First Exploration of the Altered Microbial Gut-Lung Axis in the Pathogenesis of Human Refractory Chronic Cough.

PURPOSE: Cough represents a natural mechanism that plays an important defensive role in the respiratory tract, but in some conditions, it may become persistent, nonproductive, and harmful. In general, refractory chronic cough (RCC) occurs in about 20% of individuals; hence, we aimed to assess the presence of altered gut-lung communication in RCC patients through a compositional and functional characterization of both gut (GM) and oral microbiota (OM). METHODS: 16S rRNA sequencing was used to characterize both GM and OM composition of RCC patients and healthy controls (HC). PICRUST2 assessed functional changes in microbial communities while gas chromatography was used to evaluate fecal short-chain fatty acid levels and serum-free fatty acid (FFA) abundances. RESULTS: In comparison with HC, RCC patients reported increased saliva alpha-diversity and statistically significant beta-diversity in both GM and OM. Also, a, respectively, significant increased or reduced Firmicutes/Bacteroidota ratio in stool and saliva samples of RCC patients has been shown, in addition to a modification of the abundances of several taxa in both GM and OM. Moreover, a potential fecal over-expression of lipopolysaccharide biosynthesis and lipoic acid metabolism pathways and several differences in serum FFA levels have been reported in RCC patients than in HC. CONCLUSION: Since differences in both GM and OM of RCC patients have been documented, these findings could provide new information about RCC pathogenesis and also pave the way for the development of novel nutritional or pharmacological interventions for the management of RCC through the restoration of eubiotic gut-lung communication.

Intratumour microbiota modulates adrenocortical cancer responsiveness to mitotane.

The infiltrating microbiota represents a novel cellular component of the solid tumour microenvironment that can influence tumour progression and response to therapy. Adrenocortical carcinoma (ACC) is a rare and aggressive endocrine malignancy for which mitotane (MTT) treatment represents the first-line therapy, though its efficacy is limited to a therapeutic window level (14-20 mg/L). Novel markers able to predict those patients who would benefit from MTT therapy are urgently needed to improve patient's management. The aim of our study was to evaluate the presence of intratumoural bacterial microbiota DNA in 26 human ACC tissues vs 9 healthy adrenals; moreover, the association between the relative bacterial composition profile, the tumour mass characteristics and MTT ability to reach high circulating levels in the early phase of treatment, were explored. We found the presence of bacterial DNA in all adrenal samples from both tumours and healthy cortex specimens, documenting significant differences in the microbial composition between malignancy and normal adrenals: in detail, the ACC tissues were characterised by a higher abundance of the Proteobacteria phylum (especially the Pseudomonas and Serratia genera). In addition, the Proteobacteria's low abundance was negatively associated with tumour size, Ki67 and cortisol secretion. MTT levels reached higher levels at 9 months in ACC patients with high abundance of Proteobacteria, Pseudomonas and Serratia and with low abundance of Bacteroidota, Firmicutes and Streptococcus. These findings are the first indication that human ACCs are characterised by infiltrating bacteria and their specific abundance profile seems to influence the increase in circulating MTT levels at 9 months.

Immune landscape and oncobiota in HPV-Associated Colorectal Cancer: an explorative study.

Worldwide more than 550,000 new patients suffering from malignant tumors are associated with human papillomaviruses (HPV) infection. However, only a small portion of patients infected progress to cancer, suggesting that other factors other than HPV may play a role. Some studies have investigated HPV infection in colorectal cancer (CRC) with discordant results; moreover, the role of HPV in CRC development is still unknown. We investigated HPV infection in 50 CRC from different regions, excluding the anal one, by immunohistochemistry (IHC), real-time PCR and RNA-seq. For each patient, we studied the tumor microenvironment in neoplastic and matched non-neoplastic samples, and we compared the tumor-infiltrating immune cell phenotypes among HPV-positive and negative samples. Finally, we compared the CRC-associated microbiota in HPV-positive and negative neoplastic samples by 16S rRNA sequencing. HPV infection was identified in 20% of CRC from the right side (caecum, ascending and transverse colon) and in 40% from the left side (descending colon and rectum). In all HPV-positive CRCs we found no expression of p53 and RB, thus suggesting HPV involvement in tumorigenesis. As far as the tumor microenvironment is concerned, in HPV-related cancers we observed a neoplastic environment with a reduced immune surveillance but an enhanced cytotoxic response by lymphocytes. HPV-positive and -negative CRC showed a different microbiota with lack of species normally found in CRC in the HPV-positive ones. Our results support the carcinogenic significance of HPV in CRC, suggesting a role of HPV in modulating the tumor immune microenvironment.

Crohn's disease recurrence updates: first surgery vs. surgical relapse patients display different profiles of ileal microbiota and systemic microbial-associated inflammatory factors.

Background and aims: Crohn's disease (CD) pathogenesis is still unclear. Remodeling in mucosal microbiota and systemic immunoregulation may represent an important component in tissue injury. Here, we aim to characterize the ileal microbiota in both pathological and healthy settings and to evaluate the correlated systemic microbial-associated inflammatory markers comparing first-time surgery and relapse clinical conditions. Methods: We enrolled 28 CD patients at surgery; we collected inflamed and non-inflamed mucosa tissues and blood samples from each patient. Bacterial wall adherence was observed histologically, while its composition was assessed through amplicon sequencing of the 16S rRNA gene. In addition, we evaluated the systemic microRNA (miRNA) using quantitative real-time PCR amplification and free fatty acids (FFAs) using gas chromatography-mass spectroscopy. Results: The total number of mucosal adherent microbiota was enriched in healthy compared to inflamed mucosa. In contrast, the phylum Tenericutes, the family Ruminococcaceae, and the genera Mesoplasma and Mycoplasma were significantly enriched in the pathological setting. Significant microbiota differences were observed between the relapse and first surgery patients regarding the families Bacillaceae 2 and Brucellaceae and the genera Escherichia/Shigella, Finegoldia, Antrobacter, Gemmatimonas, Moraxella, Anoxibacillus, and Proteus. At the systemic level, we observed a significant downregulation of circulating miR-155 and miR-223, as well as 2-methyl butyric, isobutyric, and hexanoic (caproic) acids in recurrence compared to the first surgery patients. In addition, the level of hexanoic acid seems to act as a predictor of recurrence risk in CD patients (OR 18; 95% confidence interval 1.24-261.81; p = 0.006). Conclusions: We describe a dissimilarity of ileal microbiota composition comparing CD and healthy settings, as well as systemic microbial-associated inflammatory factors between first surgery and surgical relapse. We suggest that patterns of microbiota, associated with healthy ileal tissue, could be involved in triggering CD recurrence. Our findings may provide insight into the dynamics of the gut microbiota-immunity axis in CD surgical recurrence, paving the way for new diagnostics and therapeutics aimed not only at reducing inflammation but also at maintaining a general state of eubiosis in healthy tissue.

Effect of ancient Khorasan wheat on gut microbiota, inflammation, and short-chain fatty acid production in patients with fibromyalgia.

BACKGROUND: Fibromyalgia (FM) syndrome is mainly characterized by widespread pain, sleeping disorders, fatigue, and cognitive dysfunction. In many cases, gastrointestinal distress is also reported, suggesting the potential pathogenic role of the gut microbiota (GM). The GM is deeply influenced by several environmental factors, especially the diet, and recent findings highlighted significant symptom improvement in FM patients following various nutritional interventions such as vegetarian diet, low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols based diets, gluten-free diet, and especially an ancient grain supplementation. In particular, a recent study reported that a replacement diet with ancient Khorasan wheat led to an overall improvement in symptom severity of FM patients. AIM: To examine the effects of ancient Khorasan wheat on the GM, inflammation, and short-chain fatty acid production in FM patients. METHODS: After a 2-wk run-in period, 20 FM patients were enrolled in this randomized, double-blind crossover trial. In detail, they were assigned to consume either Khorasan or control wheat products for 8 wk and then, following an 8-wk washout period, crossed. Before and after treatments, GM characterization was performed by 16S rRNA sequencing while the fecal molecular inflammatory response and the short-chain fatty acids (SCFAs) were respectively determined with the Luminex MAGPIX detection system and a mass chromatography-mass spectrometry method. RESULTS: The Khorasan wheat replacement diet, in comparison with the control wheat diet, had more positive effects on intestinal microbiota composition and on both the fecal immune and SCFAs profiles such as the significant increase of butyric acid levels (P = 0.054), candidatus Saccharibacteria (P = 9.95e-06) and Actinobacteria, and the reduction of Enterococcaceae (P = 4.97e-04). Moreover, the improvement of various FM symptoms along with the variation of some gut bacteria after the Khorasan wheat diet have been documented; in fact we reported positive correlations between Actinobacteria and both Tiredness Symptoms Scale (P < 0.001) and Functional Outcome of Sleep Questionnaire (P < 0.05) scores, between Verrucomicrobiae and both Widespread Pain Index (WPI) + Symptom Severity scale (SS) (P < 0.05) and WPI (P < 0.05) scores, between candidatus Saccharibacteria and SS score (P < 0.05), and between Bacteroidales and Sleep-Related and Safety Behaviour Questionnaire score (P < 0.05). CONCLUSION: The replacement diet based on ancient Khorasan wheat results in beneficial GM compositional and functional modifications that positively correlate with an improvement of FM symptomatology.

Gut Microbiota and Associated Mucosal Immune Response in Eosinophilic Granulomatosis with Polyangiitis (EGPA).

Eosinophilic granulomatosis with polyangiitis (EGPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. A genome-wide association study showed a correlation between ANCA-negative EGPA and variants of genes encoding proteins with intestinal barrier functions, suggesting that modifications of the mucosal layer and consequent gut dysbiosis might be involved in EGPA pathogenesis. Here, we characterized the gut microbiota (GM) composition and the intestinal immune response in a cohort of EGPA patients. Faeces from 29 patients and 9 unrelated healthy cohabitants were collected, and GM and derived metabolites' composition were compared. Seven intestinal biopsies from EGPA patients with gastrointestinal manifestations were analysed to assess the T-cell distribution and its correlation with GM and EGPA clinical and laboratory features. No significant differences in GM composition, nor in the total amount of faecal metabolites, emerged between patients and controls. Nevertheless, differences in bacterial taxa abundances and compositional GM-derived metabolites profile were observed. Notably, an enrichment of potential pathobionts (Enterobacteriacee and Streptococcaceae) was found in EGPA, particularly in patients with active disease, while lower levels were found in patients on immunosuppression, compared with non-immunosuppressed ones. Significantly lower amounts of hexanoic acid were found in patients, compared to controls. The analysis of the immune response in the gut mucosa revealed a high frequency of IFN-γ/IL-17-producing T lymphocytes, and a positive correlation between EGPA disease activity and intestinal T-cell levels. Our data suggest that an enrichment in potential intestinal pathobionts might drive an imbalanced inflammatory response in EGPA.