School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom.
Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand.
PLoS Negl Trop Dis. 2022 Jun 8;16(6):e0010491. doi: 10.1371/journal.pntd.0010491. eCollection 2022 Jun.
Previous reports show altered gut bacterial profiles are associated with helminth infected individuals. Our recently published molecular survey of clinical helminthiases in Thailand border regions demonstrated a more comprehensive picture of infection prevalence when Kato Katz microscopy and copro-qPCR diagnostics were combined. We revealed that Opisthorchis viverrini, hookworm, Ascaris lumbricoides and Trichuris trichiura were the most predominant helminth infections in these regions. In the current study, we have profiled the faecal and saliva microbiota of a subset of these helminth infected participants, in order to determine if microbial changes are associated with parasite infection.
A subset of 66 faecal samples from Adisakwattana et al., (2020) were characterised for bacterial diversity using 16S rRNA gene profiling. Of these samples a subset of 24 participant matched saliva samples were also profiled for microbiota diversity. Sequence data were compiled, OTUs assigned, and diversity and abundance analysed using the statistical software Calypso.
The data reported here indicate that helminth infections impact on both the host gut and oral microbiota. The profiles of faecal and saliva samples, irrespective of the infection status, were considerably different from each other, with more alpha diversity associated with saliva (p-value≤ 0.0015). Helminth infection influenced the faecal microbiota with respect to specific taxa, but not overall microbial alpha diversity. Conversely, helminth infection was associated with increased saliva microbiota alpha diversity (Chao 1 diversity indices) at both the genus (p-value = 0.042) and phylum (p-value = 0.026) taxa levels, compared to uninfected individuals. Elevated individual taxa in infected individuals saliva were noted at the genus and family levels. Since Opisthorchis viverrini infections as a prominent health concern to Thailand, this pathogen was examined separately to other helminths infections present. Individuals with an O. viverrini mono-infection displayed both increases and decreases in genera present in their faecal microbiota, while increases in three families and one order were also observed in these samples.
In this study, helminth infections appear to alter the abundance of specific faecal bacterial taxa, but do not impact on overall bacterial alpha or beta diversity. In addition, the faecal microbiota of O. viverrini only infected individuals differed from that of other helminth single and dual infections. Saliva microbiota analyses of individuals harbouring active helminth infections presented increased levels of both bacterial alpha diversity and abundance of individual taxa. Our data demonstrate that microbial change is associated with helminthiases in endemic regions of Thailand, and that this is reflected in both faecal and saliva microbiota. To our knowledge, this is the first report of an altered saliva microbiota in helminth infected individuals. This work may provide new avenues for improved diagnostics; and an enhanced understanding of both helminth infection pathology and the interplay between helminths, bacteria and their host.
先前的报告表明，肠道细菌谱的改变与感染蠕虫的个体有关。我们最近发表的泰国边境地区临床蠕虫病的分子调查表明，当结合加藤氏粪便镜检和粪便 qPCR 诊断时，感染的流行情况更为全面。我们发现，肝片形吸虫、钩虫、蛔虫和鞭虫是这些地区最主要的蠕虫感染。在本研究中，我们对这些感染蠕虫的参与者的一部分粪便和唾液微生物群进行了分析，以确定微生物变化是否与寄生虫感染有关。
从 Adisakwattana 等人的研究中选取了 66 个粪便样本进行 16S rRNA 基因谱分析，以确定细菌多样性。在这些样本中，还对 24 名匹配的参与者的唾液样本进行了亚群分析，以确定微生物多样性。使用统计软件 Calypso 编译序列数据、分配 OTUs，并分析多样性和丰度。
这里报告的数据表明，蠕虫感染会影响宿主的肠道和口腔微生物群。粪便和唾液样本的图谱，无论感染状况如何，彼此之间都有很大的不同，唾液中的 alpha 多样性更多（p 值≤0.0015）。蠕虫感染影响粪便微生物群的特定分类群，但不影响整体微生物 alpha 多样性。相反，与未感染个体相比，蠕虫感染与唾液微生物群 alpha 多样性（Chao 1 多样性指数）增加有关，无论是在属（p 值=0.042）还是在门（p 值=0.026）分类群水平上。与未感染个体相比，感染个体的唾液中存在更多的属和科水平上的个体分类群。由于肝片形吸虫感染是泰国的一个重要健康问题，因此将该病原体与其他存在的蠕虫感染分别进行了检查。患有肝片形吸虫单感染的个体的粪便微生物群中存在的属数量增加和减少，而在这些样本中也观察到三个科和一个目增加。
在这项研究中，蠕虫感染似乎改变了特定粪便细菌分类群的丰度，但不影响细菌 alpha 或 beta 多样性的整体水平。此外，肝片形吸虫单独感染个体的粪便微生物群与其他蠕虫单感染和双感染个体的粪便微生物群不同。携带活动性蠕虫感染的个体的唾液微生物群分析显示，细菌 alpha 多样性和个体分类群丰度均增加。我们的数据表明，微生物变化与泰国流行地区的蠕虫病有关，这反映在粪便和唾液微生物群中。据我们所知，这是首次报道蠕虫感染个体的唾液微生物群发生改变。这项工作可能为改进诊断提供新途径，并增强对蠕虫感染病理和蠕虫、细菌及其宿主之间相互作用的理解。
