Prospective associations of circulating bile acids and short-chain fatty acids with incident colorectal cancer

Background Human studies investigating the prospective relationship between microbial metabolites and colorectal cancer (CRC) risk are lacking. We tested whether higher serum bile acids (BAs) and lower short-chain fatty acids (SCFAs) were associated with CRC risk. Methods In baseline serum collected more than 30 years before a CRC diagnosis, we quantified concentrations of 15 BAs and 6 SCFAs using targeted liquid chromatography with tandem mass spectrometry assays in 1:1 matched cases and controls from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial (men: n = 262 cases; women: n = 233 cases) and the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (men: n = 598 cases). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for BA and SCFA quartiles and summary measures with CRC overall and by anatomic location using multivariable conditional logistic regression models. PLCO analyses were stratified by sex. All statistical tests were 2-sided. Results In PLCO women, 7 BAs were strongly associated with increased CRC risk, including the secondary BAs, deoxycholic (ORQ4 v Q1 = 2.85, 95% CI = 1.45 to 5.60, Qtrend = 0.011), glycodeoxycholic (OR Q4 v Q1 = 3.45, 95% CI = 1.79 to 6.64, Qtrend = 0.006), taurodeoxycholic (OR Q4 v Q1 = 2.36, 95% CI = 1.22 to 4.55, Qtrend = 0.023), and glycolithocholic acid (ORQ4 v Q1 = 2.71, 95% CI = 1.41 to 5.22, Qtrend = 0.015). Women in the highest compared with lowest quartile of total SCFAs had a 45% lower risk of CRC (OR = 0.55, 95% CI = 0.31 to 0.98, Ptrend = .03). Associations for total BAs and SCFAs were strongest among women with proximal colon cancer. No statistically significant associations were observed for BA or SCFA measures among men. Conclusions Serum concentrations of BAs, particularly downstream microbial metabolites of cholic acid, were strongly associated with increased risk of CRC among women

Associations of fecal microbial profiles with breast cancer and non-malignant breast disease in the Ghana Breast Health Study

The gut microbiota may play a role in breast cancer etiology by regulating hormonal, metabolic and immunologic pathways. We investigated associations of fecal bacteria with breast cancer and nonmalignant breast disease in a case-control study conducted in Ghana, a country with rising breast cancer incidence and mortality. To do this, we sequenced the V4 region of the 16S rRNA gene to characterize bacteria in fecal samples collected at the time of breast biopsy (N = 379 breast cancer cases, N = 102 nonmalignant breast disease cases, N = 414 population-based controls). We estimated associations of alpha diversity (observed amplicon sequence variants [ASVs], Shannon index, and Faith's phylogenetic diversity), beta diversity (Bray-Curtis and unweighted/weighted UniFrac distance), and the presence and relative abundance of select taxa with breast cancer and nonmalignant breast disease using multivariable unconditional polytomous logistic regression. All alpha diversity metrics were strongly, inversely associated with odds of breast cancer and for those in the highest relative to lowest tertile of observed ASVs, the odds ratio (95% confidence interval) was 0.21 (0.13-0.36; Ptrend < .001). Alpha diversity associations were similar for nonmalignant breast disease and breast cancer grade/molecular subtype. All beta diversity distance matrices and multiple taxa with possible estrogen-conjugating and immune-related functions were strongly associated with breast cancer (all Ps < .001). There were no statistically significant differences between breast cancer and nonmalignant breast disease cases in any microbiota metric. In conclusion, fecal bacterial characteristics were strongly and similarly associated with breast cancer and nonmalignant breast disease. Our findings provide novel insight into potential microbially-mediated mechanisms of breast disease

Reproducibility, stability, and accuracy of microbial profiles by fecal sample collection method in three distinct populations

The gut microbiome likely plays a role in the etiology of multiple health conditions, especially those affecting the gastrointestinal tract. Little consensus exists as to the best, standard methods to collect fecal samples for future microbiome analysis. We evaluated three distinct populations (N = 132 participants) using 16S rRNA gene amplicon sequencing data to investigate the reproducibility, stability, and accuracy of microbial profiles in fecal samples collected and stored via fecal occult blood test (FOBT) or Flinders Technology Associates (FTA) cards, fecal immunochemical tests (FIT) tubes, 70% and 95% ethanol, RNAlater, or with no solution. For each collection method, based on relative abundance of select phyla and genera, two alpha diversity metrics, and four beta diversity metrics, we calculated intraclass correlation coefficients (ICCs) to estimate reproducibility and stability, and Spearman correlation coefficients (SCCs) to estimate accuracy of the fecal microbial profile. Comparing duplicate samples, reproducibility ICCs for all collection methods were excellent (ICCs ≥75%). After 4–7 days at ambient temperature, ICCs for microbial profile stability were excellent (≥75%) for most collection methods, except those collected via no-solution and 70% ethanol. SCCs comparing each collection method to immediately-frozen no-solution samples ranged from fair to excellent for most methods; however, accuracy of genus-level relative abundances differed by collection method. Our findings, taken together with previous studies and feasibility considerations, indicated that FOBT/FTA cards, FIT tubes, 95% ethanol, and RNAlater are excellent choices for fecal sample collection methods in future microbiome studies. Furthermore, establishing standard collection methods across studies is highly desirable

Reproducibility, stability, and accuracy of microbial profiles by fecal sample collection method in three distinct populations.

The gut microbiome likely plays a role in the etiology of multiple health conditions, especially those affecting the gastrointestinal tract. Little consensus exists as to the best, standard methods to collect fecal samples for future microbiome analysis. We evaluated three distinct populations (N = 132 participants) using 16S rRNA gene amplicon sequencing data to investigate the reproducibility, stability, and accuracy of microbial profiles in fecal samples collected and stored via fecal occult blood test (FOBT) or Flinders Technology Associates (FTA) cards, fecal immunochemical tests (FIT) tubes, 70% and 95% ethanol, RNAlater, or with no solution. For each collection method, based on relative abundance of select phyla and genera, two alpha diversity metrics, and four beta diversity metrics, we calculated intraclass correlation coefficients (ICCs) to estimate reproducibility and stability, and Spearman correlation coefficients (SCCs) to estimate accuracy of the fecal microbial profile. Comparing duplicate samples, reproducibility ICCs for all collection methods were excellent (ICCs ≥75%). After 4-7 days at ambient temperature, ICCs for microbial profile stability were excellent (≥75%) for most collection methods, except those collected via no-solution and 70% ethanol. SCCs comparing each collection method to immediately-frozen no-solution samples ranged from fair to excellent for most methods; however, accuracy of genus-level relative abundances differed by collection method. Our findings, taken together with previous studies and feasibility considerations, indicated that FOBT/FTA cards, FIT tubes, 95% ethanol, and RNAlater are excellent choices for fecal sample collection methods in future microbiome studies. Furthermore, establishing standard collection methods across studies is highly desirable

Consumo y cultura masiva: reflexiones a propósito de la literatura de autoayuda y sus lectores

Teniendo en cuenta que la cultura es comprensible a partir del estudio de sus componentes simbólicos, en nuestra tesis de doctorado indagamos en una práctica cultural cuyo interés se renueva incesantemente resistiendo a los avatares del tiempo: la lectura. Acotamos el estudio a un género de la cultura de masas que ostenta una imponente presencia en el mercado editorial actual: la literatura de autoayuda. Asimismo, con la intención de dar una realidad sociocultural a la figura del lector, abordamos un caso en particular: San Salvador de Jujuy (Argentina). A partir de ello, en este artículo, reflexionamos específicamente a propósito de las expectativas de lectura y nos preguntamos: ¿qué se busca en la literatura? Sobre la base de nuestra investigación, concluimos en que el consumo de los libros de autoayuda puede vincularse, por un lado, a la necesidad de dar orden y sentido a la historia personal y, por otro, a la búsqueda de sentimientos etéreos, la libertad y la felicidadDado que a cultura é entendida através do estudo de seus componentes simbólicos, em nossa tese de doutorado, investigamos uma prática cultural que renova incessantemente interesse y resiste às vicissitudes do tempo: a leitura. Limitamos o estudo a um gênero da cultura de massa que detém uma presença dominante no mercado editorial atual: a literatura de auto-ajuda. Além disso, com a intenção de dar uma realidade sociocultural à figura do leitor, nós abordamos um caso particular: San Salvador de Jujuy (Argentina). A partir disso, neste artigo, refletimos especificamente sobre as expectativas de leitura e questionamos: o que se busca na literatura? Com base em nossa pesquisa, concluímos que o consumo de livros de autoajuda pode ser ligado, por um lado, com a necessidade de dar forma e sentido à história pessoal e, por outro, com a busca de sentimentos etéreos, a liberdade e felicidade.Given that culture is understandable from the study of symbolic components, in our doctoral thesis (Canavire, 2013) we investigate a cultural practice whose interest is renewed constantly resisting the vicissitudes of time: reading. We delimit the study to a genre of massive culture that boasts an imposing presence in the current publishing market: self-help literature. Also, with the intention of giving a sociocultural reality to the figure of the reader, we tackle a particular case: San Salvador de Jujuy (Argentina). From this, in this article, specifically we reflect with regard to expectations about reading and we ask what is searched in the literature? Based on our research, we conclude that the consumption of self-help books can be linked, on the one hand, with the need to give order and meaning to the personal history and, on the other, to looking ethereal feelings, freedom and happiness.Fil: Canavire, Vanina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Jujuy; Argentin