Do faecal samples represent the primary site of microbial plant fermentation in hindgut fermenters?

Author(s):  
Raphael Eisenhofer ◽  
Erin D’Agnese ◽  
David Taggart ◽  
Scott Carver ◽  
Beth Penrose

Abstract BackgroundMost herbivorous mammals have symbiotic microbes living in their gastrointestinal tracts that help with harvesting energy from recalcitrant plant fibre. The bulk of research into these microorganisms has focused on samples collected from faeces, representing the distal region of the gastrointestinal (GI) tract. However, the GI tract in herbivorous mammals is typically long and complex, containing different regions with distinct physico-chemical properties that can structure resident microbial communities. Therefore, to determine how representative faeces are to other regions of the GI tract in hindgut-fermenting mammals, we characterised the microbial biogeography of the GI tract of two species of wombats.ResultsUsing 16S rRNA gene sequencing, our results show that GI microbial communities of wombats are structured by GI region. For both the bare-nosed wombat (Vombatus ursinus) and the southern hairy-nosed wombat (Lasiorhinus latifrons), we observed a trend of increasing microbial diversity from stomach to distal colon. The microbial composition in the first proximal colon region was more similar between wombat species than the corresponding distal colon region in the same species. We found several microbial genera that were differentially abundant between the first proximal colon and distal colon regions. Surprisingly, only 99 (10.6%) and 204 (18.7%) amplicon sequence variants (ASVs) were shared between the first proximal colon region and the distal colon region for the bare-nosed and southern hairy-nosed wombat, respectively. ConclusionThese results suggest that microbial communities in the first proximal colon region—the putative site of primary plant fermentation in wombats—are distinct from the distal colon, and that faecal samples have limitations in capturing the diversity of these communities. While faeces are still a valuable and effective means of characterising the distal colon microbiota, future work seeking to better understand how GI microbes impact the energy economy of wombats (and potentially other hindgut-fermenting mammals) may need to take gut biogeography into account.

2021 ◽  
Author(s):  
Raphael Eisenhofer ◽  
Erin D’Agnese ◽  
David Taggart ◽  
Scott Carver ◽  
Beth Penrose

Abstract Most herbivorous mammals have symbiotic microbes living in their gastrointestinal tracts that help with harvesting energy from recalcitrant plant fibre. The bulk of research into these microorganisms has focused on samples collected from faeces, representing the distal region of the gastrointestinal (GI) tract. However, the GI tract in herbivorous mammals is typically long and complex, containing different regions with distinct physico-chemical properties that can structure resident microbial communities. In this study, we characterised the microbial biogeography of the GI tracts in individuals of two species of wombats.Using 16S rRNA gene sequencing, our results show that GI microbial communities of wombats are structured by GI region. For both the bare-nosed wombat (Vombatus ursinus) and the southern hairy-nosed wombat (Lasiorhinus latifrons), we observed a trend of increasing microbial diversity from stomach to distal colon. The microbial composition in the first proximal colon region was more similar between wombat species than the corresponding distal colon region in the same species. We found several microbial genera that were differentially abundant between the first proximal colon and distal colon regions. Surprisingly, only 99 (10.6%) and 204 (18.7%) amplicon sequence variants (ASVs) were shared between the first proximal colon region and the distal colon region for the bare-nosed and southern hairy-nosed wombat, respectively.These results suggest that microbial communities in the first proximal colon region—the putative site of primary plant fermentation in wombats—are distinct from the distal colon, and that faecal samples may have limitations in capturing the diversity of these communities. While faeces are still a valuable and effective means of characterising the distal colon microbiota, future work seeking to better understand how GI microbiota impact the energy economy of wombats (and potentially other hindgut-fermenting mammals) may need to take gut biogeography into account.


AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shenzheng Zeng ◽  
Sukontorn Khoruamkid ◽  
Warinphorn Kongpakdee ◽  
Dongdong Wei ◽  
Lingfei Yu ◽  
...  

Abstract The Pacific white shrimp, with the largest production in shrimp industry, has suffered from multiple severe viral and bacterial diseases, which calls for a more reliable and environmentally friendly system to promote shrimp culture. The “Aquamimicry system”, mimicking the nature of aquatic ecosystems for the well-being of aquatic animals, has effectively increased shrimp production and been adapted in many countries. However, the microbial communities in the shrimp intestine and surrounding environment that act as an essential component in Aquamimicry remain largely unknown. In this study, the microbial composition and diversity alteration in shrimp intestine, surrounding water and sediment at different culture stages were investigated by high throughput sequencing of 16S rRNA gene, obtaining 13,562 operational taxonomic units (OTUs). Results showed that the microbial communities in shrimp intestine and surrounding environment were significantly distinct from each other, and 23 distinguished taxa for each habitat were further characterized. The microbial communities differed significantly at different culture stages, confirmed by a great number of OTUs dramatically altered during the culture period. A small part of these altered OTUs were shared between shrimp intestine and surrounding environment, suggesting that the microbial alteration of intestine was not consistent with that of water and sediment. Regarding the high production of Aquamimicry farm used as a case in this study, the dissimilarity between intestinal and surrounding microbiota might be considered as a potential indicator for healthy status of shrimp farming, which provided hints on the appropriate culture practices to improve shrimp production.


mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Anna M. Seekatz ◽  
Matthew K. Schnizlein ◽  
Mark J. Koenigsknecht ◽  
Jason R. Baker ◽  
William L. Hasler ◽  
...  

ABSTRACTAlthough the microbiota in the proximal gastrointestinal (GI) tract have been implicated in health and disease, much about these microbes remains understudied compared to those in the distal GI tract. This study characterized the microbiota across multiple proximal GI sites over time in healthy individuals. As part of a study of the pharmacokinetics of oral mesalamine administration, healthy, fasted volunteers (n = 8; 10 observation periods total) were orally intubated with a four-lumen catheter with multiple aspiration ports. Samples were taken from stomach, duodenal, and multiple jejunal sites, sampling hourly (≤7 h) to measure mesalamine (administered att = 0), pH, and 16S rRNA gene-based composition. We observed a predominance ofFirmicutesacross proximal GI sites, with significant variation compared to stool. The microbiota was more similar within individuals over time than between subjects, with the fecal microbiota being unique from that of the small intestine. The stomach and duodenal microbiota displayed highest intraindividual variability compared to jejunal sites, which were more stable across time. We observed significant correlations in the duodenal microbial composition with changes in pH; linear mixed models identified positive correlations with multipleStreptococcusoperational taxonomic units (OTUs) and negative correlations with multiplePrevotellaandPasteurellaceaeOTUs. Few OTUs correlated with mesalamine concentration. The stomach and duodenal microbiota exhibited greater compositional dynamics than the jejunum. Short-term fluctuations in the duodenal microbiota were correlated with pH. Given the unique characteristics and dynamics of the proximal GI tract microbiota, it is important to consider these local environments in health and disease states.IMPORTANCEThe gut microbiota are linked to a variety of gastrointestinal diseases, including inflammatory bowel disease. Despite this importance, microbiota dynamics in the upper gastrointestinal tract are understudied. Our article seeks to understand what factors impact microbiota dynamics in the healthy human upper gut. We found that the upper gastrointestinal tract contains consistently prevalent bacterial OTUs that dominate the overall community. Microbiota variability is highest in the stomach and duodenum and correlates with pH.


2019 ◽  
Vol 13 (10) ◽  
pp. 1265-1272 ◽  
Author(s):  
L Godny ◽  
N Maharshak ◽  
L Reshef ◽  
I Goren ◽  
L Yahav ◽  
...  

Abstract Background Patients with ulcerative colitis [UC] who undergo proctocolectomy with an ileal pouch–anal anastomosis commonly develop pouch inflammation [pouchitis]. Pouchitis develops in a previously normal small intestine and may involve environmental factors. We explored whether diet and microbiota alterations contributed to the pathogenesis of pouchitis. Methods Patients were recruited and prospectively followed at a comprehensive pouch clinic. Pouch behaviour was clinically defined as a normal pouch [NP] or pouchitis. Patients completed Food Frequency Questionnaires [FFQs]. Faecal samples were analysed for microbial composition [16S rRNA gene pyrosequencing]. Results Nutritional evaluation was performed in 172 patients [59% females], and of these, faecal microbial analysis was performed in 75 patients (microbiota cohort: NP [n = 22], pouchitis [n = 53]). Of the entire cohort, a subgroup of 39 [22.6%] patients had NP at recruitment [NP cohort]. Of these, 5 [12.8%] developed pouchitis within a year. Patients at the lowest tertile of fruit consumption [<1.45 servings/day] had higher rates of pouchitis compared with those with higher consumption [30.8% vs 3.8%, log rank, p = 0.03]. Fruit consumption was correlated with microbial diversity [r = 0.35, p = 0.002] and with the abundance of several microbial genera, including Faecalibacterium [r = 0.29, p = 0.01], Lachnospira [r = 0.38, p = 0.001], and a previously uncharacterized genus from the Ruminococcaceae family [r = 0.25, p = 0.05]. Reduction in fruit consumption over time was associated with disease recurrence and with reduced microbial diversity [Δ = –0.8 ± 0.3, p = 0.008]. Conclusions Fruit consumption is associated with modification of microbial composition, and lower consumption was correlated with the development of pouchitis. Thus, fruit consumption may protect against intestinal inflammation via alteration of microbial composition.


2016 ◽  
Vol 62 (6) ◽  
pp. 538-541 ◽  
Author(s):  
Marija Kaevska ◽  
Petra Videnska ◽  
Karel Sedlar ◽  
Iva Bartejsova ◽  
Alena Kralova ◽  
...  

The aim of this study was to determine possible differences in the faecal microbiota of dairy cows infected with Mycobacterium avium subsp. paratuberculosis (Johne’s disease) in comparison with noninfected cows from the same herds. Faecal samples from cows in 4 herds were tested for M. avium subsp. paratuberculosis by real-time PCR, and faecal bacterial populations were analysed by 454 pyrosequencing of the 16S rRNA gene. The most notable differences between shedding and nonshedding cows were an increase in the genus Psychrobacter and a decrease in the genera Oscillospira, Ruminococcus, and Bifidobacterium in cows infected with M. avium subsp. paratuberculosis. The present study is the first to report the faecal microbial composition in dairy cows infected with M. avium subsp. paratuberculosis.


2021 ◽  
Author(s):  
Katie Bull ◽  
Gareth Davies ◽  
Timothy Patrick Jenkins ◽  
Laura Elizabeth Peachey

Abstract BackgroundChanges to the gut microbiota are associated with an increased incidence of disease in many species. This is particularly important during the process of domestication, where captive animals commonly suffer from gastrointestinal (GI) pathology. Horses are a prime example of a species which suffers from a high incidence of (often life-threatening) GI diseases in domesticated environments. We aimed to indentify the gut microbial changes which occur due to domestication in horses by profiling the faecal microbiota of adult female Exmoor ponies under three management conditions, representing increasing levels of domestication.MethodsFaecal samples were collected from 29 adult female Exmoor ponies in the South West of the UK; ponies were categorised as Feral (n=10), Semi-Feral (n=10) and Domesticated (n=9), based on their management conditions; thus controlling for age, gender and random effects between groups. Diet and medication were recorded and faecal samples taken to assess parasite infection. Faecal microbial composition was profiled via high-throughput sequencing of the bacterial 16S rRNA gene.ResultsDownstream biostatistical analysis indicated profound step-wise changes in global microbial community structure in the transition from Feral to Semi-Feral to Domesticated groups. A relatively high abundance of members of the phylum Proteobacteria and Tenericutes were associated with the Domesticated group; and higher levels of Methanobacteria were seen in the Feral group. The Semi-Feral group frequently had intermediate levels of these taxa; however, they also exhibited the greatest ‘within group’ variation in bacterial diversity and parasites burdens. Functional predictions revealed increased amino acid and lipid metabolism in the Domesticated group and increased energy metabolism in the Feral group; supporting a hypothesis that differences in diet was the key driver of gut microbial composition. ConclusionsIf assumed the Feral population has a more natural gut microbial phenotype, akin to that with which horses have evolved, these data can potentially be used to provide microbial signitures of balanced gut homeostasis in horses; which, in turn, will aid prevention of GI disease in domesticated horses.


2019 ◽  
Author(s):  
Shijie Bai ◽  
Xiaotong Peng

Abstract. The microbial diversity and functions of three high-temperature neutral hot springs water samples at different depths (0 m, 19 m and 58 m) were investigated based on 16S rRNA gene sequencing and a functional gene array (GeoChip 5.0). The results revealed that the bacterial communities were distinct at different depths in the hot springs. Additionally, in response to the depths, bacterial/archaeal community compositions exhibited shifts over the depth profiles. Aquificae, Alpha-proteobacteria, and Deinococcus-Thermus were the dominating phyla at 0 m, 19 m, and 58 m, respectively. Hydrogenobacter, Sphingobium, and Thermus were the most abundant genera at 0 m, 19 m, and 58 m, respectively. The phylum Thaumarchaeota was the most abundant member of the archaeal community in the samples at different hot spring depths. Functional results of the microbial communities indicated that microbial metabolic functions were mainly related to sulfur, nitrogen cycling, and hydrogen oxidation. In summary, our results demonstrated that distinct microbial communities and functions were found at different depths of hot springs in a very limited area. These findings will provide new insights into the deep-subsurface biosphere associated with terrestrial hot springs.


2021 ◽  
Vol 5 ◽  
Author(s):  
Sire Diedhiou-Sall ◽  
Komi B. Assigbetsee ◽  
Aminata N. Badiane ◽  
Ibrahima Diedhiou ◽  
M. Khouma ◽  
...  

The Sahel is an ecologically vulnerable region where increasing populations with a concurrent increase in agricultural intensity has degraded soils. Agroforestry offers an approach to remediate these landscapes. A largely unrecognized agroforestry resource in the Sahel are the native shrubs, Piliostigma reticulatum, and Guiera senegalensis that to varying degrees already coexist with row crops. These shrubs improve soil quality, redistribute water from the deep soil to the surface (hydraulic lift), and can improve crop growth. However, little information is available on whether these shrubs affect spatial and temporal dynamics of microbial communities. Therefore, the objective of this study was to determine microbial composition and activity in the wet and dry seasons of soil in the: shrub rhizosphere (RhizS), inter-root zone (IntrS), and outside the influence of shrub soil (OutS) for both G. senegalensis and P. reticulatum in Senegal. A 3 × 2 factorial field experiment was imposed at two locations (490 and 700 mm annual rainfall with G. senegalensis and P. reticulatum, respectively), that had the soil sampling treatments of three locations (RhizS, IntrS, and OutS) and two seasons (wet and dry). Soils were analyzed for: microbial diversity (DGGE with bacterial 16S or fungal 28S rRNA gene sequences phospholipids fatty acid, PLFA); enzyme activities; microbial biomass carbon (MBC); and nitrogen (N) mineralization potential. For the DGGE profiling, the bacterial community responded more to the rhizosphere effect, whereas, the fungal community was more sensitive to season. PLFA, MBC, enzyme activities and inorganic N were significantly higher in both seasons for the RhizS. The presence of shrubs maintained rhizosphere microbial communities and activity during the dry season. This represents a paradigm shift for semi-arid environments where logically it would be expected to have no microbial activity in the extended dry season. In contrast this study has shown this is not the case that rather the presence of shrub roots maintained the microbial community in the dry season most likely due to hydraulic lift and root exudates. This has implications when these shrubs are in cropped fields in that decomposition and mineralization of nutrients can proceed in the dry season. Thus, enabling accumulation of plant available nutrients during the dry season for uptake by crops in the rainy season.


mSphere ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Justinn Renelies-Hamilton ◽  
Kristjan Germer ◽  
David Sillam-Dussès ◽  
Kasun H. Bodawatta ◽  
Michael Poulsen

ABSTRACT A multitude of factors affect the assemblies of complex microbial communities associated with animal hosts, with implications for community flexibility, resilience, and long-term stability; however, their relative effects have rarely been deduced. Here, we use a tractable lab model to quantify the relative and combined effects of parental transmission (egg case microbiome present/reduced), gut inocula (cockroach versus termite gut provisioned), and varying diets (matched or unmatched with gut inoculum source) on gut microbiota structure of hatchlings of the omnivorous cockroach Shelfordella lateralis using 16S rRNA gene (rDNA) amplicon sequencing. We show that the presence of a preexisting bacterial community via vertical transmission of microbes on egg cases reduces subsequent microbial invasion, suggesting priority effects that allow initial colonizers to take a strong hold and which stabilize the microbiome. However, subsequent inoculation sources more strongly affect ultimate community composition and their ecological networks, with distinct host-taxon-of-origin effects on which bacteria establish. While this is so, communities respond flexibly to specific diets in ways that consequently impact predicted community functions. In conclusion, our findings suggest that inoculations drive communities toward different stable states depending on colonization and extinction events, through ecological host-microbe relations and interactions with other gut bacteria, while diet in parallel shapes the functional capabilities of these microbiomes. These effects may lead to consistent microbial communities that maximize the extended phenotype that the microbiota provides the host, particularly if microbes spend most of their lives in host-associated environments. IMPORTANCE When host fitness is dependent on gut microbiota, microbial community flexibility and reproducibility enhance host fitness by allowing fine-tuned environmental tracking and sufficient stability for host traits to evolve. Our findings lend support to the importance of vertically transmitted early-life microbiota as stabilizers, through interactions with potential colonizers, which may contribute to ensuring that the microbiota aligns within host fitness-enhancing parameters. Subsequent colonizations are driven by microbial composition of the sources available, and we confirm that host-taxon-of-origin affects stable subsequent communities, while communities at the same time retain sufficient flexibility to shift in response to available diets. Microbiome structure is thus the result of the relative impact and combined effects of inocula and fluctuations driven by environment-specific microbial sources and digestive needs. These affect short-term community structure on an ecological time scale but could ultimately shape host species specificities in microbiomes across evolutionary time, if environmental conditions prevail.


2019 ◽  
Vol 7 (9) ◽  
pp. 357 ◽  
Author(s):  
Moonsuk Hur ◽  
Soo-Je Park

Heavy metal pollution is a serious environmental problem as it adversely affects crop production and human activity. In addition, the microbial community structure and composition are altered in heavy-metal-contaminated soils. In this study, using full-length 16S rRNA gene sequences obtained by a PacBio RS II system, we determined the microbial diversity and community structure in heavy-metal-contaminated soil. Furthermore, we investigated the microbial distribution, inferred their putative functional traits, and analyzed the environmental effects on the microbial compositions. The soil samples selected in this study were heavily and continuously contaminated with various heavy metals due to closed mines. We found that certain microorganisms (e.g., sulfur or iron oxidizers) play an important role in the biogeochemical cycle. Using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis, we predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) functional categories from abundances of microbial communities and revealed a high proportion belonging to transport, energy metabolism, and xenobiotic degradation in the studied sites. In addition, through full-length analysis, Conexibacter-like sequences, commonly identified by environmental metagenomics among the rare biosphere, were detected. In addition to microbial composition, we confirmed that environmental factors, including heavy metals, affect the microbial communities. Unexpectedly, among these environmental parameters, electrical conductivity (EC) might have more importance than other factors in a community description analysis.


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