Table_1_Alterations in the Abundance and Co-occurrence of Akkermansia muciniphila and Faecalibacterium prausnitzii in the Colonic Mucosa of Inflammatory Bowel Disease Subjects.DOCX

Akkermansia muciniphila and Faecalibacterium prausnitzii, cohabitants in the intestinal mucosa, are considered members of a healthy microbiota and reduction of both species occurs in several intestinal disorders, including inflammatory bowel disease. Little is known however about a possible link between the reduction in quantity of these species, and in which circumstances this may occur. This study aims to determine the abundances and co-occurrence of the two species in order to elucidate conditions that may compromise their presence in the gut. Loads of A. muciniphila, total F. prausnitzii and its two phylogroup (16S rRNA gene copies) were determined by quantitative polymerase chain reaction in colonic biopsies from 17 healthy controls (H), 23 patients with ulcerative colitis (UC), 31 patients with Crohn's disease (CD), 3 with irritable bowel syndrome (IBS) and 3 with colorectal cancer (CRC). Data were normalized to total bacterial 16S rRNA gene copies in the same sample. Prevalence, relative abundances and correlation analyses were performed according to type of disease and considering relevant clinical characteristics of patients such as IBD location, age of disease onset, CD behavior, current medication and activity status. Co-occurrence of both species was found in 29% of H, 65% of UC and 29% of CD. Lower levels of total F. prausnitzii and phylogroups were found in subjects with CD, compared with H subjects (P ≤ 0.044). In contrast, no differences were found with the regard to A. muciniphila abundance across different disease states, but CD patients with disease onset below 16 years of age featured a marked depletion of this species. In CD patients, correlation between A. muciniphila and total F. prausnitzii (ρ = 0.362, P = 0.045) was observed, and particularly in those with non-stricturing, non-penetrating disease behavior and under moderate immunosuppressants therapy. Altogether, this study revealed that co-occurrence of both species differs between disease status. In addition, IBD patients featured a reduction of F. prausnitzii but similar loads of A. muciniphila when compared to H subjects, with the exception of those with early onset CD. Depletion of A. muciniphila in this subgroup of subjects suggests that it could be a potential biomarker to assist in pediatric CD diagnosis.

阿克曼氏菌（Akkermansia muciniphila）和普拉乌辛氏菌（Faecalibacterium prausnitzii），作为肠道黏膜中的共生微生物，被认定为健康微生物群的组成成员。这两种物种的数量减少在多种肠道疾病中均有发生，包括炎症性肠病。然而，关于这些物种数量减少的可能联系及其发生的具体环境，目前所知甚少。本研究旨在确定这两种物种的丰度和共现情况，以阐明可能损害其在肠道中存在条件的因素。通过对17名健康对照者（H）、23名溃疡性结肠炎（UC）患者、31名克罗恩病（CD）患者、3名肠易激综合症（IBS）患者和3名结直肠癌（CRC）患者的结肠活检样本进行定量聚合酶链式反应，测定了A. muciniphila的负荷、F. prausnitzii的总数及其两个系统发育群（16S rRNA基因拷贝）。数据均以同一样本中的总细菌16S rRNA基因拷贝数为基准进行归一化处理。根据疾病类型和患者的相关临床特征，如炎症性肠病的部位、疾病发病年龄、CD行为、当前用药和活动状态，进行了流行病学、相对丰度和相关性分析。在29%的健康对照者、65%的溃疡性结肠炎患者和29%的克罗恩病患者中发现了两种物种的共现。与健康对照者相比，克罗恩病患者中F. prausnitzii的总数及其系统发育群水平显著降低（P ≤ 0.044）。相反，不同疾病状态下A. muciniphila的丰度没有发现差异，但发病年龄低于16岁的克罗恩病患者中，这种物种的数量显著减少。在克罗恩病患者中，观察到A. muciniphila与F. prausnitzii的总数之间存在相关性（ρ = 0.362，P = 0.045），尤其是在那些非狭窄性、非穿透性疾病行为和接受中度免疫抑制剂治疗的患者中。总体而言，本研究揭示了两种物种的共现情况在不同疾病状态下存在差异。此外，与健康对照者相比，炎症性肠病患者中F. prausnitzii的数量减少，但A. muciniphila的负荷相似，除了那些早期发病的克罗恩病患者。这一亚组中A. muciniphila的耗竭表明，它可能是辅助儿科克罗恩病诊断的潜在生物标志物。