图片来源：medicalxpress.com
每个人都发生过腹泻，腹泻可因轻度到重度的程度对患者带来不同的影响；近日，来自密歇根州立大学的研究人员在国际杂志Microbiome上刊登了他们最新的研究成果，研究者发现，控制机体特殊肠道细菌的水平或可帮助抑制严重腹泻的发生。
仅在美国，大部分的腹泻都是由31种不同的食源性致病菌引起，这些食源性致病菌每年引发超过940万感染病例，大约5.6万患者住院以及1351名患者死亡。这项研究中研究者表示，大部分的患者感染大肠埃希氏菌的水平都有所增加，该细菌是肠道中的常见细菌，有时候该细菌具有致病性。Shannon Manning博士说道，这项研究中，相比未感染的患者而言，感染四种不同的腹泻病原体：沙门氏菌、产志贺毒素的大肠埃希氏菌、弯曲杆菌和志贺氏菌的患者机体中大肠埃希氏菌的水平都有所增加，此外，当患者恢复后其机体的大肠埃希氏菌水平则会有所下降。
本文研究对于开发新型疗法来控制严重腹泻患者机体的大肠埃希氏菌水平非常重要，对于后期促进机体有益肠道的微生物菌群的生长来帮助抵御腹泻的发生也提供了一定的研究线索；研究者通过对四种不同病原体感染的腹泻患者机体的肠道微生物DNA进行测序，通过对结果进行对比随后研究者在健康家族成员中发现了特殊的微生物，这种肠道微生物群落在患者和健康个体机体中并不相同。
研究者指出，不管引发感染的病原体是哪种，患者机体肠道的微生物群落的改变都会以相同的模式来改变，此外，拥有特殊微生物群落的患者或许会患更为严重的疾病，而且不论年龄、性别和种族，这些改变都是相似的。基于当前的研究数据，研究者后期将会进行更为深入的研究来检测益生菌疗法等其它疗法，是否可以增加机体有益微生物群落的水平，同时降低机体中变形菌门(Proteobacteria)细菌的水平，变形菌门细菌包括许多种类型的致病菌，比如大肠埃希氏菌等，而潜在降低肠道感染负担的新型疗法或可可以从根本上帮助患者快速恢复。
doi:10.1186/s40168-015-0109-2
PMC:
PMID:
Intestinal microbial communities associated with acute enteric infections and disease recovery
Pallavi Singh, Tracy K. Teal, Terence L. Marsh, James M. Tiedje, Rebekah Mosci, Katherine Jernigan, Angela Zell, Duane W. Newton, Hossein Salimnia, Paul Lephart, Daniel Sundin, Walid Khalife, Robert A. Britton, James T. Rudrik and Shannon D. Manning
Background The intestinal microbiome represents a complex network of microbes that are important for human health and preventing pathogen invasion. Studies that examine differences in intestinal microbial communities across individuals with and without enteric infections are useful for identifying microbes that support or impede intestinal health. Results 16S rRNA gene sequencing was conducted on stool DNA from patients with enteric infections (n = 200) and 75 healthy family members to identify differences in intestinal community composition. Stools from 13 patients were also examined post-infection to better understand how intestinal communities recover. Patient communities had lower species richness, evenness, and diversity versus uninfected communities, while principle coordinate ysis demonstrated close clustering of uninfected communities, but not the patient communities, irrespective of age, gender, and race. Differences in community composition between patients and family members were mostly due to variation in the abundance of phyla Proteobacteria, Bacteroidetes, and Firmicutes. Patient communities had significantly more Proteobacteria representing genus Escherichia relative to uninfected communities, which were dominated by Bacteroides. Intestinal communities from patients with bloody diarrhea clustered together in the neighbor-joining phylogeny, while communities from 13 patients post-infection had a significant increase in Bacteroidetes and Firmicutes and clustered together with uninfected communities. Conclusions These data demonstrate that the intestinal communities in patients with enteric bacterial infections get altered in similar ways. Furthermore, preventing an increase in Escherichia abundance may be an important consideration for future prevention strategies.
