Loading...
4 results
Search Results
Now showing 1 - 4 of 4
- Commensal obligate anaerobic bacteria and health: production, storage, and delivery strategiesPublication . Andrade, José Carlos; Almeida, Diana; Domingos, Melany; Seabra, Catarina Leal; Machado, Daniela; Freitas, Ana Cristina; Gomes, Ana MariaIn the last years several human commensals have emerged from the gut microbiota studies as potential probiotics or therapeutic agents. Strains of human gut inhabitants such as Akkermansia, Bacteroides, or Faecalibacterium have shown several interesting bioactivities and are thus currently being considered as food supplements or as live biotherapeutics, as is already the case with other human commensals such as bifidobacteria. The large-scale use of these bacteria will pose many challenges and drawbacks mainly because they are quite sensitive to oxygen and/or very difficult to cultivate. This review highlights the properties of some of the most promising human commensals bacteria and summarizes the most up-to-date knowledge on their potential health effects. A comprehensive outlook on the potential strategies currently employed and/or available to produce, stabilize, and deliver these microorganisms is also presented.
- Nanoprobiotics: when technology meets gut healthPublication . Machado, Daniela; Almeida, Diana; Seabra, Catarina Leal; Andrade, José Carlos; Gomes, Ana Maria; Freitas, Ana CristinaNanotechnology is a fast-rising industry not defined by a single field of research, but as the convergence of disciplines, such as chemistry, biology, physics, mathematics, and engineering, which exploits the benefits of nanoscale dimensions and characteristics for application in the macroworld. Current applications vary widely from nanorobotic industry to simple household items. However, the combination of such phenomena with probiotic science, another emerging and potentially promising area for the prevention and treatment of several human gastrointestinal and extraintestinal disorders using beneficial microorganisms, gives birth to “nanoprobiotics,” a field that focuses on the application of nanoscience into the probiotic-related world. In this chapter, we will navigate through the basic nanotech and probiotic knowledge and the current technologies employed with success for probiotic delivery and, ultimately, discuss what possibilities lie ahead in the nanoprobiotic future.
- Characterization of potential CLA-producing strains according to LA tolerancePublication . Fontes, Ana Luiza; Pimentel, Lígia; Salsinha, Ana Sofia; Cardoso, Beatriz; Andrade, José Carlos; Rodriguéz-Alcalá, Luís Miguel; Gomes, Ana MariaBackground: Conjugated linoleic acid (CLA) isomers are naturally produced from dietary linoleic acid (LA) by ruminal bacteria. However, strains of lactobacilli, bifidobacteria and propionibacteria have also demonstrated the ability to produce those bioactive fatty acids. In vitro studies normally test CLA production at 0.5 mg/mL of LA, but possibly some strains can tolerate higher concentrations and if they are producers, CLA yields may probably be higher. This work aims to determine the maximum LA concentration that potential CLA-producing strains can tolerate in an in vitro production assay. Method: Thirty five lactobacilli, 17 bifidobacteria, 1 propionibacterium and 1 lactococcus strains were submitted to a modified method described by Roméro-Pérez et al. [1]. Activated strains were inoculated in MRS agar plates containing 1, 2 or 5 mg/mL of LA for 48 h at 37 ºC. Strains from the agar plate at the highest LA tolerated concentration were then spiked into MRS broth with LA in a 96-well microplate and subsequently incubated at 37 ºC for 48 h; growth curves were recorded at 600, 620 and 660 nm in a microplate reader. Cultures without substrate were used as control. Agar plates experiment was carried out in duplicate and microplate experiment in triplicate. Results & Conclusions: Among the strains tested, 18 (~33%) could not grow at the lowest LA concentration assayed, having considered their tolerance below 1 mg/mL. A group of 16 strains showed growth at 1 mg/mL of LA, 8 tolerated up to 2 mg/mL and 12 up to 5 mg/mL. At 5 mg/mL lactobacilli was the dominant group, whereas at 2 mg/mL was bifidobacteria. At <1 mg/mL and 1 mg/mL the distribution of lactobacilli and bifidobacteria was similar. The propionibacterium and the lactococcus strains could grow a 1 mg/mL. In conclusion, potential CLA-producing strains exhibit different LA tolerance degrees. This is a parameter to consider in future production tests.
- Evolving trends in next-generation probiotics: a 5W1H perspectivePublication . Almeida, Diana; Machado, Daniela; Andrade, José Carlos; Mendo, Sónia; Gomes, Ana Maria; Freitas, Ana CristinaIn recent years, scientific community has been gathering increasingly more insight on the dynamics that are at play in metabolic and inflammatory disorders. These rapidly growing conditions are reaching epidemic proportions, bringing clinicians and researcher’s new challenges. The specific roles and modulating properties that beneficial/probiotic bacteria hold in the context of the gut ecosystem seem to be key to avert these inflammatory and diet-related disorders. Faecalibacterium prausnitzii, Akkermansia muciniphila and Eubacterium hallii have been identified as candidates for next generation probiotics (NGPs) with exciting potential for the prevention and treatment of such of dysbiosis-associated diseases. The challenges of these non-conventional native gut bacteria lie mainly on their extreme sensitivity to O2 traces. If these strains are to be used successfully in food, supplements or drugs they need to be stable and active in humans. In the present review, we present an overall perspective of the most updated scientific literature on the newly called NGPs through the 5W1H (What, Why, Who, Where, When, and How) method, an innovative and attractive problem-solving approach that provides the reader an effective understanding of the issue at hand.