Influence of raw milk microflora and starter cultures in cheese on protein hydrolysis and peptide generation during digestion

Do bacterial strains in cheese have an impact on the protein hydrolysis during human digestion, and if so, does a higher microbial diversity lead to the generation of a higher number of different peptides after digestion?Cheese bacteria are responsible for the hydrolysis of proteins already during cheese ripening. These bacterial cultures are introduced at different steps of the cheese manufacturing process. First, the raw milk flora that is dependent on the milk heat treatment before the cheese manufacturing process, is a major source of a variety of bacteria. Second, starter cultures, needed for a successful acidification of the cheese curd are added to prevent side fermentations. Third, addition of cultures is made for improving flavor or accelerating the ripening process, depending on the type of cheese. Because of bacterial proteolytic activity, proteins in cheese are partially hydrolyzed, depending on the ripening time and are further digested by gastric and pancreatic proteases, after consumption, to the level of small peptides and free amino acids. In order to elucidate possible differences in proteolysis depending on the presence of different bacteria, Swiss Raclette cheeses were produced either from raw or pasteurized milk with or without addition of a proteolytic bacterial strains (Lactobacillus helveticus) and ripened during 120 days.The microbial diversity and the relative abundance of specific strains in the different cheeses was assessed after 24 hours, 80 and 120 days of cheese ripening by sequencing the hypervariable regions V1-V2 of the 16S rRNA genes. Moreover, protein hydrolysis in the different cheeses was analyzed with gel electrophoresis, mass spectrometry, and HPLC after in vitro digestion, applying a static (Infogest) and a dynamic (DIDGI®) oro-gastrointestinal in vitro digestion protocol. In order to gain information on the influence of bacterial strains on protein hydrolysis, the 16s meta-genomic and 16s meta-transcriptomic results were correlated with protein and peptide patterns

RAMÓN, PEDRO [Material gráfico]

SRA. DECopia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

Episodic Memory and Appetite Regulation in Humans

Psychological and neurobiological evidence implicates hippocampal-dependent memory processes in the control of hunger and food intake. In humans, these have been revealed in the hyperphagia that is associated with amnesia. However, it remains unclear whether 'memory for recent eating' plays a significant role in neurologically intact humans. In this study we isolated the extent to which memory for a recently consumed meal influences hunger and fullness over a three-hour period. Before lunch, half of our volunteers were shown 300 ml of soup and half were shown 500 ml. Orthogonal to this, half consumed 300 ml and half consumed 500 ml. This process yielded four separate groups (25 volunteers in each). Independent manipulation of the 'actual' and 'perceived' soup portion was achieved using a computer-controlled peristaltic pump. This was designed to either refill or draw soup from a soup bowl in a covert manner. Immediately after lunch, self-reported hunger was influenced by the actual and not the perceived amount of soup consumed. However, two and three hours after meal termination this pattern was reversed - hunger was predicted by the perceived amount and not the actual amount. Participants who thought they had consumed the larger 500-ml portion reported significantly less hunger. This was also associated with an increase in the 'expected satiation' of the soup 24-hours later. For the first time, this manipulation exposes the independent and important contribution of memory processes to satiety. Opportunities exist to capitalise on this finding to reduce energy intake in humans

Differential effects of hunger and satiety on insular cortex and hypothalamic functional connectivity

The insula cortex and hypothalamus are implicated in eating behaviour, and contain receptor sites for peptides and hormones controlling energy balance. The insula encompasses multi-functional subregions, which display differential anatomical and functional connectivities with the rest of the brain. This study aimed to analyse the effect of fasting and satiation on the functional connectivity profiles of left and right anterior, middle, and posterior insula, and left and right hypothalamus. It was hypothesized that the profiles would be altered alongside changes in homeostatic energy balance. Nineteen healthy participants underwent two 7-min resting state functional magnetic resonance imaging scans, one when fasted and one when satiated. Functional connectivity between the left posterior insula and cerebellum/superior frontal gyrus, and between left hypothalamus and inferior frontal gyrus was stronger during fasting. Functional connectivity between the right middle insula and default mode structures (left and right posterior parietal cortex, cingulate cortex), and between right hypothalamus and superior parietal cortex was stronger during satiation. Differences in blood glucose levels between the scans accounted for several of the altered functional connectivities. The insula and hypothalamus appear to form a homeostatic energy balance network related to cognitive control of eating; prompting eating and preventing overeating when energy is depleted, and ending feeding or transferring attention away from food upon satiation. This study provides evidence of a lateralized dissociation of neural responses to energy modulations

Thick and yellowish articular effusion: a challenging diagnosis! Focus on cholesterol crystal deposition in joint

International audienc

Performance of a new rapid diagnostic test the lactate/glucose ratio of synovial fluid for the diagnosis of septic arthritis

International audienceObjective - To evaluate the diagnostic performance of the synovial lactate, glucose and lactate/glucose ratio assay for the diagnosis of septic arthritis. Methods - In this monocentric cross-sectional study, synovial fluids were prospectively obtained from patients with acute joint effusion (<30 days) on native joint. Septic arthritis was defined using Newman's criteria. To evaluate diagnostic performance, Receiver Operating Characteristic (ROC) curves with Area under the curve (AUC), Sensitivities (Se), Specificities (Sp), LR+ their 95% confidence intervals were calculated. Synovial fluid cultures with gram staining, crystal analyses, synovial fluid white blood cell counts (WBC), lactate and glucose assays were performed. Results - A total of 233 synovial fluids were included. 25 patients had septic arthritis and 208 had non-septic arthritis (104 crystal-induced arthritis, 15 RA, 8 SpA, 6 reactive arthritis, and 75 acute arthritis of undifferentiated origin). Synovial lactate/glucose ratio performed higher than the synovial lactate or glucose assay separately (AUC: 0.859 [0.772-0.945]). Best synovial lactate/glucose ratio threshold to differentiate septic arthritis from non-septic arthritis was 5 Se 52% [0.34-0.7], Sp 98.1% [0.95-0.99], LR+ 27.0[9.50-76.00]). Conclusion - The diagnostic performance of synovial lactate/glucose allows septic arthritis to be effectively and very quickly distinguished from other types of arthritis

SARS-CoV-2, polymyalgia rheumatica and giant cell arteritis: COVID19 vaccine shot as a trigger? Comment on :Can SARS-CoV-2 trigger relapse of polymyalgia rheumatica?&quot; by Manzo et al. Joint Bone Spine 2021;88:105150

International audienc

Elaboration of a new synovial predictive score of septic origin for acute arthritis on the native joint (RESAS)

International audienceOBJECTIVE: To establish a new predictive score for the diagnosis of septic arthritis (SA) according to different synovial fluid (SF) variables. METHODS: First, we analysed the different clinical, biological and SF variables associated with the diagnosis of SA (according to the Newman’s criteria) in a monocentric cohort of acute arthritis (&lt;30 days) (n = 233) (SYNOLACTATE cohort). A new score predictive of SA (RESAS) was created using the independent discriminant variables after multivariate analysis. A value was attributed to each variable of the score according to the weighting based on their likelihood ratio for the diagnosis of SA. RESAS performance was then tested on the first cohort (internal validation) and then checked on a second independent cohort (n = 70) (external validation). RESULTS: After multivariate analysis, four independent variables of the SF were included for RESAS: (i) purulent SF or white blood cells count ≥70 000/mm3; (ii) absence/presence of crystals; (iii) lactate; and (iv) glucose synovial level. RESAS ranged between -4 and +13 points. The performance of RESAS to predicted SA was excellent with area under the curve (AUC)=0.928 (0.877-0.980) in internal validation and AUC=0.986 (0.962-1.00) in external validation. For a RESAS threshold ≥+4, SA was diagnosed with Se=56.0% (0.371-0.733), Sp=98.1% (0.952-0.993), LR+=29.1 (10.4-81.6) in the first cohort and with Se=91.7% (0.646-0.985), Sp=98.3% (0.909-0.997), LR+=53.2 (7.56-373) in the second cohort. CONCLUSION: RESAS is a new composite score of four SF variables with excellent performance to predicted SA in acute arthritis population

Higher microbial diversity in raw than in pasteurized milk Raclette-type cheese enhances peptide and metabolite diversity after in vitro digestion

International audienceNumerous bacteria are responsible for hydrolysis of proteins during cheese ripening. The raw milk flora is a major source of bacterial variety, starter cultures are needed for successful acidification of the cheese and proteolytic strains like Lactobacillus helveticus, are added for flavor improvement or acceleration of ripening processes. To study the impact of higher bacterial diversity in cheese on protein hydrolysis during simulated human digestion, Raclette-type cheeses were produced from raw or heat treated milk, with or without proteolytic L. helveticus and ripened for 120 days. Kinetic processes were studied with a dynamic (DIDGI®) in vitro protocol and endpoints with the static INFOGEST in vitro digestion protocol, allowing a comparison of the two in vitro protocols at the level of gastric and intestinal endpoints. Both digestion protocols resulted in comparable peptide patterns after intestinal digestion and higher microbial diversity in cheeses led to a more diverse peptidome after simulated digestion

Influence of raw milk microflora and starter cultures in cheese on protein hydrolysis and bioactive peptide generation during digestion

Do bacterial strains in cheese have an impact on the protein hydrolysis during human digestion, and if so, does a higher microbial diversity lead to the generation of a higher number of different peptides after digestion? Cheese bacteria are responsible for the hydrolysis of proteins already during cheese ripening. These bacterial cultures are introduced at different steps of the cheese manufacturing process. First, the raw milk flora that is dependent on the milk heat treatment before the cheese manufacturing process, is a major source of a variety of bacteria. Second, starter cultures, needed for a successful acidification of the cheese curd are added to prevent side fermentations. Third, addition of cultures is made for improving flavor or accelerating the ripening process, depending on the type of cheese. Because of bacterial proteolytic activity, proteins in cheese are partially hydrolyzed, depending on the ripening time and are further digested by gastric and pancreatic proteases, after consumption, to the level of small peptides and free amino acids. In order to elucidate possible differences in proteolysis depending on the presence of different bacteria, Swiss Raclette cheeses were produced either from raw or pasteurized milk with or without addition of a proteolytic bacterial strains (Lactobacillus helveticus) and ripened during 120 days. The microbial diversity and the relative abundance of specific strains in the different cheeses was assessed after 24 hours, 80 and 120 days of cheese ripening by sequencing the hypervariable regions V1-V2 of the 16S rRNA genes. Moreover, protein hydrolysis in the different cheeses was analyzed with gel electrophoresis, mass spectrometry, and HPLC after in vitro digestion, applying a static (Infogest) and a dynamic (DIDGI®) oro-gastrointestinal in vitro digestion protocol. In order to gain information on the influence of bacterial strains on protein hydrolysis, the 16s meta-genomic and 16s meta-transcriptomic results were correlated with protein and peptide patterns