Gut microbiota-derived short-chain fatty acids (SCFAs) shape epithelial and immune homeostasis, yet systemic SCFA profiles may diverge from gut microbial composition due to absorption and host metabolism. We quantified fasting serum SCFAs in 36 surgically resected colorectal cancer (CRC) patients and 20 cancer-free controls using targeted high-performance liquid chromatography-triple quadrupole mass spectrometry, and integrated these data with fecal and serum bacterial DNA profiles generated by 16S ribosomal RNA sequencing and functional inference. CRC was associated with a distinct circulating SCFA pattern: total SCFAs and acetate were increased, branched SCFAs were higher, and butyrate and valerate were lower relative to controls. Despite this clear systemic signature, associations between serum SCFAs and the relative abundance (RA) of putative SCFA-producing genera were sparse and inconsistent across CRC and control groups, both when considering fecal producers and serum-detected taxa. Interestingly, the total RA of SCFA-producing genera was higher in controls in feces but higher in CRC in serum, further supporting compartment-specific decoupling. Finally, several circulating SCFAs showed inverse associations with indicators of tumor progression within CRC. These results motivate integrative microbiota-metabolite studies and validation in larger cohorts to clarify how circulating SCFAs relate to gastrointestinal disease biology and immune regulation.

INTRODUCTION:Intratumoral microbiota is being investigated as a potential biomarker in cancer. In this study, we investigated tissue microbiota in advanced non-small cell lung cancer (NSCLC) to evaluate response to immune checkpoint inhibitors (ICIs). MATERIAL AND METHODS:We performed a retrospective study in 41 tumor tissues from patients with advanced NSCLC treated with ICI +/- chemotherapy. Microbial profiling was analyzed through 16S rRNA amplicon sequencing using Ion Torrent technology. Bioinformatic analysis was performed with the QIIME2 pipeline. RESULTS:Cox and logistic regression identified two bacterial consortia with prognostic relevance in terms of overall survival (OS), progression-free survival (PFS) and treatment response: the KBUBe score, which included four genera (Klebsiella, Brevundimonas, Undibacterium and Beijerinckiaceae), and the OSAA score, which comprised Olsenella, Salinarimonas, Actinobacillus and Lachnospiraceae genus A2. KBUBe and OSAA scores were significant predictors of OS (hazard ratio [HR] = 0.501, p = 0.009 and HR = 0.491, p < 0.001, respectively) and PFS (HR = 0.579, p = 0.040 and HR = 0.133, p < 0.001, respectively), outperforming PD-L1 expression, ECOG performance status or neutrophil-to-lymphocyte ratio. All patients with the highest KBUBe score were responders, compared with 50% in the lowest-score group (p = 0.035). Similarly, 83.8% of patients with the highest OSAA score were responders, whereas no responders were observed in the lowest-score group (p = 0.001). These findings were confirmed by internal validation and were not confounded by tobacco smoking status, type of therapy and histology. CONCLUSION:Intratumoral microbial communities are associated with survival and treatment response in ICI-treated NSCLC. The KBUBe and OSAA scores represent novel, independent prognostic biomarkers, warranting validation in larger cohorts.

Background & Aims: Expression of P21, encoded by the CDKN1A gene, has been associated with fibrosis progression in steatotic liver disease (SLD); however, the underlying mechanisms remain unknown. In the present study, we investigated the function of CDKN1A in SLD. Methods: CDKN1A expression levels were evaluated in different patient cohorts with SLD, fibrosis, and advanced chronic liver disease (ACLD). Cdkn1a-/- and Cdkn1a+/+ mice were fed with either a Western diet (WD), a Lieber-DeCarli (LdC) diet plus multiple EtOH (ethanol) binges, or a DuAL diet (metabolic dysfunction-associated fatty liver disease and alcohol-related liver). Primary hepatocytes were isolated and functional assays performed. Results: A significant increase in CDKN1A expression was observed in patients with steatohepatitis and fibrosis (with a positive correlation with both NAFLD Activity Score and fibrosis staging scores), cirrhosis and ACLD. Cdkn1a+/+ mice, fed a DuAL diet exhibited liver injury and cell death increased reactive oxygen species (ROS), and markers of senescence (γH2AX, β-GAL, Cdkn1a/p53) contributing to steatosis and inflammation. In contrast, Cdkn1a-/- mutant mice showed a significant decrease in senescence-associated markers as well as in markers of liver injury, hepatic steatosis and an increase in fatty acid oxidation and reduction in free fatty acid uptake as well as de novo lipogenesis. Mechanistically, activation of the AMPK-SIRT3 was observed in Cdkn1a-deleted animals. Conclusions: Cdkn1a deletion protected against preclinical SLD by promoting fatty acid oxidation and preventing free fatty acid uptake and de novo lipogenesis via the AMPK-SIRT3 axis. CDKN1A expression was found to be directly correlated with increased severity of NAFLD Activity Score and fibrosis in patients with SLD. CDKN1A could be a potential theragnostic target for the treatment of metabolic dysregulation in patients with SLD, with and without alcohol consumption. Impact and implications:: Expression of p21, encoded by the CDKN1A gene, has been associated with fibrosis progression in steatotic liver disease (SLD), but the molecular mechanisms remain elusive. Interestingly, in this study we found that Cdkn1a deletion protected against preclinical SLD by promoting fatty acid oxidation and preventing free fatty acid uptake and de novo lipogenesis, via the AMPK-SIRT3 axis. Translationally, Cdkn1a expression was found to be directly correlated with increased severity of NAFLD Activity Score (NAS) and fibrosis in SLD patients, and therefore, CDKN1A might be used potential theragnostic target for the treatment of metabolically induced SLD, with and without alcohol consumption.

Microbiota could be of interest in the diagnosis of colorectal and non-small cell lung cancer (CRC and NSCLC). However, how the microbial components of tissues and feces reflect each other remains unknown. In this work, our main objective is to discover the degree of correlation between the composition of the tissue microbiota and that of the feces of patients affected by CRC and NSCLC. Specifically, we investigated tumor and non-tumor tissues from 38 recruited patients with CRC and 19 with NSCLC. DNA from samples was submitted for 16S rDNA metagenomic sequencing, followed by data analysis through the QIIME2 pipeline and further statistical processing with STATA IC16. Tumor and non-tumor tissue selected genera were highly correlated in both CRC and NSCLC (100% and 81.25%). Following this, we established tissue-feces correlations, using selected genera from a LEfSe analysis previously published. In CRC, we found a strong correlation between the taxa detected in feces and those from colorectal tissues. However, our data do not demonstrate this correlation in NSCLC. In conclusion, our findings strongly reinforce the utility of fecal microbiota as a non-invasive biomarker for CRC diagnosis, while highlighting critical distinctions for NSCLC. Furthermore, our data demonstrate that the microbiota components of tumor and non-tumor tissues are similar, with only minor differences being detected.

IntroductionThere is increasing evidence demonstrating the relationship between microbiota and colorectal cancer. Several studies have been published analyzing microbiota in tissues and feces from cancer patients; however, there are only a few publications investigating the clinical utility of serum microbiome from colorectal cancer patients. Our aim was to advance in the search for serum biomarkers for the diagnosis of colorectal cancer.MethodsWe conducted a cross-sectional study assessing bacterial DNA and metabolomic profiles in 64 serum samples from subjects affected by colorectal cancer and controls. A metagenomic analysis of the bacterial 16S rRNA gene in serum was established, and serum metabolites were detected through an untargeted metabolic study based on Gas Chromatography-Quadruple Time-Of-Flight Mass Spectrometry with accurate mass.Results and DiscussionAfter integrating the data resulting from the bioinformatics and statistical analyses, we obtained different profiles in colorectal cancer population and controls, regardless of the subjects' age, gender and body mass index. Serum levels of Firmicutes and threonic acid were the most relevant characteristics that could help differentiate both groups, achieving an excellent predictive accuracy in this discovery cohort (area under the ROC curve = 0.95). Although these results should be validated in other cohorts through multicenter studies, we consider that our data could be relevant and applicable to the early diagnosis of colorectal cancer.

The application of bacterial metagenomic analysis as a biomarker for cancer detection is emerging. Our aim was to discover gut microbiota signatures with potential utility in the diagnosis of colorectal cancer (CRC) and non-small cell lung cancer (NSCLC). A prospective study was performed on a total of 77 fecal samples from CRC and NSCLC patients and controls. DNA from stool was analyzed for bacterial genomic sequencing using the Ion Torrent™ technology. Bioinformatic analysis was performed using the QIIME2 pipeline. We applied logistic regression to adjust for differences attributable to sex, age, and body mass index, and the diagnostic accuracy of our gut signatures was compared with other previously published results. The feces of patients affected by different tumor types, such as CRC and NSCLC, showed a differential intestinal microbiota profile. After adjusting for confounders, Parvimonas (OR = 53.3), Gemella (OR = 6.01), Eisenbergiella (OR = 5.35), Peptostreptococcus (OR = 9.42), Lactobacillus (OR = 6.72), Salmonella (OR = 5.44), and Fusobacterium (OR = 78.9) remained significantly associated with the risk of CRC. Two genera from the Ruminococcaceae family, DTU089 (OR = 20.1) and an uncharacterized genus (OR = 160.1), were associated with the risk of NSCLC. Our two panels had better diagnostic capacity for CRC (AUC = 0.840) and NSLC (AUC = 0.747) compared to the application of two other published panels to our population. Thus, we propose a gut bacteria panel for each cancer type and show its potential application in cancer diagnosis.

Interstitial lung diseases (ILDs) constitute a group of more than 200 disorders, with idiopathic pulmonary fibrosis (IPF) being one of the most frequent. Telomere length (TL) shortening causes loss of function of the lung parenchyma. However, little is known about its role as a prognostic factor in ILD patients. With the aim of investigating the role of TL and telomerase activity in the prognosis of patients affected by ILDs, we analysed lung tissue samples from 61 patients. We measured relative TL and telomerase activity by conventional procedures. Both clinical and molecular parameters were associated with overall survival by the Kaplan-Meier method. Patients with IPF had poorer prognosis than patients with other ILDs (p = 0.034). When patients were classified according to TL, those with shortened telomeres reported lower overall survival (p = 0.085); differences reached statistical significance after excluding ILD patients who developed cancer (p = 0.021). In a Cox regression analysis, TL behaved as a risk-modifying variable for death associated with rheumatic disease (RD) co-occurrence (p = 0.029). Also, in patients without cancer, ferritin was significantly increased in cases with RD and IPF co-occurrence (p = 0.032). In relation to telomerase activity, no significant differences were detected. In conclusion, TL in lung tissue emerges as a prognostic factor in ILD patients. Specifically, in cases with RD and IPF co-occurrence, TL can be considered as a risk-modifying variable for death.

Colorectal Cancer (CRC) and Obesity constitute two of the most common malignancies in the western world, and previously have been associated with intestinal microbial composition alterations. Our main aim in this study is to provide molecular data on intestinal microbiota patterns in subjects with CRC, as well as to establish possible associations with their Body Mass Index (BMI). A total of 113 samples from 45 subjects were collected and submitted to metagenomics analysis for gut microbiota. This study was performed by 16S ribosomal RNA bacterial gene amplification and sequencing using the Ion Torrent™ technology. The same dominant phyla were observed in feces and colorectal tissues, although a greater proportion of Fusobacteriota was found in tumor samples. Moreover, at the genus level, LEfSe analysis allowed us to detect a significant increase in Fusobacterium and Streptococcus in colorectal tissues with respect to fecal samples, with a significant preponderance of Fusobacterium in tumor tissues. Also, our data revealed relevant associations between gut microbiota composition and tumor location. When comparing bacterial profiles between right and left colon cancers, those from the left-sided colon showed a significant preponderance, among others, of the order Staphylococcales. Moreover, phyla Firmicutes and Spirochaetota were more abundant in the group of right-sided CRCs and phylum Proteobacteria was increased in rectal cancers. In relation to BMI of patients, we detected significant differences in beta diversity between the normal weight and the obese groups of cases. Microbiota from obese patients was significantly enriched, among others, in Bacteroidales. Therefore, our results are useful in the molecular characterization of CRC in obese and non-obese patients, with a clear impact on the establishment of diagnostic and prognosis of CRC.

Background: Considering that the risk of colorectal cancer (CRC) development has been related to telomere dysfunction and obesity. However, these parameters have not clearly investigated in relation to the clinical evolution of CRC patients. The aim of this study was to evaluate the impact of obesity and telomere status in the prognosis of patients affected by CRC and submitted to curative surgical treatment.Methods: We performed a prospective study including 162 CRC patients submitted to curative surgical treatment. Subjects were classified according to their Body Mass Index (BMI). Telomere status was established through telomere length and telomerase evaluation. Statistical analyses were performed using the SPSS software package version 22.Results: Patients with shorter telomeres, both in the tumor (median telomere length < 6.5 kb) and their non-tumor paired tissues (median telomere length < 7.1 kb), had the best clinical evolution, independently of the Dukes' stage of cancers (P = 0.025, for tumor samples; P = 0.003, for non-tumor samples).Telomere shortening was inversely associated with BMI in CRC patients. Also, subjects with a BMI > 31.85kg/m2 showed the worse clinical outcomes. Of interest, the impact of BMI showed gender dependence, since only the group of men showed significant differences in CRC prognosis in relation to obesity status (P = 0.037).Conclusions: Telomere length constitutes a useful biomarker to predict prognosis in CRC. Independently of BMI values, the better clinical evolution was associated with shorter telomeres. The impact of BMI seems to be related to other factors such as gender.