多种培养基联合探究人体肠道可培养微生物多样性

Exploration of the diversity of culturable human intestinal microorganisms via multiple culture media

摘要:

目的 人体肠道蕴含着丰富的微生物资源，这些微生物在宿主的消化吸收、生长发育等方面具有重要作用。目前，培养组学被广泛应用于肠道有益微生物的分离，然而不同培养基存在偏好性，单个培养基难以全面分离肠道中的可培养微生物。方法 采用文献报道的6种培养基，即脑心浸液培养基(brain heart infusion, BHI)、Wilkins_Chalgren肉汤培养基(WCBM)、Man-Rogosa-Sharpe培养基(MRS)、强化梭菌培养基(reinforced clostridial medium, RCM)、黏蛋白培养基(mucin medium, MM)、黏蛋白改良培养基(modified mucin medium, MMM)，对58名志愿者粪便中的微生物进行分离培养，以期明确肠道中可培养微生物的多样性，并获取肠道中潜在有益菌的菌株资源。结果 从58份样品中共分离得到1 052株细菌，鉴定为5门39属101种。其中，从BHI培养基中分离出的细菌种类最多，为50种(49.50%)；从MMM培养基中分离出的细菌种类最少，为24种(23.76%)。除MM培养基外，每种培养基均能分离到独特菌属，BHI和MMM培养基分离到的特有属最多，均为5个。在分离的菌株中，有466株被报道具有益生作用，其中包括脆弱拟杆菌(Bacteroides fragilis)、植物乳植杆菌(Lactiplantibacillus plantarum)、乳酸片球菌(Pediococcus acidilactici)和两歧双歧杆菌(Bifidobacterium bifidum)等。同时，BHI和MRS培养基可分离获得较多的有益微生物物种(10/16，62.50%)。结论 本研究采用多种培养基从纯培养的角度探究了人体肠道有益细菌的多样性，为肠道源有益微生物的开发提供了丰富的菌株资源。

Abstract:

Objective The human intestinal tract is rich in microbial resources, which play a significant role in the host’s digestion, absorption, growth, development, etc. Currently, culturomics is widely used in the isolation of beneficial intestinal microorganisms. However, different culture media have preferences, and a single medium is difficult to comprehensively isolate the culturable microorganisms in the intestinal tract.Methods We used six reported culture media [brain heart infusion (BHI), Wilkins_Chalgren anaerobe broth (WCBM), (Man-Rogosa-Sharpe) MRS, reinforced clostridial medium (RCM), mucin medium (MM) and modified mucin medium (MMM)] to isolate the microorganisms in the feces of 58 volunteers, with the aim of clarifying the diversity of culturable microorganisms in the intestinal tract and obtaining potential beneficial bacterial strains in the intestinal tract.Results A total of 1 052 bacterial strains were isolated from 58 samples, and they were identified as 101 species belonging to 39 genera of 5 phyla. The BHI medium isolated the most bacterial species (50, 49.50%), while the MMM medium isolated the fewest bacterial species (24, 23.76%). Except the MM medium, each of other media could isolate unique genera, and BHI and MMM isolated the most unique genera (5 each). Among the isolated strains, 466 strains were reported to have probiotic effects, including Bacteroides fragilis, Lactiplantibacillus plantarum, Pediococcus acidilactici, and Bifidobacterium bifidum. BHI and MRS media could isolate more beneficial microbial species (10/16, 62.50%).Conclusion We explored the diversity of beneficial bacteria in the human intestinal tract from the perspective of pure culture by using multiple culture media, providing rich strain resources for the development of intestinal beneficial microorganisms.