肠道微生物群衍生的代谢产物调控结直肠癌的新进展

肠道生态系统的改变会影响人类的健康,甚至引发结直肠癌。大量证据表明,在结直肠癌患者的肠道中普遍存在一种病理性微生物群失衡状态,失衡的微生物群衍生的代谢产物也会影响结直肠癌的发生发展。本文综述了由特定肠道微生物群代谢产物触发结直肠癌进程的方式,总结了肠道微生物群代谢产物对结直肠癌贡献的最新进展,并考虑代谢产物的积累效应以及多种代谢产物相结合的方式来预测和预防结直肠癌。     

Comparative effect of ochratoxin A on inflammation and oxidative stress parameters in gut and kidney of piglets

Ochratoxin A (OTA) is a secondary metabolite produced by fungi of Aspergillus and Penicillium genra. OTA is mainly nephrotoxic but can also cause hepatotoxicity, mutagenicity, teratogenicity, neurotoxicity and immunotoxicity. As recent studies have highlighted the close relationship between gastrointestinal tract and kidney, as principal organs involved in absorption and respective excretion of xenobiotics, the aim of the present study was to analyze the effect of a subchronic exposure (30 days) to 0.05 mg/kg OTA on immune response and oxidative stress parameters at the level of intestine and kidney of young swine. The experiment was realised on twelve crossbred weaned piglets randomly allotted to both control group or toxin group fed 0.050 mg OTA/kg feed. Our results have shown that a subchronic intoxication with a low dose of OTA for 30 days affected the immune response and the anti-oxidant self-defense at gut and kidney level. The gene expression of both markers of signaling pathways involved in inflammation and inflammatory cytokines were affected in a much higher extent in the gut than in the kidney Of OTA intoxicated piglets.     

The Akkermansia muciniphila is a gut microbiota signature in psoriasis

Psoriasis is an immune‐mediated chronic inflammatory skin disease. Although its pathogenesis is not fully understood, Th17 cells and the cytokines they produce, such as IL‐17, IL‐22 and IL‐23, play critical roles in the pathogenesis of psoriasis. Evidence has demonstrated that psoriasis has some common features, including immune responses (due to Th17 cells) and inflammatory cytokine profiles, with systematic diseases including inflammatory bowel diseases (IBDs) and obesity. Recently, studies have demonstrated that the gut microbiota plays a crucial role in host homoeostasis and immune response, particular in Th17 cells, but the role of the gut microbiota in psoriasis remains unclear. To study the relationship between gut microbiota and psoriasis, we analysed microbiota profiles in psoriasis using a 16S rDNA sequencing platform, and we found that the abundance of Akkermansia muciniphila was significantly reduced in patients with psoriasis. A. muciniphila is believed to have an important function in the pathogenesis of IBD and obesity; therefore, A. muciniphila, which is an indicator of health status, may be a key node for psoriasis as well as IBD and obesity. Taken together, our study identified that gut microbiota signature and function are significantly altered in the gut of patients with psoriasis, which provides a novel angle to understanding the pathogenesis of psoriasis.     

The potential role of lung microbiota in lung cancer attributed to household coal burning exposures

Bacteria influence site‐specific disease etiology and the host's ability to metabolize xenobiotics, such as polycyclic aromatic hydrocarbons (PAHs). Lung cancer in Xuanwei, China has been attributed to PAH‐rich household air pollution from burning coal. This study seeks to explore the role of lung microbiota in lung cancer among never smoking Xuanwei women and how coal burning may influence these associations. DNA from sputum and buccal samples of never smoking lung cancer cases (n = 8, in duplicate) and controls (n = 8, in duplicate) in two Xuanwei villages was extracted using a multi‐step enzymatic and physical lysis, followed by a standardized clean‐up. V1‐V2 regions of 16S rRNA genes were PCR‐amplified. Purified amplicons were sequenced by 454 FLX Titanium pyrosequencing and high‐quality sequences were evaluated for diversity and taxonomic membership. Bacterial diversity among cases and controls was similar in buccal samples (P = 0.46), but significantly different in sputum samples (P = 0.038). In sputum, Granulicatella (6.1 vs. 2.0%; P = 0.0016), Abiotrophia (1.5 vs. 0.085%; P = 0.0036), and Streptococcus (40.1 vs. 19.8%; P = 0.0142) were enriched in cases compared with controls. Sputum samples had on average 488.25 species‐level OTUs in the flora of cases who used smoky coal (PAH‐rich) compared with 352.5 OTUs among cases who used smokeless coal (PAH‐poor; P = 0.047). These differences were explained by the Bacilli species (Streptococcus infantis and Streptococcus anginosus). Our small study suggests that never smoking lung cancer cases have differing sputum microbiota than controls. Further, bacteria found in sputum may be influenced by environmental exposures associated with the type of coal burned in the home. Environ. Mol. Mutagen. 55:643–651, 2014. © 2014 Wiley Periodicals, Inc.