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1.
J Diet Suppl ; : 1-11, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38186311

RESUMEN

Irritable bowel syndrome (IBS) is a functional gastrointestinal condition. Probiotics and other nutraceutical compounds can have specific indications in the context of IBS. A retrospective analysis was conducted on 123 IBS patients in order to evaluate the effects of an oral probiotic-based dietary supplement (Colicron, one cps/day for 4 wk) on stool consistency and pain intensity. Different time points were defined as follows: baseline (T0), 2 wk of treatment (T2), and 4 wk of treatment (T4). Stool consistency was assessed by using the Bristol Stool Scale. Pain intensity was evaluated by the Visual Analogue Scale (VAS). Patients who were initially categorized as normal retained regular bowel movements throughout the study. Both patients with constipation and diarrhea showed an improvement in the Bristol Stool Scale. The score increased from 1.5 ± 0.5 to 3.3 ± 0.7 (p < 0.001) and decreased from 6.5 ± 0.7 to 4.3 ± 0.9 (p < 0.001) at T4, respectively, compared to T0. The VAS score for pain in the pooled IBS patients improved from 6.7 ± 2.2 to 2.8 ± 1.9 at T0 vs T4 (p < 0.001), with a similar trend also observed when patients were categorized based on stool consistency: normal (from 5.2 ± 1.9 to 2.9 ± 1.7), constipation (from 7.5 ± 1.3 to 3.2 ± 2.2), and diarrhea (6.7 ± 2.3 to 2.5 ± 1.9) (p < 0.001).Colicron could be useful in symptom relief, reducing abdominal pain and improving stool consistency of IBS patients. However, further controlled clinical trials are needed to confirm these preliminary findings.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38240683

RESUMEN

BACKGROUND: Irritable bowel syndrome (IBS) is a chronic disorder with an important impact on patients' quality of life. Although several data indicate that psychological symptoms are frequently reported by patients with IBS, few therapies have been evaluated regarding these issues. METHODS: A retrospective observational study was conducted to evaluate the effectiveness of a probiotic-based dietary supplement (Colicron®) in a group of patients with diarrhea-predominant IBS (IBS-D). We included patients treated with Colicron® (1 cps/day for 8 weeks). Primary endpoint was the gastrointestinal symptoms' remission evaluated by Visual Analogue Scale (VAS); secondary endpoint was the impact of the treatment on physical and mental health evaluated by Hospital Anxiety and Depression Score (HADS) and Short Form Health Survey 36 (SF-36). VAS was assessed at week 4 (T4), week 8 (T8) and week 12 (T12), whereas HADS and SF-36 were performed even at the start of the Colicron® treatment (T0). RESULTS: An improvement of VAS Score was observed at T8 (P<0.001) and T12 (P<0.05) compared to T4. Lower HADS-A (anxiety subdomain) score was obtained at each time point versus T0 (P<0.01), and higher scores of all SF-36 domains were observed during the treatment (0.05

3.
Microbiol Spectr ; 10(3): e0276021, 2022 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-35467410

RESUMEN

Streptococcus thermophilus is widely used in the dairy industry for the manufacturing of fermented milk and cheeses and probiotic formulations. S. thermophilus evolved from closely phylogenetically related pathogenic streptococci through loss-of-function events counterbalanced by the acquisition of relevant traits, such as lactose and urea utilization for the adaptation to the milk environment. In the context of regressive evolution, the urease gene cluster accounts for 0.9% of the total coding sequence belonging to known functional categories. The fate of ammonia and carbon dioxide derived by urea hydrolysis in several biosynthetic pathways have been depicted, and the positive effect of urease activity on S. thermophilus growth fitness and lactic acid fermentation in milk has been already addressed by several authors. However, the mechanistic effect of urea hydrolysis on the energetic metabolisms of S. thermophilus is still unclear. This study aimed to assess the effect of urease activity on the growth and energy metabolism of Streptococcus thermophilus in milk. In milk, 13C-urea was completely hydrolyzed in the first 150 min of S. thermophilus growth, and urea hydrolysis was accompanied by an increase in cell density and a reduction in the generation time. By using energetically discharged cells with gene transcription and translation blocked, we showed that in the presence of fermentable carbon sources, urease activity, specifically the production of ammonia, could dramatically boost glycolysis and, in cascade, homolactic fermentation. Furthermore, we showed that ammonia, specifically ammonium ions, were potent effectors of phosphofructokinase, a key glycolytic enzyme. IMPORTANCE Finding that ammonia-generating enzymes, such as urease, and exogenous ammonia act on phosphofructokinase activity shed new light on the regulatory mechanisms that govern glycolysis. Phosphofructokinase is the key enzyme known to exert a regulatory role on glycolytic flux and, therefore, ammonia as an effector of phosphofructokinase acts, in cascade, modulating the glycolytic pathway. Apart from S. thermophilus, due to the high conservation of glycolytic enzymes in all branches of the tree of life and being aware of the role of ammonia as an effector of phosphofructokinase, we propose to reevaluate the physiological role of the ammonia production pathways in all organisms whose energy metabolism is supported by glycolysis.


Asunto(s)
Streptococcus thermophilus , Ureasa , Amoníaco/metabolismo , Fermentación , Glucólisis , Concentración de Iones de Hidrógeno , Hidrólisis , Fosfofructoquinasas/metabolismo , Streptococcus thermophilus/genética , Urea/metabolismo , Ureasa/genética , Ureasa/metabolismo
4.
Front Microbiol ; 9: 2719, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30473689

RESUMEN

Streptococcus thermophilus DSM 20167T showed autolytic behavior when cultured in lactose- and sucrose-limited conditions. The amount of cell lysis induced was inversely related to the energetic status of the cells, as demonstrated by exposing cells to membrane-uncoupling and glycolysis inhibitors. Genome sequence analysis of strain DSM 20617T revealed the presence of a pac-type temperate bacteriophage, designated Φ20617, whose genomic organization and structure resemble those of temperate streptococcal bacteriophages. The prophage integrated at the 3'-end of the gene encoding the glycolytic enzyme enolase (eno), between eno and the lipoteichoic acid synthase-encoding gene ltaS, affecting their transcription. Comparative experiments conducted on the wild-type strain and a phage-cured derivative strain revealed that the cell-wall integrity of the lysogenic strain was compromised even in the absence of detectable cell lysis. More importantly, adhesion to solid surfaces and heat resistance were significantly higher in the lysogenic strain than in the phage-cured derivative. The characterization of the phenotype of a lysogenic S. thermophilus and its phage-cured derivative is relevant to understanding the ecological constraints that drive the stable association between a temperate phage and its bacterial host.

5.
Front Microbiol ; 8: 1095, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28663745

RESUMEN

Despite studies of viromes isolated from aquatic environments are becoming increasingly frequent, most of them are limited to the characterization of viral taxonomy. Bacterial reads in viromes are abundant but the extent to which this genetic material is playing a role in the ecology of aquatic microbiology remains unclear. To this aim, we developed of a useful approach for the characterization of viral and microbial communities of aquatic environments with a particular focus on the identification of microbial genes harbored in the viromes. Virus-like particles were isolated from water samples collected across the Lambro River, from the spring to the high urbanized Milan area. The derived viromes were analyzed by shotgun metagenomic sequencing looking for the presence, relative abundance of bacterial genes with particular focus on those genes involved in antimicrobial resistance mechanisms. Antibiotic and heavy metal resistance genes have been identified in all virome samples together with a high abundance of reads assigned to cellular processes and signaling. Virome data compared to those identified in the microbiome isolated from the same sample revealed differences in terms of functional categories and their relative abundance. To verify the role of aquatic viral population in bacterial gene transfer, water-based mesocosms were perturbed or not perturbed with a low dose of tetracycline. The results obtained by qPCR assays revealed variation in abundance of tet genes in the virome and microbiome highlighting a relevant role of viral populations in microbial gene mobilization.

6.
Int J Food Microbiol ; 247: 55-64, 2017 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-26826763

RESUMEN

The proto-cooperation between Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in the yogurt consortium enhances the growth rate and size of each population. In contrast, the independent growth of the two species in milk leads to a slower growth rate and a smaller population size. In this study, we report the first evidence that the urease activity of S. thermophilus increases the intracellular pH of L. delbrueckii in the absence of carbon source. However, in milk, in the presence of lactose the alkalizing effect of urea-derived ammonia was not detectable. Nevertheless, based on glucose consumption and lactic acid production at different pHin, L. delbrueckii showed an optimum of glycolysis and homolactic fermentation at alkaline pH values. In milk, we observed that ammonia provided by urea hydrolysis boosted lactic acid production in S. thermophilus and in L. delbrueckii when the species were grown alone or in combination. Therefore, we propose that urease activity acts as an altruistic cooperative trait, which is costly for urease-positive individuals but provides a local benefit because other individuals can take advantage of urease-dependent ammonia release.


Asunto(s)
Proteínas Bacterianas/metabolismo , Ácido Láctico/biosíntesis , Lactobacillus delbrueckii/metabolismo , Streptococcus thermophilus/enzimología , Ureasa/metabolismo , Animales , Proteínas Bacterianas/genética , Fermentación , Lactobacillus delbrueckii/genética , Lactobacillus delbrueckii/crecimiento & desarrollo , Leche/microbiología , Streptococcus thermophilus/genética , Streptococcus thermophilus/crecimiento & desarrollo , Ureasa/genética , Yogur/microbiología
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