and the rate of mutations in the viral genome, leading to an increase in pathogenicity and damage to the host. This review examines viral infections, including the novel SARS-CoV-2, in the context of selenium, in order to inform potential nutritional strategies to maintain a healthy immune system.

Food insecurity is a social determinant of health associated with cognitive impairments in older adults and people living with HIV (PLWH). Few studies have examined this relation longitudinally, and no studies have explored how the frequency of food insecurity over time may impact cognitive impairment. This study aimed to examine the impact of food insecurity on cognitive impairment over a 2-y follow-up period in a cohort of people living with and without HIV. This was a 2-y longitudinal analysis of primarily economically disadvantaged, middle-aged, Black, and Hispanic participants from the Miami Adult Studies on HIV (MASH) cohort. Food insecurity was assessed with the USDA Household Food Security Module at baseline and 12- and 24-mo follow-ups. Food insecurity in all 3 assessments was considered persistent food insecurity. Cognitive impairment was assessed with the Mini-Mental State Examination. Statistical analyses consisted of logistic regressions. A total of 394 participants (247 HIV positive) with 2-y follow-up data were included in this analysis. At baseline, 104 (26.4%) were food-insecure and 58 (14.7%) had cognitive impairment. Very low food security was associated with cognitive impairment at baseline (OR: 3.23; 95% CI: 1.08, 9.65). PLWH not virally suppressed had higher risk for cognitive impairment compared with HIV-uninfected participants (OR: 2.87; 95% CI: 1.15, 7.18). Additionally, baseline food insecurity (OR: 2.28; 95% CI: 1.08, 4.81) and the frequency of food insecurity over time (OR: 1.50 per year; 95% CI: 1.08, 2.10), particularly persistent food insecurity (OR: 3.69; 95% CI: 1.15, 11.83), were associated with cognitive impairment at 2-y follow-up; the results were consistent after excluding cognitively impaired participants at baseline. Food insecurity is a significant risk factor for cognitive impairment, particularly among individuals who experience food insecurity frequently or persistently. Screening for food insecurity and interventions to secure access to sufficient, nutritious foods may help delay cognitive decline among socioeconomically disadvantaged individuals.

Objective: Over 19 million individuals globally have a cocaine use disorder, a significant public health crisis. Cocaine has also been associated with a pro-inflammatory state and recently with imbalances in the intestinal microbiota as compared to nonuse. The objective of this pilot study was to characterize the gut microbiota and plasma metabolites in people with HIV (PWH) who use cocaine compared with those who do not. Design: Cross-sectional study. Methods: A pilot study in PWH was conducted on 25 cocaine users and 25 cocaine nonusers from the Miami Adult Studies on HIV cohort. Stool samples and blood plasma were collected. Bacterial composition was characterized using 16S rRNA sequencing. Metabolomics in plasma were determined using gas and liquid chromatography/mass spectrometry. Results: The relative abundances of the Lachnopspira genus, Oscillospira genus, Bifidobacterium adolescentis species, and Euryarchaeota phylum were significantly higher in the cocaine- using PWH compared to cocaine-nonusing PWH. Cocaine-use was associated with higher levels of several metabolites: products of dopamine catabolism (3-methoxytyrosine and 3-methoxytyramine sulfate), phenylacetate, benzoate, butyrate, and butyrylglycine. Conclusions: Cocaine use was associated with higher abundances of taxa and metabolites known to be associated with pathogenic states that include gastrointestinal conditions. Understanding key intestinal bacterial functional pathways that are altered due to cocaine use in PWH will provide a better understanding of the relationships between the host intestinal microbiome and potentially provide novel treatments to improve health.

The gut–liver axis has been recognized as a potential pathway in which dietary factors may contribute to liver disease in people living with HIV (PLWH). The objective of this study was to explore associations between dietary quality, the fecal microbiome, the metabolome, and liver health in PLWH from the Miami Adult Studies on HIV (MASH) cohort. We performed a cross-sectional analysis of 50 PLWH from the MASH cohort and utilized the USDA Healthy Eating Index (HEI)–2015 to measure diet quality. A Fibrosis-4 Index (FIB-4) score < 1.45 was used as a strong indication that advanced liver fibrosis was not present. Stool samples and fasting blood plasma samples were collected. Bacterial composition was characterized using 16S rRNA sequencing. Metabolomics in plasma were determined using gas and liquid chromatography/mass spectrometry. Statistical analyses included biomarker identification using linear discriminant analysis effect size. Compared to participants with FIB-4 ≥ 1.45, participants with FIB-4 < 1.45 had higher intake of dairy (p = 0.006). Fibrosis-4 Index score was inversely correlated with seafood and plant protein HEI component score (r = −0.320, p = 0.022). The relative abundances of butyrate-producing taxa Ruminococcaceae, Roseburia, and Lachnospiraceae were higher in participants with FIB-4 < 1.45. Participants with FIB-4 < 1.45 also had higher levels of caffeine (p = 0.045) and related metabolites such as trigonelline (p = 0.008) and 1-methylurate (p = 0.023). Dietary components appear to be associated with the fecal microbiome and metabolome, and liver health in PLWH. Future studies should investigate whether targeting specific dietary components may reduce liver-related morbidity and mortality in PLWH.