Microbial colonization promotes model cockroach gut tissue growth and development
Microbial colonization promotes model cockroach gut tissue growth and development
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微生物定植促进模型蟑螂肠道组织的生长和发育
DOI：
10.1016/j.jinsphys.2021.104274
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发表时间：
2021
影响因子：
2.2
通讯作者：
Sabree, Zakee L.
中科院分区：
文献类型：
--
作者：
Jahnes, Benjamin C.;Poudel, Keyshap;Staats, Amelia M.;Sabree, Zakee L.
背景消化组织对于食物加工和营养可获得性是必不可少的，特别是在杂食动物中，这些功能的发生与存在于这些组织内和组织上的动态微生物群落无关。在无菌动物中观察到宿主发育延长和消化组织尺寸减小，并且在通过粪食重新引入典型的肠道微生物组后恢复正常的宿主表型。结果高分辨率组织学分析ofPeriplaneta americanacockroach消化组织显示，肠道微生物定殖的全面预防对肠道组织的生长和发育有严重影响，特别是后中肠和前后肠亚室，它们预期被最大数量的细菌定殖和居住。短暂暴露于正常肠道微生物群的青少年表现出部分肠道形态恢复，表明单次接种是不够的。这些数据强调肠道微生物群是它们直接接触的组织的正常生长和发育的组成部分，更广泛地说，是它们所居住的生物体。（即多代同堂、蜕皮、子代食粪和蜕皮喂养），和以前的研究提出了一个宿主发育模型，其中肠道组织反映了一种冲突-协作动态，其中1）营养-吸收性前中肠组织与瞬时和常驻细菌竞争容易吸收的饮食营养物，并且其生长受肠道细菌存在的影响最小，和2）后中肠，前后肠，并且在较小程度上，后肠组织受到肠道细菌存在的显著影响，因为它们被最大数量的细菌占据，并且宿主依赖于，并因此与之合作，它们有助于复杂的多糖催化剂加工和营养供应（即短链脂肪酸）。
BackgroundDigestive tissues are essential for diet processing and nutrient accessibility, especially in omnivores, and these functions occur despite and in collaboration with dynamic microbial communities that reside within and upon these tissues. Prolonged host development and reduced digestive tissue sizes have been observed in germ-free animals, and normal host phenotypes were recovered following the re-introduction of typical gut microbiomes via coprophagy.ResultsHigh-resolution histological analyses ofPeriplaneta americanacockroach digestive tissues revealed that total prevention of microbial colonization of the gut had severe impacts on the growth and development of gut tissues, especially the posterior midgut and anterior hindgut subcompartments that are expected to be colonized and inhabited by the greatest number of bacteria. Juveniles that were briefly exposed to normal gut microbiota exhibited a partial gut morphological recovery, suggesting that a single inoculation was insufficient. These data highlight gut microbiota as integral to normal growth and development of tissues they are in direct contact with and, more broadly, the organism in which they reside.ConclusionsWe draw on these data, host life history traits (i.e. multigenerational cohousing, molting, and filial coprophagy and exuvia feeding), and previous studies to suggest a host developmental model in which gut tissues reflect a conflict-collaboration dynamic where 1) nutrient-absorptive anterior midgut tissues are in competition with transient and resident bacteria for easily assimilable dietary nutrients and whose growth is least-affected by the presence of gut bacteria and 2) posterior midgut, anterior hindgut, and to a lesser degree, posterior hindgut tissues are significantly impacted by gut bacterial presence because they are occupied by the greatest number of bacteria and the host is relying upon, and thus collaborating with, them to assist with complex polysaccharide catabolism processing and nutrient provisioning (i.e. short-chain fatty acids).