The Potential Role of Yogurt in Weight Management and Prevention of Type 2 Diabetes

Evaluation of the in vitro probiotic properties of Ligilactobacillus salivarius JCF5 and its impact on Jersey yogurt quality

BACKGROUND

Jersey milk, known for its high protein content, is an excellent base for yogurt production. Given that Jersey milk is derived from Jersey cows, this study was to isolate probiotics from Jersey cow feces and investigate their potential as alternative starter cultures for fermenting Jersey milk. Our goal was to develop new starter cultures specifically suited for Jersey yogurt production, while also contributing to the diversity of fermentation agents available for dairy products. This study aimed to evaluate the probiotic functions of Ligilactobacillus salivarius isolated from the feces of newborn Jersey calves after colostrum consumption and to investigate its impact as a starter culture on the quality of Jersey yogurt.

RESULTS

A lactic acid bacterial strain was screened through acid and bile salt tolerance tests and simulated gastrointestinal experiments. The strain survived up to 42.8% after 3 h of cultivation at pH 2, and its viable count after 3 h of cultivation in a medium containing 0.3% bile salt was 3 log(CFU mL-1). Additionally, the survival rates after 3 h of treatment with gastric and intestinal juices were 90.67 ± 0.41% and 84.97 ± 1.40%, respectively, indicating good acid and bile salt tolerance. Identification using 16S rDNA showed that the strain was L. salivarius JCF5. This strain improved the texture properties such as viscosity, elasticity and cohesiveness of yogurt when used in combination with commercial starter cultures.

CONCLUSION

Ligilactobacillus salivarius JCF5 is a promising probiotic strain for enhancing the quality of Jersey yogurt. © 2025 Society of Chemical Industry.

Natural Bioactive Compounds Enriched Functional Yogurt: Impact on the Probiotic Bacteria and Its Potential Health Benefits

Recently, there has been a high demand for the development of yogurt-based nutraceuticals and functional medications. This surge is primarily driven by the increasing global need for pharmaceutical and nutraceutical products, arising from widespread nutrient deficiencies and the emergence of various communicable and non-communicable diseases (NCDs), including respiratory infections, cancer, gastrointestinal, diabetes, obesity, and cardiovascular diseases. Probiotic yogurt provides an effective medium for delivering essential nutrients to the human body. Additionally, various prebiotic combinations, such as bioactive compounds from plants, animals, and microbes, can enrich the viability of probiotics, nutritional value, and efficacy. However, the gastric environment can significantly impact the viability of probiotic microorganisms as well as the absorption of nutrients and bioactive molecules. Therefore, utilizing biopolymer-based encapsulation for functional nutrients, metal nanostructures, and medications can improve the bioavailability of these compounds, protect the probiotics from gastric enzymes, increase nutrient and microbial absorption in colonic fluids, and enhance the antioxidant level in the body. This review investigates various methods for producing yogurt enriched with prebiotic and probiotic combinations alongside techniques such as microencapsulation, emulsification, and the incorporation of metal nanoparticles. Key factors such as viability, texture, and syneresis are examined to optimize yogurt-based nutraceuticals and functional medications.

Functional yogurt: a comprehensive review of its nutritional composition and health benefits

Functional yogurt, renowned for its enhanced nutritional profile and potential health benefits, has emerged as a promising functional food. This review meticulously examines the nutritional composition of functional yogurt, highlighting its enriched content of probiotics, prebiotics, synbiotics, antioxidants, vitamins, minerals, proteins, and other bioactive compounds, which contribute to its health-promoting properties. Functional yogurt has positively affected digestive health, immune function, metabolic health, and mental well-being. It benefits digestive health by alleviating diarrhoeal symptoms, constipation, colon cancer, irritable bowel syndrome (IBS), Helicobacter pylori infection, and digestive-related allergies. Moreover, the immune-boosting properties of functional yogurt play a pivotal role in reducing the risk of infections and inflammation. In addition, functional yogurt has the potential to improve metabolic health, leading to decreased cholesterol levels and enhanced blood sugar regulation. Emerging research also suggests functional yogurt may positively influence mood, behavior, and cognitive function. Functional yogurt is a valuable addition to the human diet, holding significant implications for public health. In addition to its numerous health benefits, functional yogurt also faces limitations, such as the stability of functional compounds, sensory alterations, potential digestive discomfort, and inconsistent efficacy across populations, highlighting the need for further research and optimization.

Lactobacillus paracasei ZFM54 alters the metabolomic profiles of yogurt and the co-fermented yogurt improves the gut microecology of human adults

Gut microbiota imbalance could lead to various diseases, making it important to optimize the structure of the gut flora in adults. Lactobacillus paracasei ZFM54 is a bacteriocin- and folic acid-producing Lactobacillus strain. Herein, L. paracasei ZFM54 was used as the potentially probiotic bacterium to ferment milk together with a yogurt starter. We optimized the fermentation conditions, and the obtained yogurts were then subjected to volatile and nonvolatile metabolome analysis, showing that L. paracasei ZFM54 can not only improve the acidity, water holding capacity and live lactic acid bacteria counts, but also improve many volatile acid contents and increase some beneficial nonvolatile metabolites, such as N-ethyl glycine and l-lysine, endowing the yogurt with more flavor and better function. The regulatory effects of the co-fermented yogurt on the intestinal microecology of volunteers were investigated by 16S rRNA sequencing and short-chain fatty acid (SCFA) analysis after consuming the yogurt for a 2-wk period, showing a better effect to increase the relative abundance of beneficial bacteria such as Ruminococcus and Alistipes, decrease harmful bacteria (Escherichia-Shigella and Enterobacter), and enhance the production of SCFA (acetate, propionate, and butyric acid) compared with the control yogurt. We found that L. paracasei ZFM54 can significantly improve the health benefits of yogurt, laying the foundation for its commercial application in improving gut microbiota.

Role of fermented dairy products in the health benefits of a mediterranean diet

Mediterranean diet includes fermented dairy products like yogurt and cheese. These foods provide calcium, phosphorus, fat, carbohydrates and protein, all nutrients influencing various systems including bone, cardiovascular system, intermediary metabolism, cancer, central nervous system, and inflammation. In addition, they contain prebiotics and provide probiotics which are capable of modifiying microbiota composition and metabolism, potentially acting also indirectly on the various systems. A large body of evidence indicates that fermented dairy products consumption significantly contributes to the beneficial effects of a Mediterranean diet on various systems' health.

Gene-Diet Interactions: Viability of Lactoferrin-Fortified Yoghurt as an Element of Diet Therapy in Patients Predisposed to Overweight and Obesity

Given the availability of molecular tools, population studies increasingly include the gen-diet interactions in their considerations. The use of these interactions allows for the obtaining of more uniform research groups. In practice, this translates into the possibility of reducing the size of the research group while maintaining the precision of the research. The research results obtained in this way can be used to select certain ingredients and foods in a dietary intervention with a higher degree of personalisation. In both prophylaxis and dietary therapy of overweight and obesity, the proper selection of bioactive ingredients best suited to the given group of consumers is of key importance. Hence, the aim of the presented study was to assess the effectiveness of a dietary intervention with the use of lactoferrin (LF)-fortified yoghurt, in terms of the ability to regulate body weight and carbohydrate metabolism in individuals whose genomes contained single nucleotide polymorphisms that predisposed them to increased accumulation of fatty tissue and consequently overweight or obesity. A group of 137 participants (98 women and 37 men) of Polish origin were screened for the presence of four single nucleotide polymorphisms (rs993960-FTO gene, rs7903146-TCF7L2 gene, rs10830963-MTNR1B gene, and rs1121980-FTO gene). Subsequently, a group of 19 participants diagnosed with the presence of risk factors within said SNPs underwent a 21-day dietary intervention (crossover study) with the use of yoghurt fortified with lactoferrin (200 mg/day). The results of the study revealed a genetic difference between the Polish population and the European average, in terms of the SNPs analysed. The dietary intervention showed a statistically significantly higher efficiency in terms of body mass reduction (p = 0.000) and lowering the glycated haemoglobin ratio (HbA1c) (p = 0.000) when consuming specially prepared yoghurt containing lactoferrin, as compared to results registered for unfortified yoghurt. Given the above, yoghurt fortified with LF should be considered as a viable element of diet therapy in overweight and obese patients diagnosed with risk factors within the analysed polymorphisms.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

The role of probiotic supplementation on insulin resistance in obesity associated diabetes: A mini review

Obesity and diabetes are two metabolic disorders linked by an inflammatory process named insulin resistance (IR). Various research on the role of gut microbiota in developing obesity and its associated disorders has led to the growing interest in probiotic supplementation. Considering the life-threatening complications of diabesity this mini review explored the effects of probiotic supplementation on IR in obesity associated diabetes. This review is based on recent articles from 2005-2020, studying the role of probiotic supplementation on glucose and insulin parameters in healthy and diabetic mouse model. Probiotic supplementation altered the gut microbiota composition, increased short chain fatty acid production, and decreased pro inflammatory cytokines. Additionally, they decreased intestinal permeability, circulating lipopolysaccharides and metabolic endotoxemia, hence improved insulin sensitivity and reduced obesity. Although multi-strain probiotic supplementation showed greater benefits than single strain interventions, variations in the concentration of probiotics used and the duration of treatment also influenced the results.  Probiotic supplementation could manipulate the gut microbiota by reducing intestinal permeability, inflammation and ameliorate IR and obesity associated diabetes in animal models which requires further long-term clinical studies in humans. 

Application of Functional and Edible Coatings and Films as Promising Strategies for Developing Dairy Functional Products—A Review on Yoghurt Case

Edible coatings and films appear to be a very promising strategy for delivering bioactive compounds and probiotics in food systems when direct incorporation/inoculation is not an option. The production of dairy products has undergone radical modifications thanks to nanotechnology. Despite being a relatively new occurrence in the dairy sector, nanotechnology has quickly become a popular means of increasing the bioavailability and favorable health effects of a variety of bioactive components. The present review describes, in detail, the various processes being practiced worldwide for yoghurt preparation, microencapsulation, and nanotechnology-based approaches for preserving and/or enriching yoghurt with biologically, and its effect on health and in treating various diseases. In the case of yoghurt, as a perfect medium for functional ingredients supplementation, different gums (e.g., alginate, xanthan gum, and gum arabic), alone or in combination with maltodextrin, seem to be excellent coatings materials to encapsulate functional ingredients. Edible coatings and films are ideal carriers of bioactive compounds, such as antioxidants, antimicrobials, flavors, and probiotics, to improve the quality of dairy food products. Yoghurt is regarded as a functional superfood with a variety of health benefits, especially with a high importance for women’s health, as a probiotic. Consumption of yoghurt with certain types of probiotic strains which contain γ-linolenic acid or PUFA can help solve healthy problems or alleviate different symptoms, and this review will be shed light on the latest studies that have focused on the impact of functional yoghurt on women’s health. Recently, it has been discovered that fermented milk products effectively prevent influenza and COVID-19 viruses. Bioactive molecules from yoghurt are quite effective in treating various inflammations, including so-called “cytokine storms” (hypercytokinaemia) caused by COVID-19.

Dairy intake and long-term body weight status in German children and adolescents: results from the DONALD study

PURPOSE

To analyse the association between intake of total dairy (TD) and types of dairy [liquid dairy (LD), solid dairy (SD), low-fat dairy (LFD), high-fat dairy (HFD), high sugar dairy (HSD), low-sugar dairy (LSD), not fermented dairy (NFD), as well as fermented dairy (FD)] and long-term changes in body weight status and composition among children and adolescents in Germany.

METHODS

In total, 9999 3-day dietary records collected between 1985 and 2019 by 1126 participants (3.5-18.5 years; boys: 50.8%) of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study were analysed. Polynomial mixed-effects regression models were used to examine whether changes (median follow-up: 9 years) in the intake of TD and dairy types (in 100 g/1000 kcal total energy intake) were associated with changes in body-mass-index-standard-deviation-score (BMI-SDS); fat mass index (FMI); fat-free mass index (FFMI) over time.

RESULTS

An individual increase in TD intake was slightly but significantly associated with an increase in BMI-SDS (β = 0.0092; p = 0.0371), FMI (β = 0.022; p = 0.0162), and FFMI (β = 0.0156; p = 0.0417) after adjustment for potential confounder. Analyses for LD (BMI-SDS: β = 0.0139; p = 0.0052; FMI: β = 0.0258; p = 0.0125; FFMI: β = 0.0239; p = 0.0052) and LSD intake (BMI-SDS: β = 0.0132; p = 0.0041, FMI: β = 0.02; p = 0.0316, FFMI: β = 0.0183; p = 0.0189) showed similar results to TD. Both processing method and fat content showed no association with body composition in our analyses.

CONCLUSION

Increases in TD, LD, and LSD intake showed small but significant increases in BMI and concomitant increases in fat mass and lean mass. However, the observed changes were too small to expect biological or physiological meaningful effects. Overall, our results showed that policies to promote dairy intake in childhood are to be welcomed, as no negative effects on body composition are expected, while the intake of important nutrients for growth is ensured. The type of dairy does not seem to matter.

Association of Yogurt and Dietary Supplements Containing Probiotic Consumption With All-Cause and Cause-Specific Mortality in US Adults: A Population-Based Cohort Study

Background

Although probiotic intake had beneficial effects on several specific disorders, limited evidence was available about the benefits of probiotic intake in the general population. This study aimed to evaluate the relationship between yogurt (as a natural probiotic source) and dietary supplements containing probiotic consumption and mortality in US adults.

Methods

We conducted an observational cohort study comprised of a nationally representative sample of adults who were enrolled in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2014. Individuals were linked to the US National Death Index.

Results

We included 32,625 adults in our study. Of the study cohort, 3,539 participants had yogurt consumption, 213 had dietary supplements containing probiotic consumption, and the remaining participants (28,873) did not have yogurt and/or dietary supplements containing probiotic consumption. During 266,432 person-years of follow-up, 3,881 deaths from any cause were ascertained, of which 651 were due to cardiovascular disorders and 863 were due to cancer. Weighted Cox proportional hazards models suggested that yogurt consumption was inversely associated with all-cause mortality (adjusted hazard ratio (HR), 0.83 [95% confidence interval (CI), 0.71–0.98]) but not cardiovascular mortality (adjusted HR, 0.68 [95%CI, 0.43–1.08]) and cancer mortality (adjusted HR, 1.00 [95%CI, 0.72–1.38]). However, dietary supplements containing probiotic were not associated with decreased all-cause and cause-specific mortality.

Conclusions

The present study suggested that yogurt consumption was associated with a lower risk of all-cause mortality among U.S. adults. Yogurt consumption in diet might be a sensible strategy for reducing the risk of death.

Higher Yogurt Consumption Is Associated With Lower Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis of Observational Studies

Background: Yogurt is known to be nutrient-rich and probiotic content, which gather optimism due to their potential role in preventing and managing cancers. The effect of yogurt consumption on colorectal cancer (CRC) is inconsistent.

Objective: This study aims to investigate the association of yogurt consumption with the risk of CRC.

Methods: Three databases, namely, PubMed, Web of Science, and Embase, were searched for all relevant studies from July 2021 on the association of yogurt consumption with CRC risk. We pooled the odds ratios (ORs) and their 95% CIs using a random-effects meta-analysis to assess the association.

Results: Finally, 16 studies met the inclusion criteria and were chosen in the meta-analysis. Yogurt consumption was significant with lower risk of CRC risk in the overall comparison (OR = 0.87, 95% CI: 0.81–0.94), in the cohort studies (OR = 0.91, 95% CI: 0.86–0.97), and case-control studies (OR = 0.75, 95% CI: 0.65–0.85). With regard to subgroup analyses by study region, cancer type, publication year, and sex, yogurt consumption significantly decreased overall CRC, colon cancer, and distal colon cancer risks. In stratified analyses, we observed significantly decreased CRC risk in Europe and Africa and published after 2010 and overall population. Sensitivity analysis indicated the result is stable and there is no publication bias in the meta-analysis.

Conclusions: Overall, this study indicated that yogurt intake was related to a decreased risk of CRC.

Pasteurized non-fermented cow's milk but not fermented milk is a promoter of mTORC1-driven aging and increased mortality

Recent epidemiological studies in Sweden, a country with traditionally high milk consumption, revealed that the intake of non-fermented pasteurized milk increased all-cause mortality in a dose-dependent manner. In contrast, the majority of epidemiological and clinical studies report beneficial health effects of fermented milk products, especially of yogurt. It is the intention of this review to delineate potential molecular aging mechanisms related to the intake of non-fermented milk versus yogurt on the basis of mechanistic target of rapamycin complex 1 (mTORC1) signaling. Non-fermented pasteurized milk via its high bioavailability of insulinotropic branched-chain amino acids (BCAAs), abundance of lactose (glucosyl-galactose) and bioactive exosomal microRNAs (miRs) enhances mTORC1 signaling, which shortens lifespan and increases all-cause mortality. In contrast, fermentation-associated lactic acid bacteria metabolize BCAAs and degrade galactose and milk exosomes including their mTORC1-activating microRNAs. The Industrial Revolution, with the introduction of pasteurization and refrigeration of milk, restricted the action of beneficial milk-fermenting bacteria, which degrade milk's BCAAs, galactose and bioactive miRs that synergistically activate mTORC1. This unrecognized behavior change in humans after the Neolithic revolution increased aging-related over-activation of mTORC1 signaling in humans, who persistently consume large quantities of non-fermented pasteurized cow's milk, a potential risk factor for aging and all-cause mortality.

Dairy Consumption and Liver Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

The relationship of dairy consumption and liver cancer risk is still controversial. We conducted a meta-analysis of published cohort and case-control studies to summarize the epidemiologic evidence on the relationship between dairy products consumption and the risk of liver cancer. The literatures were screened from PubMed, EMBASE, and Cochrane Library before May 2020. A total of seven cohort studies and eight case-control studies (5,121 cases) were included. The summary relative risks (RRs) were 1.17 (95% CI: 0.87‒1.57) and 1.08 (95% CI: 0.78‒1.51) for milk and total dairy, respectively. 0.50 (95% CI: 0.27-0.91) and 1.16 (95% CI: 0.83-1.52) were yogurt, cheese, and curd. Subgroup analysis revealed that study duration, alcohol, and design were associated the RRs. Dose-response analysis showed that the liver cancer risk was decreased by 5.4% (P for linear trend = 0.002) with a 40 g/day increment of yogurt intake. These results suggested that total dairy, milk, cheese, and curd were positive associations with the liver cancer risk although they were not statistically significant, however higher yogurt intake would reduce the risk. Further studies are necessary to verify the relationship of dairy foods with cancer.

Effect of Differents Cowmilk and Soymilk (soy yogurt) Formulation on Blood Glucose Level and <i>Glut4</i> Gene Expression in Rats Soleus Muscle

BACKGROUND AND OBJECTIVE

Soy yogurt is fermented soy milk and its nutrient-rich with isoflavones. Soy yogurt decreases blood glucose levels by utilizing the conversion of isoflavones. This study aimed to analyze the effect of soy yogurt on blood glucose level and Glut4 gene expression on rats' soleus muscle.

MATERIALS AND METHODS

Twenty-five rats (eighteen-weeks old) were divided into 5 groups, e.g., the control (P0), positive control (P1, 100% yogurt) and three treatment groups (P2, 50% soy yogurt+50% yogurt; P3, 75% yogurt+25% soy yogurt and P4, 75% soy yogurt+25% yogurt). All treatment groups were treated with different soy yogurt formula and administered for 12 weeks by gavaging. Under anesthetized, rats were sacrificed, then blood samples and soleus muscle were collected and stored at -80°C until use. RNA was extracted from soleus muscle and run for Glut4 mRNA expression using (RT)-PCR. Data were analyzed using one way ANOVA and followed by post hoc test LSD (Least Significant Differences test).

RESULTS

There is no difference in rat body weight among groups after 12 weeks of soy yogurt consumption. Blood glucose levels were decreased at least 25% lower level compared to the control baseline by the various formulation of soy yogurt. Interestingly, there is a distinct pattern of Glut4 mRNA expression level in the soleus muscle, P1 increased the expression but not with other formulations decreased the expression (P2, P3 and P4).

CONCLUSION

Taken together, a different formulation of soymilk and cowmilk effectively reduces blood glucose level and modulates Glut4 mRNA expression. In addition, a specific combination of bacteria type for fermenting soy yogurt could be a key to effectiveness for modulating blood glucose levels.

The role of yoghurt consumption in the management of type II diabetes

Enrichment of yoghurt with specific ingrdients beneficially affects the management of Type II Diabetes Mellitus (DMII). As far as the role of yoghurt in the management of DMII is concerned, the limited number of randomized clinical trials (RCTs) which have been conducted suggest that daily intake of yoghurt enriched with vitamin D and/or calcium as well as probiotics positively influences glycemic regulation and may contribute to more effective control of the disease. It is argued that the various ingredients which are already contained in the complex matrix of food, such as bioactive peptides, calcium, B-complex vitamins and beneficial microbes, as well as the fact that it can be used as a vehicle for the inclusion of other effective ingredients can have an impact on the metabolic control of diabetic patients. The aim of this review is to present the RCTs which have been conducted in the last decade in patients with DMII in an attempt to highlight the positive effects of yoghurt in the management of the disease.

Traditional plain yogurt: a therapeutic food for metabolic syndrome?

Dairy products have an important role in a healthy diet due to their high-quality protein and rich micronutrients. Yogurt, a fermented milk product, has a similar composition to milk but is a more concentrated product in terms of group B vitamins, minerals, and proteins. It is known that bioactive metabolites and live enzymes that occur by fermentation and digestion, affect the health positively by improving gut microbiota. In recent years, the prevalence of metabolic syndrome, which threatens public health, is increasing rapidly. As with other noninfectious diseases, the diet has an important effect on the prevention and treatment of metabolic syndrome. It has been demonstrated that yogurt has a high-quality amino acid pattern, reduces energy intake by stimulating satiety, and regulates blood glucose level. In addition to the rich protein variety, yogurt also contains peptides that positively affect blood pressure. Unlike milk, increased acidity during the fermentation of yogurt positively affects calcium absorption. Calcium plays an important role in the control of blood glucose and energy metabolism through insulin-dependent and non-insulin-dependent routes. In addition to reducing inflammation, calcium has a positive effect on the regulation of the blood lipid profile by increasing fecal fat excretion. There are many lipid and lipoid nutrients such as saturated fatty acids, phospholipids, sphingolipids, and conjugated linoleic acid that may affect the blood lipid profile in yogurt positively or negatively. There are seen very few randomized controlled studies that are focused on the relationship between yogurt and metabolic syndrome, and these are based on contradictory results. In this review, based on the clinical studies conducted to date, and the nutrient content of yogurt, possible mechanisms of these contradictory results are investigated.

Fermented Dairy Products, Probiotic Supplementation, and Cardiometabolic Diseases: A Systematic Review and Meta-analysis

Fermented dairy foods (FDFs) and probiotics are promising tools for the prevention and management of cardiometabolic diseases (CMDs), respectively. The relation between the regular consumption of FDFs and CMD risk factors was assessed by prospective cohort studies (PCSs), and the effect of probiotic supplementation added into a dairy matrix on CMD parameters was evaluated by randomized controlled trials (RCTs). Moreover, the effects of probiotic supplementation added into a dairy matrix were compared with those administered in capsule/powder form. Twenty PCSs and 52 RCTs met the inclusion criteria for the systematic review and meta-analysis. In PCSs, fermented milk was associated with a 4% reduction in risk of stroke, ischemic heart disease, and cardiovascular mortality [RR (95% CI); 0.96 (0.94, 0.98)]; yogurt intake was associated with a risk reduction of 27% [RR (95% CI); 0.73 (0.70, 0.76)] for type 2 diabetes (T2D) and 20% [RR (95% CI); 0.80 (0.74, 0.87)] for metabolic syndrome development. In RCTs, probiotic supplementation added into dairy matrices produced a greater reduction in lipid biomarkers than when added into capsules/powder in hypercholesterolemic subjects, and probiotic supplementation by capsules/powder produced a greater reduction in T2D biomarkers than when added into dairy matrices in diabetic subjects. Both treatments (dairy matrix and capsules/powder) resulted in a significant reduction in anthropometric parameters in obese subjects. In summary, fermented milk consumption is associated with reduced cardiovascular risk, while yogurt intake is associated with a reduced risk of T2D and metabolic syndrome development in the general population. Furthermore, probiotic supplementation added into dairy matrices could be considered beneficial for lowering lipid concentrations and reducing anthropometric parameters. Additionally, probiotic capsule/powder supplementation could contribute to T2D management and reduce anthropometric parameters. However, these results should be interpreted with caution due to the heterogeneity of the studies and the different probiotic strains used in the studies. This trial is registered with PROSPERO (CRD42018091791) and the protocol can be accessed at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018091791.

Predictive associations between lifestyle behaviours and dairy consumption: The IDEFICS study

BACKGROUND AND AIM

Physical activity (PA) and sedentary behaviours (SB) are related to obesity and cardiometabolic risk; however, the literature is controversial regarding the effect of dairy consumption on the development of cardiovascular disease (CVD) risk factors. The aim of this study was to assess longitudinally the relationship between specific lifestyle behaviours (PA and SB) and dairy consumption in a sample of European children and adolescents.

METHODS AND RESULTS

Children from the IDEFICS study were included in the analyses. Two measurements, with 2 years' interval, were conducted. A total of 1688 (50.8% boys) children provided information regarding diet, measured by a 24-h dietary recall, PA measured by accelerometers and parent-reported sedentary screen time (SST) at both time points. Different combinations of these behaviours, at each survey and over time, were derived applying specific recommendations. Multilevel ordinal logistic regression and analysis of covariance were used to assess their association with dairy consumption, adjusted for potential confounders. Differences by gender were found regarding dairy product consumption and also adherence to SB and PA recommendations at T0 and T1. Children meeting both lifestyle recommendations, at the two measurement points, had higher probability to consume more milk and yogurt and less cheese than the rest of combinations.

CONCLUSIONS

These results suggest that European children with a healthy lifestyle, especially regarding PA and SB over time, consumed more milk and yogurt. This study suggests that the protective effect of specific dairy products found in literature could be partially due to the association of their consumption with specific healthy lifestyles.

Yogurt Intake Reduces All-Cause and Cardiovascular Disease Mortality: A Meta-Analysis of Eight Prospective Cohort Studies

OBJECTIVE

To assess the relationship between yogurt intake and mortality risk from prospective cohort studies.

METHODS

The PubMed, EMBASE, and Web of Science databases were searched for all records related to yogurt intake and mortality risk [all-cause or cardiovascular disease (CVD) or cancer mortality] before October 1, 2018. The Newcastle-Ottawa Quality Scale was used to estimate the quality of all eligible articles. The results of the highest and lowest categories of yogurt intake in each study were collected and the effect size was pooled using a random effects model. The dose-response analysis was calculated using the generalized least squares trend estimation model.

RESULTS

Eight eligible cohort studies were included in this meta-analysis. There were 235,676 participants in the 8 studies, and the number of deaths was 14,831. Compared with the lowest category, the highest category of yogurt intake was not significantly related with all-cause mortality [hazard ratio (HR)=0.93; 95% confidence interval (CI): 0.85, 1.01], CVD mortality (HR=0.92; 95% CI: 0.81, 1.03) and cancer mortality (HR=0.97; 95% CI: 0.83, 1.12). These studies were homogenous, since the homogeneity test showed that I² was 28.7%, 15.1% and 11.8%, respectively. However, yogurt intake ⩾200 g/d was significantly associated with a lower all-cause mortality (HR=0.88; 95% CI: 0.80, 0.96) and CVD mortality (HR=0.87; 95% CI: 0.77, 0.99) in the subgroup analysis. The dose-response analysis showed that yogurt intake of 200 g/d was inversely associated with all-cause mortality (P=0.041, HR=0.95, 95% CI: 0.92, 1.00) and CVD mortality (P=0.009, HR=0.92, 95% CI: 0.86, 0.98), and all of which were linear relationship (P>0.05).

CONCLUSIONS

This review provided the evidence regarding yogurt intake can reduce all-cause and CVD mortality. Although some positive findings were identified, more high-quality cohort studies and randomized controlled trials are warranted on a possible protective effect of yoghurt on health.

Bioprospecting for Bioactive Peptide Production by Lactic Acid Bacteria Isolated from Fermented Dairy Food

With rapidly ageing populations, the world is experiencing unsustainable healthcare from chronic diseases such as metabolic, cardiovascular, neurodegenerative, and cancer disorders. Healthy diet and lifestyle might contribute to prevent these diseases and potentially enhance health outcomes in patients during and after therapy. Fermented dairy foods (FDFs) found their origin concurrently with human civilization for increasing milk shelf-life and enhancing sensorial attributes. Although the probiotic concept has been developed more recently, FDFs, such as milks and yoghurt, have been unconsciously associated with health-promoting effects since ancient times. These health benefits rely not only on the occurrence of fermentation-associated live microbes (mainly lactic acid bacteria; LAB), but also on the pro-health molecules (PHMs) mostly derived from microbial conversion of food compounds. Therefore, there is a renaissance of interest toward traditional fermented food as a reservoir of novel microbes producing PHMs, and “hyperfoods” can be tailored to deliver these healthy molecules to humans. In FDFs, the main PHMs are bioactive peptides (BPs) released from milk proteins by microbial proteolysis. BPs display a pattern of biofunctions such as anti-hypertensive, antioxidant, immuno-modulatory, and anti-microbial activities. Here, we summarized the BPs most frequently encountered in dairy food and their biological activities; we reviewed the main studies exploring the potential of dairy microbiota to release BPs; and delineated the main effectors of the proteolytic LAB systems responsible for BPs release.

The Metabolic Concept of Meal Sequence vs. Satiety: Glycemic and Oxidative Responses with Reference to Inflammation Risk, Protective Principles and Mediterranean Diet

With increasing exposure to eating opportunities and postprandial conditions becoming dominant states, acute effects of meals are garnering interest. In this narrative review, meal components, combinations and course sequence were questioned vis-à-vis resultant postprandial responses, including satiety, glycemic, oxidative and inflammatory risks/outcomes vs. protective principles, with reference to the Mediterranean diet. Representative scientific literature was reviewed and explained, and corresponding recommendations discussed and illustrated. Starting meals with foods, courses and/or preloads high in innate/added/incorporated water and/or fibre, followed by protein-based courses, delaying carbohydrates and fatty foods and minimizing highly-processed/sweetened hedonic foods, would increase satiety-per-calorie vs. obesogenic passive overconsumption. Similarly, starting with high-water/fibre dishes, followed by high-protein foods, oils/fats, and delayed/reduced slowly-digested whole/complex carbohydrate sources, optionally closing with simpler carbohydrates/sugars, would reduce glycaemic response. Likewise, starting with foods high in innate/added/incorporated water/fibre/antioxidants, high monounsaturated fatty acid foods/oils, light proteins and whole/complex carbohydrate foods, with foods/oils low in n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratios, and minimal-to-no red meat and highly/ultra-processed foods/lipids, would reduce oxidative/inflammatory response. Pyramids illustrating representative meal sequences, from most-to-least protective foods, visually communicate similarities between axes, suggesting potential unification for optimal meal sequence, consistent with anti-inflammatory nutrition and Mediterranean diet/meal principles, warranting application and outcome evaluation.

Decreasing the main maternal and fetal complications in women undergoing in vitro fertilization (IVF) trained by nutrition and healthy eating practices during pregnancy

PURPOSE

In vitro fertilization (IVF) can lead to undesirable consequences for pregnant women and their newborns. Reducing the adverse maternal (mainly, gestational diabetes mellitus (GDM) and preeclampsia (PE)), and fetal outcomes in IVF-pregnant women (IVF-PW) was aimed with the correct training of nutrition principles during pregnancy.

MATERIALS AND METHODS

A quasi-experimental clinical trial with 170 IVF-PW in intervention and control groups was conducted. The subjects before the dietary intervention completed questionnaires of nutritional and lifestyle and 24-h food recall. The intervention group was trained with the diet modification programs from early (12-16 weeks) to late (week 34) pregnancy in six weekly, 15-20-min sessions. The GDM diagnosis was based on 75-g OGTT and FBS tests, respectively, in 24-28 weeks' gestation. Other adverse maternal (e.g. PE, cesarean delivery, and preterm delivery (<37 weeks)), and fetal (e.g. intrauterine growth retardation (IUGR), birth weight, and fetal viability) outcomes were also monitored. The dataset was assessed using both inferential and descriptive statistics.

RESULTS

A diet modification program with an increased intake of lactose, fiber, and some minerals (e.g. magnesium and zinc) and vitamins (e.g. B3 and B5) in conjunction with a lower intake rate of glucose and lipid could control the prevalence of adverse maternal and neonatal outcomes in IVF-PW. Although the GDM reduction in the two intervention (8.2%) and control (20.0%) groups was statistically insignificant, there was a significant difference in PE prevalence at a lower rate (39.0%) in the intervention group than the control. No significant difference in cesarean delivery (94.1-95.2%), and preterm delivery (45.9%) between the two groups was found. The IUGR (24.7-25.9%), birth weight (2.791-2.820 kg), and fetal viability (95.3-97.6%) also did not change significantly after the healthy eating practices during pregnancy.

CONCLUSIONS

Diet-based interventions in IVF-PW during pregnancy were efficient in improving the outcomes for both mother and baby.

Greek Yogurt and 12 Weeks of Exercise Training on Strength, Muscle Thickness and Body Composition in Lean, Untrained, University-Aged Males

Milk and/or whey protein plus resistance exercise (RT) increase strength and muscle size, and optimize body composition in adult males and females. Greek yogurt (GY) contains similar muscle-supporting nutrients as milk yet it is different in several ways including being a semi-solid food, containing bacterial cultures and having a higher protein content (mostly casein) per serving. GY has yet to be investigated in the context of a RT program. The purpose of this study was to assess the effects of GY consumption plus RT on strength, muscle thickness and body composition in lean, untrained, university-aged males. Thirty untrained, university-aged (20.6 ± 2.2 years) males were randomized to 2 groups (n = 15/group): fat-free, plain GY or a Placebo Pudding (PP; isoenergetic carbohydrate-based pudding) and underwent a combined RT/plyometric training program 3 days/week for 12 weeks. They consumed either GY (20 g protein/dose) or PP (0 g protein/dose) daily, 3 times on training days and 2 times on non-training days. After 12 weeks, both groups significantly increased strength, muscle thickness and fat-free mass (FFM) (p < 0.05). The GY group gained more total strength (GY; 98 ± 37 kg, PP; 57 ± 15 kg), more biceps brachii muscular thickness (GY; 0.46 ± 0.3 cm, PP; 0.12 ± 0.2 cm), more FFM (GY; 2.4 ± 1.5 kg, PP; 1.3 ± 1.3 kg), and reduced % body fat (GY; −1.1 ± 2.2%, PP; 0.1 ± 2.6%) than PP group (p < 0.05 expressed as absolute change). Thus, consumption of GY during a training program resulted in improved strength, muscle thickness and body composition over a carbohydrate-based placebo. Given the results of our study, the general benefits of consuming GY and its distinctiveness from milk, GY can be a plausible, post-exercise, nutrient-rich alternative for positive strength, muscle, and body composition adaptations.

Increased Dairy Product Intake Modifies Plasma Glucose Concentrations and Glycated Hemoglobin: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Dairy product intake is inversely associated with the risk of type 2 diabetes (T2D) in numerous cohort studies; yet, the beneficial effects of increased dairy product intake on T2D risk factors such as fasting plasma glucose, fasting insulin, insulin resistance with the homeostasis model assessment, and glycated hemoglobin (HbA1c) remain inconclusive in clinical trials. The objective of this study was to systematically review clinical trials observing the effects of elevated compared with minimal intake of dairy products on T2D risk factors in subjects without diabetes. Five databases [Medline, EMBASE, Central, CINAHL, AMED (Allied and Complementary Medicine)] were searched to identify randomized controlled trials that used elevated quantities of dairy products from ruminant sources in comparison with a lower intake in control groups. The review outcomes were fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and HbA1c. Risk of bias and quality of evidence according to Grading of Recommendations Assessment, Development, and Evaluation were addressed. From the 10,627 citations screened, 44 studies (3016 participants) were included, 38 of which were used in the meta-analyses. Fasting glucose was positively associated with elevated dairy intake [34 studies, n = 2678; mean difference (MD): 0.07 mmol/L; 95% CI: 0.01, 0.12 mmol/L; P = 0.01, I2 = 23%]. Fasting insulin (29 studies, n = 1902; MD: -2.97 pmol/L; 95% CI: -7.05, 1.10 pmol/L; P = 0.15, I2 = 21%) and HOMA-IR (13 studies, n = 840; standardized MD: -0.07; 95% CI: -0.26, 0.12; P = 0.49, I2 = 38%) were not associated with elevated dairy consumption. HbA1c was negatively associated with elevated dairy product intake in 4 studies (n = 512; MD: -0.09%; 95% CI: -0.09%, -0.03%; P = 0.005, I2 = 0%). Most studies had high risk of bias and the quality of evidence was very low or low. In conclusion, evidence suggests that elevated dairy product intake is associated with increased fasting plasma glucose concentrations together with reduced HbA1c in nondiabetic subjects. Hence, the clinical significance of these results remains uncertain. Additional well-designed, long-term studies are required.

Effects of Dairy Products Consumption on Body Weight and Body Composition Among Adults: An Updated Meta-Analysis of 37 Randomized Control Trials

SCOPE

Effects of dairy consumption on body weight and body composition have been inconsistently observed in randomized control trials (RCTs). Our meta-analysis aims to systematically evaluate the effects of dairy consumption on body weight and body composition among the adults.

METHODS AND RESULTS

We conducted a comprehensive search of the Cochrane Library, PubMed, and Embase databases of the relevant studies from 1966 to Mar 2017 regarding dairy consumption on body weight and body composition including body fat, lean mass, and waist circumference (WC). The summary results are pooled by using a random-effects meta-analysis. Thirty-seven RCTs with 184 802 participants are included in this meta-analysis. High dairy intervention increased body weight (0.01, 95% CI: -0.25, 0.26, I² = 78.3%) and lean mass (0.37, 95% CI: 0.11, 0.62, I² = 83.4%); decreased body fat (-0.23, 95% CI: -0.48, 0.02, I² = 78.2%) and WC (-1.37, 95% CI: -2.28, -0.46, I² = 98.9%) overall. In the subgroup analysis, we found that consumption of dairy products increases body weight (0.36, 95% CI: 0.01, 0.70, I² = 83.1%) among participants without energy restriction. Dairy consumption decreases body weight (-0.64, 95% CI: -1.05, -0.24, I² = 60.2%), body fat (-0.56, 95%CI: -0.95, -0.17, I² = 66.6%), and waist circumference (-2.18, 95%CI: -4.30, -0.06, I² = 99.0%) among the adults with energy restriction.

CONCLUSIONS

This meta-analysis suggests a beneficial effect of energy-restricted dairy consumption on body weight and body composition. However, high dairy consumption in the absence of caloric restriction may increase body weight.

Dairy food intake, diet patterns, and health: Findings from the Maine-Syracuse Longitudinal Study

This study compared the intake of yogurt and other dairy foods in relation to other dietary habits, and associations with cardiovascular health indicators. Comparative analyses of dietary intakes and cardiometabolic health indicators were conducted in participants from the Maine-Syracuse Longitudinal Study, conducted in 2001-2006 (n = 699). Participants (10.2% of sample) who consumed yogurt more frequently (≥ 5 serves per week) also consumed more fruit, vegetables, nuts, and fish, but fewer sweets, sugar-sweetened soft drinks, and alcohol. The yogurt-healthy food score was significantly inversely associated with fasting plasma glucose (p = 0.044), waist circumference (p = 0.004), and smoking (p = 0.004), and significantly positively associated with physical activity (p < 0.001). In addition, the yogurt-healthy food score was associated with protection against MetS abdominal obesity (OR: 0.80, 95% CI: 0.66-0.07, p = 0.02). The yogurt-healthy dietary pattern was significantly associated with a better cardiometabolic profile.

Diet and prevention of type 2 diabetes mellitus: beyond weight loss and exercise

INTRODUCTION

Insulin resistance (IR) and pancreatic beta-cell dysfunction are core pathophysiologic features of type 2 diabetes mellitus (T2DM). Select lifestyle and pharmacologic interventions, including weight loss, physical activity, a Mediterranean diet intervention, and hypoglycemic agents, have been shown to prevent or delay T2DM. However, dietary factors other than weight loss may also impact risk, mainly through effects to enhance insulin sensitivity, although some may also directly or indirectly impact pancreatic beta-cell function.

AREAS COVERED

A literature review of observational studies and randomized controlled trials (RCTs) was conducted, and the research indicates dietary factors showing promise for reducing T2DM risk include higher intakes of cereal fibers, unsaturated fatty acids, magnesium, and polyphenols (e.g. anthocyanins), while reducing dietary glycemic load, added sugars, and high-sugar beverages.

EXPERT COMMENTARY

While these dietary factors are mainly supported by evidence from observational studies and RCTs of surrogate markers for T2DM, they are consistent with current recommendations to emphasize consumption of whole grains, nuts, seeds, legumes, seafood, fruits, and vegetables, while limiting intakes of saturated fatty acids, refined carbohydrates, and processed meats. Additional dietary intervention RCTs are needed to assess the efficacy of these promising dietary interventions for delaying or preventing the onset of T2DM.

French and Mediterranean-style diets: Contradictions, misconceptions and scientific facts-A review

The determination of appropriate dietary strategies for the prevention of chronic degenerative diseases, cancer, diabetes, and cardiovascular diseases remains a challenging and highly relevant issue worldwide. Epidemiological dietary interventions have been studied for decades with contrasting impacts on human health. Moreover, research scientists and physicians have long debated diets encouraging alcohol intake, such as the Mediterranean and French-style diets, with regard to their impact on human health. Understanding the effects of these diets may help to improve in the treatment and prevention of diseases. However, further studies are warranted to determine which individual food components, or combinations thereof, have a beneficial impact on different diseases, since a large number of different compounds may occur in a single food, and their fate in vivo is difficult to measure. Most explanations for the positive effects of Mediterranean-style diet, and of the French paradox, have focused largely on the beneficial properties of antioxidants, among other compounds/metabolites, in foods and red wine. Wine is a traditional alcoholic beverage that has been associated with both healthy and harmful effects. Not withstanding some doubts, there is reasonable unanimity among researchers as to the beneficial effects of moderate wine consumption on cardiovascular disease, diabetes, osteoporosis, and longevity, which have been ascribed to polyphenolic compounds present in wine. Despite this, conflicting findings regarding the impact of alcohol consumption on human health, and contradictory findings concerning the effects of non-alcoholic wine components such as resveratrol, have led to confusion among consumers. In addition to these contradictions and misconceptions, there is a paucity of human research studies confirming known positive effects of polyphenols in vivo. Furthermore, studies balancing both known and unknown prognostic factors have mostly been conducted in vitro or using animal models. Moreover, current studies have shifted focus from red wine to dairy products, such as cheese, to explain the French paradox. The aim of this review is to highlight the contradictions, misconceptions, and scientific facts about wines and diets, giving special focus to the Mediterranean and French diets in disease prevention and human health improvement. To answer the multiplicity of questions regarding the effects of diet and specific diet components on health, and to relieve consumer uncertainty and promote health, comprehensive cross-demographic studies using the latest technologies, which include foodomics and integrated omics approaches, are warranted.

Dairy Consumption and Body Mass Index Among Adults: Mendelian Randomization Analysis of 184802 Individuals from 25 Studies

BACKGROUND

Associations between dairy intake and body mass index (BMI) have been inconsistently observed in epidemiological studies, and the causal relationship remains ill defined.

METHODS

We performed Mendelian randomization (MR) analysis using an established dairy intake-associated genetic polymorphism located upstream of the lactase gene (LCT-13910 C/T, rs4988235) as an instrumental variable (IV). Linear regression models were fitted to analyze associations between (a) dairy intake and BMI, (b) rs4988235 and dairy intake, and (c) rs4988235 and BMI in each study. The causal effect of dairy intake on BMI was quantified by IV estimators among 184802 participants from 25 studies.

RESULTS

Higher dairy intake was associated with higher BMI (β = 0.03 kg/m² per serving/day; 95% CI, 0.00-0.06; P = 0.04), whereas the LCT genotype with 1 or 2 T allele was significantly associated with 0.20 (95% CI, 0.14-0.25) serving/day higher dairy intake (P = 3.15 × 10^-12) and 0.12 (95% CI, 0.06-0.17) kg/m² higher BMI (P = 2.11 × 10^-5). MR analysis showed that the genetically determined higher dairy intake was significantly associated with higher BMI (β = 0.60 kg/m² per serving/day; 95% CI, 0.27-0.92; P = 3.0 × 10^-4).

CONCLUSIONS

The present study provides strong evidence to support a causal effect of higher dairy intake on increased BMI among adults.

Yogurt and Cardiometabolic Diseases: A Critical Review of Potential Mechanisms

Associations between yogurt intake and risk of diet-related cardiometabolic diseases (CMDs) have been the subject of recent research in epidemiologic nutrition. A healthy dietary pattern has been identified as a pillar for the prevention of weight gain and CMDs. Epidemiologic studies suggest that yogurt consumption is linked to healthy dietary patterns, lifestyles, and reduced risk of CMDs, particularly type 2 diabetes. However, to our knowledge, few to no randomized controlled trials have investigated yogurt intake in relation to cardiometabolic clinical outcomes. Furthermore, there has been little attempt to clarify the mechanisms that underlie the potential beneficial effects of yogurt consumption on CMDs. Yogurt is a nutrient-dense dairy food and has been suggested to reduce weight gain and prevent CMDs by contributing to intakes of protein, calcium, bioactive lipids, and several other micronutrients. In addition, fermentation with bacterial strains generates bioactive peptides, resulting in a potentially greater beneficial effect of yogurt on metabolic health than nonfermented dairy products such as milk. To date, there is little concrete evidence that the mechanisms proposed in observational studies to explain positive results of yogurt on CMDs or parameters are valid. Many proposed mechanisms are based on assumptions that commercial yogurts contain strain-specific probiotics, that viable yogurt cultures are present in adequate quantities, and that yogurt provides a minimum threshold dose of nutrients or bioactive components capable of exerting a physiologic effect. Therefore, the primary objective of this review is to investigate the plausibility of potential mechanisms commonly cited in the literature in order to shed light on the inverse associations reported between yogurt intake and various cardiometabolic health parameters that are related to its nutrient profile, bacterial constituents, and food matrix. This article reviews current gaps and challenges in identifying such mechanisms and provides a perspective on the research agenda to validate the proposed role of yogurt in protecting against CMDs.

Dairy product intake and mortality in a cohort of 70-year-old Swedes: a contribution to the Nordic diet discussion

Introduction

Conflicting results in the literature exist on the role of dairy products in the context of a Nordic Healthy Diet (NHD). Two recent Swedish studies indicate both negative and positive associations with total mortality when comparing key dairy products. There is no consensus about how to include these foods into the NHD.

Purpose

To study consumption of cheese and milk products (milk, sour milk and unsweetened yoghurt) by 70-year-old Swedes in relation to all-cause mortality.

Methods

Cox proportional hazard models, adjusted for potential confounders and stratified by follow-up duration, were used to assess the prediction of all-cause mortality by the above foods. The associations of fat from cheese and milk products with mortality were tested in separate models.

Results

Cheese intake inversely predicted total mortality, particularly at high protein intakes, and this association decreased in strength with increasing follow-up time. Milk products predicted increased mortality with stable HRs over follow-up. The association between milk products and mortality was strongly influenced by the group with the highest consumption. Fat from cheese mirrored the protective association of cheese intake with mortality, whereas fat from milk products predicted excess mortality, but only in an energy-adjusted model.

Conclusion

Based on our results, it may be argued that the role of dairy products in the context of a Nordic healthy diet should be more clearly defined by disaggregating cheese and milk products and not necessarily focusing on dairy fat content. Future epidemiological research should consider dairy products as disaggregated food items due to their great diversity in health properties.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-017-1556-2) contains supplementary material, which is available to authorized users.

Proteomes of Lactobacillus delbrueckii subsp. bulgaricus LBB.B5 Incubated in Milk at Optimal and Low Temperatures

Lactobacillus delbrueckii subsp. bulgaricus has a long history of use in yogurt production. Although commonly cocultured with Streptococcus salivarius subsp. thermophilus in milk, fundamental knowledge of the adaptive responses of L. delbrueckii subsp. bulgaricus to the dairy environment and the consequences of those responses on the use of L. delbrueckii subsp. bulgaricus as a probiotic remain to be elucidated. In this study, we identified proteins of L. delbrueckii subsp. bulgaricus LBB.B5 that are produced in higher quantities in milk at growth-conducive and non-growth-conductive (refrigeration) temperatures compared to laboratory culture medium and further examined whether those L. delbrueckii subsp. bulgaricus cultures were affected differently in their capacity to survive transit through the murine digestive tract. This work provides novel insight into how a major, food-adapted microbe responds to its primary habitat. Such knowledge can be applied to improve starter culture and yogurt production and to elucidate matrix effects on probiotic performance.

We identified the proteins synthesized by Lactobacillus delbrueckii subsp. bulgaricus strain LBB.B5 in laboratory culture medium (MRS) at 37°C and milk at 37 and 4°C. Cell-associated proteins were measured by gel-free, shotgun proteomics using high-performance liquid chromatography coupled with tandem mass spectrophotometry. A total of 635 proteins were recovered from all cultures, among which 72 proteins were milk associated (unique or significantly more abundant in milk). LBB.B5 responded to milk by increasing the production of proteins required for purine biosynthesis, carbohydrate metabolism (LacZ and ManM), energy metabolism (TpiA, PgK, Eno, SdhA, and GapN), amino acid synthesis (MetE, CysK, LBU0412, and AspC) and transport (GlnM and GlnP), and stress response (Trx, MsrA, MecA, and SmpB). The requirement for purines was confirmed by the significantly improved cell yields of L. delbrueckii subsp. bulgaricus when incubated in milk supplemented with adenine and guanine. The L. delbrueckii subsp. bulgaricus-expressed proteome in milk changed upon incubation at 4°C for 5 days and included increased levels of 17 proteins, several of which confer functions in stress tolerance (AddB, UvrC, RecA, and DnaJ). However, even with the activation of stress responses in either milk or MRS, L. delbrueckii subsp. bulgaricus did not survive passage through the murine digestive tract. These findings inform efforts to understand how L. delbrueckii subsp. bulgaricus is adapted to the dairy environment and its implications for its health-benefiting properties in the human digestive tract.

IMPORTANCELactobacillus delbrueckii subsp. bulgaricus has a long history of use in yogurt production. Although commonly cocultured with Streptococcus salivarius subsp. thermophilus in milk, fundamental knowledge of the adaptive responses of L. delbrueckii subsp. bulgaricus to the dairy environment and the consequences of those responses on the use of L. delbrueckii subsp. bulgaricus as a probiotic remain to be elucidated. In this study, we identified proteins of L. delbrueckii subsp. bulgaricus LBB.B5 that are synthesized in higher quantities in milk at growth-conducive and non-growth-conductive (refrigeration) temperatures compared to laboratory culture medium and further examined whether those L. delbrueckii subsp. bulgaricus cultures were affected differently in their capacity to survive transit through the murine digestive tract. This work provides novel insight into how a major, food-adapted microbe responds to its primary habitat. Such knowledge can be applied to improve starter culture and yogurt production and to elucidate matrix effects on probiotic performance.

Factors Influencing the Gut Microbiota, Inflammation, and Type 2 Diabetes

The gut microbiota is a complex community of bacteria residing in the intestine. Animal models have demonstrated that several factors contribute to and can significantly alter the composition of the gut microbiota, including genetics; the mode of delivery at birth; the method of infant feeding; the use of medications, especially antibiotics; and the diet. There may exist a gut microbiota signature that promotes intestinal inflammation and subsequent systemic low-grade inflammation, which in turn promotes the development of type 2 diabetes. There are preliminary studies that suggest that the consumption of probiotic bacteria such as those found in yogurt and other fermented milk products can beneficially alter the composition of the gut microbiome, which in turn changes the host metabolism. Obesity, insulin resistance, fatty liver disease, and low-grade peripheral inflammation are more prevalent in patients with low α diversity in the gut microbiome than they are in patients with high α diversity. Fermented milk products, such as yogurt, deliver a large number of lactic acid bacteria to the gastrointestinal tract. They may modify the intestinal environment, including inhibiting lipopolysaccharide production and increasing the tight junctions of gut epithelia cells.

Consumption of Yogurt and the Incident Risk of Cardiovascular Disease: A Meta-Analysis of Nine Cohort Studies

Previous systematic reviews and meta-analyses have evaluated the association of dairy consumption and the risk of cardiovascular disease (CVD). However, the findings were inconsistent. No quantitative analysis has specifically assessed the effect of yogurt intake on the incident risk of CVD. We searched the PubMed and the Embase databases from inception to 10 January 2017. A generic inverse-variance method was used to pool the fully-adjusted relative risks (RRs) and the corresponding 95% confidence intervals (CIs) with a random-effects model. A generalized least squares trend estimation model was used to calculate the specific slopes in the dose-response analysis. The present systematic review and meta-analysis identified nine prospective cohort articles involving a total of 291,236 participants. Compared with the lowest category, highest category of yogurt consumption was not significantly related with the incident risk of CVD, and the RR (95% CI) was 1.01 (0.95, 1.08) with an evidence of significant heterogeneity (I² = 52%). However, intake of ≥200 g/day yogurt was significantly associated with a lower risk of CVD in the subgroup analysis. There was a trend that a higher level of yogurt consumption was associated with a lower incident risk of CVD in the dose-response analysis. A daily dose of ≥200 g yogurt intake might be associated with a lower incident risk of CVD. Further cohort studies and randomized controlled trials are still demanded to establish and confirm the observed association in populations with different characteristics.