Gut dysbiosis, inflammation and type 2 diabetes in mice using synthetic gut microbiota from diabetic humans / Disbiose intestinal, inflamação e diabetes tipo 2 em camundongos usando microbiota intestinal sintética de humanos diabéticos

Abstract The study was aimed to assess impact of high fat diet (HFD) and synthetic human gut microbiota (GM) combined with HFD and chow diet (CD) in inducing type-2 diabetes (T2D) using mice model. To our knowledge, this is the first study using selected human GM transplantation via culture based method coupled dietary modulation in mice for in vivo establishment of inflammation leading to T2D and gut dysbiosis. Twenty bacteria (T2D1-T2D20) from stool samples of confirmed T2D subjects were found to be morphologically different and subjected to purification on different media both aerobically and anerobically, which revealed seven bacteria more common among 20 isolates on the basis of biochemical characterization. On the basis of 16S rRNA gene sequencing, these seven isolates were identified as Bacteroides stercoris (MT152636), Lactobacillus acidophilus (MT152637), Lactobacillus salivarius (MT152638), Ruminococcus bromii (MT152639), Klebsiella aerogenes (MT152640), Bacteroides fragilis (MT152909), Clostridium botulinum (MT152910). The seven isolates were subsequently used as synthetic gut microbiome (GM) for their role in inducing T2D in mice. Inbred strains of albino mice were divided into four groups and were fed with CD, HFD, GM+HFD and GM+CD. Mice receiving HFD and GM+modified diet (CD/HFD) showed highly significant (P<0.05) increase in weight and blood glucose concentration as well as elevated level of inflammatory cytokines (TNF-α, IL-6, and MCP-1) compared to mice receiving CD only. The 16S rRNA gene sequencing of 11 fecal bacteria obtained from three randomly selected animals from each group revealed gut dysbiosis in animals receiving GM. Bacterial strains including Bacteroides gallinarum (MT152630), Ruminococcus bromii (MT152631), Lactobacillus acidophilus (MT152632), Parabacteroides gordonii (MT152633), Prevotella copri (MT152634) and Lactobacillus gasseri (MT152635) were isolated from mice treated with GM+modified diet (HFD/CD) compared to strains Akkermansia muciniphila (MT152625), Bacteriodes sp. (MT152626), Bacteroides faecis (MT152627), Bacteroides vulgatus (MT152628), Lactobacillus plantarum (MT152629) which were isolated from mice receiving CD/HFD. In conclusion, these findings suggest that constitution of GM and diet plays significant role in inflammation leading to onset or/and possibly progression of T2D. .

Resumo O estudo teve como objetivo avaliar o impacto da dieta rica em gordura (HFD) e da microbiota intestinal humana sintética (GM) combinada com HFD e dieta alimentar (CD) na indução de diabetes tipo 2 (T2D) usando modelo de camundongos. Para nosso conhecimento, este é o primeiro estudo usando transplante de GM humano selecionado através do método baseado em cultura acoplada à modulação dietética em camundongos para o estabelecimento in vivo de inflamação que leva a T2D e disbiose intestinal. Vinte bactérias (T2D1-T2D20) de amostras de fezes de indivíduos T2D confirmados verificaram ser morfologicamente diferentes e foram submetidas à purificação em meios diferentes aerobicamente e anaerobicamente, o que revelou sete bactérias mais comuns entre 20 isolados com base na caracterização bioquímica. Com base no sequenciamento do gene 16S rRNA, esses sete isolados foram identificados como Bacteroides stercoris (MT152636), Lactobacillus acidophilus (MT152637), Lactobacillus salivarius (MT152638), Ruminococcus bromii (MT152639), Klebsiella aerogenides (MT152640), Bacteroides fragilis (MT152909), Clostridium botulinum (MT152910). Esses sete isolados foram, posteriormente, usados ​​como microbioma intestinal sintético (GM) por seu papel na indução de T2D em camundongos. Linhagens consanguíneas de camundongos albinos foram divididas em quatro grupos e foram alimentadas com CD, HFD, GM + HFD e GM + CD. Camundongos que receberam a dieta modificada com HFD e GM + (CD / HFD) mostraram um aumento altamente significativo (P < 0,05) no peso e na concentração de glicose no sangue, bem como um nível elevado de citocinas inflamatórias (TNF-α, IL-6 e MCP-1) em comparação com os ratos que receberam apenas CD. O sequenciamento do gene 16S rRNA de 11 bactérias fecais obtidas de três animais selecionados aleatoriamente de cada grupo revelou disbiose intestinal em animais que receberam GM. Cepas bacterianas, incluindo Bacteroides gallinarum (MT152630), Ruminococcus bromii (MT152631), Lactobacillus acidophilus (MT152632), Parabacteroides gordonii (MT152633), Prevotella copri (MT152634) e Lactobacillus Gasseri (MT152635D), foram tratadas com dieta modificada / CD) em comparação com as linhagens Akkermansia muciniphila (MT152625), Bacteriodes sp. (MT152626), Bacteroides faecis (MT152627), Bacteroides vulgatus (MT152628), Lactobacillus plantarum (MT152629), que foram isoladas de camundongos recebendo CD / HFD. Em conclusão, esses resultados sugerem que a constituição de GM e dieta desempenham papel significativo na inflamação levando ao início ou/e possivelmente à progressão de T2D.

The use of Prevotella bryantii 3C5 for modulation of the ruminal environment in an ovine model

In the Southern Hemisphere, ruminants are mostly raised in grazing systems where animals consume forage and are supplemented with low amounts of concentrates. Concentrates are usually given separately and are rapidly ingested. This practice leads to changing rumen environment conditions during the day, may alter the rumen microbial metabolism and could affect host performance. The native ruminal Prevotella bryantii strain 3C5 was administered every 48 h to wethers under experimental conditions simulating Southern-Hemisphere feeding to evaluate its potential as a rumen fermentation modulator. The inoculum potential was assessed on day 17. The ammonia nitrogen (NH3-N), volatile fatty acids and ruminal pH were monitored on a 24-h basis 19 days after the beginning of the experiment, and the microbial community structure was assessed by pyrosequencing. The administration of P. bryantii modified the fermentation products and daily pH values compared to the control. The NH3-N concentration in the rumen of treated animals was significantly higher than that of the untreated animals. Modification of the ruminal environment and fermentation pathways was achieved without altering the general structure of the microbial community or the potential methane production. P. bryantii 3C5 could be considered in potential probiotic formulations for ruminants in semi-intensive systems.(AU)

Presence of Porphyromonas and Prevotella species in the oral microflora of cattle with periodontitis / Presença de espécies de Porphyromonas e Prevotella na microbiota oral de bovinos com periodontite

Bovine periodontitis is a progressive purulent infectious process associated with the presence of strictly and facultative anaerobic subgingival biofilm and epidemiologically related to soil management in large geographic areas of Brazil. This study aimed to detect species of the genera Porphyromonas and Prevotella, which occurr in periodontal pockets of cattle with lesions deeper than 5mm (n=26) and in gingival sulcus of animals considered periodontally healthy (n=25). Presence of the microorganisms was evaluated by independent-culture medium diagnostic method, using polymerase chain reaction (PCR) with specific primers of Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melaninogenica, P. nigrescens, P. oralis and P. tannerae. The species P. endodontalis (80.7%), P. melaninogenica (73.1%) and P. intermedia (61.5%) were the most predominant in samples of cattle with periodontitis. Regarding non-injured gingival sulcus of cattle, P. endodontalis (40%) and P. loeschei (40%) prevailed. Porphyromonas gingivalis, P. gulae and Prevotella tannerae were not detected in the 51 samples studied. Data evaluation by T test, enabled to verify that ocorrence of Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melaninogenica (p=0.00006) and P. oralis (p=0.0028) is correlated with bovine periodontitis.(AU)

A periodontite bovina é um processo infeccioso purulento e progressivo associado à presença de biofilme subgengival anaeróbio estrito e facultativo e de incidência em extensas áreas geográficas do Brasil. O trabalho teve por objetivo detectar espécies dos gêneros Porphyromonas e Prevotella presentes na bolsa periodontal de bovinos com lesões de profundidade maior que 5mm (n=26) e do sulco gengival de animais com idade de 6 a 24 meses e considerados periodontalmente sadios (n=25). A presença dos microrganismos foi avaliada pelo método independente de cultivo bacteriano, por meio da reação em cadeia da polimerase (PCR) com iniciadores específicos para Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melalinogenica, P. nigrescens, P. oralis e P. tannerae. P. endodontalis (80,7%), P. melalinogenica (73,1%) e P. intermedia (61,5%) foram os mais prevalentes nas amostras de bovinos com periodontite. Já no sulco gengival de bovinos sem lesões prevaleceram P. endodontalis (40%) e P. loeschei (40%). Porphyromonas gingivalis, P. gulae e Prevotella tannerae não foram detectados nas 51 amostras pesquisadas. A partir da avaliação dos dados pelo teste T, verificou-se que a ocorrência de Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melalinogenica (p=0.00006) e P. oralis (p=0.0028) está associada à periodontite bovina.(AU)