Abstract

Gluten is a cereal protein that is incompletely digested by human proteolytic enzymes that create immunogenic peptides that accumulate in the gastrointestinal tract (GIT). Although both environmental and human bacteria have been shown to expedite gluten hydrolysis, gluten intolerance is a growing concern. Here we hypothesize that together with food, we acquire environmental bacteria that could impact our GIT with gluten-degrading bacteria. Using in vitro gastrointestinal simulation conditions, we evaluated the capacity of endophytic bacteria that inhabit root vegetables, potato (Solanum tuberosum), carrot (Daucus sativus), beet (Beta vulgaris), and topinambur (Jerusalem artichoke) (Helianthus tuberosus), to resist these conditions and degrade gluten. By 16S rDNA sequencing, we discovered that bacteria from the families Enterobacteriaceae, Bacillaceae, and Clostridiaceae most effectively multiply in conditions similar to the human GIT (microoxic conditions, 37 °C) while utilizing vegetable material and gluten as nutrients. Additionally, we used stomach simulation (1 h, pH 3) and intestinal simulation (1 h, bile salts 0.4%) treatments. The bacteria that survived this treatment retained the ability to degrade gluten epitopes but at lower levels. Four bacterial strains belonging to species Bacillus pumilus, Clostridium subterminale, and Clostridium sporogenes isolated from vegetable roots produced proteases with postproline cleaving activity that successfully neutralized the toxic immunogenic epitopes.

Key points

• Bacteria from root vegetables can degrade gluten.

• Some of these bacteria can resist conditions mimicking gastrointestinal tract.

中文翻译：

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根菜类微生物-面筋降解细菌的来源。

摘要

谷蛋白是一种谷物蛋白，不会被人类蛋白水解酶完全消化，从而产生在胃肠道（GIT）中积累的免疫原性肽。尽管已经证明环境细菌和人类细菌都促进面筋水解，但是面筋不耐受性已成为人们日益关注的问题。在这里，我们假设与食物一起获得了环境细菌，这些环境细菌可能会通过面筋降解细菌影响我们的GIT。使用体外胃肠模拟条件中，我们评估内生细菌的能力，居住根菜类，马铃薯（马铃薯），胡萝卜（胡萝卜属黄瓜），甜菜（甜菜）和topinambur（菊芋）（菊芋），以抵抗这些条件并降解面筋。通过16S rDNA序列分析，我们发现，从家庭，细菌肠杆菌科细菌，芽孢杆菌，和梭菌类似于人类的GIT（microoxic条件下，37℃），同时利用植物材料中最有效地繁衍条件和面筋的营养成分。此外，我们使用了胃模拟（1 h，pH 3）和肠模拟（1 h，胆盐0.4％）治疗。在该处理中存活的细菌保留了降解面筋表位的能力，但水平较低。属于短小芽孢杆菌，亚末端梭状芽胞杆菌和产孢梭状芽胞杆菌的四种细菌菌株 从植物根中分离得到的蛋白酶具有脯氨酸后裂解活性，可成功中和毒性免疫原性表位。

关键点

•根类蔬菜中的细菌可以降解面筋。

•其中一些细菌可以抵抗模拟胃肠道的疾病。