Effect of the Consumption of Alcohol-Free Beers with Different Carbohydrate Composition on Postprandial Metabolic Response.

BACKGROUND: We investigated the postprandial effects of an alcohol-free beer with modified carbohydrate (CH) composition compared to regular alcohol-free beer. METHODS: Two randomized crossover studies were conducted. In the first study, 10 healthy volunteers received 25 g of CH in four different periods, coming from regular alcohol-free beer (RB), alcohol-free beer enriched with isomaltulose and a resistant maltodextrin (IMB), alcohol-free beer enriched with resistant maltodextrin (MB), and a glucose-based beverage. In the second study, 20 healthy volunteers were provided with 50 g of CH from white bread (WB) plus water, or with 14.3 g of CH coming from RB, IMB, MB, and extra WB. Blood was sampled after ingestion every 15 min for 2 h. Glucose, insulin, incretin hormones, TG, and NEFAs were determined in all samples. RESULTS: The increase in glucose, insulin, and incretin hormones after the consumption of IMB and MB was significantly lower than after RB. The consumption of WB with IMB and MB showed significantly less increase in glucose levels than WB with water or WB with RB. CONCLUSIONS: The consumption of an alcohol-free beer with modified CH composition led to a better postprandial response compared to a conventional alcohol-free beer.

An alcohol-free beer enriched with isomaltulose and a resistant dextrin modulates gut microbiome in subjects with type 2 diabetes mellitus and overweight or obesity: a pilot study.

We aimed to study the effect of consuming an alcohol-free beer with modified carbohydrates composition (almost completely eliminating maltose and adding isomaltulose (16.5 g day-1) and resistant maltodextrin (5.28 g day-1)) in gut microbiome, compared to regular alcohol-free beer in subjects with T2DM or prediabetes and overweight/obesity. This is a pilot, randomized, double-blinded, crossover study including a sub-sample of a global study with 14 subjects: (a) consuming 66 cl day-1 of regular alcohol-free beer for the first 10 weeks and 66 cl day-1 of modified alcohol-free beer for the next 10 weeks; (b) the same described intervention in opposite order. BMI homogeneously decreased after both interventions. Glucose and HOMA-IR significantly decreased just after the participants consumed modified alcohol-free beer. These findings were in the same line as those reported in the global study. Dominant bacteria at baseline were Bacteroidetes, Firmicutes, Proteobacteria and Tenericutes. Parabacteroides, from the Porphymonadaceae family, resulted as the feature with the greatest difference between beers (ANCOM analysis, W = 15). Feature-volatility analysis confirmed the importance of Parabacteroides within the model. Alcohol-free beers consumption resulted in an enhancement of pathways related to metabolism according to PICRUSt analysis, including terpenoid-quinone, lipopolysaccharides and N-glycan biosynthesis. Thus, an alcohol-free beer including the substitution of regular carbohydrates for low doses of isomaltulose and the addition of maltodextrin within meals significantly impacts gut microbiota in diabetic subjects with overweight or obesity. This could, at least partially, explain the improvement in insulin resistance previously found after taking modified alcohol-free alcohol.Clinical Trial Registration: Registered under ClinicalTrials.gov identifier no. NCT03337828.

Effect of an alcohol-free beer enriched with isomaltulose and a resistant dextrin on insulin resistance in diabetic patients with overweight or obesity.

BACKGROUND & AIMS: The quality of carbohydrates has an essential role in nutritional management of type 2 diabetes mellitus (T2DM) because of its substantial impact on glucose homeostasis. Alcohol-free beer has beneficial bioactive components but it has a relatively high glycemic-index so its consumption is restricted in diabetic subjects. We aimed to explore the effect of an alcohol-free beer with modified carbohydrate composition almost completely eliminating maltose and adding isomaltulose (16.5 g/day) and a resistant maltodextrin (5.28 g/day) in comparison to a regular alcohol-free beer on glycemic control of diabetic subjects with overweight or obesity. DESIGN: We randomized 41 subjects into two groups: a) consumption of 66 cL/day of; regular alcohol-free beer for the first 10 weeks and 66 cL/day of alcohol-free beer with modified carbohydrate composition for the next 10 weeks; b) the same described intervention in opposite order. There was a washout period for 6-8 weeks between the two interventions. Participants were counseled to adhere to a healthy diet for cardiovascular health and to increase physical activity. Clinical, biochemical, anthropometric, lifestyle and satiety assessments were performed at the beginning and at the end of each period. RESULTS: Subjects showed significantly weight loss after the two ten weeks periods (-1.69 ± 3.21% and -1.77 ± 3.70% after experimental and regular alcohol-free beers, respectively, P = 0.881). Glucose and glycated hemoglobin did not significantly change after any period. Insulin concentrations and HOMA-IR significantly decreased (-11.1 [-21.3-4.64]% and -1.92 ± 32.8% respectively) after the intake of experimental alcohol-free beer but not after regular alcohol-free beer. Reductions remained statistically significant after adjusting for weight loss, energy intake, physical activity and intervention order. Subjects reported higher satiety scores after consuming experimental alcohol-free beer. CONCLUSIONS: An alcohol-free beer including the substitution of regular carbohydrates for low doses of isomaltulose and the addition of a resistant maltodextrin within meals led to an improvement in insulin resistance in subjects with T2DM and overweight or obesity. CLINICAL TRIAL REGISTRATION: The clinical trial has been registered in ClinicalTrials.gov (Identifier: NCT03337828).

Phosphorylation of rat mitochondrial transcription termination factor (mTERF) is required for transcription termination but not for binding to DNA.

Despite the crucial importance of mitochondrial transcription, knowledge of its regulation is poor. Therefore, characterization of mammalian mitochondrial transcription termination factor (mTERF) functionality and regulation is of fundamental biological interest in order to understand the regulation of mitochondrial transcription. Here we report that mTERF is the first protein having a role in mammalian mitochondrial gene expression that appears to be controlled by phosphorylation. Recombinant mature rat mTERF protein has specific DNA-binding capacity for the sequence required for transcription termination. Furthermore, unlike recombinant human mTERF, the rat protein bound to its mitochondrial DNA binding site promotes the termination of transcription initiated with heterologous RNA polymerase. Interestingly, mTERF is a phosphoprotein with four phosphate groups, and while the DNA-binding activity of mTERF is unaffected by the phosphorylation/dephosphorylation state, only the phosphorylated form of the protein is active for termination activity. Moreover, natural human mTERF is also a phosphoprotein and its termination activity is inhibited by dephosphorylation. These data suggest that mTERF functioning in vivo is regulated by phosphorylation.

New DNA-binding activity of rat mitochondrial transcription termination factor (mTERF).

The molecular mechanisms involved in the regulation of the balance between rRNA and mRNA in mitochondria are poorly understood. The mitochondrial transcription termination factor (mTERF) was highlighted as a potential transcription-control point. In this study, rat mTERF has been expressed in vitro and in Escherichia coli. The mature protein, in addition to the expected specific DNA-binding capacity for the sequence required for termination, has a new DNA-binding activity, and is able to bind to rat mitochondrial promoter region. This finding suggests communication between transcription initiation and termination regions. However, the results of a competition experiment argue against the formation of a complex between rat mTERF and the termination probe and promoter probe simultaneously, although it remains to be investigated whether another factor(s) might be involved in this interaction. In addition, recombinant human mTERF is also able to bind to human mitochondrial promoter region.