Browsing by Subject "intestinal microbiota"

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  • Suutarinen, Maiju (Helsingin yliopisto, 2019)
    Imbalance of intestinal microbiota is called dysbiosis. Signs of dysbiosis are altered abundance of different bacterial species and reduced diversity together with altered interactions between bacterial species and microbiota and the host. Dysbiosis of intestinal microbiota is connected to many intestinal diseases and today many studies are focused to find so called “next generation” probiotics to be used for the alleviation of dysbiosis instead of traditional antibiotic treatments. The study was made in the Human Microbiome Research Program, Faculty of Medicine, University of Helsinki. Aim of the study was to isolate spore-forming bacterial species for the treatment of intestinal inflammation and infections with bacterial therapy. For this purpose, feces from a healthy adult who had acted as a donor for fecal microbiota transplantation was used to isolate spore-forming commensal bacteria. The isolated bacteria were identified and their ability to adhere into intestinal epithelium and strengthen it was investigated. Also anti-inflammatory potential of these isolated bacterial strains was investigated. For isolating bacteria three different heat treatments and ethanol and methanol treatments were used as a pre-treatment step. Pre-treated samples were cultivated on YCFA-media and isolates were picked from plates at different growth points for further cultivation. Selected isolates were purified, their DNA was isolated and they were identified by partial 16S rRNA -gene sequencing. From these identified isolates four isolates were chosen for further investigation and their full length 16S rRNA -gene was sequenced. These isolates were studied also by using API and aerotolerance tests. Potential anti-inflammatory and adhesion properties of the isolates were investigated by attenuation, adhesion and TER-experiments. In the isolation, the effect of different pre-treatments on the recovery of isolates was clear and based on sequencing isolates that were spore-forming anaerobic bacteria were selected for further investigation. Three of the isolates were Clostridium butyricum and one Blautia wexlerae species. Anti- and pro-inflammatory properties of these isolates were very different depending on isolate and one of them was potentially anti-inflammatory. Isolates also adhered differentially and two of them possibly strengthened gut epithelial barrier so they are promising for further research and in the future investigation with these isolates continues. Experience and results with different cultivation methods can be used to for further development of cultivation for anaerobic intestinal bacteria.
  • Jouhten, Hanne; Ronkainen, Aki; Aakko, Juhani; Salminen, Seppo; Mattila, Eero; Arkkila, Perttu; Satokari, Reetta (2020)
    Fecal microbiota transplantation (FMT) is an effective treatment for recurrentClostridioides difficileinfection (rCDI) and it's also considered for treating other indications. Metagenomic studies have indicated that commensal donor bacteria may colonize FMT recipients, but cultivation has not been employed to verify strain-level colonization. We combined molecular profiling ofBifidobacteriumpopulations with cultivation, molecular typing, and whole genome sequencing (WGS) to isolate and identify strains that were transferred from donors to recipients. SeveralBifidobacteriumstrains from two donors were recovered from 13 recipients during the 1-year follow-up period after FMT. The strain identities were confirmed by WGS and comparative genomics. Our results show that specific donor-derived bifidobacteria can colonize rCDI patients for at least 1 year, and thus FMT may have long-term consequences for the recipient's microbiota and health. Conceptually, we demonstrate that FMT trials combined with microbial profiling can be used as a platform for discovering and isolating commensal strains with proven colonization capacity for potential therapeutic use.
  • Huurinainen, Outi (Helsingfors universitet, 2009)
    Microbiota inhabiting the colon fermentate carbohydrates, proteins and endogenous substrates to volatile fatty acids (VFA) and produce energy for the microbial growth. Because all species of bacteria ferment some component of the digesta and produce various VFAs, alterations in microflora may modify these fermentative end products. Thus, measuring the amount and type of VFA produced gives an instrument which reflects changes in the bacterial microbiota of the intestine. This study set out to explain the connections between diet composition and the formation of VFAs. The general hypothesis was that different food compositions cause differences in the VFA profile, and this may have systemic effect on animal health. Graeco Latin Square design study with 5 healthy Beagles was performed, feeding high protein (diet A, starch 54 g/kg, crude protein 609 g/kg), high carbohydrate (diet B, starch 438 g/kg, crude protein 194 g/kg), and a balanced commercial (diet C, starch 277 g/kg, crude protein 264 g/kg) diets for three weeks each. The diet C was used also for the baseline. VFA, fecal dry matter and fecal consistency score were assessed. All dogs had formed feces during diets B and C but diarrhea during diet A, leading to significant differences in fecal consistency score between the diets (p < 0.0001). The results indicate that alterations in diet had a large influence on the amount and quality of VFAs produced. Mixed-effect model analysis shows that the diets had a statistically significant (p<0.05) influence on all of the VFAs produced excluding butyric acid. The most significant changes from the baseline diet were seen with the high protein diet. Compared to the baseline diet, valeric acid production increased 24-fold, isobutyric acid by 79.5% and isovaleric acid by 42.4 %. Production of propionic acid decreased by 43.3%, acetic acid by 25.0%, and butyric acid by 10.2 %. In previous studies similar changes in VFA profile have been coupled with various intestinal diseases as well as inhibition in biotin absorption. Furthermore, this might have an influence on inflammatory response at the cellular level. Thus, changes in VFA profile may have an influence at least on the local intestinal health. The total amount of fatty acids decreased on both experimental diets. It seems that having moderate protein and carbohydate levels in the diet is a virtue and more is not necessarily better. This study provides additions to existing understanding of the relationship between diet composition and the formation of VFAs in the intestine. The findings suggest that observing the alterations in VFA levels formed in the intestine and therefore present in feces, may provide an instrument to indirectly observe changes in the bacterial microbiota of the intestine. Thus, there is a need to find the link between the changes in VFA profiles and colonic microbiota, and bacterial diversity in feces by using molecular methods. Having this greater level of understanding would lead to more robust insights into the role of intestinal microbiota in animal health, and to potential advances in the prevention and curing of related diseases.
  • Konig, Emilia; Sali, Virpi; Heponiemi, Paulina; Salminen, Seppo; Valros, Anna; Junnikkala, Sami; Heinonen, Mari (2021)
    Simple Summary Selection for hyper-prolific sows has led to increased litter size, decreased birth weight, and increased within-litter variation. This is accompanied by impaired colostrum intake of piglets and poor performance. We aimed to investigate the total count of fecal lactobacilli and species diversity in growing pigs on two herds. Study pigs were categorized either small or large according to their birth weight. Sow colostrum quality and colostrum supply of piglets were determined. We hypothesized that the birth weight and growth performance of pigs are associated with fecal lactobacilli composition, which is influenced by colostrum. Small pigs had higher lactobacilli counts in both herds, but the difference was significant only for one herd (p = 0.01). Colostrum quality was numerically better in the herd that appeared also better managed in comparison to the other study herd. Colostrum intake tended to be significantly associated with the total lactobacilli count in the better-managed herd. In conclusion, herd-level factors clearly contribute to the microbiota of pigs, but birth weight also plays a potential role in the gastrointestinal tract lactobacilli dynamics. Our results revealed a potential long-term effect of colostrum, and therefore give a reason to investigate more thoroughly the associations between maternal immunity, pig microbiota, and performance. We studied the fecal lactobacilli count and species diversity of growing pigs along with immune parameters associated with intestinal lactobacilli. Thirty pigs categorized as small (S, n = 12) or large (L, n = 18) at birth were followed from birth to slaughter in two commercial herds, H1 and H2. Herds differed in terms of their general management. We determined sow colostrum quality, colostrum intake, piglet serum immunoglobulins, and pig growth. We took individual fecal samples from pigs in the weaning and finishing units. We studied lactobacilli count and identified their diversity with 16S PCR. Total lactobacilli count increased in H1 and decreased in H2 between samplings. Lactobacilli species diversity was higher in H1 in both fecal sampling points, whereas diversity decreased over time in both herds. We identified altogether seven lactobacilli species with a maximum of five (one to five) species in one herd. However, a relatively large proportion of lactobacilli remained unidentified with the used sequencing technique. Small pigs had higher lactobacilli counts in both herds but the difference was significant only in H2 (p = 0.01). Colostrum quality was numerically better in H1 than in H2, where colostrum intake tended to be associated with total lactobacilli count (p = 0.05).
  • Jian, Ching (Helsingfors universitet, 2016)
    Non-alcoholic fatty liver disease (NAFLD) is currently the most common liver disease in the western world. The human intestinal microbiota possesses enormous metabolic and immunomodulatory capabilities, and together with increased intestinal permeability, changes in the microbiota have been linked to the development of NAFLD. However, human studies so far have yielded contradictory findings regarding the compositional microbiota changes and provided little mechanistic understanding due to the predominance of cross-sectional studies. The aim of this study was to study human intestinal microbiota and gut permeability in NAFLD. Real-time PCR was employed to quantify the key intestinal bacterial groups in overweight or obese subjects with (n = 12) and without (n = 19) NAFLD, and in response to hypercaloric overfeeding, where participants were provided with three compositionally distinct diets to temporarily increase liver fat. In addition to the comparative analysis, the microbiota results were correlated to serum markers of intestinal permeability and metabolic endotoxemia, as well as clinical parameters related to NAFLD. The results show that host lipid metabolism and the gut microbiota, specifically Bacteroidetes and Clostridium cluster XIVa, are firmly intercorrelated. Bacteroidetes were found to be less abundant in subjects with NAFLD and correlate negatively with liver fat and serum triglycerides at baseline. Clostridium cluster XIVa, a dominant Firmicute group, was positively associated with serum triglycerides and pro-inflammatory markers but negatively with intestinal permeability. The relative abundance of Bacteroidetes as well as the markers of metabolic endotoxemia changed significantly in response to overfeeding, while no diet-induced systematic effects were found in Clostridium cluster XIVa, total bacteria, Escherichia coli group, Bifidobacterium or gut permeability. Our results based on a targeted microbiota analysis suggest that the role of the intestinal microbiota and gut permeability on triggering metabolic disarrangement and NAFLD in humans is inferior to other stimuli, such as diet.
  • Niinimäki, Viola (Helsingfors universitet, 2013)
    The aim of this research was to investigate the effects of two different probiotics on intestinal microbiota and secretory immunoglobulin A (sIgA) in healthy, well-trained adults from Canberra, Australia. Master thesis work was performed as a part of a clinical, placebo-controlled double-blind test, which aimed to investigate the ability of probiotics to improve immunity and reduce the risk of respiratory tract infections in above-mentioned group. Also research aimed to find out the possible correlation between health effects, changes in intestinal microbiota and sIgA. A hypothesis of this work is that amounts of probiotic L. acidophilus NCFM, B. lactis Bi-07, B. lactis Bl-04 strains, Bifidobacterium and Lactobacillus species will arise during intervention in groups using probiotics. A number of potentially pathogenic Clostridium cluster XIVab and Enterococcus species will decrease, whereas amounts of secretory IgA will supposedly grow towards the end of intervention. The total number of intestinal bacteria will presumably remain relatively stable. Totally 450 subjects participated in the study and 120 of them gave samples for microbiological and immunological analyses of this work. Intervention was performed in winter season and continued for 150 days. Flow cytometry was used to investigate the total number of intestinal bacteria and quantitative PCR (qPCR) was used to investigate the changes in intestinal microbiota respectively. Sandwich-ELISA was used study changes in sIgA concentrations. The total number of intestinal bacteria was typical for the large intestine and remained stable between time-points. The changes in amounts of sIgA and intestinal bacterial groups weren’t statistically significant in any group. The numbers of bacterial groups studied by qPCRmethod were also normal. Although the results for intestinal microbiota and secretory IgA weren’t statistically significant, a clinical part associated with this research showed that both probiotics reduced the frequency of lower respiratory tract infections and use of medicines. However, B. lactis Bl-04 strain was more effective in preventing upper respiratory tract infections in studied population. Intestinal microbiota and secretory IgA weren’t probably important parameters in the assessment of probiotic effects on respiratory tract infections in healthy, well-trained adults. The reliability of results for this work could be improved by adding the number of subjects and time-points.