Comparison of Experimental Methodologies Based on Bulk-Metagenome and Virus-like Particle Enrichment: Pros and Cons for Representativeness and Reproducibility in the Study of the Fecal Human Virome.

Studies on the human virome based on the application of metagenomic approaches involve overcoming a series of challenges and limitations inherent not only to the biological features of viruses, but also to methodological pitfalls which different approaches have tried to minimize. These approaches fall into two main categories: bulk-metagenomes and virus-like particle (VLP) enrichment. In order to address issues associated with commonly used experimental procedures to assess the degree of reliability, representativeness, and reproducibility, we designed a comparative analysis applied to three experimental protocols, one based on bulk-metagenomes and two based on VLP enrichment. These protocols were applied to stool samples from 10 adult participants, including two replicas per protocol and subject. We evaluated the performances of the three methods, not only through the analysis of the resulting composition, abundance, and diversity of the virome via taxonomical classification and type of molecule (DNA versus RNA, single stranded vs. double stranded), but also according to how the a priori identical replicas differed from each other according to the extraction methods used. Our results highlight the strengths and weaknesses of each approach, offering valuable insights and tailored recommendations for drawing reliable conclusions based on specific research goals.

Analysis of the Microbial Intestinal Tract in Broiler Chickens during the Rearing Period.

Gut microbiota contributes to animal health. However, identifying which microorganisms or associated functions are involved remains, still, difficult to assess. In the present study, the microbiota of healthy broiler chickens, under controlled diet and farm conditions, was investigated by 16S rRNA gene sequencing in four intestine segments and at four ages. In detail, 210 Ross-308 male chickens were raised according to the EU guidelines and fed on a commercial diet. The duodenum, jejunum, ileum, and caecum microbiota were analyzed at 11, 24, 35, and 46 days of life. Although the microbial composition was revealed as homogeneous 11 days after chicks hatched, it was found to be similar in the proximal intestine segments and different in ileum and caecum, where almost the same genera and species were detected with different relative abundances. Although changes during the later growth stage were revealed, each genus remained relatively unchanged. Lactobacillus mostly colonized the upper tract of the intestine, whereas the Escherichia/Shigella genus the ileum. Clostridium and Bacteroides genera were predominant in the caecum, where the highest richness of bacterial taxa was observed. We also analyze and discuss the predicted role of the microbiota for each intestine segment and its potential involvement in nutrient digestion and absorption.

The Pretreatment Gut Microbiome Is Associated With Lack of Response to Methotrexate in New-Onset Rheumatoid Arthritis.

OBJECTIVE: Although oral methotrexate (MTX) remains the anchor drug for rheumatoid arthritis (RA), up to 50% of patients do not achieve a clinically adequate outcome. In addition, there is a lack of prognostic tools for treatment response prior to drug initiation. This study was undertaken to investigate whether interindividual differences in the human gut microbiome can aid in the prediction of MTX efficacy in new-onset RA. METHODS: We performed 16S ribosomal RNA gene and shotgun metagenomic sequencing on the baseline gut microbiomes of drug-naive patients with new-onset RA (n = 26). Results were validated in an additional independent cohort (n = 21). To gain insight into potential microbial mechanisms, we conducted ex vivo experiments coupled with metabolomics analysis to evaluate the association between microbiome-driven MTX depletion and clinical response. RESULTS: Our analysis revealed significant associations of the abundance of gut bacterial taxa and their genes with future clinical response (q < 0.05), including orthologs related to purine and MTX metabolism. Machine learning techniques were applied to the metagenomic data, resulting in a microbiome-based model that predicted lack of response to MTX in an independent group of patients. Finally, MTX levels remaining after ex vivo incubation with distal gut samples from pretreatment RA patients significantly correlated with the magnitude of future clinical response, suggesting a possible direct effect of the gut microbiome on MTX metabolism and treatment outcomes. CONCLUSION: Taken together, these findings are the first step toward predicting lack of response to oral MTX in patients with new-onset RA and support the value of the gut microbiome as a possible prognostic tool and as a potential target in RA therapeutics.

Reputation, loneliness, satisfaction with life and aggressive behavior in adolescence.

The present study analyses the relationship between adolescents' perception of reputation and aggressive behavior among peers. The sample is made up of 1319 adolescents aged 11 to 16-years-old. Statistical analyses with structural equation modeling were carried out to examine the direct and indirect effect of perception of reputation (real and ideal) on aggressive behavior. Results indicate that adolescents' real and ideal reputations are related both directly and indirectly to aggressive behavior. The indirect effects suggest that loneliness and life satisfaction mediate the relationship between adolescents' reputation and their aggressive behavior. These findings and their implications are discussed.

Factores asociados al consumo juvenil de alcohol: una revisión desde una perspectiva psicosocial y ecológica / Factors associated with youth alcohol consumption: a review from a psychosocial and ecological perspective

El consumo abusivo de alcohol en la adolescencia es, en el momento actual, un importante problema de salud pública, hasta el punto de que su prevención se ha convertido en una de las prioridades en las políticas de salud. También, y en el ámbito de la intervención social, se ha venido estudiando, en los últimos años, los factores psicosociales implicados en ese consumo. En el presente trabajo se lleva a cabo una revisión de esos factores en el marco de la perspectiva ecológica, en la que se integran las variables psicológicas, relacionales y socioculturales. El consumo de alcohol es analizado como parte integrante dela cultura juvenil, despojando la explicación de contenidos patologistas o moralistas, y aproximándonos ala concepción de que el consumo de alcohol es un medio que utiliza el adolescente para lograr su ajuste en una sociedad que se caracteriza por la complejidad. Se analiza, en primer lugar, las variables disposicionales del sujeto, seguidamente se repasan las provenientes del contexto familiar y, finalmente, se explora la relación entre el consumo de alcohol y los factores del entorno sociocultural (AU)

Abusive alcohol consumption in adolescence is currently an important problem of public health, to the point that prevention has become a priority in health policies. Also, in the field of social intervention, the psychosocial factors involved in that consumption has been studied in the last years. In the present work a revision of those factors is carried out from the ecological perspective, in which psychological, relational and sociocultural variables are integrated. Alcohol consumption is analyzed as part of the youth culture, rejecting explanations of pathological or moralistic content, and following an approach in which alcohol consumption is understood as a mean used by the adolescent in order to achieve adjustment in a society characterized by complexity. First, individual dispositional variables are analysed; following this ,variables from the family context are examined, and finally the relationship between alcohol consumption and factors of the sociocultural context are explored (AU)

Reputation, Loneliness, Satisfaction with Life and Aggressive Behavior in Adolescence

The present study analyses the relationship between adolescents’ perception of reputation and aggressive behavior among peers. The sample is made up of 1319 adolescents aged 11 to 16 years old. Statistical analyses with structural equation modeling were carried out to examine the direct and indirect effect of perception of reputation (real and ideal) on aggressive behavior. Results indicate that adolescents’ real and ideal reputations are related both directly and indirectly to aggressive behavior. The indirect effects suggest that loneliness and life satisfaction mediate the relationship between adolescents’ reputation and their aggressive behavior. These findings and their implications are discussed (AU)

Este trabajo estudia las relaciones entre la percepción de reputación del adolescente y la conducta agresiva entre iguales adolescentes. La muestra está formada por 1319 adolescentes de edades comprendidas entre los 11 y los 16 años. Se utiliza un modelo de ecuaciones estructurales para analizar el efecto directo e indirecto de la reputación (real e ideal) en la conducta agresiva. Los resultados obtenidos confirman que la percepción de reputación real e ideal del adolescente se relaciona tanto directa como indirectamente con la conducta violenta. Los efectos indirectos sugieren que la soledad y la satisfacción con la vida median la relación entre la reputación del adolescente y la conducta agresiva. Se discuten estos resultados y sus implicaciones (AU)